DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

NONRESIDENT

TRAININGCOURSE

April 1992

Engineman 2NAVEDTRA 14076

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

Although the words “he,” “him,” and“his” are used sparingly in this course toenhance communication, they are notintended to be gender driven or to affront ordiscriminate against anyone.

COMMANDING OFFICERNETPDTC

6490 SAUFLEY FIELD RDPENSACOLA, FL 32509-5237

ERRATA #l 26 July 1999

Specific Instructions and Errata

ENGINEMAN 2

1. No attempt has been made to issue corrections for errorsin typing, punctuation, etc., that do not affect yourability to answer the question or questions.

2. To receive credit for deleted questions, show thiserrata to your local course administrator (ESO/scorer).The local course administrator is directed to correct thecourse and the answer key by indicating the questiondeleted.

3. Assignment Booklet

Make the following changes:

4-44 ADD the word "rise" after 20°F

4-54 CHANGE "clean oil" to "cleaning fluid"

Delete the following questions, and leave the correspondingspace blank on the answer sheet:

Question

4-4

4-63

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PREFACE

By enrolling in this self-study course, you have demonstrated a desire to improve yourself and the Navy.Remember, however, this self-study course is only one part of the total Navy training program. Practicalexperience, schools, selected reading, and your desire to succeed are also necessary to successfully roundout a fully meaningful training program.

COURSE OVERVIEW: In completing this nonresident training course, you will demonstrate aknowledge of the subject matter by correctly answering questions on the following subjects: Administrationand Training; Measuring and Repair Instruments; Internal Combustion Engines; Speed Control Devices;Refrigeration and Air Conditioning; Compressed Air Systems; Laundry, Mess Decks, Galley, and SculleryEquipment; Auxiliary Equipment; and Lathe and Machining Operations.

THE COURSE: This self-study course is organized into subject matter areas, each containing learningobjectives to help you determine what you should learn along with text and illustrations to help youunderstand the information. The subject matter reflects day-to-day requirements and experiences ofpersonnel in the rating or skill area. It also reflects guidance provided by Enlisted Community Managers(ECMs) and other senior personnel, technical references, instructions, etc., and either the occupational ornaval standards, which are listed in the Manual of Navy Enlisted Manpower Personnel Classificationsand Occupational Standards, NAVPERS 18068.

THE QUESTIONS: The questions that appear in this course are designed to help you understand thematerial in the text.

VALUE: In completing this course, you will improve your military and professional knowledge.Importantly, it can also help you study for the Navy-wide advancement in rate examination. If you arestudying and discover a reference in the text to another publication for further information, look it up.

1992 Edition Prepared byENC Renato D. Dizon

Published byNAVAL EDUCATION AND TRAINING

PROFESSIONAL DEVELOPMENTAND TECHNOLOGY CENTER

NAVSUP Logistics Tracking Number0504-LP-026-7420

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Sailor’s Creed

“I am a United States Sailor.

I will support and defend theConstitution of the United States ofAmerica and I will obey the ordersof those appointed over me.

I represent the fighting spirit of theNavy and those who have gonebefore me to defend freedom anddemocracy around the world.

I proudly serve my country’s Navycombat team with honor, courageand commitment.

I am committed to excellence andthe fair treatment of all.”

CONTENTS

CHAPTER Page

1. Administration and Training . . . . . . . . . . . . . . . . . . . . . . . 1-1

2. Measuring and Repair Instruments . . . . . . . . . . . . . . . . . . . . 2-1

3. Internal Combustion Engines . . . . . . . . . . . . . . . . . . . . . . 3-1

4. Speed Controlling Devices . . . . . . . . . . . . . . . . . . . . . . . . 4-1

5. Refrigeration and Air Conditioning . . . . . . . . . . . . . . . . . . . 5-1

6. Compressed Air Systems . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

7. Laundry, Mess Decks, Galley, and Scullery Equipment . . . . . . . . . 7-1

8. Other Auxiliary Equipment . . . . . . . . . . . . . . . . . . . . . . . . 8-1

9. Lathe and Machining Operations . . . . . . . . . . . . . . . . . . . . 9-1

APPENDIX

I. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AI-1

II. Units of Measurement Charts . . . . . . . . . . . . . . . . . . . . AII-1

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INDEX-1

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iv

INSTRUCTIONS FOR TAKING THE COURSE

ASSIGNMENTS

The text pages that you are to study are listed atthe beginning of each assignment. Study thesepages carefully before attempting to answer thequestions. Pay close attention to tables andillustrations and read the learning objectives.The learning objectives state what you should beable to do after studying the material. Answeringthe questions correctly helps you accomplish theobjectives.

SELECTING YOUR ANSWERS

Read each question carefully, then select theBEST answer. You may refer freely to the text.The answers must be the result of your ownwork and decisions. You are prohibited fromreferring to or copying the answers of others andfrom giving answers to anyone else taking thecourse.

SUBMITTING YOUR ASSIGNMENTS

To have your assignments graded, you must beenrolled in the course with the NonresidentTraining Course Administration Branch at theNaval Education and Training ProfessionalDevelopment and Technology Center(NETPDTC). Following enrollment, there aretwo ways of having your assignments graded:(1) use the Internet to submit your assignmentsas you complete them, or (2) send all theassignments at one time by mail to NETPDTC.

Grading on the Internet: Advantages toInternet grading are:

• you may submit your answers as soon asyou complete an assignment, and

• you get your results faster; usually by thenext working day (approximately 24 hours).

In addition to receiving grade results for eachassignment, you will receive course completionconfirmation once you have completed all the

assignments. To submit your assignmentanswers via the Internet, go to:

http://courses.cnet.navy.mil

Grading by Mail: When you submit answersheets by mail, send all of your assignments atone time. Do NOT submit individual answersheets for grading. Mail all of your assignmentsin an envelope, which you either provideyourself or obtain from your nearest EducationalServices Officer (ESO). Submit answer sheetsto:

COMMANDING OFFICERNETPDTC N3316490 SAUFLEY FIELD ROADPENSACOLA FL 32559-5000

Answer Sheets: All courses include one“scannable” answer sheet for each assignment.These answer sheets are preprinted with yourSSN, name, assignment number, and coursenumber. Explanations for completing the answersheets are on the answer sheet.

Do not use answer sheet reproductions: Useonly the original answer sheets that weprovide—reproductions will not work with ourscanning equipment and cannot be processed.

Follow the instructions for marking youranswers on the answer sheet. Be sure that blocks1, 2, and 3 are filled in correctly. Thisinformation is necessary for your course to beproperly processed and for you to receive creditfor your work.

COMPLETION TIME

Courses must be completed within 12 monthsfrom the date of enrollment. This includes timerequired to resubmit failed assignments.

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PASS/FAIL ASSIGNMENT PROCEDURES

If your overall course score is 3.2 or higher, youwill pass the course and will not be required toresubmit assignments. Once your assignmentshave been graded you will receive coursecompletion confirmation.

If you receive less than a 3.2 on any assignmentand your overall course score is below 3.2, youwill be given the opportunity to resubmit failedassignments. You may resubmit failedassignments only once. Internet students willreceive notification when they have failed anassignment--they may then resubmit failedassignments on the web site. Internet studentsmay view and print results for failedassignments from the web site. Students whosubmit by mail will receive a failing result letterand a new answer sheet for resubmission of eachfailed assignment.

COMPLETION CONFIRMATION

After successfully completing this course, youwill receive a letter of completion.

ERRATA

Errata are used to correct minor errors or deleteobsolete information in a course. Errata mayalso be used to provide instructions to thestudent. If a course has an errata, it will beincluded as the first page(s) after the front cover.Errata for all courses can be accessed andviewed/downloaded at:

http://www.advancement.cnet.navy.mil

STUDENT FEEDBACK QUESTIONS

We value your suggestions, questions, andcriticisms on our courses. If you would like tocommunicate with us regarding this course, weencourage you, if possible, to use e-mail. If youwrite or fax, please use a copy of the StudentComment form that follows this page.

For subject matter questions:

E-mail: n314.products@cnet.navy.milPhone: Comm: (850) 452-1001, Ext. 1826

DSN: 922-1001, Ext. 1826FAX: (850) 452-1370(Do not fax answer sheets.)

Address: COMMANDING OFFICERNETPDTC N3146490 SAUFLEY FIELD ROADPENSACOLA FL 32509-5237

For enrollment, shipping, grading, orcompletion letter questions

E-mail: fleetservices@cnet.navy.milPhone: Toll Free: 877-264-8583

Comm: (850) 452-1511/1181/1859DSN: 922-1511/1181/1859FAX: (850) 452-1370(Do not fax answer sheets.)

Address: COMMANDING OFFICERNETPDTC N3316490 SAUFLEY FIELD ROADPENSACOLA FL 32559-5000

NAVAL RESERVE RETIREMENT CREDIT

If you are a member of the Naval Reserve,you may earn retirement points for successfullycompleting this course, if authorized undercurrent directives governing retirement of NavalReserve personnel. For Naval Reserve retire-ment, this course is evaluated at 6 points. (Referto Administrative Procedures for NavalReservists on Inactive Duty, BUPERSINST1001.39, for more information about retirementpoints.)

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Student Comments

Course Title: Engineman 2

NAVEDTRA: 14076 Date:

We need some information about you:

Rate/Rank and Name: SSN: Command/Unit

Street Address: City: State/FPO: Zip

Your comments, suggestions, etc.:

Privacy Act Statement: Under authority of Title 5, USC 301, information regarding your military status isrequested in processing your comments and in preparing a reply. This information will not be divulged withoutwritten authorization to anyone other than those within DOD for official use in determining performance.

NETPDTC 1550/41 (Rev 4-00

CHAPTER 1

ADMINISTRATION AND TRAINING

Everytime you advance in paygrade, you increaseyour responsibility for administration and training. Thischapter deals briefly with some of your administrativeresponsibilities and then touches on certain aspects ofyour responsibility for training others.

ENGINEERING RECORDS AND LOGS

As an EN2, you will be primarily concerned withupdating logs and similar records. Some of the logs andrecords are official, legal records. Others are used toensure proper and timely upkeep of the ship’sequipment. The information given in the followingsections is intended to help you learn how to prepare anduse the logs and records. The standard forms for the logsand records are prepared by the various systemscommands and the CNO. The forms are for issue toforces afloat and are available as indicated in theUnabridged Navy Index of Publications and Forms,NPFC PUB 2002 D. These forms are revised asconditions warrant and personnel ordering them mustbe sure they order the most current forms. If you needsimilar forms for local use, ensure that an existingstandard form will not serve the purpose before yourequest that a special form be prepared and printed.

LEGAL ENGINEERING RECORDS

The Engineering Log and the Engineer’s Bell Bookare the only legal records compiled by the engineeringdepartment. The Engineering Log is a midnight-to-midnight record of the ship’s engineering depart-ment. The Engineer’s Bell Book is a legal record of anyorder regarding change in the movement of thepropellers.

Engineering Log

The Engineering Log is a complete daily record, bywatches. It covers important events and data pertainingto the engineering department and the operation of theship’s propulsion plant. The log must show thefollowing information:

1. The total engine miles steamed for the day

2. Draft and displacement upon getting underwayand anchoring

3. The disposition of the engines, boilers, andprincipal auxiliaries and any changes in their disposition

4. Any injuries to engineering departmentpersonnel

5. Any casualties to engineering departmentmachinery, equipment, or material

6. Other matters specified by competent authority

Depending on your training and watch position, youmay have to either make entries in the Engineering Logor both make and verify such entries. Whatever the case,each entry must be made according to instructions givenin (1) the Engineering Log form, NAVSHIPS 3120/2D;(2) the Naval Ships’ Technical Manual (NSTM), chapter090; and (3) directives issued by the type commander.Each entry must be a complete statement using standardphraseology. The type commander’s directives maycontain other specific requirements pertaining to theRemarks section of the Engineering Logs for ships ofthe type.

The original Engineering Log, prepared neatly andlegibly in ink or pencil, is a legal record. Do NOT keepa rough log. Keep the Engineering Log current. Entereach event onto the Engineering Log as it happens. Noerasures are permitted in the log. When a correction isnecessary, draw a single line through the original entryso that the entry remains legible. The correct entry mustbe clear and legible. Corrections, additions, or changesare made only by the person required to sign the log forthe watch This person then initials the margin of the

page.

The engineering officr of the watch (EOOW) orthe senior petty officer of the watch (SPOW) shouldprepare the remarks for the log and should sign the logbefore being relieved at the end of the watch or duty day.The engineer officer verifies the accuracy andcompleteness of all entries and signs the log daily. Thelog sheets must be submitted to the engineer officer intime to allow him or her to check and sign them beforenoon of the day following the date of the log sheet(s).The commanding officer approves the log and signs iton the last calendar day of each month and on the date

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he or she relinquishes command. Completed pages ofthe log, filed in a post-type binder, are numberedconsecutively. They begin with the first day of eachmonth and run through the last day of the month.

When the commanding officer (or engineer officer)directs a change or addition to the Engineering Log, theperson directed must comply unless he or she believesthe proposed change or addition to be incorrect. In thatevent, the commanding officer or engineer officer willpersonally enter his or her comments and sign the log.After the log has been signed by the the commandingofficer, it may not be changed without his or herpermission or direction.

Engineer’s Bell Book

The Engineer’s Bell Book, NAVSHIPS 3120/l, is arecord of all bells, signals, and other orders received bythe throttleman for movement of the ship’s propellers.Entries are made in the Bell Book by the throttleman (oran assistant) as soon as an order is received. Entries areusually made by the assistant when the ship is enteringor leaving port, or engaging in any maneuver that islikely to involve numerous or rapid speed changes. Thisprocedure allows the throttleman to devote his or herundivided attention to answering the signals.

The Bell Book is maintained in the followingmanner:

1. A separate bell sheet is used for each shaft eachday, except where more than one shaft is controlled bythe same throttle station. In that case, the same bell sheetis used to record the orders for all shafts controlled bythe station. All sheets for the same date are filed togetheras a single record.

2. The time of receipt of the order is recorded incolumn number 1.

3. The order received is recorded in columnnumber 2. Minor speed changes (generally received viarevolution indicator) are recorded by entering thenumber of rpm ordered. Major speed changes (normallyreceived via engine order telegraph) are recorded usingthe following symbols:

a. 1/3-ahead 1/3 speed

b. 2/3-ahead 2/3 speed

C. I-ahead standard speed

d. II-ahead full speed

e. III-ahead flank speed

f. z-stop

g. B1/3-back 1/3 speed

h. B2/3-back 2/3 speed

i. BF-back full speed

j. BEM-back emergency speed

4. The number of revolutions corresponding to themajor speed change ordered is entered in column 3.When the order received is recorded as rpm in column2 (minor speed changes), no entry is made in column 3.

5. The shaft revolution counter reading (totalrevolutions) at the time of the speed changes is recordedin column 4. The shaft revolution counter reading-astaken hourly on the hour while underway-also is enteredin column 4.

For ships and craft equipped with controllablereversible pitch propellers, the propeller pitch in feet andfractions of feet set in response to a signaled speedchange, rather than the shaft revolution counterreadings, is recorded in column 4. The entries for asternpitch are preceded by the letter B. Each hour, on the hour,entries are made of counter readings. This helps incalculating engine miles steamed during the time thepropeller pitch remained constant at the last value set inresponse to a signaled order.

On ships with gas turbine propulsion plants, a belllogger provides an automatic printout each hour. Thisprintout is also provided whenever propeller rpm orpitch is changed by more than 5 percent, when theengine order telegraph is changed, or when thecontrolling station is shifted. Provision must be madefor manual logging of data in the event the bell loggeris out of commission (OOC).

Before going off watch, the EOOW signs the BellBook on the line following the last entry for his or herwatch. The next officer of the watch continues the recordimmediately thereafter. In machinery spaces where anEOOW is not stationed, the bell sheet is signed by thewatch supervisor.

NOTE: A common practice is also to have thethrottleman sign the Bell Book before it is signed by theEOOW or his or her relief.

The Bell Book is maintained by bridge personnel inships and craft equipped with controllable reversiblepitch propellers and those in which the engines aredirectly controlled from the bridge. When control isshifted to the engine room, however, the Bell Book ismaintained by the engine-room personnel. The last entrymade in the Bell Book on the bridge shows the time thatcontrol is shifted. The first entry made in the Bell Book

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in the engine room shows the time that control is takenby the engine room. Similarly, the last entry made byengine-room personnel shows when control is shifted tothe bridge. When the Bell Book is maintained by thebridge personnel, it is signed by the officer of the deck(OOD).

Alterations or erasures are not permitted in the BellBook. An incorrect entry is corrected by drawing asingle line through the entry and recording the correctentry on the following line. Deleted entries are initialedby the EOOW, the OOD, or the watch supervisor, asappropriate.

OPERATING RECORDS AND REPORTS

Engineering operating records are used to ensureregular inspection of operating machinery and toprovide data for performance analysis. Operatingrecords do not replace frequent inspections of operatingmachinery by supervisory personnel nor do theynecessarily warn of impending casualties. Personnelwho maintain operating records must be properlytrained to correctly obtain, interpret, and record data,and to report any abnormal conditions.

The type commander’s directives specify whichengineering operating records must be maintained andprescribe the forms to be used when no standard recordforms are available. The engineer officer may requireadditional operating records when he or she deems themnecessary.

The operating records discussed in this chapter aregenerally retained on board for a period of 2 years, afterwhich they may be destroyed according to currentdisposal regulations. Completed records must be stowedso they will be properly preserved and can be easilylocated.

Diesel Engine Operating Record

The Diesel Engine Operating Record-All Ships,NAVSEA 9231/2 (figs. 1-1 and 1-2), is a daily recordmaintained for each operating diesel engine. In shipswith more than one main engine in the same engineroom, a separate record sheet is maintained for eachoperating engine.

The watch supervisor enters the remarks and signsthe record for his or her watch. The petty officer incharge of the engine room or the senior enginemanchecks the accuracy of the record and signs the recordin the space provided on the back of the record. Anyunusual conditions noted in the record are immediately

reported to the engineer officer, and the record is sent tothe engineer officer for approval.

Fuel and Water Accounts

The maintenance of daily diesel fuel, lubricating oil,and water accounts is vital to the efficient operation ofthe engineering department. Forms and proceduresnecessary to account for fresh water and fuel aregenerally prescribed by the type commanders.

The accounts tell the engineer officer the status ofthe ship’s liquid load and form the basis of engineeringreports submitted to higher authority.

Ship and unit commanders must know the exactamount of burnable fuel on hand. When you computethe amount of burnable fuel on board, consider only thefuel in the service and storage tanks. All the fuel belowthe fuel suction line is considered not burnable.

Fuel and Water Reports

The Fuel and Water Report, NAVSEA 9255/9 (rev.2-80) (figs. 1-3 and 1-4), is a report submitted daily tothe commanding officer. This report indicates theamount of fuel oil and water on hand as of midnight, theprevious day. The Fuel and Water Report also includesthe previous day’s feed and potable water consumptionfigures and results of water tests. The original and onecopy are submitted to the OOD in sufficient time forsubmission to the commanding officer or command dutyofficer with the 1200 reports. The copy is retained bythe OOD.

Monthly Summary

The Monthly Summary of Fuel Inventory andSteaming Hours Report, CINCLANTFLT 3100-4, is acomprehensive monthly report of engineering data.These data are used to calculate the operating efficiencyand general performance of the ship’s engineering plant(see fig. 1-5). Requirements for this report are containedin fleet commander instructions. The engineer officerprepares the report, has the supply officer verify the fuelreceipt figures, and forwards it to the commandingofficer. The commanding officer approves the report andsends it directly to the fleet commander. One copy isretained on board in the files of the engineeringdepartment. An additional copy of the report may beprovided to the type commander.

The Monthly Summary includes the ship’s fuelreceipts data, fuel consumption and steaming hoursnecessary to establish monthly financial obligations,

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Figure 1-1.

1-4

Figure 1-2.

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Figure 1-3.—Fuel and Water Report (front).

and fuel requirements data for budget justification. This consumed not underway, and fuel consumed by boats.

report includes all fuel data as of 2400 hours of the last Space is also provided for total steaming hours brokenday of the month. Fleet commander instructions contain down as underway and not underway.

detailed instructions for completing the forms, as well Most engineer officers prefer to compile theas the definitions of the terms used. necessary data for this summary on a daily basis rather

In addition to data on fuel inventory, the report than wait until the end of the month and make

contains space for fuel consumed underway, fuel computations from the various records. If you prepare

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Figure 1-4.—Fuel and Water Report (back).

or assist in preparing this report, be very careful withyour mathematical calculations and ensure that they areaccurate. Doing so will help to avoid the necessity ofresubmitting a corrected form later.

Daily Boat Fueling Record

The Daily Boat Fueling Record is a routine record

of daily fueling, which is highly recommended for any

ship that carries or maintains a number of boats. Use of

this schedule will help prevent special fuelings at

unusual hours and will keep the boats ready for

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Figure 1-5.—Monthly Summary of Fuel Inventory and Steaming Hours Report, CINCLANTFLT Report 31004.

unexpected calls. The following list contains the — Operating hours of fuel remainingrecommended headings for this record:

— Fueled or not fueled to capacity— Boat number

— Fuel capacity in gallons Distilling Plant Operating Record

— Gallons on hand

— Approximate fuel consumption in gallons perhour

The Distilling Plant Operating Record is a dailyrecord of the operation of the ship’s evaporators andtheir auxiliaries. Entries are made for each hour of the

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watch while the distilling plants are in operation.Different ships have different types of distilling plants,but all of the daily distilling plant operating recordsrequire practically the same data.

The information required by this record consists ofthe following:

1. Temperature, pressure, vacuum, flow, chemicalanalysis, and density data from various points in thedistilling plant

2. Scaling record for each evaporator unit, whichincludes the date of the last scaling, the hours operated,and the quantity of distilled water produced

3. Starting, stopping, and total operating time ofeach evaporator and various auxiliary machinery parts,such as air ejector and pumps

4. Remarks concerning the operation andmaintenance of the distilling plant for each watch of the

day

You must make accurate entries in the DistillingPlant Operating Record! Accurate entries not only helppredict troubles but, should abnormal operatingconditions suddenly develop, aid in locating the sourcesof trouble.

For other recommended miscellaneous records,refer to NSTM, chapter 90.

DISPOSAL OF ENGINEERING RECORDSAND REPORTS

Before you destroy any of the engineeringdepartment records, study the Disposal of Navy andMarine Corps Records, USN and USNS Vessels,SECNAVINST P5212.5 (revised). This publicationprovides the procedures for disposing of records. Foreach department aboard the ship, these instructions listthe permanent records that must be kept and thetemporary records that may be disposed of according toan established schedule.

Both the Engineering Log and Engineer’s Bell Bookmust be preserved as permanent records on board shipfor a 3-year period unless they are requested by a navalcourt or board, or by the Navy Department. In such case,copies (preferably photostatic) of records that are sentfrom the ship are certified by the engineer officer asbeing true copies and are put in the ship’s files.

At regular intervals, such as each quarter, recordsthat are over 3 years old are destroyed. When a ship thatis less than 3 years old is decommissioned, the currentbooks are retained on board. If a ship is scrapped, the

current books are forwarded to the nearest NavalRecords Management Center.

All reports forwarded to, and received from,NAVSEA or another superior command may bedestroyed when they are 2 years old, if they are no longerrequired.

Finally, to control the volume of paper work, reportsshould only be kept on board ship if they

1. are required,

2. serve a specific purpose, or

3. may provide repair personnel with informationnot found in publications or manuals.

MEASURE PROGRAM

All equipment requiring calibration or servicingshould be maintained at maximum dependability. Tomeet this requirement, the Chief of Naval Materialimplemented the Metrology Automated System forUniform Recall and Reporting (MEASURE).

The MEASURE system is a tool for your use. It isonly as good as the information that you put into it.Therefore, it is important that alI the information becomplete, legible, accurate, and consistent.

As an EN you will be required to read gauges todetermine if the equipment is operating properly. Thegauges must be calibrated periodically to assure theiraccuracy. The MEASURE program provides thiscalibration. In this section, we will discuss some of themajor parts of the MEASURE system.

METER CARD

The METER card is a five-part color-coded form towhich the equipment identification and receipt tag isattached. It is filled out by either the customer or thecalibrating activity. You will have a METER card forevery item for which you are responsible that requirescalibration.

This card is used to record a calibration action, toadd or delete items from inventory, to reschedulecalibration, to transfer custody, or to record manhoursfor a completed calibration.

The white copy of a completed METER card is sentto the MEASURE Operational Control Center(MOCC), where the information is keypunched into acomputer to update the MEASURE data base. The newinformation is then printed on another METER card and

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sent back to the customer activity to be used the nexttime another transaction is to be completed.

Accurate data, completeness, and legibility in fillingout the meter card is essential. Remember a computerCANNOT think!

FORMAT 310

This report is sent to you every month and is aninventory of all your items, including overdue anddelayed items. If you have any additions, deletions, orcorrections to this format, submit them to the MOCC oneither the METER card or on the Add-On-Inventoryform.

FORMAT 350Figure 1-6.—CAUTION tag.

This report is also sent to you monthly and is fori n f o r m a t i o n p u r p o s e s . I t i s p r e p a r e d i n acustomer/subcustodian sequence to readily identify allitems held on subcustodian basis by other activities. Thisformat is produced concurrently with format 310. Bothformats 310 and 350 will have the last calibration datesof all items and the due dates of their calibrations.

FORMAT 802

Format 802 is a recall schedule. It is updated anddistributed monthly. It tells you what equipment is duefor calibration that month. It is sequenced by customeractivity, by subcustodian, and by calibrationlaboratories.

EQUIPMENT AND INSTRUMENTTAG-OUT

Whenever you make repairs, you will be required toisolate and tag-out that equipment or section of thesystem. The tag-out program provides a procedure to beused when a component, piece of equipment, system, orportion of a system must be isolated because of someabnormal condition. The tag-out program also providesa procedure to be used when an instrument becomesunreliable or is not operating properly. The majordifference between equipment tag-out and instrumenttag-out is that tags are used for equipment tag-out andlabels are used for instrument tag-out.

Tag-out procedures are described in StandardOrganization and Regulations of the U.S. Navy,OPNAVINST 3120.32B. and represent the minimumrequirements for tag-out. These procedures aremandatory and are standardized aboard ships and repair

Figure 1-7.–DANGER tag.

activities. The following definitions are used in the

tag-out bill:

1. Authorizing officer-This individual has the

authority to sign tags and labels and to have tags and

labels issued or cleared. The authorizing officer is

always the officer responsible for supervising the

tag-out log. The commanding officer designatesauthorizing officers by billet or watch station. The

authorizing officer for engineering is normally the

EOOW underway and the engineering duty officer

(EDO) in port.

2. Department duty officer (DDO) (repair activities

only)-This individual is designated as DDO on theapproved watch bill or plan of the day.

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3. Engineering officer of the watch (EOOW)–Thisindividual may be either the EOOW or the EDO,depending on engineering plant conditions.

4. Officer of the deck (OOD)–This individual maybe either the OOD or the ship’s duty officer, dependingon the ship’s condition.

5. CAUTION tag (See fig. 1-6.)–This is aYELLOW tag used as a precautionary measure. Itprovides temporary special instructions or warns thatunusual caution must be used to operate the equipment.These instructions must state exactly why the tag isinstalled. Use of phrases such as “DO NOT OPERATEWITHOUT EOOW PERMISSION” is not appropriate.Yellow tagged equipment or systems must not beoperated without permission from the responsiblesupervisor. The CAUTION tag may not be used ifpersonnel or equipment can be endangered whileworking under normal operating procedures. In suchcases, a DANGER tag must be used.

6. DANGER tag (See fig. 1-7.)–This is a RED tagthat prohibits the operation of equipment that couldjeopardize the safety of personnel or endangerequipment, systems, or components. Equipment maynot be operated or removed when tagged withDANGER tags.

7. OUT-OF-CALIBRATION labels (See fig.1-8.)–These are ORANGE labels used to identifyinstruments that are out of calibration and do not giveaccurate readings. These labels warn that theinstruments may be used for system operation, but onlywith extreme caution.

8. OUT-OF-COMMISSION labels (See fig.1-9)–These are RED labels used to identify instrumentsthat will not give accurate readings because they areeither defective or isolated from the system. Theinstruments should not be used until they have beenrecertified for use.

9. Repair activity–This is any activity other thanthe ship’s force that is involved in the construction,testing, repair, overhaul, refueling, or maintenance ofthe ship (intermediate or depot level maintenanceactivities).

10. Ship’s force–These are personnel who areassigned to the ship and are responsible for themaintenance and operation of the ship’s systems andequipment. Only qualified personnel are authorized tomake a tag-out.

11. Tag-out log–This is the control document usedto administer the entire tag-out procedure.

Figure 1-8.–Out-of-calibration label.

Figure 1-9.–Out-of-commision label.

TAG-OUT LOGS

The number of tag-out logs on a ship depends on theship’s size. For example, a minesweeper ornonnuclear-powered submarine may need only onetag-out log; a major surface combatant may need aseparate log for each major department. Individual forcecommanders specify the number of logs needed andtheir location.

A tag-out log is a record of authorization for eachtag-out action. It includes the following information:

1. A copy of OPNAVINST 3120.32B and anyamplifying directives needed to administer the system.

2. The DANGER/CAUTION Tag-out Index andRecord of Audit (Index/Audit Record). This is asequential list of all tag-outs issued. It provides a readyreference of existing tag-outs, ensures that serialnumbers are issued sequentially, and is useful inconducting audits of the log. A sample of this index isshown in figure 1-10. Index pages with all tag-outs listedas cleared may be removed by the department head.

3. DANGER/CAUTION Tag-out Record Sheet(figs. 1-11 and 1-12). All tags that have been used in thetag-out of a particular system are logged on oneDANGER/CAUTION tag-out record sheet along withthe reason for the tag-out. All effective sheets are keptin one section of the log.

4. Instrument Log (fig. 1-13). Labels used withOUT-OF-CALIBRATION and OUT-OF-COM-MISSION instruments are logged in the instrument log.

5. Cleared DANGER/CAUTION Tag-out RecordSheets. Sheets that have been cleared and completed are

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Figure 1-10.—Danger/Caution Tag-out Index and Record of Audit.

Figure 1-11.—Danger/Caution Tag-out Record Sheet (front).

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Figure 1-12.—Danger/Caution Tag-out Record Sheet (back).

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Figure 1-13.—Instrument Log.

transferred to this section of the log until they arereviewed and removed by the department head.

TAG-OUT INFORMATION

A tag-out procedure is necessary because of thecomplexity of modem ships and the cost, delays, andhazards to personnel that can result from the improperoperation of equipment. Learn and use the followingguidelines:

1. Enforce the tag-out procedure at all times. Youmust do this during normal operations as well as duringconstruction, testing, repair, or maintenance.

2. Do not use tags or labels as a substitute for othersafety measures. Examples are chaining or lockingvalves, removing fuses, or racking out circuit breakers.However, you must attach tags to the fuse panel, the

racked-out circuit breaker cabinet, or a locked valve toshow a need for action. You do not need to use tagswhere a device will be locked during normal operations.

3. Use tags to show the presence of, and therequirement for, freeze seals, blank flanges, or similar

safety devices. When equipment or components areplaced out of commission, use the tag-out procedures tocontrol the status of the affected equipment. Examplesare disconnecting electrical leads, providing jumpers, orpulling fuses for testing or maintenance.

4. Never use tag-outs to identify valves, to mark

leaks, or for any purpose not specified in the tag-out

procedure.

5. Do not laminate tags or labels for reuse. Thereuse of tags or labels is not allowed.

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6. The absence of a tag or label may not be takenas permission for unauthorized operation of equipment.

7. Whenever a tag or label is issued, correct thesituation requiring the tag or label so it can be removedas soon as possible.

8. The tag-out procedure is for use by the ship’spersonnel on the equipment and systems for which theyare responsible. However, repair activity personnelshould use the procedure to the maximum extentpracticable with systems and equipment that are stillunder construction.

9. Standard Organization and Regulations of theU.S. Navy, OPNAV Instruction 3120.32B, is alsorequired when work is being done by an intermediatelevel maintenance activity on equipment or systems thatare the responsibility of the ship’s force. Sometimes aship is under construction or assigned to a repair activitynot under the control of the type commander. When thathappens, the ship’s force and the repair activity mayhave to agree on the use of tags and labels. In this case,the tag-out system should be formal in nature andfamiliar to both the repair activity and the ship’s force.

10. Any person who knows of a situation requiringtags or labels should request that they be issued andapplied.

11. When using labels, you should list on the log anyassociated requirements specified for installationprocedures, test procedures, work permits (ripouts orreentries), or system turnover agreements.

12. Make each decision on a case-by-case basis asto whether an OUT-OF-COMMISSION or anOUT-OF-CALIBRATION instrument label is to beused. In general, if the instrument error is small andconsistent, you can use an OUT-OF-CALIBRATIONlabel and the operator may continue to use theinstrument . When you use anOUT-OF-CALIBRATION label, mark on the label themagnitude and units of the required correction.However, when you use an OUT-OF-COMMISSIONlabel, the instrument should not be used.

13. Use enough tags to completely isolate a sectionof piping or circuit being worked on, or to prevent theoperation of a system or component from all stations thatcould exercise control. Use system diagrams or circuitschematics to determine the adequacy of all tag-outactions.

14. Careful planning of tag-outs can significantlyreduce the number of record sheets and tags. Planningcan also reduce the effort required to perform audits,

particularly during periods of overhaul or repair. Forexample, a system and the equipment serviced by thesystem can be isolated and tagged-out at its boundarieswith other systems. Then several different actions canbe performed within the boundaries. Also, only onetag-out record sheet with associated tags will be requiredfor the work within the boundaries. When you initiatethe tag-out, include all known work items in theOperations/Work Items Included in Tag-out section. Ifyou add work items to a tag-out record sheet after initialissue, take the following action:

a. If no additional tags are required for the newwork, have the authorizing officer and, if required, therepair activity representative make sure the work isconsistent with the purpose of the tag-out. New workmust be fully described in the Operations/Work ItemsIncluded in Tag-out section of the record sheet. Theauthorizing officer should make a thorough review toensure the completeness and accuracy of the existingtag-out. This is the same procedure used to initiate a newtag-out record sheet for the added work The authorizingofficer (and repair activity representative) should signthe appropriate blocks next to the added item.

b. Additional tags may be needed to provideenough isolation for work that is to be added. If so, youmust follow the procedures described later in thischapter for adding tags to an existing record sheet.

PROCEDURES

Assume that a requirement for tags has beenidentified, and that the affected system will be out ofcommission as a result of the tag-out action. Theauthorizing officer must ask the commanding officerand the responsible department head for permission tobegin the tag-out. The authorizing officer must alsonotify the responsible division officer of the requirementfor tag-out. On ships having damage control central(DCC), the authorizing officer must notify DCC if theaffected system or component will be out ofcommission. The authorizing officer should haveapproval from either the OOD or the EOOW if thetag-out will affect systems under their responsibility.After obtaining permission, the authorizing officershould direct the preparation of the tag-out record sheetand tags according to the following procedures. Theprocedures may be modified during overhaul periods atthe discretion of the commanding officer.

1. PREPARING TAGS AND THE RECORDSHEET. DANGER and CAUTION tags and theassociated tag-out record should be prepared as follows:

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a. The person designated to prepare the tag-outis normally the ship’s force petty officer in charge of thework This person fills out and signs the record sheet andprepares the tags.

b. A tag-out record sheet is prepared for aspecific purpose. All tags used for that purpose are listedon an initial record sheet and additional sheets asnecessary. The stated purpose may include several workitems. Each record sheet is assigned a log serial numberin sequence, from the index/audit record. Log serialnumbers are also used to identify all tags associated witha given purpose. Each tag is given its own sequentialnumber as it is entered in the record sheet. For example,tag 7-16 would be the sixteenth tag issued on a singlerecord sheet with the log serial number seven. Todifferentiate among tag-out logs, a prefixed system,approved by the commanding officer, is used with thelog serial numbers.

c. The tag-out record sheet includes referencesto other documents that apply. Some examples are workpermits, work procedures, repair directives, reentrycontrol forms, test forms, and rip-out forms. Certaininformation should be gotten either from referencedocuments or from the personnel requesting the workSome examples are the reasons for tag-out, the hazardsinvolved, the amplifying instructions, and the worknecessary to clear the tags. This information should bedetailed enough to give watch standers a clearunderstanding of the purpose of, and necessity for, eachtag-out action.

d. Use enough tags to completely isolate thesystem, piping, or circuit being worked on. Be sure youuse tags to prevent the operation of a system orcomponent from all the stations that could exercisecontrol. Use system diagrams or circuit schematics todetermine the number of tags needed. Indicate thelocation and position/condition of each tagged item byan easily identifiable means. Some examples are MS-l,STBD TG BKR, OPEN, SHUT, BLANK FLANGEINSTALLED.

e. After you have filled out the tags and thetag-out record sheet, have a second person make anindependent check of the tag-out coverage and usage.That person should use appropriate circuit schematicsand system diagrams. The second person verities thecompleteness of the tag-out action by signing the recordsheet.

f. The authorizing officer then reviews therecord sheet and tags for adequacy and accuracy. Whensatisfied, the officer signs the record sheet and the tags.

(1) If a tag-out is requested by a repairactivity, the repair activity representative (shopsupervisor or equivalent) must sign the tag-out recordsheet. This shows that the repair activity is satisfied withthe completeness of the tag-out. Verified tags alert allpersonnel that the repair activity must approve theremoval of the tags.

(2) If the repair activity representative’sconcurrence is not required, this space on the recordsheet need not be filled in.

(3) On ships with DCC, the authorizingofficer annotates the tag-out record sheet in the upperright-hand corner with the words DCC notified, and theninitials it. This ensures that DCC knows the extent of thetag-out and the status of the material condition of theunit.

(4) The authorizing officer then authorizesinstallation of the tags.

g. The person attaching the tag must make surethe item tagged is in the prescribed position or condition.If the item is not in the prescribed position or condition,he or she must get permission from the authorizingofficer to change it to the prescribed condition orposition. As each tag is attached and the position orcondition is verified, the person attaching the tag mustsign the tag and initial the record sheet.

NOTE: Only a qualified person from the ship’sforce may position equipment and affix tags and labels.The tags should be attached so they will be noticed byanyone who wants to operate the component. Tags mustNOT be attached to breaker covers or valve caps thatmay be removed later.

h. After all tags have been attached, a secondperson must independently verify proper itempositioning and tag attachment, sign each tag, and initialthe record sheet. If repair activity concurrence isrequired, a repair activity representative must witnessthe verification, sign the tags, and initial the tag-outrecord sheet.

NOTE: Only qualified ship’s force personnel mayperform the second check of tag installation.

i. Sometimes additional tags are requiredbecause of added work on an existing tag-out recordsheet. In that case, the person making the change musthandle the DANGER and CAUTION tags and tag-outrecord sheet as follows:

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(1) Ensure that the purpose of the existingrecord sheet remains unchanged by the new work andits associated tags.

(2) Fill out the tag-out record sheet to reflectthe added work. Prepare whatever additional tags arerequired. Review the reason for the tag-out, the hazardsinvolved, the amplifying instructions, and the worknecessary to clear the tags. Do this on the existingtag-out record sheet to ensure that it reflects the old workand the new work being added to the record sheet. Aftercompleting the review of the record sheet, have the pettyofficer in charge of the work sign the first coveragecheck block next to the added work item.

(3) Number each tag added to the existingtag-out sequentially, beginning with the number after thelast number in the original tag-out. Annotate the serialnumbers of the new tags next to the associated new workitem on the record sheet. Enter the updated number ofeffective tags at the top of the record sheet by crossingthrough the previous number and writing in the newnumber.

(4) After the new tags and the tag-out recordsheet have been filled out and signed by the petty officerin charge of the work, have a second person make areview. The second person makes an independent checkof the tag coverage and usage by referring to appropriateschematics and diagrams. This person should sign therecord sheet in the block for the new work item to showsatisfaction with the completeness of the tag-out actions.This includes both the additional and the previouslyissued tags.

(5) Request that the authorizing officer and,when required, the repair activity representative reviewthe entire record sheet and the new tags for completenessand accuracy. They should then sign their respectiveblocks for the added work item. The authorizing officerwill then issue the tags.

j. Do not allow work to start until all theDANGER tags required for the protection of personnelor equipment have been attached according toestablished procedures.

2. REMOVING DANGER AND CAUTIONTAGS. Remove these tags immediately after thesituation requiring the tag-out has been corrected. Aseach work item identified on the tag-out record sheet iscompleted, delete it from the tag-out record sheet.Completed work items listed in the Operations/WorkItems Included in Tag-Out section of the record sheetmust be signed off. This is done by the authorizingofficer (and repair activity representative, when

required) in the designated signature block. AllDANGER tags must be properly cleared and removedbefore a system or portion of a system can beoperationally tested and restored to service. To removeindividual tags, the authorizing officer must ensure thatthe remaining tags provide adequate protection forwork, testing, or operations that still remain to beperformed. Tags may only be removed following thesigned authorization of the authorizing officer. When atag-out action was initiated by a repair activity, anauthorized representative of that repair activity mustconcur that the job is complete. A shop supervisor orequivalent must sign the tag-out record sheet before thetags may be removed. As the tags are removed, thedate/time of removal must be initialed. Ditto marks arenot allowed. All tags must be returned immediately tothe authorizing officer. This officer then requires asystem lineup or a lineup check Tags that have beenremoved must be destroyed after they have beendelivered to the authorizing officer. All tags associatedwith each specific tag-out action must be destroyed andthe system or component returned to normal operating(shutdown) condition. The authorizing officer must thencertify these actions by entering the date and time whenthe system lineup or lineup check was completed. In acase where a system or component restoration wasperformed according to a specific document, referenceto that document is made in the Condition Prescribed Byblock Inapplicable portions of the statements on therecord sheet are lined out and initialed when a valvelineup check is not required or when the system is notreturned to a normal condition. The authorizing officermust also enter the date and time cleared on theappropriate line of the tag-out index/audit record. Thecompleted record sheets must be removed from theeffective section of the log and placed in the completedsection, They will be reviewed and removed by adesignated officer. On ships having a DCC, theauthorizing officer must notify DCC that the tag-out hasbeen cleared. To complete the process, the authorizingofficer must annotate the completed tag-out record sheetin the lower right-hand corner on the reverse side withthe words DCC notified, and then initial it.

a. When any component is tagged more thanonce, the DANGER tag takes precedence over all othertags. All DANGER tags must be removed and clearedbefore the equipment may be operationally tested oroperated.

b. A missing or damaged tag is reissued byindicating on the tag-out record sheet, on the linecorresponding to the damaged or missing tag, that thetag was missing or damaged and that a replacement was

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issued. The new tag is issued using the next number inthe tag-out record sheet. The authorizing officer shouldsign the tag-out record sheet to authorize the clearing ofdamaged or missing tags and to authorize theirreplacement.

3. ISSUING AND REMOVING LABELS. Labelsare issued and removed in a manner similar to thatrequired for tags.

a. The authorizing officer authorizes the use oflabels by signing the label and the instrument log. Whenlabels are required for reactor plant systems and reactorplant support systems, the repair activity representativeconcurs by signing on the label and in the instrument lognext to the signature of the authorizing officer.

b. Second check signatures are not required onthe label or on the instrument log.

c. When a label like one of those shown infigures l-8 and l-9 is assigned, it must be affixed to theexterior surface of the affected instrument, so operatorscan easily determine the status of the instrument.

d. A different procedure is used for installedinstruments not associated with propulsion plants onnuclear-powered ships and for portable test and radiacequipment. In these cases, the labels shown in figuresl-8 and l-9 may be replaced by those affixed by aqualified instrument repair or calibration facility.

ENFORCEMENT

Tag-out logs are kept in the spaces designated.Supervisory watch standers must review the logs duringwatch relief. They must also check outstanding tags andlabels and conduct an audit of the tag-out log asdescribed in the following list. The authorizing officermust ensure that the checks and audits are performed atthe required frequency and that the results are reportedto the cognizant officer.

1. All outstanding tags listed on each tag-outrecord sheet must be checked to ensure they are installedcorrectly. This is done by comparing the information onthe tag with the record sheet and the item on which eachtag is posted. When a valve or switch position isprescribed, a visual check of the item is made unless acover, cap, or closure must be removed. Checking theoperation of a valve or switch is not authorized as partof a routine tag-out audit. A spot check of installed tagsmust be conducted to ensure the tags are effective; thatis, that they are covered by an active tag-out recordsheet. All discrepancies in actual position must bereported at once to the responsible watch/duty officer

before the tag audit is continued. The date, time, type ofdiscrepancies (including corrective action), andsignature of the person conducting the check must belogged on each tag-out record sheet.

2. All outstanding tag-out record sheets must beaudited against the index/audit record section. As partof the audit, each tag-out record sheet should be checkedboth for completeness and to ensure that the installedtags were checked. The date, discrepancies noted, andthe signature of the person conducting the audit must belogged by a line entry in the index/audit record sectionof the tag-out log.

3. The installation of instrument labels and theauditing of logs must also be checked. A line entry madein the instrument log containing the date, the time, thediscrepancies noted, and the signature confirms thecheck

4. Checks and audits of all tag-outs are usuallyperformed every 2 weeks.

5. Results of audits are reported to the responsibledepartment head.

The responsible department head should frequentlycheck the tag-out log, note errors, and bring them to theattention of the persons responsible. This is to ensurethat tag-out/label procedures are being enforcedproperly. Completed tag-out record sheets andinstrument logs should be removed after the review.

A violation of any tag-out compromises the entiretag-out system and may have serious consequences.Therefore, strict adherence to the tag-out procedure,without exception, is required of all personnel.

1. Labels must be removed immediately when theaffected instrument has been satisfactorily repaired,replaced, aligned, or calibrated.

2. Tags, which have been removed, must bedestroyed.

Remember, always insist on proper tag-out. It helpsto prevent accidents, both minor and major.

SHIP-TO-SHOP WORK

Many repair jobs are designated by the ship orapproved by the repair activity as “ship-to-shop” jobs.In this type of job, the ship’s force does a large part ofthe repair work For example, the repair or renewal of adamaged pump shaft might well be written up as aship-to-shop job. The ship’s force will disassemble thepump and remove the shaft. Then the shaft and anynecessary blueprints or technical manuals are delivered

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to the designated shop of the repair activity. After theshaft has been repaired, or a new one has been made, itis picked up and brought back to the ship by the ship’sforce. The pump is reassembled, inspected, and testedby the ship’s force to make sure it is operatingsatisfactorily.

An important thing to remember is that the repairfacility is responsible for ensuring that its personnelrepair or manufacture this this to the manufacturer’sspecifications, perform all tests required by qualityassurance (QA), and fill out properly all the requiredforms. You, however, are responsible for witnessing anytest required by QA, monitoring the status of the job atall times, and reassembling and test operating the pumpproperly. The end results will produce a reliable,operating piece of equipment.

EQUIPMENT TESTS

As an EN2, you will assist in scheduling andperforming various tests on your equipment. Thepurpose of those tests is to determine how yourequipment is performing and if there are any equipmentmalfunctions. The tests are performed at various times,such as (1) before the ship goes to the shipyard foroverhaul, (2) after post deployment, (3) during a tenderavailability, or (4) as required by PMS. The tests areperformed by the ship’s force, IMA personnel, shipyardpersonnel, or an inspection team (such as a Board ofInspection and Survey [INSURV]). Detailed types ofinspections are described in COMNAVSURFLANTMaintenance Manual, COMNAVSURFLANT INST.9000.lC or COMNAVSURFPAC Ship and CraftMaintenance Manual, Volumes 1 and 2, PlannedMaintenance, COMNAVSURPAC INST. 4700.lB.

Two types of inspections and tests that can be usedto “spot” impending trouble in an internal combustionengine are called trend and spectrographic analyses. Wewill now discuss and explain their importance and usein detecting problems in internal combustion engines.

ENGINE TREND ANALYSIS

Preventive maintenance receives a great deal ofattention from everyone in the field of diesel engineoperation, since letting an engine run as long as it willrun and fixing it only after a breakdown occurs is notonly foolish, but extremely costly. On the other hand,you would be just as foolish to constantly tear down anengine just to inspect it. You should know that vital partsof an engine last longer and operate better if they are nottampered with unnecessarily. Therefore, an attempt

must be made to find a happy medium between thesetwo forms of maintenance.

One way to determine the condition of an engine isby monitoring its operation. This is done by regularlyobtaining certain engine operating data and by studying,analyzing, and comparing it with previous data. Thisinformation is then reduced to a form that allengineering personnel can interpret and decide whetherthe engine needs to be overhauled or just temporarilyshut down for simple maintenance. For more detailedp r o c e d u r e s , r e f e r t o N A V S E A S 9 2 3 3 - C 3 -HBK-010/010, Diesel Engine, Over 400 BHP, TrendAnalysis Handbook

SPECTROGRAPHIC ANALYSIS

Spectrographic analysis is a method of determiningengine or equipment wear by analyzing engine oil andhydraulic oil samples for chemicals and particles notfound in new oil or hydraulic fluid. This analysis is donein laboratories on samples provided by ships accordingto instructions given in their sampling kits.

Ships must maintain accurate records of operatinghours since major overhauls, oil changes, and samplingsto provide the testing facility with the informationrequested in the sampling kit. (COMNAVSURFLANTuses the services of the Charleston Naval Shipyard, andCOMNAVSURFPAC uses intermediate maintenanceactivities (IMAs) for analyzing oil samples frommachinery employing closed lube oil/hydraulicsystems.) In addition, ships must maintain a record ofconditions found and repairs made as a result oflaboratory recommendations.

When the shipyard or IMA laboratory receives theoil sample, a physical test and a spectrometric analysisare performed. The physical test consists of thefollowing actions:

1. All samples are tested for fuel dilution, and areport by percent volume is provided to all concerned.

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2. All samples are tested for solids by being spunin a centrifuge. Solids will settle at the bottom of thesample.

3. Allowable “use limits” are tested and recorded.

When the physical test is completed, theshipyard/IMAs will make a spectrometric analysis ofeach used oil sample, then report to all concerned theconcentrations of the following elements in parts permillion (ppm).

Additional information on trend analysis and oilspectrometric a n a l y s i s i s c o n t a i n e d i nCOMNAVSURFLANTINST 9000.1C orCOMNAVSURFPACINST 4700.lB.

POTABLE WATER SYSTEMS

The potable water system supplies scuttlebutts,sinks, showers, sculleries, and galleys and providesmakeup water for various freshwater cooling systems.This system is often called the freshwater system. Theterm fresh water is not correct because fresh water is notpotable unless it is safe for human consumption.

Potable water may be contaminated duringproduction, handling, storage, or distribution. Treatmentwith a halogen, such as chlorine or bromine, is the onlyapproved method of disinfecting potable water.Submarines and servicecraft are not equipped to use thehalogen treatment method. They are provided withemergency methods to treat fresh water. The ship’sengineering and medical departments are responsiblefor the receipt, distribution, and quality testing ofpotable water. For more in-depth informationconcerning potable water systems, refer to NSTM,Chapter 533, “Potable Water Systems.” Additionalreferences related to potable water systems are shownin the following list.

NSTM, Chapter 090, “Inspections, Tests, Records,and Reports”

NSTM, Chapter 220, “Boiler Water/Feedwater”

NSTM, Chapter 9580, “Distilling Plants LowPressure Submerged Tube Steam Plants”

NSTM, Chapter 9480, “Piping Systems”

NSTM, Chapter 631, “Preservation of Ships InService (Surface Preparation and Painting)”

NSTM, Chapter 670, “Stowage, Handling, andDisposal of Hazardous General Use Consummables”

Manual of Naval Preventive Medicine for PotableWater Shore-to-Ship Delivery, NAVMED P-5010-5

Manual of Naval Preventive Medicine for PotableWater Ship-to-Ship Delivery, NAVMED P-5010-6

Potable Water Standards, BUMEDINST 6240.3

TRAINING

By the time you have reached the EN2 level ofexperience, you have acquired many skills and aconsiderable amount of theoretical knowledge. As anEN2, you will be responsible for passing these skills andknowledges on to other, lower-rated Enginemen.Success in training others requires that you have ordevelop certain additional skills as an instructor.

TRAINING RESPONSIBILITIES

You must be technically competent before you canteach others, but your technical competence must besupplemented by the ability to organize information, topresent it effectively, and to arouse and keep the interestof your trainees.

You will find excellent general information on howto plan, carry out, and evaluate an instructional programin Military Requirements for Petty Officer SecondClass, NAVEDTRA 12045, and in Mili taryRequirements for Petty Officer First Class, NAVEDTRA 12046.

Our discussion does not include the basicinformation given in these references. Instead, it dealswith some of the difficulties peculiar to the training ofthe engine-room and auxiliary personnel and some ofthe ways in which you can overcome or minimize thesedifficulties.

What kinds of things cause special problems in thetraining of engine-room personnel? For one thing, theinterrelationship of propulsion plant operations. Eachperson must be trained to perform not only as anindividual but also as a member of a team. Take forinstance the duties of the watch standers. They are veryclosely related, and the actions taken by one persondepend in some way upon the actions taken by otherpersons. From a long-range point of view, however, theteamwork required for engine-room operations canactually be turned to a training advantage. As a personis being trained for one specific duty, he or she willnaturally learn something about the other duties. As arule, therefore, the first part of a person’s engine-roomtraining may take quite a while, but the last part will takemuch less time.

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The procedures for training a new person inengine-room operations vary considerably, dependingupon such factors as the ship’s steaming schedule, thecondition of the engine-room machinery, the number ofexperienced personnel available to assist in the training,and the amount of time that can be devoted to thetraining. In general, however, you will probably beginby training the trainee to act as messenger. Then, beforethe trainee is assigned to any actual duty, he or sheshould be introduced to the engine room and becomefamiliar with the location of all machinery, equipment,piping, and valves. The trainee must also be instructedin certain basic safety precautions and be specificallywarned about the dangers of turning valve wheels ortampering with machinery. “IF IN DOUBT, ASKQUESTIONS!” is a pretty good rule for any new personin the engine room to follow.

A person ready to be trained in the duties ofmessenger should be shown all the gauges that are inuse, told what the gauges indicate, and shown how totake readings. The trainee should understand why thereadings are important, exactly how often each gaugemust be read, and how to make accurate entries in theengine-room log. When you are sure the traineeunderstands everything about gauges, teach the traineehow to check lube-oil levels and how to clean metaledge-type filters and basket strainer-type.

For a while you will have to keep a close watch onthe trainee’s performance of these duties. When thetrainee becomes proficient in the duties of messenger,start the training in the throttleman’s duties. Fist, let thetrainee observe the throttleman Then, if conditionspermit, let the trainee start and secure machinery.

As far as manual skills are concerned, thethrottleman’s job is probably easier than themessenger’s job. But the throttle watch requires theutmost vigilance and reliability, and a new person willhave a lot to learn before being trusted to stand thethrottle watch alone. Personnel should always start outunder the supervision of an experienced throttleman andshould remain under this supervision until the pettyofficer in charge of the engine room is fully satisfied thatthe trainee is completely qualified for this duty.

In training engine-room personnel who have not hadprevious engine-room experience, remember that anengine room can be a complicated and confusing placeto someone who walks into it for the first time. A lot ofequipment is crammed into a small space, and a lot ofcomplex actions are going on at the same time. Whentraining new personnel, try to think back to the timewhen you first went into an engine room. What aspects

of engine-room operations were most confusing to youat first? What kind of training would have made yourlearning easier and faster? By analyzing your own earlyexperience and reactions, you get a bearing on what anew person may experience and you may be able toprovide more effective training.

When you train new personnel, remember that theyvary widely in their methods and rates of learning. Somepeople will learn most effectively if you give them anoverall view of main engine operations, including acertain amount of theory, before going into the detailsof the hardware and the manual operations. Others willlearn most effectively if they are taught some manualskills before getting too involved with theory. Somepeople learn manual skills rapidly but take a long timeto absorb the theory; for others, the reverse is true. And,of course, some people learn everything slowly. Sometrainees benefit from patient, almost endless repetitionof information; others may become bored and restless ifyou go over the same point too often. The importantthing to remember is that your training efforts will bemost successful if you are able to observe and allow forthe individual differences that are bound to exist.Closely related to this point is another: Don’t make snapjudgments about people’s abilities until they have had achance to DEMONSTRATE them. You may turn out tobe very wrong if you make snap judgments on the basisof a general impression, such as appearance, or the rateat which they learn when they first come into the engineroom.

When training personnel who have already hadsome engine-room experience but who have been onsome other type of ship, you may find that a certainamount of retraining is needed before the individual canqualify as an engine-room watch stander on your ship.No two engine rooms are precisely alike in all details,and no two main engines that appear to be identicalbehave in precisely the same way under all conditions.Each engine has its own individuality, and operatingpersonnel must adjust to the engine to obtain the bestresults. Practically all Enginemen learn this sooner orlater; you can speed up the learning process byencouraging engine-room personnel to notice and todiscuss differences between engines.

SAFETY TRAINING

Because of the necessity for strict observance ofsafety precautions, all engine-room operational trainingmust be rigidly controlled and supervised. On-the-jobtraining is necessary if an individual is to acquire theactual skills needed for main engine operation;

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however, the person must not be allowed to learn by trialand error, since errors could be too dangerous and toocostly. Safety precautions should be taught from the verybeginning and should be emphasized constantlythroughout the training program.

Many of the NSTMs, manufacturer’s technicalmanuals, and every Planned Maintenance System(PMS) maintenance requirement card (MRC) includesafety precautions. Additionally, OPNAVINST5100.19B. Naval Occupational Safety and Health(NAVOSH) Program Manual for Forces Afloat, andOPNAVINST 5100.23B, NAVOSH Program Manual,provide safety and occupational health information. Thesafety precautions are for your protection and to protectequipment.

During preventive and corrective maintenance, theprocedures may call for personal protective equipment(PPE) such as goggles, gloves, hearing protection, andrespirators. When specified, your use of PPE ismandatory. You must select PPE appropriate for the jobsince the equipment is manufactured and approved fordifferent levels of protection. If the procedure does notspecify the PPE, and you aren’t sure, ask your safetyofficer.

Most machinery, spaces, and tools requiring you towear hearing protection are posted with hazardous noisesigns or labels. Eye hazardous areas requiring you towear goggles or safety glasses are also posted. In areaswhere corrosive chemicals are mixed or used, such asthe morpholine tank or brominators, an emergency eyewash station must be installed.

All lubricating agents, oils, cleaning materials,refrigerants (R-12), and boiler water and feedwaterchemicals used in maintenance and repair are hazardousmaterials. Hazardous materials require careful handling,storage, and disposal. PMS documentation provideshazard warnings or refers the maintenance person to theHazardous Materials User’s Guide (HMUG). Materialsafety data sheets (MSDSs) also provide safetyprecautions for hazardous materials. All commands arerequired to have an MSDS for each hazardous materialthey have in their inventory. You must be familiar withthe dangers associated with the hazardous materials youuse in your work Additional information is availablefrom your command’s hazardous material/hazardouswaste coordinator.

Workers must always consider electrical safetywhen working around any electrical or electronicmachinery or equipment. Procedures normally includespecial precautions and tag-out requirements for

electrical safety. You should review your command’selectrical safety program instruction and proceduresbefore beginning any work on electrical or electronicequipment or before working with portable electricaltools.

TRAINING PROGRAMS

As an EN2, you are required to assist your EN1 orENC in establishing or maintaining a training programfor your work center. For this program you are requiredto teach the proper methods of equipment operation,repair, and safety. You should use all appropriatematerials as teaching aids, such as manufacturer’smanuals, instructions, and NSTMs. In addition, youshould know what schools are available.

In recent years, one of the best ways to check onhow well personnel retain the information being taughtin the training program has been the use of the PersonnelQualification Standard (PQS).

A PQS is a written list of knowledge and skillsrequired to qualify for a specific watch station, maintaina specific piece of equipment or system, or perform asa team member within an assigned unit. The PQSprogram is a method for qualifying personnel to performtheir assigned duties.

Most standards are divided into four sections:Fundamentals, Systems, Watchstations, and aQualification Card. The Fundamentals section containsthe facts, principles, and fundamentals concerning thesubject for which a person is qualifying. The Systemssection deals with the major working parts of theinstallation, organization, or equipment with which thePQS is concerned. The Watchstation section defines theactual duties, assignments, and responsibilities neededfor qualification. The Qualification Card has questionsthat match those in the Watchstation section andprovides a space for the supervisor’s or the qualifyingofficer’s signature.

In addition to qualifying under PQS, both you andyour subordinates must satisfy Maintenance andMaterial Management (3-M) Systems and generaldamage control qualification requirements.

ENGINEERING OPERATIONALSEQUENCING SYSTEM (EOSS)

Each new ship that joins the Navy is moretechnically advanced and complex than the one before.The main propulsion plants call for engineering skills atever higher levels of competence. That means more and

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better training of personnel who must keep the shipscombat ready. The need for training and the problem offrequent turnover of trained personnel call for some kindof system that can be used to keep things going smoothlyduring the confusion. The EOSS was developed for thatpurpose.

EOSS is a set of manuals designed to eliminateproblems due to operator error during the alignment ofpiping systems and the starting and stopping ofmachinery. It involves the participation of all personnelfrom the department head to the fireman on watch.EOSS consists of a set of detailed written procedures,using charts, instructions, and diagrams. These aids aredeveloped for safe operation and casualty control of aspecific ship’s engineering plant and configuration.EOSS improves the operational readiness of the ship’sengineering plant by providing positive control of theplant. This, in turn, reduces operational casualties andextends machinery life.

EOSS is divided into two subsystems: (1)engineering operational procedures (EOPs) and (2)engineering operational casualty control (EOCC).

ENGINEERING OPERATIONALPROCEDURES (EOPs)

EOPs are prepared specifically for each level ofoperation: plant supervision (level l), space supervision(level 2), and component/system operator (level 3). Thematerials for each level or stage of operation containonly the information necessary at that level. Allmaterials are interrelated. They must be used together tomaintain the proper relationship and to ensure positivecontrol and sequencing of operational events within theplant. Ships that do not have EOSS use operatinginstructions and a casualty control manual for plantoperations.

ENGINEERING OPERATIONALCASUALTY CONTROL (EOCC)

This subsystem of EOSS enables plant and spacesupervisors to RECOGNIZE the symptoms of a possiblecasualty. They can then CONTROL the casualty toprevent possible damage to machinery, and RESTOREplant operation to normal. The documents of the EOCCsubsystem contain procedures and information thatdescribe symptoms, causes, and actions to be taken inthe most common engineering plant casualties.

ENGINEERING CASUALTY CONTROL

The best form of casualty control is prevention. Ifyou do not let a casualty happen, you will not have tofix it.

Preventive maintenance is one of the principalfactors of casualty control. Preventive inspections, tests,and maintenance are vital to casualty control. Theseactions minimize casualties caused by MATERIALfailures. Continuous detailed inspections are necessaryto discover worn or partly damaged parts, which mayfail at a critical time. These inspections eliminatemaladjustments, improper lubrication, corrosion,erosion, and other enemies that could cause early failureof a vital piece of machinery.

The inspections, tests, and maintenance called forin the 3-M systems must be performed conscientiouslysince they are based on the known requirements ofpreventive maintenance.

Still, casualties do happen. When they do, thesuccess of the mission, the safety of your ship, and thelives of your shipmates may depend on your ability tohandle the situation. That means continuous training andfrequent refresher drills to be sure you can do your part,and do it well.

Engineering casualty control is used to prevent,minimize, and correct the effects of operational andbattle casualties. These casualties will be on engineeringspace machinery, related machinery outside ofengineering spaces, and the piping installationsassociated with the various pieces of machinery. Themission of engineering department personnel is tomaintain all engineering services in a state of maximumreliability under all conditions. If you cannot providethese services, the ship may not be able to fight.

The use of EOCC procedures was discussed at thebeginning of this chapter. These procedures are preparedand approved for your ship.

Steps involved in handling engineering casualtiescan be divided into three general phases:

1. Immediate action to prevent further damage.

2. Supplementary action to stabilize the plantcondition.

3. Restoration action to restore equipment tooperation after a casualty. Where equipment damage hasoccurred, repairs may be necessary to restoremachinery, plants, or systems to their original condition.

Communication of accurate information is one ofthe major problems in casualty control. Be sure you

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know the names and operations of the equipment at yournormal watch station and your battle station. Be sure youknow what the casualty is before you take correctiveaction. If you are reporting a casualty to the bridge ormain control, be sure you use the correct terminologyand ensure they understand what your casualty is.

The primary sources of instructions used to handleany engineering casualty and to maintain the overalldamage resistance to your ship are listed as follows:

l The EOCC procedure

l The ship’s casualty control manual (for a shipwithout EOCC)

l The ship’s damage control manual

l The ship’s damage control bills

l The ship’s organization and regulation manual(SORM)

SYMPTOMS OF OPERATIONALCASUALTIES

You must be on the alert for even the most minorsign of faulty operation of machinery. Pay particular andcontinuous attention to the following symptoms ofmalfunctioning:

- Unusual noises

- Vibrations

- Abnormal temperatures

- Abnormal pressures

- Abnormal operating speeds

- Leakage from systems or associated equipment

You should become thoroughly familiar with thenormal operating temperatures, pressures, and speeds ofequipment specified for each condition of operation;departures from normal will then be readily apparent.NEVER assume that an abnormal reading on a gauge orother indicating instrument is due to a problem with theinstrument. Investigate each case to learn the cause ofthe abnormal reading. Substitute a spare instrument orperform a calibration test to quickly show whether aninstrument error exists. Trace abnormal readings that arenot caused by faulty instruments to their source. Somespecific advance warnings of failure are outlined in thefollowing paragraphs.

The safety factor commonly incorporated in pumpsand similar equipment can allow a considerable loss of

capacity before you see any external evidence oftrouble. In pressure-governor-controlled equipment,view changes in operating speeds from normal for theexisting load with suspicion. Variations from normal inchest pressures, lubricating oil temperatures, and systempressures indicate either improper operation or poorcondition of the machinery. When a material failureoccurs in any unit, promptly inspect all similar units todetermine whether they are subject to the same type offailure. Prompt inspection may eliminate a wave ofsimilar casualties.

Abnormal wear, fatigue, erosion, or corrosion of apart may indicate that the equipment is not beingoperated within its designed limits of loading, speed,and lubrication. It also may indicate a design or materialdeficiency. If any of these symptoms have appeared, youshould routinely carry out special inspections to detectdamage unless you can take action to ensure that such acondition will not recur.

ENGINE-ROOM CASUALTIES

Even with the best-trained personnel and thebest-planned maintenance programs, casualties willoccur. WHEN COMBATING AN ENGINE-ROOMCASUALTY, USE YOUR EOCC.

DIESEL ENGINE CASUALTIES

The Engineman’s duties concerning engineeringcasualties and their control depend upon the type ofship–which may be anything from a torpedo weaponsretriever (TWR) to a carrier. An Engineman operateseng ines o f va r ious s i zes , made by va r iousmanufacturers, and intended for different types ofservices.

Some examples of the types of engineeringcasualties that may occur and the action to be taken aregiven in the sections that follow. The observance of allnecessary safety precautions is essential in all casualtycontrol procedures.

1. Inoperative speed governor

a. Control the engine manually, if possible.

b. Notify the engineer officer and the bridge,and request permission to secure the engine for repairs.

c. When you get permission, check thegovernor control mechanism.

d. Check the linkage for binding or sticking.

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e. Check the lubrication; flush the governorsump and refill it with proper oil.

f. Check the setting of the needle valve.

g. Make repairs. When you have completed therepairs, start the engine and check its operation. Whenit is operating properly, notify the engineer officer andthe bridge.

2. Engine cooling water temperature above theallowed limit

a.

b.

c.tank

d.

e.valves.

f.

g.

Notify the bridge.

Reduce the load and the speed of the engine.

Check the freshwater level in the expansion

Check the saltwater discharge pressure.

Check the sea suction and the discharge

Vent the freshwater and the saltwater pumps.

Check the setting and operation of thetemperature regulating valve,

3. Failed main engine lube oil pressure

a. Secure the engine immediately.

b. Notify the engineer officer and the bridge.

c. Check the sump oil level, the piping, thefilters, the strainers, and the lube oil pump capacity.Make the repairs.

d. After you have completed the repairs, notifythe engineer officer and the bridge.

For more generalized examples of main engine(diesel-drive) casualties, refer to “Damage Control -Engineering Casualty Control,” Chapter 079, Volume3, of NSTM.

To obtain detailed information on diesel enginecasualty control procedures, refer to the manufacturer’sinstructions, the pertinent type commander’sinstructions, and the ship’s Engineering CasualtyControl Manual.

WATCH STANDING

You will spend much of your time aboard ship as awatch stander. How you stand your watch is veryimportant to the reliability of the engineering plant andthe entire ship. To be a successful watch stander, youmust do the following;

l Have the skills to detect unusua1 noises,vibrations, or odors that may indicate faulty machineryoperation.

l Take appropriate and prompt correctivemeasures.

l Be ready, in emergencies, to act quickly andindependently.

l Know the ship’s piping systems and HOW,WHERE, and WHY they are controlled.

l Know each piece of machinery: how it isconstucted, how it operates, how it fits into theengineering plant, and where related equipment iscontrolled.

l Be able to read and interpret measuringinstruments.

l Understand how and why protective devicesfunction (relief valves, speed limiting governors,overspeed trips, and cut-in and cutout devices).

l Recognize and remove fire hazards, stow gearthat is adrift, and keep deck plates clean and dry.

l NEVER try to operate a piece of equipment thatis defective.

l Report all unsafe conditions to the space or plantsupervisor.

l Know the status of every piece of machinery atyour station.

l Promptly handle any necessary change in speedor setup, and record correctly all data concerning theoperation and maintenance of the machinery.

l Be sure the log is up-to-date and the status boardsare current.

l Know what machinery is operating and what thenight orders and standing orders are before you relievethe watch.

Above all, if you don’t know-ASK! A noise, odor,or condition may seem abnormal to you, but you maynot be certain whether it is a problem. When thathappens, call your immediate watch supervisor.

You can best gain the respect and confidence of yoursupervisors and shipmates if you stand a good watch.Relieve the watch on time or even a little early if possibleto be sure you know the condition of the machinery andwhat you need to do. DON’T TRY TO RELIEVE THEW A T C H F I R S T A N D F I G U R E O U T T H E

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SITUATION LATER. The same applies when you arebeing relieved; don’t be in a big hurry to take off. Besure your relief understands the situation completely.Before you are relieved, make sure your station is cleanand squared away. These little considerations will getyou a good reputation and improve the overall qualityof watch standing within the department.

OTHER SOURCES OF INFORMATION

One of the most useful things you can learn about asubject is how to find out more about it. No singlepublication can give you all the information you need toperform the duties of your rating. Learn where to lookfor accurate, authoritative, up-to-date information on allsubjects (military and occupational) related to yourrating.

NAVSEA PUBLICATIONS

The publications, bulletins, and briefs issued by theNaval Sea Systems Command are of particularimportance to engineering department personnel.Although you do not need to know everything in thesepublications, you should have a general idea of whereto find the information they contain.

ENGINEERING HANDBOOKS

For certain types of information, you may need toconsult various kinds of engineering handbooks, suchas the mechanical engineering handbooks, marineengineering handbooks, piping handbooks, and otherhandbooks that provide detailed, specialized technicaldata.

NAVAL SAFETY CENTER BULLETINS

The bulletins such as Safetyline, Flush, and Ship'sSafety Bulletin are published by the Naval SafetyCenter. The bulletins contain information aboutequipment and personnel safety that helps reducepersonnel and material losses due to mishaps. You areencouraged to review these bulletins and pass them toyour subordinates.

SHOP EQUIPMENT

In your work center or shop, there is equipment thatwill help you do your job easier and more quickly. Thisequipment, the sandblaster, hydraulic press, electric drillpress, electric bench grinder, hydropneumatic test standand other electric, hydro, pneumatic, and manually

driven types, requires special knowledge of safeoperation and proper maintenance.

You, as an EN2, will be involved in providingtraining on how to use this equipment. All shoppersonnel, including you, must complete the PQS foreach piece of equipment before using it. In most cases,you will assist your supervisor in providing theinformation and training, although in some cases youmay be given total responsibility for the training.

Normally in the shop or work center, every piece ofequipment must have a posted operating procedure anda list of personnel who are qualified to use it. If a pieceof equipment does not have posted operatingprocedures, post a copy of the procedures given in themanufacturer’s manual.

QUALITY ASSURANCE PROGRAM

The quali ty assurance (QA) program wasestablished to provide personnel with information andguidance necessary to administer a uniform policy ofmaintenance and repair of ships and submarines. TheQA program is intended to introduce discipline into therepair of equipment, safety of personnel, andconfiguration control, thereby enhancing readiness.

The various QA manuals set forth minimum QArequirements for both the surface fleet and thesubmarine force. If more stringent requirements areimposed by higher authority, such requirements takeprecedence. If a conflict exists between the QA manualand previously issued letters and transmittals by theappropriate force commanders, the QA manual takesprecedence. All such conflicts should be reported to theappropriate officials.

The instructions contained in the QA manual applyto every ship and activity of the force. Although therequirements are primarily applicable to the repair andmaintenance done by the force IMAs, they also apply tomaintenance done aboard ship by ship’s force. In allcases where specif icat ions cannot be met, adeparture-from-specifications request must becompleted and reported.

Because of the wide range of ship types andequipment and the varied resources available formaintenance and repair, the instructions set forth in theQA manual are necessarily general in nature. Eachactivity must implement its own QA program to meetthe intent of the QA manual. The goal should be to haveall repairs conform to QA specifications.

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PROGRAM COMPONENTS

The basic thrust of the QA program is to make sureyou comply with technical specifications during allwork on ships of both the surface fleet and submarineforce. The key elements of the program are as follows:

- Administrative. This includes training andqualifying personnel, monitoring and auditingprograms, and completing the QA forms and records.

- Job execution. This includes preparing workprocedures, meeting controlled material requirements,requisitioning material, conducting in-process controlof fabrication and repairs, testing and recertifying, anddocumenting any departure from specifications.

A properly functioning QA program points outproblem areas to maintenance managers so they can takeappropriate action in a timely manner. The followinggoals are common to all Navy QA programs:

1. To improve the quality, uniformity, andreliability of the total maintenance effort.

2. To improve work environment, tools, andequipment used in the performance of maintenance.

3. To eliminate unnecessary man-hour and dollarexpenses.

4. To improve the training, work habits, andprocedures of all maintenance personnel.

5. To increase the excellence and value of reportsand correspondence originated by the maintenanceactivity.

6. To distribute required technical informationmore effectively.

7. To establish realistic material and equipmentrequirements in support of the maintenance effort.

THE QUALITY ASSURANCEORGANIZATION

The QA program for naval forces is organized intodifferent levels of responsibility. For example, theCOMNAVSURFPAC QA program is organized into thefollowing levels of responsibility: type commander,readiness support group/area maintenance coordinator,and the IMAs. The QA program for the submarine forceis organized into four levels of responsibility: typecommander, group and squadron commanders, IMAcommanding officers , and ship commandingofficer/officers in charge. The QA program for the NavalSurface Force for the Atlantic Fleet is organized into five

levels of responsibility: force commander, audits,

squadron commanders, IMAs, and force ships.

The QA program organization (Navy) begins withthe commander in chief of the fleets, who provides the

basic QA program organization responsibilities and

guidelines.

The type commanders (TYCOMS) provideinstruction, policy, and overall direction for

implementation and operation of the force QA program.

TYCOMs have a force QA officer assigned toadminister the force QA program.

The commanding officers (COs) are responsible tothe force commander for QA in the maintenance andrepair of the ships. The CO is responsible for organizingand implementing a program within the ship to carry out

the provisions of the TYCOMs QA manual.

The CO ensures that all repair actions performed byship’s force conform to provisions of the QA manual aswell as other pertinent technical requirements.

The quality assurance officer (QAO) isresponsible to the CO for the organizat ion,

administration, and execution of the ship’s QA program

according to the QA manual.

The QAO is responsible for coordinating the ship’s

QA training program, for maintaining ship’s QArecords, and for test and inspection reports. The QAOconducts QA audits as required and follows up oncorrective actions to ensure compliance with the QAprogram.

The ship quality control inspectors (SQCIs),usually the work center supervisor and two others from

the work center, must have a thorough understanding ofthe QA program. Some of the other responsibilities anSQCI will have are as follows:

1. Inspect al l work for compliance withspecifications.

2. Maintain ship records to support the QAprogram.

3. Ensure that only calibrated equipment is used inacceptance testing and inspection of work

4. Witness and document all tests.

5. Ensure that all materials or test results that fail

to meet specifications are recorded and reported.

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LEVELS OF ESSENTIALITY

A number of early failures in certain submarine andsurface ship systems were traced to use of the wrongmaterials. This led to a system of prevention thatinvolved levels of essentiality. A level of essentiality isa range of controls, in two broad categories, representinga certain high degree of confidence that procurementspecifications have been met. These categories are

l verification of material, and

l confirmation of satisfactory completion of testand inspections required by the ordering data.

Levels of essentiality are codes, assigned by the shipaccording to the QA manual, that indicate the degree towhich the ship’s system, subsystem, or components arenecessary in the performance of the ship’s mission.These codes indicate the impact that catastrophic failureof the associated part or equipment would have on theship’s mission capability and personnel safety.

LEVELS OF ASSURANCE

QUALITY ASSURANCE IS DIVIDED INTOTHREE LEVELS: A, B, or C. Each level reflects certainquality verification requirements of individualfabrication in process or repair items. Here, verificationrefers to the total level of quality controls, tests, and/orinspections. Level A assurance provides for the moststringent of restrictive verification techniques. This

normally will require both quality controls and test orinspection methods. Level B assurance provides foradequate verification techniques. This normally willrequire limited quality controls and may or may notrequire tests or inspections. Level C assurance providesfor minimum or “as necessary” verification techniques.This level will require very little quality control of testsor inspections.

The QA concept involves preventing the occurrenceof defects. QA covers all events from the start of amaintenance action to its completion and is theresponsibility of all maintenance personnel.

By carefully following the methods and proceduresoutlined in your QA program manuals and by payingcareful attention to the quality of work in your area, youwill contribute greatly to the operational effectivenessof your ship as well as tended units. For further in-depthknowledge concerning the QA procedures andpractices, consult your area COMNAVSURF LANT/PACINST QA manual.

SUMMARY

In this chapter, we have discussed some of yourimportant administrative and training responsibilitiesand the different methods you can use to properlyperform these responsibilities. Remember, informationis usually available when you need it. You just have toknow where to look for it and make the effort to secureit.

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CHAPTER 2

MEASURING AND REPAIR INSTRUMENTS

You, as an Engineman, must he able to identify thebasic measuring and repair instruments and the basiccomponents of these instruments. This chapter will helpyou to recognize the how and when to use and maintainbasic measuring and repair instruments and engine testequipment.

Measuring instruments are used to check tolerancesand specifications during inspections and repairs ofinternal combustion engines and auxiliary equipment.You, as an Engineman, need measuring instruments todetermine what parts are worn and need to be repairedor replaced. The following measuring and repairinstruments are discussed in this chapter: dial indicator,dial/vernier caliper, micrometer, snap gauge, boregauge, strain gauge, borescope, stroboscope, torquewrench, multiplier, adapter, ridge reamer, cylinder hone,and dynamometer.

SENSITIVE MEASURING TOOLS

Sensitive measuring tools are measuring devicesthat provide measurement readings to a thousandth ofan inch or less. The more common sensitive measuringtools you will use are the dial indicator, dial/verniercaliper, micrometer, snap gauge, bore gauge, and straingauge.

DIAL INDICATOR

A dial indicator is used to measure shaft runout,shaft thrust, gear backlash, flywheel face runout,flywheel housing concentricity, and valve seatconcentricity. You can mount a dial indicator on a teststand or, with clamps and a magnetic base, directly onthe equipment to be measured. Figure 2-1 shows atypical dial indicator with mounting accessories,

Most dial indicators have components such as abezel, indicator pointer, tool post and clamp, magnetictoolholder, and sensor button that are used in takingmeasurements.

The following procedures explain how to use theindicator to take shaft runout and crankshaft end playmeasurements . P rocedures fo r t ak ing o the rmeasurements are similar.

Figure 2-1.—Typical dial indicator wlth mounting accessories.

Shaft Runout

When you need to measure a shaft’s runout, selecta suitable position on the shaft, free of keyways,

corrosion, or other damage. Clean the surface and

remove any burrs around scratches or dents. To take the

runout measurement, use the following procedure:

1. Place the shaft in well-oiled V-blocks. If the

shaft is a crankshaft, place the bearing journals in theV-blocks.

2. Attach the magnetic base to a machined surface.

Mount the dial indicator on a tool mounting holder and

attach the holder to the base.

3. Adjust the mounting post so you can easily readthe face of the dial.

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4. Move the indicator toward the shaft until thesensor button just touches the surface you wish tomeasure.

5. Continue moving the indicator slowly towardthe shaft until the dial pointer has moved to the midpointof its travel on the dial face.

6. Leave the pointer at midtravel and turn the bezeluntil the zero on the dial is aligned with the pointer.

7. You can now rotate and watch the pointer to seeif it moves. The total amount the pointer moves is calledthe total indicator reading (TIR). If the shaft is straight,the pointer should remain at zero.

Crankshaft End Play or Thrust Readings

To measure crankshaft end play or thrust, use thefollowing procedure:

1. Attach the dial indicator to a convenient placenear the vibration damper.

2. Position the dial indicator gauge so the contactpoint touches the front of the vibration damper andmoves the dial indicator near the midpoint of its range.

3. Insert one end of a pry bar between a main

NOTE: DO NOT INSERT THE PRYBARBETWEEN THE VIBRATION DAMPER AND THEBLOCK TO MEASURE THE CRANKSHAFT ENDPLAY. You may dent the damper and render itineffective.

4. Move the crankshaft toward the dial indicator.Be sure to maintain a constant pressure on the prybar.

5. Set the dial indicator to zero.

6. Remove the prybar and then reinsert it on theother side of the main bearing cap.

7. Carefully pry the crankshaft in the oppositedirection to measure the crankshaft end play. Repeatyour measurement a minimum of two times foraccuracy.

DIAL/VERNIER CALIPER

The dial/vernier caliper is used to measure the insideor outside diameter of an object. Figure 2-2 shows atypical dial/vernier caliper.

Most dial/vernier calipers have a slide, slidelockscrew, thumb button, scale, dial with measured

bearing cap and a crankshaft counterweight. increments of 0.001 inch, and a bezel.

Figure 2-2.—Typical dial/vernier caliper.

2-2

For specif ic instruct ions on how to takemeasurements with a dial/vernier caliper, refer to eitherthe manufacturer’s instructions or to Tools and TheirUses, NAVEDTRA 10085-B2.

Regardless of what type of caliper you use, be sureto take the following precautions to avoid damaging thecaliper:

1. Wash your hands before you handle the verniercaliper to remove dirt and oils that might damage thecaliper.

2. Wipe the caliper components clean both beforeand after you use the caliper.

3. Do NOT drop or otherwise mishandle thecaliper. Doing so may damage or destroy the caliper.

Figure 2-3 illustrates the use of a dial/vernier caliperin measuring the inside and outside diameters of twodifferent components.

Figure 2-3.—Measuring (A) inside and (B) outside diameterswith a dial/vernier caliper.

The micrometer is a precision measuring instrumentused to measure distances between surfaces inthousandths of an inch Figure 2-4 shows the mostcommon types of micrometers.

Most micrometers have a frame, anvil, spindle,sleeve, thimble, and ratchet stop.

Micrometers are used to measure the outsidediameters; inside diameters; the distance betweenparallel surfaces; the depth of holes, slots, counterbores,and recesses; and the distance from a surface to somerecessed part. There are other uses of micrometers, butthose mentioned here are uses you are most likely toencounter. Instructions on how to read a micrometer aregiven in the manufacturer’s owner’s manual and Toolsand Their Uses, NAVEDTRA 10085-B2.

Whenever you use a micrometer, carefully observethe “DO’s” and “DON’Ts” in the following list to obtainaccurate measurements and to protect the instrument:

Figure 2-4.—Common types of micrometers.

2-3

1. Always stop the work before you take ameasurement. DO NOT measure moving parts becausethe micrometer may get caught in the rotating work andbe severely damaged.

2. Always open a micrometer by holding the framewith one hand and turning the knurled sleeve with theother hand. Never open a micrometer by twirling theframe, because such practice will put unnecessary strainon the instrument and cause excessive wear of thethreads.

3. Apply only moderate force to the knurledthimble when you take a measurement. Always use thefriction slip ratchet if there is one on the instrument. Toomuch pressure on the knurled sleeve will not only resultin an inaccurate reading, but also will cause the frameto spring and force the measuring surface out of line.

4. When a micrometer is not in use, place it whereit will not drop. Dropping a micrometer will cause themicrometer frame to spring. If you drop a micrometer,check it for accuracy before you take further readings.

5. Before you store a micrometer, back the spindleaway from the anvil, wipe all exterior surfaces with aclean, soft cloth, and coat the surfaces with a light oil.Do not reset the measuring surfaces to close contactbecause the protecting film of oil on these surfaces willbe squeezed out.

SNAP GAUGE

The snap gauge compares the outside diameters ofparts such as shafts and journals to a standard. It cancompare diameters from zero to 8 inches at an accuracyof 0.0001 inch. Figure 2-5 shows a typical snap gauge.

Most snap gauges consist of a frame with aninsulated handle, a hex wrench mounted in the handle,dial indicator digits calibrated in 0.00l-inch divisions, abezel clamp, adjustment wheels, locking wheels, abackstop, a lower anvil, an upper anvil, and a guard.

Whenever you use a snap gauge, use the handle andavoid touching the gauge proper because body heat mayaffect the reading. For the same reason, handle thestandard plugs only by their plastic end. Clean the anvilsand the backstop with a clean cloth. To use the snapgauge, follow the manufacturer’s operating instructions.

After you record the readings and compare thereadings with the design specifications, clean and storethe snap gauge in its appropriate storage location.

Figure 2-5.—Typical snap gauge.

BORE GAUGES

The dial bore gauge is one of the most accurate toolsfor measuring a cylindrical bore or for checking a borefor out-of-roundness or taper. The gauge does not givea direct measurement. It identifies the amount ofdeviation from a preset size or the amount of deviationfrom one part of the bore to another. A master ring gauge,outside micrometer, or vernier caliper can be used topreset the gauge. Figure 2-6 shows a typical bore gauge.

Figure 2-6.—Typical bore gauge.

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Most bore gauges consist of a dial indicator,extension pieces, bezel and locknut, spring-loadedguide, and sensor button.

Before you start a measuring procedure, exposeboth the bore gauge and the master ring gauge, or anyother tools used to preset the bore gauge, and the part tobe measured to the same work place environment forone hour. If you fail to do this, a temperature differentialmay cause your readings to be inaccurate. When you usethe bore gauge, touch only its insulated handle.

The gauge has two stationary spring-loaded pointsand an adjustable point to permit a variation in range.These points are evenly spaced to allow accuratecentering of the tool in the bore. A fourth point, the tipof the dial indicator, is located between the twostationary points. By simply rocking the tool in the bore,you can observe the amount of variation on the dial.Figure 2-7 shows a bore gauge inside a bore beingmoved in a gentle rocking motion. Always follow thebore gauge manufacturer’s operating manual. Measurethe bore and mark the areas you measure. A good

Figure 2-7.—Measuring a bore with a bore gauge.

practice is to check the bore gauge in the standard afteryou take each set of measurements to ensure thatreadings are accurate.

STRAIN/DEFLECTION GAUGE

A strain or deflection gauge is used to check thecrankshaft alignment on large diesel engines. It is aspecially adapted dial indicator that fits between thecrank webs. The strain gauge reads the flexing motionof the webs directly as the crankshaft is slowly rotated(correct engine rotation). The gauge dial reads in0.00l-inch graduations.

The strain gauge consists of a dial indicator, contactpoint, balancing attachment, clamping nut, springplunger, rods and extension, and bezel.

Before you take a reading, be sure the engine iscompletely assembled and cold. Place the strain gaugebetween the webs of a crankthrow, as far as possiblefrom the axis of the crankpin. The ends of the indicatorshould rest in the prick-punch marks in the crank webs.If these marks are not present , consult themanufacturer’s technical manual for the proper locationof the marks. Ensure that the strain gauge is at the sametemperature as the engine. A temperature differentialmay cause inaccurate readings. Readings are generallytaken at the four crank positions; top dead center,inboard, near or at bottom dead center, and outboardHowever, the manufacturer’s technical manual for thespecific engine provides information concerning theproper positions of the crank for taking readings. Insome situations, due to the position of the dial, you mayneed to use a mirror and a flashlight to read the gauge.Once you have placed the indicator in position for thefirst reading, DO NOT touch the gauge until you havetaken and recorded all four readings. Variations in thereadings taken at the four crank positions indicatedistortion of the crank, which may be caused by any ofseveral factors, such as a bent crankshaft, worn bearings,or improper engine alignment. The manufacturer’stechnical manual will provide you with the maximumallowable deflection. Figure 2-8 shows the locations fortaking crankshaft deflection readings.

BORESCOPE

A borescope is used to inspect internal parts on anengine without having to disassemble the engine. Thisinstrument helps a great deal in estimating the amountof repair work needed and the time required for therepair. Figure 2-9 shows a typical borescope.

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Figure 2-8.—Locations for taking crankshaft deflectionreadings.

Most borescopes have the following basiccomponents:

1. Eyepiece (zoom or wide angle)

2. Scan control ring

3. Probe tube

4. Scan mirror

5. Quartz-lined lamp

6. Focus control ring

7. Other electrical accessories

As with any optical instrument, you should handlethe borescope with care to avoid damaging its lenses andmirrors. The borescope is powered by alternatingcurrent. So, before you first use it, be sure to read andfollow the manufacturer’s operating instructions. Theborescope can be inserted through any engine opening,such as a cylinder port, to identify problems, such ascracked pistons, cracks in the cylinder head, burnedvalves, and scuffed or pitted liners. You can remove the

crankcase cover to inspect the bottom section of theengine.

STROBOSCOPE

A stroboscope is a flashing light source used tomeasure the speed of fast-moving objects. it producesthe optical effect of stopping or slowing down an objectto allow you to observe and analyze the object’s motion.Figure 2-10 shows a typical stroboscope.

A stroboscope consists of a power switch, rpmcontrol dial, range switch, calibration indicator light,calibration screws, combination adjustments, reflectorlamp assembly, and other electrical accessories. Forinformation about the functions of the components,consult the operator’s manual.

Before you use the stroboscope, be sure to read andfollow the manufacturer’s operating instructions. Theinstrument commonly operates from a 120-volt, 60-Hz,alternating current supply. Any change in currentfrequency will affect the flashing speed and affect thestroboscope’s accuracy for speed measurements. Thestroboscope can be used to measure the speed and toobserve the motion of rotating, reciprocating, orvibrating mechanisms. Never leave the stroboscopeunattended while it is in use. Since the stroboscopemakes a moving object appear to be standing still,someone could be seriously injured by the apparently“stationary” object.

TORQUE WRENCH

The torque wrench is used to measure an object’sresistance to turning and to provide precise tightening

Figure 2-9.—Typical borescope.

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of threaded fasteners. Figure 2-l1 shows three types oftorque wrenches.

To use a torque wrench, first select the proper torquevalue for the torquing procedure you are using. Next,

Figure 2-10.—A typical stroboscope.

Figure 2-11.—Typical torque wrenches.

select the torque wrench with the correct capacity. Thetorque value should be in the second or third quarter ofthe wrench’s torque scale because the first and lastquarters of the scale are not as accurate as the middlequarters.

Torque wrenches are precision tools. Handle themwith care and always follow the manufacturer’s manualwhen you use them.

TORQUE MULTIPLIER

Torque multipliers are geared devices attached tothe torque wrench to increase the force of torque. Themost preferred ratio of the torque multiplier is 4 to 1. Touse a torque multiplier, select one with an outputcapacity above the required torque. Be sure to follow themanufacturer’s operating manual to avoid personnelinjury and damage to the equipment.

TORQUE ADAPTERS

Torque adapters allow the torque wrench to be usedto tighten parts and fasteners other than standard nutsand bolts. Adapters are available in a variety of shapesgeared to the repair of different parts of the dieselengine. Several types of torque adapters are shown infigure 2-12.

When you use an extension adapter, the torqueapplied to the part or fastener will be greater than thetorque indicated on the torque wrench. Therefore, youmust account for the length of the adapter to apply theproper torque to the part or fastener. Figure 2-13illustrates the points of measurement.

The torque applied by the adapter is directly relatedto the length of the adapter. As the length of the adapterincreases, so does the applied torque.

To determine the actual torque applied to the part orfastener, assume that the length of the torque wrench isL and the length of the adapter is A. Assume also thatTw is the torque indicated on the scale of the torquewrench and Ta is the torque exerted at the end of theadapter.

To determine Ta, simply multiply the torqueindicated on the torque wrench (Tw) by the ratio of thetotal effective length of the assembly (L + A) to thelength of the torque wrench (L).

or

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Figure 2-12.—Torque adapters.

Figure 2-13.—Torque adapters and points of measurement.

An easy to remember rule of thumb is that theapplied torque will be greater than the indicated torqueby an amount equal to the length of the adaptercompared to the length of the torque wrench. Forexample, if the adapter is the same length as the torquewrench, the applied torque will be twice as great as theindicated torque. If the adapter is one-third as long asthe torque wrench, the applied torque will be one-thirdgreater than the indicated torque.

Figures 2-14 and 2-15 illustrate how to calculateapplied torque.

RIDGE REAMER

A ridge reamer is used to remove ridges formed atthe tops of cylinders produced by piston rings movingup and down in the cylinders. Figure 2-16 illustrates atypical ridge reamer.

The ridge reamer consists of a carbon cutter,adjustable guides, adjustable cutter head, adjustablecutter, and threaded feed screw.

Whenever you use a ridge reamer, you must weareye protection, such as a face shield or goggles.

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Figure 2-14.—Torque calculation for eithcr adapters or extensions.

Remember that the cutter will take out the ridge with alathelike cutting action. Read and follow themanufacturer’s manual on how to use the reamer. Afterall the ridges are removed, take a measurement with abore gauge, and verify that the cylinder is withinspecifications.

CYLINDER HONE

To reuse the cylinder sleeve, you must refinish theglazed surface caused by piston ring travel. Honing willremove high spots and a s l ight taper or

out-of-roundness. Do not hone new or chromium-platedliners unless specified by the liner manufacturer. Figure2-17 shows a typical cylinder hone.

Before you use a cylinder hone, read or review theoperator’s manual. When you use a hone, use only anapproved cleaning solvent and ensure that there isadequate ventilation in the work area. When solventfumes are present, do not allow eating, drinking,smoking, open flames, or lights in the work area.Dispose of hazardous materials, such as solvent-soakedrags and used solvents, properly.

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Figure 2-15.—How to calculate applied torque.

Figure 2-16.—A typical ridge reamer. Figure 2-17.—A typical cylinder hone.

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ENGINE TEST EQUIPMENT

When an engine has been repaired or overhauled, itmay need to be tested for proper operation and poweroutput. A piece of test equipment used to conduct suchtests is the dynamometer. The following is a basicexplanation of how a dynamometer works. For in-depthinformation about this test equipment, refer to themanufacturer’s manual.

The dynamometer is used to apply specific loads toan engine. It allows the technician to inspect and checkthe engine while it is operating. The dynamometerabsorbs and measures the engine’s output. The basiccomponents of a dynamometer are the frame, enginemounts, absorption unit, heat exchanger, and torque andmeasuring device. To properly operate a dynamometeryou must complete a shop qualifications course.

Dynamometers are found primarily in shore activityshops. For maintenance, refer to assigned PMS for theequipment. If your shop has no PMS maintenance forthe dynamometer, follow the maintenance schedulerecommended by the manufacturer.

SUMMARY

In this chapter, you have learned to identify thenecessary measuring and repair instruments and theirbasic components and how to use them. Additionally,you have learned basic information about thedynamometer, its operation and maintenance. Foradditional information about basic measuring and repairinstruments and the dynamometer, refer to each item’smanufacturer’s manual, assigned PMS, and your workcenter’s shop equipment qualifications program.

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CHAPTER 3

INTERNAL COMBUSTION ENGINES

This chapter is designed to help you understand themaintenance and repair of internal combustion engines.You as an EN2 should be able to describe the basicprocedures used to test and repair diesel engines. Also,you should be able to identify the procedures used totroubleshoot diesel and gasoline engines. This chapterwill cover the general procedures used to repair andoverhaul gasoline engines; the procedures used toinspect, test, and repair jacking gear; and the proceduresused to troubleshoot and repair fuel and oil purifiers.

To help ensure that an engine will operateefficiently, you must follow its preventive maintenanceschedule. By following the preventive maintenanceschedule, you will reduce engine casualties and help theengine achieve its normal number of operating hoursbetween overhaul periods.

When you must finally perform an engine repair oroverhaul, take the following precautions:

l Plan the work in definite steps, so you canperform it smoothly.

l Have the necessary tools and parts on handbefore you begin a repair or overhaul.

l Have the necessary forms ready to record theclearances, dimensions, and other vital measurementreadings that must be kept as part of the engine’s history.

l Always check precision measuring instrumentsbefore you use them; then recheck your readings. Thefirst reading may not be correct.

l Keep the work area clean. Do not allow oil toaccumulate on the deck or on the tools. Place the toolsor parts neatly away from the immediate area.

The test, maintenance, and repair procedurespresented in this chapter are general in nature. Thespecific procedures vary with different engines. Beforeyou begin a maintenance or repair procedure, consultthe manufacturer’s technical manual or the equipment’spreventive maintenance schedules. They are valuablesources of information on tests, maintenance, andrepairs.

INSPECTING AND TESTING THEENGINE FRAME OR BLOCK

Before you begin an inspection or test, make surethe outside of the engine is cleaned thoroughly. This willhelp you spot cracks, leaks, and other problems moreeasily than if the engine is dirty. By cleaning the engine,you will also help prevent dirt and other contaminantsfrom entering and damaging parts and accessories of theengine.

Some of the inspections and tests you may performare listed in the following sections.

VISUAL INSPECTIONS

Inspect the top surface of the cylinder block, the topand bottom crankcase flanges, and the oil pan forwarpage. You can use a straightedge, a feeler gauge, anda good light. Figure 3-1 illustrates how to use astraightedge and a feeler gauge to check the top surfaceof the cylinder block Compare your measurements tothe manufacturer’s specifications to determine if thesurface is warped.

Visually inspect the cylinder block for cracks,breaks, or other damage.

MEASUREMENTS

Visually inspect the engine block’s bolts todetermine if they are bent, broken, or worn.

Figure 3-1.—Checking the top surface of a typical cylinder block.

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Measure the bore in the cylinder block, with a dialindicating bore gauge, to determine if wear or anout-of-round condition exceeds the manufacturer’sspecification. Figure 3-2 illustrates the use of a boregauge to measure a cylinder bore. You can use an insidemicrometer as well, but a dial indicating bore gauge iseasier to use.

Inspect and measure the engine block’s hold-downbolt holes. Use a telescoping snap gauge to determine ifwear has caused enlargement of the holes. If atelescoping snap gauge is not available, try to move eachbolt from side to side with your fingers. If a bolt movesfrom side to side, its hole has enlarged and must berepaired. Always follow the manufacturer’s instructionson how to correct a hole enlargement problem.

DYE PENETRANT TEST

Conduct a preliminary dye penetrant test on theengine block’s surface to identify cracks that you cannotsee otherwise. Be sure to follow the manufacturer’sinstructions on how to conduct this test. Remember thatonly a certified nondestructive testing technician canperform a dye penetrant test that meets the requirementsof quality assurance.

AIR AND WATER PRESSURE TESTS

Test the cylinder block for cracks in the cylinderbores between the water jacket and the oil passages byusing either air pressure or water pressure. The purposeof each test is to pressurize the water Jacket to the point,within safe limits, that leaks show.

Figure 3-2.—Checking the cylinder bore for wear orout-of-roundness.

Air Pressure Test

Before you perform the air pressure test, make sureyou completely strip and clean the block. Then, followthese basic procedures:

1. Seal all of the block’s freshwater passages withgaskets and flanges.

2. Connect a low-pressure air hose to a fixture onone of the flanges.

3. Immerse the block into a tank of water heated tothe engine’s normal operating temperature. Allow theengine to soak for approximately 20 to 40 minutes, asspecified by the manufacturer. This allows the block towarm to the temperature of the water.

4. Apply approximately 40 psi of pressure to theblock and watch for bubbles. Bubbles indicate a crackor leak in the block. Determine what repair is needed orcan be made when you identify the source of thebubbles.

If you cannot dip the block, you may still performthe air pressure test. Attach the hose to a fixture securedto an opening to the water jacket. Pressurize the waterjacket. Carefully spray soapy water over the block andlook for air bubbles caused by the pressurized air.

Water Pressure Test

The water pressure test is similar to the air pressuretest, except that defects are indicated by water leaksrather than by air leaks. Before you perform the waterpressure test, strip and clean the block Then, followthese procedures:

1. Seal off all but one of the freshwater openingswith flanges and gaskets. Make seals airtight.

2. Fill the water jacket with fresh water until all airis purged from the water jacket. Seal the fill openingwith a flange that contains an air hose coupling.

3. Attach an air hose and pressurize the waterjacket to approximately 40 psi (see the manufacturer’smanual). Maintain the pressure in the water jacket for atleast 2 hours.

4. Inspect the cylinder bores, air box, oil passages,crankcase, and cylinder block exterior for the presenceof water. The presence of water at any of these locationsindicates that the water jacket has one or more defects.

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REPAIRING THE ENGINE FRAME ORBLOCK

Some engine block repairs are cost efficient, whileothers are not. The following paragraphs briefly discussbasic repairs to the block itself. Later paragraphs discussrepairs to block components.

LEAKING WATER JACKET

Most engine blocks that have a leaking water jacketare not worth the cost to repair. To determine if such ablock can be repaired economically, consult theappropriate MILSTD and technical manuals for theengine.

WARPED CYLINDER BLOCK ORCRANKCASE FLANGES

You may use a hand surface grinder to correct smallamounts of surface warpage. Do not remove more metalthan necessary. The manufacturer’s manual will specifyhow much metal you may remove with the hand grinder.If the warpage exceeds the maximum allowed for handgrinding, send the block to the machine shop formachine grinding.

WORN BOLT HOLES

Over a period of time, bolt holes may becomeoversize due to wear from threading and unthreading thefasteners. You may correct a worn bolt problem by oneof three primary methods, depending on the situation.

1. If the bolt hole is slightly oversize, you may beable to simply use a larger bolt in the hole, if such use isauthorized for the component the bolt fastens down.

2. If enough metal remains around the hole, youmay be able to install a helicoil. Check the helicoilinstallation instructions and appropriate technicalmanuals to determine whether or not a helicoil isacceptable.

3. You may also till the hole with weld metal andthen drill and tap a new hole.

Whatever method you use to correct the problem,always check the bolt and bolt hole for proper fit.

INSPECTING, TESTING, ANDREPAIRING CYLINDER LINERS

Cylinder liners may become damaged or wornexcessively. The following paragraphs discuss the morecommon causes and repairs.

CRACKED, BROKEN, AND DISTORTEDLINERS

You should suspect one or more cylinder linerswhenever you notice one of the following indications:

l Excessive water in the lubricating oil

l An accumulation of water in one or morecylinders of a secured engine

l An abnormal loss of water in the cooling system

l High cooling water temperature or fluctuatingpressure (caused by combustion gases blowinginto the water jacket)

l Oil in the cooling water

When you suspect that a liner is cracked, try tolocate the cracks visually. If you cannot locate the cracksvisually, use another testing method, such as the waterpressure test or air pressure test described earlier. Tocheck liners with integral cooling passages, plug theoutlets and fill the passages with glycol-type antifreeze.This liquid will leak from even the smallest cracks.

Cracks in dry liners may be more difficult to locatebecause there is no liquid to leak through the cracks. Youmay need to use magnaflux equipment or penetratingdye to locate these cracks.

Causes

Cylinder liners may crack because of poor cooling,improper fit of piston or pistons, incorrect installation,foreign bodies in the combustion space, or erosion andcorrosion. Improper cooling, which generally resultsfrom restricted cooling passages, may cause hot spots inthe liners, resulting in liner failure due to thermal stress.Scale formation on the cooling passage surfaces of linersmay also cause hot spots; wet liners are subject to scaleformation. You may remove the scale by following theprocedures outlined in chapter 233 of the Naval Ships’Technical Manual (NSTM).

Proper cooling of dry liners requires clean contactsurfaces between the liners and the cylinder block.Particles of dirt between these surfaces cause air spaces,which are poor conductors of heat. Films of oil or greaseon these mating surfaces also resist the flow of heat.

Distortion, wear, or breakage may result if a liner isnot properly seated. Causes of improper liner seatingmay be metal chips, nicks, or burrs, or improper fillets,In figure 3-3 an improper fillet on the cylinder deckprevents the liner from seating properly. To correct an

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Figure 3-3.—Improperly seated cylinder liner.

improper fillet, grind it down until the lower surface ofthe flange seats properly on the mating surface of thecylinder deck.

An oversized sealing ring may cause improperpositioning of the liner. As the sealing ring isovercompressed, the rubber loses its elasticity andbecomes hard, which may cause the liner to becomedistorted.

Use feeler gauges to check the clearance betweenthe mating surfaces. If the manufacturer’s technicalmanual specifies the distance from the cylinder deck tothe upper surface of the liner flange, use this dimensionto check on the seating of the liner.

Obstructions in the combustion chamber may bedestructive not only to the liner but also to the cylinderhead and other parts.

Erosion and corrosion may take place in a fewisolated spots and weaken a liner sufficiently to causecracks.

Repairs

Replacement is the only satisfactory means ofcorrecting cracked, broken, or badly distorted cylinderliners.

SCORED CYLINDER LINERS

Scored cylinder liners may become scored(scratched) by several means. These scratches degradethe engine’s performance and require some type ofrepair.

Scored cylinder liners may be caused by brokenpiston rings, a defective piston, improper cooling,improper lubrication, or the presence of foreign particles

or objects. Dust particles drawn into an engine cylinderwill mix with the oil and become an effective butundesirable lapping compound that may cause extensivedamage. The importance of keeping the intake air cleancannot be overemphasized.

Another precaution you should take is to make surethat when you replace a cylinder head, you leave nometal chips, nuts, bolts, screws, or tools in the cylinder.

Causes

Scoring may be in the form of deep or shallowscratches in the liner surface. With most liner scoring,there will be corresponding scratches on the piston andpiston rings. The symptoms of scoring may be low firingor compression pressure and rapid wear of piston rings.The best method for detecting scoring is visualinspection through liner ports, through the crankcasehousing with pistons in their top position, or when theengine is disassembled.

Badly worn pistons and rings may cause scoringbecause blowby of combustion gases increases thetemperature of the liner and may reduce the oil film untilmetal-to-metal contact takes place. Inspect the pistonsand rings carefully. A piston with a rough surface (suchas one that has seized) will score the liner.

Scoring as a result of insufficient lubrication or dirtin the lubricating oil can be prevented if lubricatingequipment (filters, strainers, and centrifuges) ismaintained properly. Lube oil must be purifiedaccording to required procedures.

Repairs

Ship’s force personnel normally do not repair scoredliners; they replace them with spare liners. Whennecessary, liners with minor scoring may be kept inservice, if the cause of scoring is eliminated and theminor defects can be corrected. The surface of the linermust be inspected carefully, especially in the region nextto the ports, for any burrs, projections, or sharp edgesthat will interfere with piston and ring travel. Mostprojections can be removed by handstoning, using a finestone. Figure 3-4 shows a liner before and after the portswere stoned.

EXCESSIVELY WORN LINERS

Over a period of time, cylinder liners become wornsimply because of engine operation. The best method offinding excessive wear is to take measurements of thecylinder liner with an inside micrometer caliper. Two

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Figure 3-4.–Liner before and after stoning.

types of liner wear check are illustrated in figure 3-5.Excessive maximum diameter results from general wearequally around the cylinder. Out-of-roundness isproduced by the piston thrusting against one or two sidesof the cylinders.

Clearance between a piston and a liner is generallychecked by measuring both parts with a micrometer. Onsmaller engines, you can use a feeler gauge. Clearancein excess of that specified by the manufacturer isgenerally due to liner wear, which normally is greaterthan piston wear.

To determine liner wear, take measurements at threelevels in the liner. Take the first measurement slightlybelow the highest point to which the top ring travels;take the next measurement slightly above the lowestpoint of compression ring travel; and take the thirdmeasurement at a point about midway between the firsttwo. (Record all readings, so that rapid wear of anyparticular cylinder liner will be evident.) If wear orout-of-roundness exists beyond specified limits, replacethe liner. Figure 3-6 shows two examples of taking

Figure 3-5.–Measurements for determining liner wear.

Figure 3-6.–Measuring the inside of a cylinder liner.

inside measurements. The liner shown in figure 3-6,view B, requires at least twice as many measurementsas other types of liners because it is from an opposedpiston.

You will not get accurate measurements unless youposition the caliper or gauge properly in the liner.Common errors in positioning are illustrated in views Aand B of figure 3-7. Hold one end of the caliper firmlyagainst the liner wall as shown in view A of figure 3-6.Then move the free end back and forth, and up anddown, until you establish the true diameter of the liner.The moving end will trace a patch similar to thatillustrated in figure 3-8.

Considerable experience in using an insidemicrometer or cylinder gauge is necessary to ensureaccuracy. As a precaution against error, it is a good

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Figure 3-7.—Errors to avoid when taking liner measurements.

Figure 3-8.—Trace of caliper end when determining the truediameter of a liner.

practice for two persons to take the liner measurement;then any discrepancy between the two sets of readingscan be rechecked.

Causes

Excessive or abnormal wear of cylinder liners maybe caused by insufficient lubrication, dirt, improperstarting procedures, or low cooling water temperature.

The lubricating system must be carefullymaintained in proper working order. The method ofcylinder liner lubrication varies with different engines.The proper grade of oil, according to enginespecifications, should be used

The engine must not be operated in a dirty condition.The air box, crankcase, and manifold should be cleaned

and maintained in a clean condition, to avoid cylinderwear and scoring. (Attention to the air cleaner, oil filters,and oil centrifuge are the best precautions against theentrance of dirt into the engine.)

Improper starting procedures will cause excessivewear on the liners and pistons. When an engine is firststarted, some time may elapse before the flow oflubricating oil is completed; also, the parts are cold andcondensation of corrosive vapors is acceleratedaccordingly. These two factors (lack of lubrication andcondensation of corrosive vapors) make the periodimmediately after starting a critical time for cylinderliners. If an independently driven oil pump is installed,it must be used to prime the lube oil system and buildup oil pressure before the engine is started The engineshould not be subjected to high load during the warm-upperiod. Follow the manufacturer’s instruction manualconcerning warm-up time and load application for theengine concerned

The cooling water of an engine should always bemaintained within the specified temperature ranges. Ifthe temperature is allowed to drop too low, corrosivevapors will condense on the liner walls.

Repairs

Cylinder liners worn beyond the maximumallowable limit should be replaced. You will find themaximum allowable wear limits for engines in theappropriate manufacturer’s technical manual or theDiesel Engine Wear Limit Chart available from theNaval Sea Systems Command. In the absence of suchspecific information, the following wear limits(established by NAVSEA) apply in general to

1. two-stroke cycle engines with aluminumpistons: 0.0025 inch per inch diameter,

2. slow-speed engines over l8-inch bore: 0.005inch per inch diameter, and

3. all other engines: 0.003 inch per inch diameter.

If you must remove a liner, follow the instructionsgiven on the appropriate maintenance requirement card(MRC) or in the manufacturer’s technical manual for theparticular type of engine. Figure 3-9 illustrates themethod generally used to remove a cylinder liner.

To remove the cylinder liner, proceed as follows:

1. Drain the water from the engine.

2. Remove the cylinder head.

3. Remove the piston(s).

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Figure 3-9.—Removing a cylinder liner.

4. Attach the special liner puller to the liner studsand tighten the nuts by hand. (The nuts must be handtightened; if a wrench is used, the threads on both thenuts and the studs may be damaged.)

5. Attach the hook of the chain fall and pull slightlyuntil the liner breaks free (fig. 3-9). If the liner fails tobreak loose immediately, apply pressure at the bottomof the liner. To do this, place a block of wood on thecrankshaft throw, and force it up against the liner byrotating the turning gear.

6. Lift the liner up until it clears the top of theengine block and remove it to a safe place. You may needto rotate the liner slightly while removing it from theengine block.

INSPECTING, TESTING, ANDREPAIRING CYLINDER HEADS

Conditions requiring repair of a cylinder head aresimilar to those for cylinder liners and can be groupedunder cracks, corrosion, distortion, and fouling.

CRACKS

The symptoms of a cracked cylinder head are thesame as those of a cracked liner. Cracks in cylinderheads are best located by either visual inspection ormagnetic powder inspection. On some types of engines,a defective cylinder can be located by bringing thepiston of each cylinder, in turn, to top dead center andapplying compressed air. When air is applied to adamaged cylinder, a bubbling sound indicates leakage.

When the cylinder head is removed from the engine,it can be checked for cracks by the hydrostatic test usedon cylinder liners equipped with integral coolingpassages.

Cracks generally occur in cylinder heads on thenarrow metal sections between such parts as valves andinjectors. The cracks may be caused by adding coldwater to a hot engine, by restricted cooling passages, byobstructions in the combustion space, or by impropertightening of studs.

Aboard ship, cracked cylinder heads usually mustbe replaced. It is possible to repair them by welding, butthis process requires special equipment and highlyskilled personnel normally found only at repairactivities.

CORROSION

Burning and corrosion of the mating surfaces of acylinder head may be caused by a defective gasket.Although regular planned maintenance ordinarilyprevents this type of trouble, burning and corrosion maystill take place under certain conditions. When corrosionand burning occur, there may be a loss of power due tocombustion gas leakage out of or water leakage into thecombustion space. Other symptoms of leakage may be(1) hissing or sizzling in the head where gases or watermay be leaking between the cylinder head and the block,(2) bubbles in the cooling water expansion tank sightglass, or (3) overflow of the expansion tank.

Gaskets and grommets that seal combustion spacesand water passages must be in good condition; otherwisethe fluids will leak and cause corrosion or burning of thearea contacted. Improper cooling water treatment mayalso accelerate the rate of corrosion.

In general, cylinder heads that are burned orcorroded by gas or water leakage are so damaged thatthey must be replaced.

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DISTORTION

Warpage or distortion of cylinder heads becomesapparent when the mating surfaces of the head and blockfail to match properly. If distortion is severe, the head

will not lit over the studs. Distortion may be caused byimproper welding of cracks or by improper tighteningof the cylinder head studs. Occasionally, new heads maybe warped because of improper casting or machiningprocesses.

Repair of distorted or damaged cylinder heads isoften impracticable. They should be replaced as soon as

possible and turned in to the nearest supply activity,which will determine the extent of damage and themethod of repair.

FOULING

If the combustion chambers become fouled, theefficiency of combustion will decrease. Combustion

chambers are designed to create the desired turbulencefor mixing the fuel and air; any accumulation of carbondeposits in the space will impair both turbulence andcombustion by altering the shape and decreasing thevolume of the combustion chamber.

Symptoms of fouling in the combustion chambersare smoky exhaust, loss of power, or high compression.Such symptoms may indicate the existence of extensive

carbon formation or clogged passages. In some engines,these symptoms indicate that the shutoff valves for theauxiliary combustion chambers are stuck

Combustion chambers may also become fouledbecause of faulty injection equipment, improper

assembly procedures, or excessive oil pumping.

Cleaning of fouled combustion spaces generallyinvolves removing the carbon accumulation. The bestmethod is to soak the dirty parts in an approved solventand then wipe off all traces of carbon. You may use ascraper to remove carbon, but be careful to avoiddamaging the surfaces. If oil pumping is the cause ofcarbon formation, check the wear of the rings, bearings,

pistons, and liners. Replace or recondition excessively

worn parts. Carbon formation resulting from improperlyassembled parts can be avoided by following proceduresdescribed in the manufacturer’s technical manual.

INSPECTING, TESTING, AND REPAIRINGVALVES AND VALVE ASSEMBLIES

Regardless of differences existing in engineconstruction, there are certain troubles common to allassemblies.

STICKING VALVES

Sticking valves will produce unusual noise at thecam followers, pushrods, and rocker arms and maycause the engine to misfire. Sticking is usually causedby resinous deposits left by improper lube oil or fuel.

To free sticking valves without having todisassemble the engine, use one of several approvedcommercial solvents. If the engine is disassembled, useeither a commercial solvent or a mixture of half lube oiland half kerosene to remove the resins. Do NOT use thekerosene mixture on an assembled engine, since a smallamount of this mixture settling in a cylinder could causea serious explosion.

BENT VALVES

Bent or slightly warped valves tend to hang open. Avalve that hangs open not only prevents the cylinderfrom firing, but also is likely to be struck by the pistonand bent so that it cannot seat properly. Symptoms ofwarped or slightly bent valves will usually show up asdamage to the surface of the valve head. To lessen thepossibility that cylinder head valves will be bent ordamaged during overhaul, NEVER place a cylinderhead directly on a steel deck or grating; use a protectivematerial such as wood or cardboard. Also, NEVER prya valve open with a screwdriver or similar tool.

WEAK SPRINGS

Valves may close slowly, or fail to close completely,because of weak springs. At high speeds, valves may“float,” thus reducing engine efficiency. Valve springswear quickly when exposed to excessive temperaturesand to corrosion from moisture combining with sulfurpresent in the fuel.

BURNED VALVES

Burned valves are indicated by irregular exhaust gastemperatures and sometimes by excessive noise. Ingeneral, the principal causes of burned valves are carbondeposits, insufficient tappet clearance, defective valveseats, and valve heads that have been excessivelyreground.

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The principal cause of burned exhaust valves issmall particles of carbon that lodge between the valvehead and the valve seat. These particles come fromincomplete combustion of the fuel or oil left by thepiston rings in the cylinder. The particles hold the valveopen just enough to prevent the valve head fromtouching the valve seat. The valve is cooled by severalmeans, including its contact with the valve seat. Whencarbon particles prevent contact, the heat normallytransferred from the valve head to the seat remains inthe valve head. The valve seat seldom burns because thewater jackets surrounding the seat usually provideenough cooling to keep its temperature below adangerous point.

When cleaning carbon from cylinder heads, removeall loose particles from the crevices; be extremelycareful that you do not nick or scratch the valve or seat.Removing the valves from the engine will make it easierto clean the passages and remove the carbon depositsfrom the underside of the valve heads.

Check the tappet clearance adjustments at frequentintervals to be certain they are correct and that thelocking devices are secure. The adjustment of valveclearances is discussed later in this chapter.

Most engines are equipped with valve seat insertsmade of hard, heat-resisting, alloy steel. Occasionally, aseat will crack and allow the hot gases to leak, burningboth the insert and the valve. Sometimes a poor contactbetween the valve seat insert and the counterboreprevents the heat from being conducted away, and thehigh temperatures deform the insert. When this occurs,both the seat and the valve will burn; the seat insert mustbe rep1aced.

LOOSE VALVE SEATS

You can avoid causing loose valve seats only byinstalling them properly. Clean the counterborethoroughly to remove all carbon before shrinking in aninsert. Chill the valve seat with dry ice and place thecylinder head in boiling water for approximately 30minutes; then drive the insert into the counterbore witha valve insert installing tool, as illustrated in figure 3-10.Never strike a valve seat directly. Do the drivingoperation quickly, before the insert reaches thetemperature of the cylinder head

When replacing a damaged valve with a new one,inspect the valve guides for excessive wear. If the valvemoves from side to side as it seats, replace the guides.

Figure 3-10.–Driving a valve iusert into the cylinder headcounterbore.

PITTING

If the valve seat is secured firmly in the counterboreand is free of cracks and burns, you may remove slightdamage such as pitting by hand grinding (fig. 3-11).Generally, you will use prussian blue to check the valveand valve seat, but if this is not available, use any thindark oil-based paint. Allow the valve to seat by droppingit on the valve seat from a short distance. If the surfacesfail to make complete contact, regrinding is necessary.

75.72Figure 3-11.–Hand grinding a valve and valve seat.

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In any valve reconditioning job, the valve seat must beconcentric with the valve guide. You can determine theconcentricity with a dial indicator, as shown in figure3-12.

If you must grind a valve seat, hold hand grindingto a minimum and never use it in place of machinegrinding, in which a grinding stone is used to refinishthe seat (fig. 3-13). Grind the seat a few seconds at atime until it is free of pits. Check the seat after each cut.

The primary objection to hand grinding the valve tothe seat is that a groove or indentation may be formedin the valve face. Since the grinding is done when thevalve is cold, the position of the groove with respect tothe seat is displaced as the valve expands slightly whenthe engine is running. This condition is illustrated(greatly exaggerated) in figure 3-14. Note that when thevalve is hot, its ground surface does not make contact atall with the ground surface of the seat. Therefore, handgrinding should be used only to remove slight pitting oras the final and finishing operation in a valvereconditioning job.

Some valves and seat are not pitted sufficiently torequire replacement but are pitted to such an extent thathand grinding would be unsatisfactory. Such valves maybe refaced on a lathe (fig. 3-15), and the valve seats maybe reseated by power grinding equipment (fig. 3-13).

Figure 3-12.—Determining concentricity of the valve seat with adial indicator.

Figure 3-13.—Machine grinding a valve seat.

Normally, these operations are done at a repair base ornaval shipyard.

A valve head that is excessively reground to such anextent that its edge is sharp, or almost sharp, will soonburn. A sharp edge cannot conduct the heat away fastenough to prevent burning. This is the factor that limitsthe extent to which a valve may be refaced.

BROKEN VALVE SPRINGS

Broken valve springs cause excessive valve noiseand may cause erratic exhaust gas temperatures. Theactual breaking of the valve springs is not always themost serious consequence. Actions following thebreaking cause the most serious damage to the engine.When a spring breaks, it may collapse just enough toallow the valve to drop into the cylinder, where it maybe struck by the piston. In addition, the valve stem locksor keepers may release the valve and allow it to dropinto the cylinder, causing severe damage to the piston,cylinder head, and other nearby parts.

You can take a number of precautions to prevent orminimize corrosion and metal fatigue, which causevalve springs to break Be reasonably careful when you

3-10

Figure 3-14.—Excessively band-ground valve.

assemble and disassemble a valve assembly. Before youreassemble a valve assembly, be sure to thoroughlyclean and inspect the valve spring. (Use kerosene ordiesel fuel for cleaning. NEVER use an alkalinesolution; it will remove the protective coating.) Thecondition of the surface of a valve spring is the bestindication of impending failure. (Use magnafluxing tohelp find cracks that would otherwise be invisible.)

The free length of a valve spring should be withinthe limits specified in the manufacturer’s technical

manual. If such information is not available, comparethe length of a new spring with that of the used spring.If the length of the used spring is more than 3 percentshorter than that of the new spring, replace the usedspring immediately. Remember, however, that loss ofspring tension will NOT always show up as a loss inoverall length. Springs may be the proper length, butthey may have lost enough tension to warrantreplacement.

Figure 3-15.—Facing a valve on a lathe.

Do not reinstall springs with nicks, cracks, orsurface corrosion. Replace them. To minimize corrosiveconditions, use clean lube oil, eliminate water leaks, andkeep vents open and clean

WORN VALVE KEEPERS AND RETAININGWASHERS

Worn valve keepers and retaining washers mayresult if valve stem caps (used in some engines) areimproperly fitted Caps are provided to protect andincrease the service life of the valve stems. Troubleoccurs when the cap does not bear directly on the end ofthe stem, but bears instead on the valve stem lock or thespring retaining washer. This transmits the actuatingforce from the cap to the lock or the retaining washer,and then to the stem, causing excessive wear on the stemgroove and the valve stem lock As a result, the retainingwasher wiIl loosen and the valve stem may break

An improper fit of a valve stem cap may be due tothe use of improper parts or the omission of spacershims. Steel spacer shims, required in some caps toprovide proper clearance, are placed between the end ofthe valve stem and the cap; leaving out the shims willcause the shoulder of the cap to come in contact with thelock. When you disassemble a valve assembly,determine whether or not shims are used. If shims areused, record their location and exact thickness. Valvecaps must be of the proper size, or troubles similar tothose resulting from shim omission will occur. Neverattempt to use caps or any other valve assembly partsthat are worn.

BROKEN VALVE HEADS

Broken valve heads usually cause damage to thepiston, liner, cylinder head, and other associated parts.This damage is generally repairable only byreplacement of these parts.

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Whether the causes of broken valve heads aremechanical deformation or metal fatigue, you must takeevery precaution to prevent their occurrence. If a valvehead breaks loose, be sure to make a thorough inspectionof all associated parts before you replace the valve.

ROCKER ARMS AND PUSHRODS

The principal trouble that rocker arms and pushrodsmay have is WEAR, which may occur in bushings, oron the pads, end fittings, or tappet adjusting screws.

Worn rocker arm bushings are usually caused bylubricating oil problems. A bushing with excessive wearmust be replaced. When installing a new bushing, youusually need to use a reamer for the final fit.

Wear at the points of contact on a rocker arm isgenerally in the form of pitted, deformed, or scoredsurfaces. Wear on the rocker arm pads and end fittingsis greatly accelerated if lubrication is insufficient or ifthere is excessive tappet clearance. Pushrods are usuallypositioned to the cam followers and rocker arms by endfittings. The pads are the rocker arm ends that bear thevalve stem or valve stem cap. When the tappet clearanceis excessive, the rods shift around, greatly increasing therate of wear of both the rocker arm and the rod contactsurfaces. Worn fittings necessitate the replacement ofparts. Continued use of a poor fitting and worn pushrodis likely to result in further damage to the engine,especially if the rod should come loose.

Worn tappet adjusting screws and locknuts usuallymake maintaining proper clearances and keeping thelocknuts tight very difficult. Wear of the adjustingscrews is usually caused by loose locknuts, which allowthe adjusting screw to work up and down on the threadseach time the valve is opened and closed. To prevent thiswear, tighten the locknuts after each adjustment andcheck the tightness at frequent intervals.

If the threads are worn, replace the entire rockerarm. Do NOT attempt to repair the threads or to use anew tappet adjusting screw except in cases ofemergency.

The adjustment of the rocker arm assembly consistschiefly of adjusting the tappets for proper runningclearance. The valve clearance for both intake andexhaust valves should be readjusted after overhaul. Theprocedure for adjusting the rocker arm tappets of atypical 4-stroke cycle engine is as follows:

1. Rotate the crankshaft and move the piston whosetappets you plan to adjust to top dead center of thecompression stroke.

2. Loosen the locknut (jam nut) on the tappetscrew, and insert a screwdriver in the slot of the screw.

3. Insert a feeler gauge of the proper thicknessbetween the tappet bearing and the end of the valve stem.

4. Tighten the tappet screw (fig. 3-16) until thefeeler gauge will just slide freely between the bearingand the valve stem.

5. lighten the jam nut and check the clearance. Thejam nut has a tendency to increase the clearance whentightened; therefore, ALWAYS check the clearance afteryou tighten the jam nut.

The procedure just outlined is a preliminary, or coldengine check. Check and readjust the clearance, ifnecessary, after the engine has been in operation for ashort time and has reached the normal operatingtemperature. The manufacturer’s technical manual willgive the recommended valve clearances for a specificmake and model of engine and will indicate whether theclearances given apply to cold or hot engines.

CAM FOLLOWERS AND LASHADJUSTERS

Regardless of the type of cam follower, wear is themost common trouble. Worn rollers will usually developholes or pit marks in the roller surfaces. The mushroomtype may develop a shallow channel when the cam

Figure 3-16.—Adjusting valve clearance.

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follower fails to revolve and the cams wipe the same INSPECTING AND REPAIRINGsurface each time the camshaft revolves. CAMSHAFTS

Normal use will cause surface disintegration,usually as the hardened surfaces begin to fatigue. Thecondition is aggravated by abrasive particles. Nicks anddents on rollers will also cause disintegration.

You must make constant checks for defective rollersor surfaces and for nicks, scratches, or dents in thecamshaft. Whenever you find a defective cam follower,you should replace it. In roller-type cam followers youmust replace a worn cam follower body and guide orroller needle bearings (if used).

Defective or poorly operating valve adjusters allowclearance or lash in the valve gear. Noisy operation of alash adjuster indicates that there is insufficient oil in thecylinder of the unit. When you discover a noisy lashadjuster and the oil supply or pressure is not the sourceof trouble, remove and disassemble the unit accordingto the manufacturer’s instructions.

Since the parts of lash adjusters are notinterchangeable, disassemble only one unit at a time.Check for resinous deposits, abrasive particles, a stuckball check valve, a scored check valve seat, andexcessive leakage. Carefully wash all parts of thehydraulic lash adjuster in kerosene or diesel fuel. Checksuch parts as the cam follower body, plunger or piston,and hydraulic cylinder for proper fit.

Camshafts can be saved when the cams alone aredamaged, if the cams are of the individual type, sincesuch cams may be removed and replaced. Figure 3-17illustrates the method of removing an individual camfrom its shaft.

When you remove a camshaft from an engine, cleanit thoroughly with either kerosene or diesel fuel. Aftercleaning the shaft, dry it with compressed air. Aftercleaning the cam and journal surfaces, inspect them forany signs of scoring, pitting, or other damage.

When you remove or insert a camshaft through theend of the camshaft recess, rotate it slightly. Rotating thecamshaft allows it to enter easily and reduces thepossibility of damage to the cam lobes and bearings.

After you visually inspect a camshaft, place it onV-blocks and measure the shaft runout by using a dialindicator. When you measure the runout, take theout-of-roundness into consideration. Compare yourmeasurements to the manufacturer’s specifications.Also, measure the camshaft bearing journals with amicrometer. Figure 3-18 illustrates a camshaft withbearing journals.

A camshaft needs to be replaced if the followingconditions occur:

1. The lobes are damaged, as lobes cannot berepaired.

2 . R u n o u t e x c e e d s t h e m a n u f a c t u r e r ’ sspecifications.

3. Wear on the shaft bearing journals exceeds themanufacturer’s specifications.

4. The keyways are damaged.

Figure 3-18.—Camshaft with bearing journals in a V-typeengine.Figure 3-17.—Removing an individual cam.

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Before you reinstall a good camshaft, remove theminor surface defects on the cams and the camshaft byusing crocus cloth or a fine stone.

INSPECTING, MAINTAINING, ANDREPLACING PISTON RINGS AND PISTONS

The following paragraphs are general proceduresfor inspections, maintenance, and replacement of pistonrings and pistons. You must consult the manufacturer’stechnical manual for specific instructions.

PISTON RINGS

Over a period of time all piston rings wear. Somestick and may even break. While you may be able to freestuck rings and make them serviceable, you mustreplace excessively worn or broken rings with new ones.The installation of a new set of rings in an enginerequires great care. Most of the damage that is doneoccurs when the rings are being placed in the groovesof a piston or when the piston is being inserted into thecylinder bore.

Be very careful when you remove the piston andconnecting rod from the cylinder. In most engines, youshould not remove a piston from a cylinder until youhave scraped the cylinder surface above the ring travelarea. In addition to removing all carbon, you mustremove any appreciable ridge before removing thepiston. Do not remove a ridge by grinding, as this willallow small abrasive particles from the stone to enter theengine. Use a metal scraper and place a cloth in thecylinder to catch all metal cuttings. You can usuallyscrape enough from the lip of a cylinder to allow thepiston assembly to slide out of the liner. After removingthe piston, you can make a more detailed inspection ofthe ridge.

Finish scraping the remaining ridge, but be carefulnot to go too deep. Finish the surface with a handstone.For large ridges, you may need to remove the liner anduse a small power grinder.

With the piston and connecting rod removed, checkthe condition and wear of the piston pin bushing, bothin the piston and in the connecting rod.

The best way to remove and install piston rings iswith a tool similar to that shown in figure 3-19. Thesetools generally have a device that limits the amount thering can be spread and prevents the rings from beingdeformed or broken.

A ring that is securely stuck in the groove willrequire additional work. You may need to soak the piston

Figure 3-19.–Piston ring tools used for removal or installation.

overnight in an approved cleaning solvent or in dieseloil. If soaking does not free the ring, you must drive itout with a brass drift. The end of the drift should beshaped and ground to permit its use without damage tothe lands.

After removing the rings, thoroughly clean thepiston with special attention to the ring grooves. (Dieseloil or kerosene are satisfactory cleaning agents.) Inaddition, you may need to clean excessive deposits fromthe oil return holes in the bottom of the oil control ringgrooves with a twist drill of a diameter correspondingto the original size of the holes.

Make another complete inspection after cleaningthe piston. Check all parts for any defects that couldrequire replacement of the piston. Give particularattention to the ring grooves, especially if the pistonshave been in service for a long period of time. A certainamount of enlargement of the width of the grooves isnormal, and SHOULDERING of the groove may occur.Shouldering, as illustrated in figure 3-20, results fromthe “hammering out” motion of the rings. The radialdepth of thickness of the ring is much less than thegroove depth, and while the ring wears away an amountof metal corresponding to its own width, the metal at thebottom of the groove remains unchanged. Shouldering

3-14

Figure 3-20.—Ring groove shoulders due to wear.

usually requires replacement of the piston since theshoulders prevent the proper fitting of new rings.

After determining that a piston is serviceable,inspect the rings carefully todetermine whether they canbe reused. If they do not meet specifications, you mustinstall new rings.

When installing rings, measure the gap with a feelergauge. To measure the gap, place the new rings insidethe cylinder liner (fig. 3-21, view A) or in a ring gauge.When the gap is measured with the ring in the liner (fig.

3-21, view B), two measurements are necessary—onejust below the upper limit of ring travel, and the otherwithin the lower limit of travel. These measurements arenecessary because the liner may have a slight amount oftaper caused by wear. The ring gap must be within thelimits specified in the manufacturer’s technical manual.If the gap of a new ring is less than specified, file theends of the ring with a straight-cut mill file to obtain theproper gap. If the gap is more than specified, installoversized rings.

To measure the ring gap of used rings, hold the ringsin place on the piston with a ring compressing tool (fig.3-22). But before you measure the ring gap with the ringon the piston, first measure the piston for wear andout-of-roundness.

After ensuring the proper gap clearance, you canreinstall the piston pin and connecting rod. Duringreassembly and installation of a piston and connectingrod assembly, be sure that all parts are well lubricated.Install the rings on the piston with tools similar to thoseused for ring removal. When installing piston rings,spread them as little as possible to avoid breaking therings. Insert the lowest ring first. When all the rings have

Figure 3-21.–A. Leveling a piston ring. B. Measuring ring gap clearance in a cylinder bore.

3-15

Figure 3-22.–Checking ring gap clearance.

been installed, check the ring-to-land clearance. (Seefig. 3-23.) If the clearance is too small, the ring maybind or seize, allowing improper sealing and blowby tooccur. If the clearance is excessive, the ring may flutterand break itself or the piston land.

After you have properly installed all the rings, coatthe entire assembly with oil, then insert it into thecylinder bore. Position the rings so the gap of eachsuccessive ring is on an alternate side and the gaps arein line with the piston pin bosses. On large engines, usea chain fall to hold the piston assembly in position asyou lower it into the cylinder. (See fig. 3-24.)

Figure 3-23.–Checking ring groove side clearance.

75.56Figure 3-24.–Installing a piston in a cylinder bore with a

funnel-type ring compressor.

When a piston is being inserted into a cylinder, thepiston rings must be compressed evenly. Specialfunnel-type tools, similar to the one shown in figure 3-24are usually provided for this purpose. Another type ofring compressing tool is a steel band that can be placedaround the ring and tightened.

PISTONS

Trunk-type pistons are subject to forces such as gaspressure, side thrust, inertia, and friction. These forces,together with overheating and the presence of foreignmatter, may cause troubles such as undue piston wear,crown and land dragging, cracks, piston seizure,clogged oil holes, and piston pin bushing wear.

Excessive Piston-to-Liner Clearance

Symptoms of excessive clearance between a pistonand its cylinder are piston slap and excessive oilconsumption. Piston slap occurs just after top deadcenter and bottom dead center, as the piston shifts itsthrust from one side to the other. As the cylinder taperincreases with wear, oil consumption increases. Sincetaper causes the rings to flex on each stroke of the piston,excess ring wear occurs, allowing lube oil to pass and

3-16

be burned in the cylinder. This results in theaccumulation of excessive carbon deposits.

Crown and Land Dragging

Pistons and liners may become sufficiently worn topermit the piston to cock over in the cylinder. Thisallows the crown and ring lands to drag on the cylinderwall. The results of dragging can be determined byvisually inspecting the parts of the piston in question.

Piston Wear

Although piston wear is normal in all engines, theamount and rate of piston wear depend on severalcontrollable factors. (The causes of excessive pistonwear, and crown and land dragging, are also the causesof other piston troubles.)

One of the controllable factors is LUBRICATION.An adequate supply of oil is essential to provide the filmnecessary to cushion the piston and other parts withinthe cylinder and prevent metal-to-metal contact.Inadequate lubrication will not only cause piston wearand crown and land dragging, but also may cause pistonseizure, and piston pin busing wear.

Lack of lubrication is caused either by a lack of lubeoil pressure or by restricted oil passages. Thepressure-recording instruments usually give warning oflow oil pressure before any great harm results. However,clogged passages offer no such warnings, and theirdiscovery depends on the care that is exercised ininspecting and cleaning the piston and connecting rodassembly.

Another controllable factor that may be directly orindirectly responsible for many piston troubles isIMPROPER COOLING WATER TEMPERATURE.

If an engine is not operated within the specifiedtemperature limits, lubrication troubles will develop.High cylinder surface temperatures will reduce theviscosity of the oil. As the cylinder lubricant thins, it willrun off the surfaces. The resulting lack of lubricationleads to excessive piston and liner wear. However, iftemperatures are below those specified for operation,viscosity will be increased, and the oil will not readilyreach the parts requiring lubrication.

Oil plays an important role in the cooling of thepiston crown. If the oil flow to the underside of thecrown is restricted, deposits caused by oxidation of theoil will accumulate, lowering the rate of heat transfer.Therefore, the underside of the piston crown should bethoroughly cleaned whenever pistons are removed

While insufficient and uneven cooling may causering land failure, excessive temperatures may causepiston seizure; an increase in the rates of oxidation ofthe oil, resulting in clogged oil passages; or damage topiston pin bushings.

Seizure or excessive wear of pistons may be causedby IMPROPER PIT. New pistons or liners must beinstalled with the piston-to-cylinder clearancesspecified in the manufacturer’s instruction manual.

PISTON PINS AND SLEEVE BEARINGS ORBUSHINGS

Every time you remove a piston assembly from anengine, inspect it for wear. Measure the piston pins andsleeve bearings or bushings with a micrometer, as shownin figure 3-25, to determine whether wear is excessive.Do NOT measure areas that do not make contact. Suchareas include those between the connecting rod andpiston bosses and areas under the oil holes and grooves.

You can press bushings out of the rod with a mandreland an arbor press or with special tools, as shown infigure 3-26. You can also remove bushings by firtshrinking them with dry ice. Dry ice will also make iteasier to insert the new bushing.

Figure 3-25.—Measuring a piston pin and piston bushing forwear.

3-17

Figure 3-26.–Removing or installing a piston pin bushing.

When you insert new bushings, be sure that the bore

into which they are pressed is clean and that the oil holesin the bushing and the oil passages in the rod are aligned.To obtain proper clearance, sometimes you will need toream a piston pin bushing after it has been installed.

Figure 3-27 shows equipment used to ream a bushing.

After installing a new bushing, check the alignment

of the rod with equipment such as illustrated in figure3-28. Be sure to check the manufacturer’s technicalmanual for details concerning clearances and alignmentprocedures.

INSPECTING, MAINTAINING, ANDREPAIRING CONNECTING RODS

Most connecting rod troubles involve either theconnecting rod bearing or the piston pin bearing. Youcan avoid these troubles by performing propermaintenance procedures and by following instructionsin the manufacturer’s service manual. There are,however, certain unavoidable troubles, such as crackedconnecting rods caused by defective material. Suchcracks must be discovered before they develop to a pointthat the rod fails. Magniflux testing is considered thebest method for locating cracks. If you discover a crackin a connecting rod, replace the rod; do not try to repairit. If you have to replace a damaged rod, send it, withother damaged parts, to a salvage center for possiblereclamation.

Do not repair defective connecting rod bolts, exceptfor removing small burrs by using a fine rectangular file.If you doubt the condition of a bolt or a nut, replace it.

Check the connecting rod bore for out-of-roundnesswith an inside micrometer. Make the correction andrecheck the bore. If the distortion is permanent, replace

the rod.

You can make plugged oil passages of connectingrods serviceable by running a wire through them. Inextreme cases, you may need to drill the passages freeof foreign matter.

Figure 3-27.–Reaming equipment.

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Figure 3-28.—Checking the alignment of a connecting rod.

REPAIRING CRANKSHAFTS ANDJOURNAL BEARINGS

The repair of crankshafts and bearings variesdepending on the extent of damage. There is no doubtabout the necessity for replacing such items as brokenor bent crankshafts. Out-of-round journals may bereground and undersize bearing shells may be installed,but this requires personnel skilled in the use of precisiontools. If a new shaft is available, it should be installedand the damaged shaft should be sent to a salvagereclamation center. Under certain conditions, scoredcrankshaft journals or damaged journal bearings may bekept in service if proper repair is performed.

Repair of SCORED JOURNALS depends on theextent of scoring. If a crankshaft has been overheated,the effect of the original heat treatment will have beendestroyed. In this case, the crankshaft should bereplaced.

If journal scoring is only slight, you can use anoilstone for dressing purposes if you take precautionarymeasures with respect to abrasives during the procedure.During the dressing operation, plug all oil passageswithin the journal and those connecting the mainbearingjournal and the adjacent connecting rod journal.

In the dressing procedure, use a fine oilstone,followed with crocus cloth, to polish the surface. Afterdressing journals, always wash them with diesel oil.This procedure must include washing the internal oilpassages as well as the outside journal surfaces. Somepassages are large enough to accommodate a cleaningbrush; smaller passages can be cleaned by blowing themout with compressed air. Always dry the passages byblowing compressed air through them.

NEVER STOW A CRANKSHAFT OR BEARINGPART ON ANY METAL SURFACE. When you removea shaft from an engine, place it on a wooden plank with

Figure 3-29.—Using a strain or deflection gauge between crankwebs.

all journal surfaces protected. If the shaft is to beexposed for some time, protect each journal surface witha coating of heavy grease. Always place bearings onwooden boards or clean cloths.

CRANKSHAFT overhaul consists of an inspection,servicing for scoring and wear, and a determination ofeach crank web deflection. Take crank web deflectionreadings according to the Planned Maintenance System(PMS).

A strain gauge, often called a crank web deflectionindicator, is used to take deflection readings. The gaugeis merely a dial-reading inside micrometer used tomeasure the variation in the distance between adjacentcrank webs as the engine shaft is barred over. Figure3-29 shows a strain gauge between crank webs.

When you install the gauge, or indicator, betweenthe webs of a crank throw, be sure to place the gauge asfar as possible from the axis of the connecting rodjournal. Rest the ends of the indicator in prick-punchmarks in the crank webs. If these marks are not present,make them so that the indicator can be placed in itscorrect position. Consult the manufacturer’s technicalmanual for the proper location of new marks.

Readings are generally taken at the four crankpositions: top dead center, inboard, near or at bottomdead center, and outboard. In some engines, it is possibleto take readings at bottom dead center. In others, theconnecting rod may interfere, making it necessary totake the reading as near as possible to bottom deadcenter without having the gauge come in contact withthe connecting rod. When the gauge is in its lowest

3-19

position, the dial will be upside down, making itnecessary to use a mirror and flashlight to obtain areading.

NOTE: Once you have placed the indicator inposition for the first deflection reading, do not touch thegauge until you have taken and recorded all fourreadings.

Deflection readings are also used to determinecorrect alignment between the engine and the generatoror between the engine and the coupling. However, whendetermining alignment, you should take a set ofdeflection readings at the crank nearest the generator orthe coupling. In aligning an engine and generator, youmay need to install new chocks between the generatorand its base to bring the deflection within the allowablevalue. You may also need to shift the generatorhorizontally to obtain proper alignment. To align anengine and a coupling, first, correctly align the couplingwith the drive shaft; then, properly align the engine tothe coupling, rather than aligning the coupling to theengine.

BEARING TROUBLES

Bearings become a continual source of troubleunless personnel entrusted with operating the enginefollow the recommended operation and maintenanceprocedures exactly.

Severe bearing failures are indicated during engineoperation by a pounding noise or by the presence ofsmoke in the vicinity of the crankcase. Impendingfailures may sometimes be identified by a rise in thelubricating oil temperature or a lowering of thelubricating oil pressure. Impending bearing failure maybe detected during periodic maintenance checks orduring engine overhauls by inspection of the bearingshells and backs for pits, grooves, scratches, or evidenceof corrosion.

The indication of an impending failure does notnecessarily mean that the bearing has completed itsuseful life. Journal bearings may perform satisfactorilywith as much as 10 percent of the load-carrying arearemoved by fatigue failure. Other minor casualties maybe repaired so that a bearing will give additional hoursof satisfactory service.

Bearings should not be rejected or discarded forminor pits or minute scratches; however, areasindicating metallic contact between the bearing surfaceand the journal do mean replacement is needed. Use abearing scraping tool to smooth minute pits and raised

Figure 3-30.—Using a torque wrench to tighten a main bearing.

surfaces. After working on bearings, make every effortto ensure that the bearing surfaces are clean. This alsoapplies to the bearing back and the connecting rodjournal Place a film of clean lubricating oil on thejournals and the bearing surfaces before you reinstallthem.

INSTALLING JOURNAL BEARINGS

Always check the markings of the lower and upperbearing halves so you install them correctly. Manybearings are interchangeable when new, but once theyhave become worn to tit a particular journal they mustbe reinstalled on that particular journal. You must markor stamp each bearing half with its location (cylindernumber) and the bearing position (upper or lower) toprevent incorrect installation.

You must also pull the connecting rod bearing capnuts down evenly on the connecting rod bolts to preventpossible distortion of the lower bearing cap andconsequent damage to the bearing shells, cap, and bolts.Use a torque wrench (fig. 3-30) to measure the torqueapplied to each bolt and nut assembly. Apply the sametorque to each bolt. If a manufacturer recommends theuse of a torque wrench, the specified torque will be listedin the manufacturer’s technical manual.

Another method for pulling down the nuts evenly isto stretch each bolt an equal amount and measure thedistance from end to end of the bolt before and aftertightening. Figure 3-31 shows the type of gauge used,

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Figure 3-31.—Gauge used for measuring bolt elongation.

Figure 3-32.—Measuring bolt elongation.

and figure 3-32 illustrates the gauge in use. The proper

elongation is listed in the engine manufacturer’s

technical manual.

After you reassemble a bearing, always bar or jack

over the engine by hand through several revolutions.

Check to see that all reciprocating and rotating parts

function freely and that the main and connecting rod

bearings do not bind on the crankshaft. Turn larger diesel

engines over first by the manual jacking gear provided

and then by the engine starting system.

Figure 3-33.—Measuring bearing shell thickness.

Figure 3-34.—Checking bearing clearance with a Plastlgage.

MEASURING BEARING CLEARANCES

Do not use leads, shim stock, or other such items todetermine clearance of precision bearings. These itemsmay seriously damage the soft bearing material. Instead,use a micrometer fitted with a spherical seat to measurethe thickness of bearing shells. Place the spherical tipagainst the inside of the bearing shell to obtain anaccurate reading and to prevent injury to the bearingmaterial. Figure 3-33 shows a micrometer caliper fittedwith a steel ball for measuring bearing thickness.

An alternate method for determining clearance iswith a Plastigage (fig. 3-34). The Plastigage will not

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Figure 3-35.—Crankshaft bridge gauge.

leave an impression in the soft bearing metal becausethe gauge material is softer than the bearing. To use thismethod, place a length of the Plastigage of proper gaugeacross the bearing. Then, assemble the bearing cap andtighten it in place. DO NOT TURN the crankshaft, asthat will destroy the Plastigage. After you install andproperly fasten the bearing cap, remove it. Compare thewidth of the crushed Plastigage with the Plastigage chartto determine the exact clearance.

You must take measurements at specified intervals,usually at every overhaul, to establish the amount ofbearing wear. Also take a sufficient number ofcrankshaft journal diameter measurements at suitablepoints to determine possible out-of-roundness.

With some types of engines, a crankshaft bridgegauge (fig. 3-35) is used to check the wear of the mainbearing shells. To use the gauge, place it on thecrankshaft and measure the clearance between thebridge gauge and the shaft with a feeler gauge. Anyvariation between the measured clearance and thecorrect clearance (usually stamped on the housing ofeach bearing) indicates that main bearing wear hasoccurred. The maximum limits of wear are listed in themanufacturer’s technical manual. Some enginemanufacturers recommend that bridge gauge readingsbe taken at every overhaul in conjunction with crankweb deflection measurements.

The important point to remember is that if youcannot overhaul an engine due to lack of space,manpower, or expertise, you may request outside helpby using an OPNAV Form 4790/2K. This form, whenused as a work request, will be sent to a ship intermediate

maintenance activity (SIMA). The SIMA will thenaccept or reject the work request. If the work request isaccepted, the SIMA will order all repair parts, overhaulthe engine, and perform an operational test according tothe manufacturers’ technical manuals and the NSTM,chapter 233.

As stated earlier in this section, maintenance cards,manufacturers’ maintenance manuals, and various otherinstructions discuss repair procedures in detail.Therefore, this chapter will be limited to generalinformation on some of the troubles encountered duringoverhaul, the causes of such troubles, and the methodsof repair.

TROUBLESHOOTINGINTERNAL-COMBUSTION ENGINES

The procedures for troubleshootinginternal-combustion engines are somewhat similar forboth diesel and gasoline engines. In many instances, theinformation that follows will apply to both types ofengine. However, it also discusses principal differences.Since most of the internal-combustion engines used bythe Navy are diesel, the following sections dealprimarily with this type of engine.

This chapter is concerned with troubles that occurboth when an engine is starting and running. Thetroubles are chiefly the kind that can be identified byerratic engine operation, warnings by instruments, orinspection of the engine parts and systems and that canbe corrected without major repair or overhaul. There isalso a section devoted to the systems of the gasolineengine that are basically different from those of thediesel engine.

Keep in mind that the troubles listed here are generaland may or may not apply to a particular diesel engine.When you work with a specific engine, check themanufacturer’s technical manual and any instructionsissued by the Naval Sea Systems Command.

An engine may continue to operate even when aserious casualty is imminent. However, symptoms areusually present. Your success as a troubleshooterdepends partially upon your ability to recognize thesesymptoms when they occur. You will use most of yoursenses to detect trouble symptoms. You may see, hear,smell, or feel the warning of trouble to come. Of course,common sense is also a requisite. Another factor in yoursuccess as a troubleshooter is your ability to locate thetrouble once you decide something is wrong with theequipment. Then, you must be able to determine asrapidly as possible what corrective action to take. In

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learning to recognize and locate engine troubles,experience is the best teacher.

Instruments play an important part in detectingengine troubles. You should read the instruments andrecord their indications regularly. If the recordedindications vary radically from those specified byengine operating instructions, the engine is notoperating properly and some type of corrective actionmust be taken. You must be familiar with thespecifications in the engine operating instructions,especially those pertaining to temperatures, pressures,and speeds. You should know the probable effect on theengine when instrument indications vary considerablyfrom the specified values. When variations occur ininstrument indications, before taking any correctiveaction be sure the instruments are not at fault before youtry corrective actions on the engine. Check theinstruments immediately if you suspect them of beinginaccurate.

Periodic inspections are also important in detectingengine troubles. Such inspections will reveal the failureof visible parts, presence of smoke, or leakage of oil,fuel, or water. Cleanliness is probably one of the greatestaids in detecting leakage.

When you secure an engine because of trouble, yourprocedure for repairing the casualty should follow anestablished pattern, if you have diagnosed the trouble.If you do not know the location of the trouble, find it.To inspect every part of an engine whenever troubleoccurs would be an almost endless task. You can findthe cause of the trouble much more quickly by followinga systematic and logical method of inspection,Genernlly speaking, a well-trained troubleshooter canisolate the trouble by identifying it with one of theengine systems. Once you have associated the troublewith a particular system, the next step is to trace out thesystem until you find the cause of the trouble. Troublesgenerally originate in only one system, but rememberthat troubles in one system may cause damage to anothersystem or to basic engine parts. When a casualtyinvolves more than one system of the engine, trace eachsystem separately and make corrections as necessary. Itis obvious that you must know the construction,function, and operation of the various systems as wellas the parts of each system for a specific engine beforeyou can satisfactorily locate and remedy troubles.

Even though there are many troubles that may affectthe operation of a diesel engine, satisfactoryperformance depends primarily on sufficiently high

compression pressure and injection of the right amountof fuel at the proper time. Proper compression dependsbasically on the pistons, piston rings, and valve gear,while the right amount of fuel obviously depends on thefuel injectors and their actuating mechanism. Suchtroubles as lack of engine power, unusual or erraticoperation, and excessive vibration may be caused byeither insufficient compression or faulty injector action.

You can avoid many troubles by following theprescribed instructions for starting and operating theengine, The troubles discussed in the following sectionsdo not comprise a complete list, nor do they allnecessarily apply to all diesel engines because ofdifferences in design. Specific information ontroubleshooting for all the diesel engines used by theNavy would require more space than is available here.

Even though a successful troubleshooter generallyassociates certain troubles with a particular system orassembly, the following sections discuss troublesaccording to when they might be encountered, eitherbefore or after the engine starts.

ENGINE FAILS TO START

In general, the troubles that prevent an engine fromstarting are (1) the engine can neither be cranked norbarred over, (2) the engine cannot be cranked, but it canbe barred over, and (3) the engine can be cranked, but itstill fails to start. Figure 3-36 illustrates variousconditions that commonly cause difficulties in cranking,jacking over, or starting the engine.

Engine Cannot Be Cranked nor Barred Over

Most prestarting instructions for large enginesrequire you to turn the crankshaft one or morerevolutions before applying starting power. If youcannot turn the crankshaft over, check the turning gearto be sure it is properly engaged. If the turning gear isproperly engaged and the crankshaft still fails to turnover, check to see whether the cylinder test valves orindicator valves are closed and are holding water or oilin the cylinder. When the turning gear operates properlyand the cylinder test valves are open but the engine stillcannot be cranked or barred over, check for a seriousproblem. A piston or other part may be seized or abearing may be fitting too tightly. Sometimes you mayneed to remove a part of an assembly to remedy thedifficulty.

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Figure 3-36.—Troubles that may prevent a diesel engine from starting.

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Some engines have ports through which pistons canbe inspected. If inspection reveals that the piston isdefective, remove the piston assembly. Figure 3-37illustrates testing for stuck piston rings through thescavenging-air port.

If the condition of an engine without cylinder portsindicates that a piston inspection is required, you musttake the whole piston assembly out of the cylinder.

Engine bearings must be carefully fitted or installedaccording to the manufacturer’s instructions. When anengine cannot be jacked over because of an improperlyfitted bearing, someone probably failed to followinstructions when the unit was being reassembled.

Engine Cannot Be Cranked but Can Be BarredOver

You can trace most of the troubles that prevent anengine from cranking, but not serious enough to preventbarring over, to the starting system. Although otherfactors may prevent an engine from cranking, onlytroubles related to starting systems are identified in thischapter.

If an engine fails to crank when you apply starting

power, first check the turning or jacking gear to be sureit is disengaged. If this gear is not the source of thetrouble, the trouble is probably with the starting system.

Figure 3-37.—Checking the condition of the piston rings.

Engine Can Be Cranked, but Fails to Start

Although the design of air starting systems mayvary, the function remains the same. In general, suchsystems must have a source of air, such as thecompressor or the ship’s air system; a storage tank; airflask(s); an air timing mechanism; and a valve in theengine cylinder to admit the air during starting and toseal the cylinder while the engine is running.

All air starting systems have a unit that admitsstarting air to the proper cylinder at the proper time. Thetype of unit as well as its name-timer, distributor, airstarting pilot valve, air starting distributor, or airdistributor-may vary from one system to another. Thetypes of air timing mechanisms are the directmechanical lift, the rotary distributor, and theplunger-type distributor valve. The timing mechanismof an air starting system is relatively trouble-free exceptas noted in the following situations.

DIRECT MECHANICAL LIFT.—The directmechanical lift air timing mechanism includes cams,pushrods, and rocker arms. These parts are subject to thesame failures as engine cams, pushrods, and rockerarms. Therefore, you can find the causes of trouble inthe actuating gear and the necessary maintenanceprocedures under information covering similar engine

parts.

Most troubles are a result of improper adjustment.Generally, this involves the lift of the starting air cam orthe timing of the air starting valve. The starting air cammust lift the air starting valve enough to give a properclearance between the cam and the cam valve followerwhen the engine is running. If there is not enoughclearance between these two parts, hot gases will flowbetween the valve and the valve seat, overheating them.Since the starting air cam regulates the opening of theair starting valve, check those with adjustable cam lobesfrequently to ensure that the adjusting screws are tight.

Obtain the proper values for lift, tappet clearance,and time of valve opening for a direct mechanical lifttiming mechanism from the manufacturer’s technicalmanual for the particular engine. Make adjustments onlyas specified.

ROTARY DISTRIBUTOR.—The rotarydistributor timing mechanism requires a minimum ofmaintenance, but there may be times when the unitbecomes inoperative and you will need to disassembleand inspect it. Generally, the difficulty is caused by ascored rotor, a broken spring, or improper timing.

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Foreign particles in the air can score the rotor,resulting in excessive air leakage. You must, therefore,keep the air supply as clean as possible. Lack oflubrication also causes scoring. If the rotor in ahand-oiled system becomes scored because ofinsufficient lubrication, the equipment could be at fault,or the lubrication instructions may not have beenfollowed. To prevent problems in either a hand-oiled orpressure-lubricated system, check the piping and thepassages to see that they are open. When scoring is nottoo serious, lap the rotor and body together. Use a thincoat of prussian blue to determine whether the rotorcontacts the distributor body.

A broken spring may be the cause of an inoperativetiming mechanism if a coil spring is used to maintain therotor seal. If the spring is broken, replace it to ensure aneffective seal.

An improperly timed rotary distributor will preventan engine from cranking. Use the information given inthe instructions for the specific engine to check thetiming.

PLUNGER-TYPE DISTRIBUTOR VALVE.—Ina plunger-type distributor valve timing mechanism, thevalve requires little attention. However, it may stickoccasionally and prevent the air starting system fromfunctioning properly. On some engine installations, thepilot air valve of the distributor may not open, while onother installations this valve may not close. The troublemay be caused by dirt and gum deposits, broken returnsprings, or lack of lubrication. Deposits and lack oflubrication will cause the unit valve plungers to bind andstick in the guides, while a broken valve return springwill keep the plunger from following the cam profile.Disassemble and thoroughly clean a distributor valvethat sticks; replace any broken springs.

Faulty Air Starting Valves

Air starting valves admit starting air into the enginecylinder and then seal the cylinder while the engine isrunning. These valves may be the pressure-actuated ormechanical-lift type.

PRESSURE-ACTUATED VALVES.—In apressure-actuated valve, the most frequent trouble issticking. The valve may stick open for a number ofreasons. A gummy or resinous deposit may cause theupper and lower pistons to stick to the cylinders. (Thisdeposit is formed by the oil and condensate that may becarried into the actuating cylinders and lower cylinders.Oil is necessary in the cylinders to provide lubricationand to act as a seal; however, moisture should be

eliminated.) You can prevent this resinous deposit fromforming by draining the system storage tanks and watertraps as specified in the operating instruction. Thedeposit on the lower piston may be greater than that inthe actuating cylinder because of the heat andcombustion gases that add to the formation if the valveremains open. When the upper piston is the source oftrouble, you can usually relieve the sticking, withoutremoving the valve, by using light oil or diesel fuel andworking the valve up and down. When you use thismethod, be sure that the valve surfaces are not burnedor deformed. If this method does not relieve the stickingcondition, you will need to remove, disassemble, andclean the valve.

Pressure-actuated starting valves sometimes fall tooperate because of broken or weak valve return springs.Replacement is generally the only solution to thiscondition; however, some valves are constructed with ameans of adjusting spring tension. In such valves,increasing the spring tension may eliminate the trouble.

Occasionally the actuating pressure of a valve willnot release, and the valve will stick open or be sluggishin closing. The cause is usually clogged or restricted airpassages. Combustion gases will enter the airpassageways, burning the valve surfaces. These burnedsurfaces usually must be reconditioned before they willmaintain a tight seal. Keeping the air passages open willeliminate extra maintenance work on the valve surfaces.

MECHANICAL LIFT VALVES.—The mechanicallift-type air starting valve is subject to leakage which, ingeneral, is caused when the valve sticks open. Any airstarting valve that sticks or leaks creates a condition thatmakes an engine hard to start. If the leakage in the airstarting valve is excessive, the loss in pressure mayprevent the engine from starting.

Leakage in this type of valve can be caused by anovertightened packing nut. The packing nut issometimes overtightened to stop minor leaks around thevalve stem when starting pressure is applied, butovertightening may prevent the air valve from seating.As in the pressure-actuated valve, there may not beenough return spring tension to return the valve to thevalve seat after admitting the air charge.

Obstructions such as particles of carbon between thevalve and valve seat will hold the valve open, permittingcombustion gases to pass. A valve stem bent by carelesshandling during installation may also prevent a valvefrom closing properly.

If a valve hangs open for any of these reasons, hotcombustion gases will leak past the valve and valve seat.

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The gases burn the valve and seat and may cause a leakbetween these two surfaces even though the originalcauses of the sticking are eliminated.

Completely disassemble and inspect a leakingvalve. It is subject to a resinous deposit similar to thatfound in a pressure-actuated air valve. Use a specifiedcleaning compound to remove the deposit. Be sure thevalve stem is not bent. Check the valve and valve seatsurfaces carefully. Eliminate scoring or discoloration bylapping with a fine lapping compound. You may usejewelers’ rouge or talcum powder with fuel oil forlapping.

From the preceding discussion, you have learnedthat the air starting system may be the source of manytroubles that will prevent an engine from cranking eventhough it can be barred over. You will avoid a few ofthese troubles by following prestarting and startinginstructions. One such instruction, sometimesoverlooked, is that of opening the valve in the air line.Obviously, with this valve closed the engine will notcrank. Recheck the instructions for such oversights as aclosed valve, an empty air storage receiver, or anengaged jacking gear before starting any disassembly.

ELECTRIC START MALFUNCTION

Electric starting system malfunctions fall into thefollowing categories:

1. Nothing happens when the starter switch isclosed.

2. The starter motor runs, but it does not engage theengine.

3. The starter motor engages, but it cannot turn theengine.

If nothing happens when you close the starterswitch, there is a failure in the electrical system. Thefailure could be an open circuit caused by brokenconnections or burned out components. Test the circuitcontinuity to make sure the relay closes and the batteryprovides sufficient voltage and current to the startercircuit. If the circuit is complete, there may be resistancethrough faulty battery connections. Considerablecurrent is needed to operate the solenoid and startermotor.

If the starter runs without engaging, it will producea distinctive hum or whine. The lack of engagement isusually caused by dirt or corrosion, which keeps thesolenoid or Bendix gears from operating properly.

If the starter motor engages the flywheel ring gearbut is not able to turn the engine or cannot turn it quicklyenough to obtain starting speed, the cause may be lackof battery power or, more likely, a mechanical problem.If the engine can be barred over, there is excessivefriction in the meshing of the starter pinion and the ringgear. Either the teeth are burred, or the starter pinion isout of alignment. Either case would have been precededby noise the last time the starter was used. A major repairmay be necessary.

Other problems and malfunctions of electricstarting systems are discussed in association withgasoline engines at the end of this chapter.

ENGINE CRANKS BUT FAILS TO START

Even when the starting equipment is in an operatingcondition, an engine may fail to start. Most troubles thatprevent an engine from starting are associated with fueland the fuel system. However, defective or inoperativeparts or assemblies may be the source of some trouble.Failure to follow instructions may be the cause of anengine failing to start. The corrective action is obviousfor such items as leaving the fuel throttle in the OFFposition and leaving the cylinder indicator valves open.If an engine fails to start, follow the prescribed startinginstructions and recheck the procedure.

Foreign Matter in the Fuel Oil System

In the operation of an internal-combustion engine,cleanliness is of paramount importance. This isespecially true in the handling and care of diesel fuel oil.Impurities are the prime source of fuel pump andinjection system troubles. Sediment and water causewear, gumming, corrosion, and rust in a fuel system.Even though fuel oil is generally delivered clean fromthe refinery, handling and transferring increase thechances that fuel oil will become contaminated.

Corrosion often leads to replacement or at least torepair of the part. You must continually take steps toprevent water from accumulating in a fuel system, notonly to eliminate the cause of corrosion but also toensure proper combustion in the cylinders. Centrifugeall fuel, and drain the fuel filter cases periodically toprevent excessive collection of water.

Water in fuel will cause irreparable damage to theentire fuel system in a short time. It corrodes the fuelinjection pump, where close clearances must bemaintained, and also corrodes and erodes the injectionnozzles. The slightest corrosion can cause a fuelinjection pump to bind and seize which, if not corrected,

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will lead to excessive leakage. Water will erode theorifices of injection nozzles until they will not spray thefuel properly, thus preventing proper atomization. Whenthis occurs, incomplete combustion and engine knocksresult.

Air in the fuel system is another possible trouble thatmay prevent an engine from starting. Even if the enginewill start, air in the fuel system will cause the engine tomiss and knock, and perhaps to stall.

When an engine fails to operate, stalls, misfires, orknocks, there may be air in the high-pressure pumps andlines. In many systems, the expansion and compressionof such air may take place even if the injection valvesdo not open. If this occurs, the pump is AIRBOUND. Todetermine if there is air in a fuel system, bleed a smallamount of fuel from the top of the fuel filter; if the fuelappears quite cloudy, there are probably small bubblesof air in the fuel.

Insufficient Fuel Supply

An insufficient fuel supply may result from adefective or inoperative part in the system. Such itemsas a closed inlet valve in the fuel piping or an emptysupply tank are more likely to be the fault of the operatorthan of the equipment. But an empty tank may be causedby leakage, either in the lines or in the tank

LEAKAGE.-You can usually trace leakage in thelow-pressure lines of a fuel system to cracks in thepiping. Usually these cracks occur on threaded pipejoints at the root of the threads. Such breakage is causedby the inability of the nipples and pipe joints towithstand shock, vibration, and strains resulting fromthe relative motion between smaller pipes and theequipment to which they are attached.

Metal fatigue can also cause breakage. Each systemshould have a systematic inspection of its fittings andpiping to determine if all the parts are satisfactorilysupported and sufficiently strong. In some instances,nipples may be connected to relatively heavy parts, suchas valves and strainers, which are free to vibrate. Sincevibration contributes materially to the fatigue of nipples,rigid bracing should be installed. When practicable,bracing should be secured to the unit itself, instead of tothe hull or other equipment.

Breakage can also cause leakage in thehigh-pressure lines of a fuel system. The breakageusually occurs on either of the two end fittings of a lineand is caused by lack of proper supports or by excessivenozzle opening pressure. Supports are usually supplied

with an engine and should not be discarded. Excessiveopening pressure of a nozzle-generally due to improperspring adjustment or to clogged nozzle orifices-mayrupture the high-pressure fuel lines. A faulty nozzleusually requires removal, inspection, and repair plus theuse of a nozzle tester.

Leakage from fuel lines may also be caused byimproper replacement or repairs. When a replacementis necessary, always use a line of the same length anddiameter as the one you remove. Varying the length anddiameter of a high-pressure fuel line will change theinjection characteristics of the injection nozzle.

In an emergency, you can usually repair ahigh-pressure fuel line by silver soldering a new fittingto the line. After making the silver solder repair, test theline for leaks and be certain no restrictions exist.

Most leakage trouble occurs in the fuel lines, butleaks may occasionally develop in the fuel tank. Theseleaks must be eliminated immediately because ofpotential fire hazard.

The principal causes of fuel tank leakage areimproper welds and metal fatigue. Metal fatigue isusually the result of inadequate support; excessivestresses develop in the tank and cause cracks.

CLOGGED FUEL FILTERS-Another problemthat can limit the fuel supply to such an extent that anengine will not start is clogged fuel filters. Definite rulesfor filter replacement cannot be established for allengines. But instructions generally state that elementswill not be used longer than a specified time. Since thereare reasons that an element may not always functionproperly for its expected service life, it should bereplaced whenever it is suspected of being clogged.

Filter elements may become clogged because ofdirty fuel, too small filter capacity, failure to drain thefilter sump, and failure to use the primary strainer.Usually, clogging is indicated by such symptoms asstoppage of fuel flow, increase in pressure drop acrossthe filter, increase in pressure upstream of the filter, orexcessive accumulation of dirt on the element (observedwhen the filter is removed for inspection). Symptoms ofclogged filters vary in different installations, and eachinstallation should be studied for external symptoms,such as abnormal instrument indications and engineoperation. If external indications are not apparent, visualinspection of the element will be necessary, especiallyif it is known or suspected that dirty fuel is being used.

Fuel filter capacity should at least equal fuel supplypump capacity. A filter with a small capacity clogs more

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rapidly than a larger one, because the space available fordirt accumulation is more limited. There are twostandardized sizes of fuel filter elements-large andsmall. The small element is the same diameter as thelarge but is only one-half as long. This constructionpermits substitution of two small elements for one largeelement.

You can increase the interval of time betweenelement changes by using the drain cocks on a filtersump. Removal of dirt through the drain cock will makeroom for more dirt to collect.

If new filter elements are not available forreplacement and the engine must be operated, you canwash some types of totally clogged elements and getlimited additional service. This procedure is foremergencies only. An engine must never be operatedunless all the fuel is filtered; therefore, a “washed filter”is better than none at all.

Fuel must never flow from the supply tanks to thenozzles without passing through all stages of filtration.Strainers, as the primary stage in the fuel filtrationsystem, must be kept in good condition if sufficient fuelis to flow in the system. Most strainers have a blademechanism that can be turned by hand. If you cannotreadily turn the scraper by hand, disassemble and cleanthe strainer. This minor preventive maintenance willprevent the scraping mechanism from breaking.

TRANSFER PUMPS.—If the supply of fuel oil tothe system is to be maintained in an even anduninterrupted flow, the fuel transfer pumps mustfunction properly. These pumps may becomeinoperative or defective to the point that they fail todischarge sufficient fuel for engine starting. Generally,when a pump fails to operate, some parts have to bereplaced or reconditioned. For some types of pump, it iscustomary to replace the entire unit. However, for wornpacking or seals, satisfactory repairs may be made. Ifplunger-type pumps fail to operate because the valveshave become dirty, submerge and clean the pump in abath of diesel oil.

Repairs of fuel transfer pumps should be madeaccording to maintenance manuals supplied by theindividual pump manufacturers.

Malfunctioning of the Injection System

The fuel injection system is the most intricate of thesystems in a diesel engine. Since the function of aninjection system is to deliver fuel to the cylinder at a highpressure, at the proper time, in the proper quantity, and

properly atomized, special care and precautions must betaken in making adjustments and repairs.

HIGH-PRESSURE PUMP.-If a high-pressurepump in a fuel injection system becomes inoperative, anengine may fail to start. Information on the causes andremedies for an inoperative pump can be found in themanufacturer’s technical manual. Any ship using fuelinjection equipment should have available copies of theapplicable manufacturer’s technical manual.

TIMING.-Regardless of the installation or the typeof fuel injection system used, the timing of the injectionsystem must be correct to obtain maximum energy fromthe fuel. Early or late injection timing may prevent anengine from starting. Operation will be uneven andvibration will be greater than usual.

If fuel enters a cylinder too early, detonationgenerally occurs, causing the gas pressure to rise toorapidly before the piston reaches top dead center. Thisin turn causes a loss of power and high combustionpressure. Low exhaust temperature may be an indicationthat fuel injection is too early.

If fuel is injected too late in the engine cycle,overheating, lowered firing pressure, smoky exhaust,high exhaust temperature, or loss of power may occur.

Follow the instructions in the manufacturer’stechnical manual to correct an improperly timedinjection system.

Insufficient Compression

Proper compression pressures are essential if adiesel engine is to operate satisfactorily. Insufficientcompression may cause an engine to fail to start. If yoususpect low pressure as the reason, check thecompression with the appropriate instrument. If the testindicates pressures below standard, disassembly isrequired for complete inspection and correction.

Inoperative Engine Governor

There are many troubles that may cause a governorto become inoperative. The most frequent troubleassociated with starting an engine is generally caused bybound control linkage or, if the governor is hydraulic,by low oil level. Whether the governor is mechanical orhydraulic, binding of linkage is generally due todistorted, misaligned, defective, or dirty parts. If yoususpect binding, move the linkage and governor partsby hand and check their movement. Eliminate anyundue stiffness or sluggishness in the movement of thelinkage.

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Low oil level in hydraulic governors may be causedby oil leaking from the governor or failure to maintainthe proper oil level. Leakage of oil from a governor cangenerally be traced to a faulty oil seal on the drive shaftor power piston rod, or to a poor gasket seal betweenparts of the governor case.

Check the condition of the oil seals if oil must beadded too frequently to governors with independent oilsupplies. Oil seal leakage may or may not be visible onexternal surfaces. There will be no external sign ifleakage occurs through the seal around the drive shaft,while leakage through the seal around the power pistonwill be visible.

Oil seals must be kept clean and pliable. Store themproperly so they do not become dirty or dry and brittle.Leaky oil seals cannot be repaired. They must bereplaced. You can prevent some leakage troubles simplyby following proper installation and storage instructionsfor the seals.

Most manufacturer’s technical manuals supplyinformation on the governor. Special hydraulic governormaintenance manuals made available by the Naval SeaSystems Command are the Marquette GovernorManual, NAVSHIPS 341-5505 (0341-LP-550-5000),and the Woodward Governor Manual, NAVSHIPS341-5017 (0341-LP-501-7000).

Inoperative Overspeed Safety Devices

Overspeed safety devices are designed to shut offfuel or air in case of excessive engine speed. Thesedevices must be maintained in operable condition at alltimes. Inoperative overspeed devices may also cause anengine not to start. They may be inoperative because ofimproper adjustment, faulty linkage, or a broken spring,or the overspeed device may have been accidentallytripped during the attempt to start the engine.

If the overspeed device fails to operate when theengine overspeeds, the engine may be secured bymanually cutting off the fuel oil or the air supply to theengine. Most engines have special devices or valves tocut off the air or fuel in an emergency.

Insufficient Cranking Speed

If the engine cranks slowly, the necessarycompression temperature cannot be reached. Lowstarting air pressure may be the cause of such trouble.

Slow cranking speed may also be the result of anincrease in the viscosity of the lubricating oil. Thistrouble occurs during periods when the air temperature

is lower than usual. The oil specified for use duringnormal operation and temperature is not generallysuitable for cold climate operation.

IRREGULAR ENGINE OPERATION

As the engine operator, you must constantly be alertto detect any symptoms that might indicate trouble. Suchsymptoms may be sudden or abnormal changes in thesupply, temperature, or pressure of the lubricating oil orcooling water. Color and temperature of the exhaust mayalso indicate abnormal conditions. Check themfrequently. Fuel, oil, and water leaks indicate possibletroubles. Keep the engine clean to make such leakseasier to spot.

You will soon become accustomed to the normalsounds and vibrations of a properly operating engine. Ifyou are alert, an abnormal or unexpected change in thepitch or tone of an engine’s noise or a change in themagnitude or frequency of a vibration will warn you thatall is not well. A new sound such as a knock a drop inthe fuel injection pressure, or a misfiring cylinder areother trouble warnings for which you should beconstantly alert during engine operation.

The following discussion on possible troubles, theircauses, and the corrective action necessary is generalrather than specific. The information is based oninstructions for some of the engines used by the Navyand is typical of most. A few troubles listed may applyto only one model. For specific information on anyparticular engine, consult the manufacturer’s technicalmanual.

ENGINE STALLS FREQUENTLY OR STOPSSUDDENLY

We discussed earlier several of the troubles that maycause an engine to stall or stop. Such troubles as air inthe fuel system, clogged fuel filters, unsatisfactoryoperation of fuel injection equipment, and incorrectgovernor action not only cause starting failures orstalling but also cause other troubles as well. Forexample, clogged fuel oil filters and strainers may leadto a loss of power, to misfires or erratic firing, or to lowfuel oil pressure. Unfortunately, a single engine troubledoes not always manifest itself as a single difficulty butmay be the cause of several major difficulties.

Factors that may cause an engine to stall includemisfiring, low cooling water temperature, improperapplication of load, improper timing, obstruction in thecombustion space or in the exhaust system, insufficient

3-30

intake air, piston seizure, and defective auxiliary drivemechanisms.

Misfiring

When an engine misfires or fires erratically or whenone cylinder misfires regularly, the possible troubles areusually associated with the fuel or fuel system, wornparts, or the air cleaner or silencer. In determining whatcauses a cylinder to misfire, you should followprescribed procedures in the appropriate technicalmanual. Procedures will vary among engines because ofdifferences in the design of parts and equipment.

Many of the troubles caused by fuel contaminationrequire overhaul and repair. However, a cylinder maymisfire regularly in some systems because of the fuelpump cutout mechanism. Some fuel pumps have thistype of mechanism so the fuel supply can be cut off froma cylinder to measure compression pressures. When acylinder is misfiring, check first for an engaged cutoutmechanism (if installed), and disengage it during normalengine operation.

LOSS OF COMPRESSION.–A cylinder maymisfire due to loss of compression, which may be causedby a leaking cylinder head gasket, leaking or stickingcylinder valves, worn pistons, liners or rings, or acracked cylinder head or block If loss of compressionpressure causes an engine to misfire, check thecompression pressure of each cylinder. Some indicatorsmeasure compression as well as firing pressure whilethe engine is running at full speed. Others check onlythe compression pressures with the engine running at arelatively slow speed. Figure 3-38 illustrates theapplication of some different types of pressureindicators.

After you install an indicator, operate the engine atthe specified rpm and record the cylinder compressionpressure. Follow this procedure on each cylinder in turn.The pressure in any one cylinder should not be lowerthan the specified psi, nor should the pressure for anyone cylinder be excessively lower than the pressures inthe other cylinders. The maximum pressure variationpermitted between cylinders is given on engine datasheets or in the manufacturer’s technical manual. Acompression leak is indicated when the pressure in onecylinder is considerably lower than that in the othercylinders.

If a test indicates a compression leak, you will haveto do some disassembly, inspection, and repair. Checkthe valve seats and cylinder head gaskets for leaks, andinspect the valve stems for sticking. A cylinder head or

block may be cracked. If these parts are not the sourceof trouble, compression is probably leaking past thepiston because of insufficient sealing of the piston rings.

Improper Cooling Water Temperature

If an engine is to operate properly, the cooling watertemperature must be maintained within specifiedtemperature limits. When cooling water temperaturedrops lower than recommended for a diesel engine,

Figure 3-38.–Engine cylinder pressure indicator application.

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ignition lag is increased, causing detonation, whichresults in rough operation. This may cause the engine tostall.

If the water temperature is higher than normal, theengine may not cool properly and may suffer heatdamage. Water temperature is controlled primarily by athermostatic valve (thermostat). The thermostatnormally operates with a minimum of trouble. High orlow cooling water temperature may indicate amalfunctioning thermostat. But before you remove thethermostat to check it, check to see whether the impropertemperature may be caused by an insufficient engineload or an inaccurate temperature gauge.

When you suspect that the thermostat is notoperating properly, remove it from the engine and testit. Use the following procedure to test the thermostat:

1. Obtain an open-topped container such as abucket or a pot.

2. Heat the water to the temperature at which thethermostat is supposed to start opening. Thistemperature is usually specified in the appropriatetechnical manual. Use an accurate thermometer to checkthe water temperature. Use a hot plate or a burner as asource of heat. Stir the water frequently to ensureuniform distribution of the heat.

3. Suspend the thermostat by a string or a wire sothat operation of the bellows will not be restricted.

4. Immerse the thermostat and observe its action.Check the thermometer readings carefully to seewhether the thermostat begins to open at therecommended temperature. (The thermostat andthermometer must NOT touch the container.)

5. Increase the temperature of the water until thespecified FULL OPEN temperature is reached. Theimmersed thermostat should be fully open at thistemperature.

Replace the thermostat if it does not open when youtest it, or if the temperatures at which the thermostatopens and closes vary more than allowed from themanufacturer’s specifications.

The Fulton-Sylphon automatic temperatureregulator is relatively trouble-free. The unit controlstemperatures by a valve that bypasses some wateraround the cooler. This system provides a full flow ofthe water, although only a portion may be cooled. Inother words, the full volume of cooling water iscirculated at the proper velocity, which eliminates thepossibility of steam pockets in the system.

Usually, if the automatic temperature regulator failsto maintain cooling water at the proper temperature, itsimply needs to be readjusted. However, the element ofthe valve may be leaking or some part of the valve maybe defective. Failure to follow the proper adjustmentprocedure is the only cause for improper adjustment ofan automatic temperature regulator. Check and followthe proper procedure in the manufacturer’s technicalmanual issued for the specific equipment.

Adjust the regulator by changing the tension of thespring (which opposes the action of the thermostaticbellows) with a special tool that turns the adjusting stemknob or wheel. Increasing the spring tension raises thetemperature range of the regulator, and decreasing itlowers the temperature range.

When you place a new valve of this type intoservice, you must take a number of steps to ensure thatthe valve stem is the proper length and that all scalepointers make accurate indications. Make alladjustments according to the valve manufacturer’stechnical manual.

Obstruction in the Exhaust System

This type of trouble seldom occurs if properinstallation and maintenance procedures are followed.When a part of an engine exhaust system is restricted,there will be an increase in the exhaust back pressure.This may cause high exhaust temperatures, loss ofpower, or even stalling. An obstruction that causesexcessive back pressure in an exhaust system isgenerally associated with the silencer or muffler.

The manifolds of an exhaust system are relativelytrouble-free if related equipment is designed andinstalled properly. Improper design or installation maycause water to back up into the exhaust manifold. Insome installations, the design of the silencer may causewater to flow into the engine. The source of water thatmay enter an engine must be found and eliminated. Thismay require replacing some parts of the exhaust systemwith components of an improved design or may requirerelocating such items as the silencer and piping.

Inspect exhaust manifolds for water or symptoms ofwater. Accumulation of salt or scale in the manifoldusually indicates that water has been entering from thesilencer. Turbochargers on some engines have beenknown to seize because salt water entered the exhaustgas turhine from the silencer. Entry of water into anengine may also be detected by the presence of corrosionor of salt deposits on the engine exhaust valves.

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If inspection reveals signs of water in an engine orin the exhaust manifold, take steps immediately tocorrect the trouble. Check the unit for properinstallation. Wet-type silencers must be installed withthe proper sizes of piping. If the inlet water piping is toolarge, too much water may be injected into the silencer.There must be continuous-type water drains on thesilencer. If a silencer has no continuous drain and if theengine is at a lower level than the exhaust outlet, watermay back up into the engine.

Dry-type silencers may become clogged with anexcessive accumulation of oil or soot. When this occurs,exhaust back pressure increases, causing troubles suchas high exhaust temperature, loss of power, or possiblestalling. A dry-type silencer clogged with oil or soot isalso subject to fire. Clogging can usually be detected byfire, soot, or sparks coming from the exhaust stack Anexcessive accumulation of oil or soot in a dry-typesilencer may be due to a number of factors, such asfailure to drain the silencer, poor condition of the engine,or improper engine operating conditions.

Insufficient Intake Air

Insufficient intake air, which may cause an engineto stall or stop, may be due to blower failure or to aclogged air silencer or air filter. Even though all otherengine parts function perfectly, efficient engineoperation is impossible if the air intake system fails tosupply a sufficient quantity of air for completecombustion of the fuel.

CLOGGED AIR CLEANERS AND SILEN-CERS.—Sometimes an engine will fire erratically ormisfire because of a clogged air cleaner or silencer. Aircleaners must be cleaned at specified intervals, asrecommended in the engine manufacturer’s technicalmanuals. A clogged cleaner reduces the intake air,thereby affecting the operation of the engine. Cloggedair cleaners may cause not only misfiring or erratic firingbut also such difficulties as hard starting, loss of power,engine smoke, and overheating.

When you clean an air cleaner element, if you use avolatile solvent, be SURE the element is dry before youreinstall it on the engine. Volatile solvents are excellentcleaning agents but, if permitted to remain in the filter,may cause engine overspeeding or a serious explosion.

Oil-bath type air cleaners and filters cause very littletrouble if serviced properly. Cleaning directions areusually given on the cleaner housing. The frequency ofcleaning is usually based on a specified number of

operating hours, but more frequent cleaning may benecessary where unfavorable conditions exist.

When you fill an oil bath-type cleaner, follow themanufacturer’s instructions. Most air cleaners of thistype have a FULL mark on the oil reservoir. Fillingbeyond this mark does not increase the efficiency of theunit and may lead to serious trouble. When the oil bathis too full, the intake air may draw oil into the cylinders.This excess oil-air mixture, over which there is nocontrol, may cause an engine to “run away,” resulting inserious damage.

BLOWER FAILURE.—Troubles that may preventa centrifugal blower from performing its functionusually involve damage to the rotor shaft, thrustbearings, turbine blading, nozzle ring, or blowerimpeller. Damage to the rotor shaft and thrust bearingsusually results from insufficient lubrication, anunbalanced rotor, or operation with excessive exhausttemperature.

Centrifugal blower lubrication problems may becaused by failure of the oil pump to prime, low lube oillevel, clogged oil passages or oil filter, or a defectiverelief valve, which is designed to maintain proper lubeoil pressure.

If an unbalanced rotor is the cause of shaft or bearingtrouble, there will be excessive vibration. Unbalancemay be caused by a damaged turbine wheel blading orby a damaged blower impeller.

Operating a blower when the exhaust temperatureis above the specified maximum safe temperaturegenerally causes severe damage to turbochargerbearings and other parts. Make every effort to find andeliminate causes of excessive exhaust temperaturebefore the turbocharger is damaged.

Turbine blading damage may be caused byoperating with an excessive exhaust temperature,operating at excessive speeds, bearing failures, failureto drain the turbine casing, the entrance of foreignbodies, or by turbine blades that break loose.

Damage to an impeller may be caused by thrust orshaft bearing failure, entrance of foreign bodies, orloosening of the impeller on the shaft.

Since blowers are high-speed units and operate witha very small clearance between parts, minor damage toa part could cause extensive blower damage and failure.

Although there is considerable difference inoperating principle and construction between thepositive-displacement blower (Roots) and the

3-33

axial-f low posit ive-displacement blower(Hamilton-Whitfield), the problems of operation andmaintenance are similar.

Some of the troubles in a positive-displacementblower are similar to those already mentioned in ourdiscussion of the centrifugal-type blowers. However,the source of some troubles may be different because ofconstruction differences.

Positive-displacement blowers have a set of gearsto drive and synchronize the rotation of the rotors. Manyof these blowers are driven by a serrated shaft.Regardless of construction differences, the basicproblem in both types of blowers is in maintaining thenecessary small clearances. If these clearances are notmaintained, the rotors and the case will be damaged andthe blower will fail to perform its function.

Worn gears are one source of t rouble inpositive-displacement blowers. A certain amount of gearwear is expected, but damage caused by excessivelyworn gears indicates improper maintenance procedures.Whenever you inspect a positive-displacement blower,record the backlash values, according to PMS. You can

use this record to establish the rate of increase in wear,to estimate the life of the gears, and to determine whenit will be necessary to replace the gears.

Scored rotor lobes and casing may cause blowerfailure. Scoring of blower parts may be caused by worngears, improper timing, bearing failure, improper endclearance, or by foreign matter. Any of these troublesmay be serious enough to cause the rotors to contact anddamage the blower extensively.

Timing of blower rotors involves both gear backlashand the clearances between the leading and trailingedges of the rotor lobes and between rotor lobes and thecasing. You can measure the clearance between theseparts with thickness gauges, as illustrated in figure 3-39.If the clearances are incorrect, check the backlash of thedrive gear first. Then retime the rotors according to themethod outlined in the manufacturer’s technicalmanual.

Failure of serrated blower shafts may be due tofailure to inspect the parts or of improper replacementof parts. When you inspect serrated shafts, be sure thatthey fit snugly and that wear is not excessive. When

Figure 3-39.—Checking clearances of positive-displacement blower lobes.

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serrations of either the shaft or the hub have failed forany reason, replace both parts.

Obstruction in the Combustion Space

Such items as broken valve heads and valve stemlocks or keepers that come loose because of a brokenvalve spring may cause an engine to come to an abruptstop. If an engine continues to run when suchobstructions are in the combustion chamber, the piston,liner, head, and injection nozzle will be severelydamaged.

Piston Seizure

Piston seizure may also cause an engine to stopsuddenly. The piston becomes galled and scuffed. Whenthis occurs, the piston may possibly break or extensivedamage may be done to other major engine parts. Theprincipal causes of piston seizure are insufficientclearance, excessive temperatures, or inadequatelubrication.

Defective Auxiliary Drive Mechanisms

Defects in auxiliary drive mechanisms may causean engine to stop suddenly. Since most troubles in geartrains or chain drives require some disassembly, thisdiscussion will be limited to the causes of such troubles.

Gear failure is the principal trouble in gear trains.Engine failure and extensive damage can occur becauseof a broken or chipped gear. If you hear a metallicclicking noise in the vicinity of a gear housing, it isalmost a certain indication that a gear tooth has broken.

Gears are most likely to fail because of improperlubrication, corrosion, misalignment, torsionalvibration, excessive backlash, wiped bearings andbushings, me ta l obs t ruc t ions , o r impropermanufacturing procedures.

Gear shafts, bushings and bearings, and gear teethmust be checked during periodic inspections for scoring,wear, and pitting. All oil passages, jets, and spraysshould be cleaned to ensure proper oil flow. Allgear-locking devices must fit tightly to preventlongitudinal gear movement.

Chains are used in some engines for camshaft andauxiliary drives; in other engines, chains are used todrive certain auxiliary rotating parts. Troubles in chaindrives are usually caused by wear or breakage. Troublesof this nature may be caused by improper chain tension,lack of lubrication, sheared cotter pins, or misalignment.

Figure 3-40 is a summary of the possible troublesthat may cause an engine to stall frequently or stopsuddenly. There may be some doubt as to the differencebetween stalling and stopping. In reality, there is noneunless we associate certain troubles with each. Ingeneral, troubles that cause FREQUENT STALLINGare those that can be eliminated with minor adjustmentsor maintenance. If such troubles are not eliminated, it isquite possible that the engine can be started, only to stallagain. Failure to eliminate some of the troubles thatcause frequent stalling may lead to troubles that causeSUDDEN STOPPING.

ENGINE WILL NOT CARRY A LOAD

Many of the troubles that can lead to loss of powerin an engine may also cause the engine to stop and stallsuddenly or may even prevent it from starting. Comparethe list of some of the troubles that may cause a powerloss (fig. 3-41) with those in figures 3-36 and 3-40. Suchitems as insufficient air, insufficient fuel, and faultyoperation of the governor appear on all three charts.Many of the troubles listed are closely related, and theelimination of one may eliminate others.

The operator of an internal-combustion engine maybe confronted with additional major difficulties, such asthose indicated in figure 3-42. Here, again, you can seethat many of these possible troubles are similar to thosethat have already been discussed in connection withstarting failures and with engine stalling and stopping.The discussion that follows covers only those troublesnot previously considered.

ENGINE OVERSPEEDS

When an engine overspeeds, the trouble is usuallycaused by either the governor mechanism or the fuelcontrol linkage, as previously discussed When you needinformation on a specific fuel system or speed controlsystem, check the manufacturer’s technical manual andthe special technical manuals for the particular system.These special manuals are available for the most widelyused models of hydraulic governors and overspeed trips,and they contain specific details on testing, adjusting,and repairing each controlling device.

ENGINE HUNTS OR WILL NOT STOP

Some troubles that may cause an engine to hunt, orvary its rpm at constant throttle setting, are similar tothose that may cause an engine to resist stopping.Generally, these two forms of irregular engine operation

3-35

Figure 3-40.—Possible troubles that may cause an engine to stall frequently or to stop suddenly.

are caused by troubles originating in the speed control

system and the fuel system.

Speed Control System

The speed control system of an internal-combustion

engine includes those parts designed to maintain the

engine speed at some exact value or between desired

limits, regardless of changes in the load on the engine.

Governors are provided to regulate fuel injection so thespeed of the engine can be controlled as the load is

applied. Governors also prevent overspeeding as may

happen in rough seas when the load is suddenly reduced

as the propellers leave the water.

Fuel Control Racks

Fuel control racks that have become sticky orjammed may cause governing difficulties. If the controlrack of a fuel system is not functioning properly, theengine speed may increase as the load is removed, theengine may hunt continuously, or it may hunt only whenthe load is changed. A sticky or jammed control rackmay prevent the engine from responding to changes inthrottle setting and may even prevent it from stopping.Any such condition could be serious in an emergencysituation. Your job is to make every effort possible toprevent such conditions from occurring.

You can check for a sticky rack by stopping theengine, disconnecting the linkage to the governor, andthen attempting to move the rack by hand. There should

3-36

Figure 3-41.—Possible causes of insufficient power in an engine.

be no apparent resistance to the motion of the rack if thereturn springs and linkage are disconnected. A stuckcontrol rack may be caused by the plunger’s sticking inthe pump barrel; dirt in the rack mechanism; damage tothe rack, sleeve, or gear; or improper assembly of theinjector pump.

If the rack sticks or jams, you must determine thecause and replace any damaged parts. If sticking is dueto dirt, thoroughly clean all the parts to correct thetrouble. You can avoid errors in assembly by carefullystudying the assembly drawings and instructions.

Leakage of Fuel Oil

Leakage of fuel oil from the injectors may cause anengine to continue to operate when you attempt to shutit down. Regardless of the type of fuel system, the resultsof internal leakage from injection equipment are, in

general, somewhat the same. Injector leakage will causeunsatisfactory engine operation because of theexcessive amount of fuel entering the cylinder. Leakagemay also cause detonation, crankcase dilution, smokyexhaust, loss of power, and excessive carbon formationon the spray tips of nozzles and other surfaces of thecombustion chamber.

Accumulation of Lube Oil

Another trouble that may prevent you from stoppingan engine is accumulation of lube oil in the intake airpassages-manifold or air box. Such an accumulationcreates an extremely dangerous condition. You candetect excess oil by removing the inspection plates onthe covers and examining the air box and manifold. Ifyou discover oil, remove it and perform the necessary

3-37

Figure 3-42.

3-38

corrective maintenance. If oil is drawn suddenly in largequantities from the manifold or air box into the cylinderof the engine and burns, the engine may run away. Theengine governor has no control over the sudden increasein speed.

An air box or air manifold explosion is also apossibility if excess oil is allowed to accumulate. Someengine manufacturers have provided safety devices toreduce the hazards of such explosions.

Excess oil in the air box or manifold of an enginealso increases the tendency of carbon to form on linerports, cylinder valves, and other parts of the combustionchamber.

The causes of excessive lube oil accumulation in theair box or manifold will vary depending on the specificengine. Generally, the accumulation is due to anobstruction in either the air box or separator drains.

In an effort to reduce the possibility of crankcaseexplosions and runaways, some engine manufacturershave designed a means to ventilate the crankcase. Insome engines, a passage between the crankcase and theintake side of the blower provides ventilation. In otherengines, an oil separator or air maze in the passagebetween the crankcase and blower intake providesventilation.

In either type of installation, stopped up drains willcause an excessive accumulation of oil. Drain passagesmust be kept open by proper cleaning whenevernecessary.

Oil may enter the air box or manifold from sourcesother than crankcase vapors. A defective blower oil seal,a carryover from an oil-type air cleaner, or defective oilpiping may be the source of trouble.

Another possible source may be an excessively highoil level in the crankcase. Under this condition, an oilfog is created in some engines by the moving parts. Anoil fog may also be caused by excessive clearance in theconnecting rod and main journal bearings. In some typesof crankcase ventilating systems, the oil fog will bedrawn into the blower. When this occurs, an abnormalamount of oil may accumulate in the air box. Removalof the oil will not remove the trouble. The cause of theaccumulation must be determined and the necessaryrepair made.

If a blower oil seal is defective, replacement is theonly satisfactory method of correction. When you installnew seals, be sure the shafts are not scored and thebearings are in satisfactory condition. Take specialprecautions during the installation to avoid damaging

the oil seals. Damage to an oil seal during installation isusually not discovered until the blower has beenreinstalled and the engine has been put into operation.Be sure an oil seal gets the necessary lubrication. Theoil not only lubricates the seal, reducing friction, but alsocarries away any heat that is generated. For mostpurposes, soak new oil seals in clean, light lube oilbefore you install them.

CYLINDER SAFETY VALVES

On some engines, a cylinder relief (safety valve) isprovided for each cylinder. The valve opens when thecylinder pressure exceeds a safe operating limit. Thevalve opens or closes a passage leading from thecombustion chamber to the outside of the cylinder. Thevalve face is held against the valve seat by springpressure. Tension on the spring is varied by an adjustingnut, which is locked when the desired setting is attained.The desired setting varies with the type of engine andmay be found in the manufacturer’s technical manual.

Cylinder relief valves should be set at the specifiedlifting pressure. Continual lifting (popping) of thevalves indicates excessive cylinder pressure ormalfunction of the valves, either of which should becorrected immediately. Repeated lifting of a relief valveindicates that the engine is being overloaded, the load isbeing applied improperly, or the engine is too cold. Also,repeated lifting may indicate that the valve spring hasbecome weakened, ignition or fuel injection is occurringtoo early, the injector is sticking and leaking, too muchfuel is being supplied, or, in air injection engines, thespray valve air pressure is too high. When frequentpopping occurs, stop the engine and determine andremedy the cause of the trouble. In an emergency, cutoff the fuel supply in the affected cylinder. NEVER lockrelief valves closed, except in an emergency. When youmust take emergency measures, be sure to repair orreplace the valves, as necessary, as soon as possible.

When excessive fuel is the cause of frequent safetyvalve lifting, the trouble may be due to the improperfunctioning of a high-pressure injection pump, a leakynozzle or spray valve, or a loose fuel cam (if adjustable).In some systems, such as the common rail, the fuelpressure may be too high.

A safety valve that is not operating properly shouldbe removed, disassembled, cleaned, and inspected.Check the valve and valve seat for pitting and excessivewear and the vale spring for possible defectiveconditions. When you remove a safety valve for anyreason, you must reset the spring tension. This

3-39

procedure varies to some extent, depending on the valveconstruction.

Except in emergencies, it is advisable to shut theengine down when troubles cause safety valve popping.

Clogged or partially obstructed exhaust ports mayalso cause the cylinder safety valve to lift. This conditionwill not occur often if proper planned maintenanceprocedures are followed. If it does occur, the resultingincrease in cylinder pressure may be enough to causesafety valve popping. Clogged exhaust ports will alsocause overheating of the engine, high exhausttemperatures, and sluggish engine operation.

You can prevent clogged cylinder ports by removingcarbon deposits at prescribed intervals. Some enginemanufacturers make special tools for port cleaning.Round wire brushes of the proper size are satisfactoryfor this work You must be careful in cleaning cylinderports to prevent carbon from entering the cylinder-barthe engine to such a position that the piston blocks theport.

SYMPTOMS OF ENGINE TROUBLE

In learning to recognize the symptoms that may helplocate the causes of engine trouble, you will find thatexperience is the best teacher. Even though writteninstructions are essential for efficient troubleshooting,the information usually given serves only as a guide. Itis very difficult to describe the sensation that you shouldfeel when checking the temperature of a bearing byhand; the specific color of exhaust smoke when pistonsand rings are worn excessively; and, for some engines,the sound that you will hear if the crankshaftcounterweights come loose. You must actually workwith the equipment to associate a particular symptomwith a particular trouble. Written information, however,can save you a great deal of time and eliminate muchunnecessary work. Written instructions will makedetection of troubles much easier in practical situations.

A symptom that indicates that trouble exists may bein the form of an unusual noise or instrument indication,smoke, or excessive consumption or contamination ofthe lube oil, fuel, or water. Figure 3-43 is a general listingof various trouble symptoms that you may encounter.

NOISES

The unusual noises that may indicate that troubleexists or is impending may be classified as pounding,knocking, clicking, and rattling. Each type of noise must

be associated with certain engine parts or systems thatmight be the source of trouble.

Pounding or hammering is a mechanical knock (notto be confused with a fuel knock). It may be caused bya loose, excessively worn, or broken engine part. Gen-erally, troubles of this nature will require major repairs.

Detonation (knocking) is caused by the presence offuel or lubricating oil in the air charge of the cylindersduring the compression stroke. Excessive pressuresaccompany detonation. If detonation is occurring in oneor more cylinders, stop the engine immediately toprevent possible damage.

Clicking noises are generally associated with animproperly functioning valve mechanism or timinggear. If the cylinder or valve mechanism is the source ofmetallic clicking, the trouble may be due to a loose valvestem and guide, insufficient or excessive valve tappetclearances, a loose cam follower or guide, broken valvesprings, or a valve that is stuck open. A clicking in thetiming gear usually indicates that there are somedamaged or broken gear teeth.

Rattling noises are generally due to vibration ofloose engine parts. However, an improperly functioningvibration damper, a failed antifriction bearing, or agear-type pump operating without prime are alsopossible sources of rattling noises.

When you hear a noise, first make sure it is a troublesymptom. Each diesel engine has a characteristic noiseat any specific speed and load. The noise will changewith a change in speed or load. As an operator, you mustbecome familiar with the normal sounds of the engine.Investigate all abnormal sounds promptly. Knocks thatindicate a trouble may be detected and located by specialinstruments or by the use of a “sounding bar,” such as asolid iron screwdriver or bar.

INSTRUMENT INDICATIONS

As an engine operator, you will probably rely moreon the instruments to warn you of impending troublesthan on all the other trouble symptoms combined.Regardless of the type of instrument being used, theindications are of no value if the instrument isinaccurate. Be sure an instrument is accurate andoperating properly before you accept a low or highreading. Test all instruments at specified intervals orwhenever you suspect them of being inaccurate.

3-40

SMOKE

Smoke can be quite useful as an aid in locating sometypes of trouble, especially if used in conjunction withother trouble symptoms.

The color of exhaust smoke, a good indication ofengine performance, can also be used as a guide introubleshooting. The exhaust of an efficiently operating

engine has little or no color. A dark, smoky exhaustindicates incomplete combustion; the darker the color,the greater the amount of unburned fuel in the exhaust.Incomplete combustion may be due to a number oftroubles. Some manufacturers associate a particulartype of trouble with the color of the exhaust. The moreserious troubles are generally identified with eitherblack or bluish-white exhaust colors.

NOISESINSTRUMENT INDICATIONS CONTAMINATIOF

PRESSURESMOKE

TEMPERATURE SPEED OF LUBE OIL,FUEL, OR WATER

Pounding(mechanical)

Knocking(detonation)

Clicking(metalIic)

Rattling

Low lube oil Low lube oil Idling speed not Black exhaust Fuel oil in thepressure temperature normal smoke lube oil

High lube oil High lube oil Maximum speed Bluish-white Water in the lubepressure temperature not normal exhaust smoke oil

Low fuel oil Low cooling Smoke arising Oil or grease inpressure (in water tempera- from crankcase the waterlow-pressure fuel ture (fresh) Water in the fuelsupply system) oil

Low cooling High cooling Smoke arising Air or gas in the

water pressure water tempera- from cylinder water

(fresh) ture (fresh) head Smoke Metal particles

from engine in lube oil

auxiliary equipment (blowers,pumps, etc.)

Low cooling Low cylinder ex-water pressure haust temperature(salt)

High cooling High exhaustwater pressure temperature in(salt) one cylinder

Low compres-sion pressure

Low firingpressure

High firingpressure

Low scavengingair receiver pres-sure (super-charge engine)

High exhaustback pressure

Figure 3-43.—Symptoms of engine troubles.

3-41

Figure 3-44.

3-42

EXCESSIVE CONSUMPTION OF LUBEOIL, FUEL, OR WATER

You should suspect engine trouble wheneverexcessive consumption of any of the essential liquidsoccurs. The possible troubles indicated by excessiveconsumption will depend on the system in question.Leakage, however, is one trouble that may be commonto all. Before you start any disassembly, check for leaksin the system in which excessive consumption occurs.

TROUBLESHOOTING GASOLINEENGINES

The troubleshooting procedures used for a marinegasoline engine are, in many ways, similar to those fora diesel engine. The two types of engines are quitesimilar with two exceptions, the manner of getting fueland air into the cylinders and the method of ignition.

This section deals primarily with the systems thatdiffer in the gasoline and diesel engines. In addition,troubleshooting information is given on the electricalsystems.

Even though most electrical maintenance and repairis the responsibility of an Electrician’s Mate, you, as anEngineman, can reduce the amount of electrical troublesby following the correct operating procedures. Mostelectrical system troubles develop from improper use,care, or maintenance.

The following information will help you detectelectrical troubles and take corrective action.

When a gasoline engine fails to start, one of threeconditions exists. The engine is not free to turn, thestarter does not crank the engine, or the engine cranksbut does not start. Figure 3-44 lists many of theconditions and sources of such difficulties,

If the engine will not turn over, some part isprobably seized In this case you should make a throughinspection, which may necessarily include somedisassembly.

STARTER DOES NOT RUN

If the starter fails to turn, the trouble can usually betraced to the battery, connections, switch, or startermotor.

Symptoms of battery trouble generally occur beforethe charge gets too low to perform the required workBattery failure is normally preceded by a gradual declinein the strength of the battery charge. A dead battery may

be the result of insufficient charging, damaged plates, orimproper starting technique.

The generator, used to maintain the charge of thestarting battery, may become defective. The normalsymptoms are a low battery charge when the engine isstarted and a zero or low ammeter reading when theengine is running.

The battery must be in good condition to ensure theproper operation of the ignition system. A starter drawsa heavy current from the best of batteries. When thebattery is weak, it will be unable to operate the ignitionsystem satisfactorily for starting because the heavystarting current will drop the voltage to an extremely lowvalue.

NOTE: Keep flames and sparks of all kinds awayfrom the vicinity of storage batteries. A certain amountof hydrogen gas is given off from a battery at all times.In confined spaces this gas can form a dangerousexplosive mixture.

When you use tools around a battery, be careful notto short circuit the battery terminals. Never use a tool ormetal object to make a so-called test of a storage battery.

Keep batteries in exposed locations subject to lowtemperatures fully charged during cold weather. Inextreme cold weather, remove storage batteries andplace them in a warm compartment, if possible.

Electrical connections are another possible sourceof trouble if the starter does not turn. All connectionsmust be tight and free from corrosion to providemaximum voltage and amperage from the battery.Battery terminals, since they are more vulnerable tocorrosion, looseness, and burning, are the principalsources of trouble.

Burned battery terminals may be caused by a looseconnection, a corroded terminal, or a short circuit.Burning of terminals usually occurs when an engine isbeing started Burning may be indicated by such thingsas smoke, a flash, or a spattering of molten metal in thevicinity of the battery. Usually, the starting motor willcease to turn after these symptoms appear.

Switches, electrical relays, or contactors that aredefective or inoperative may be the reason a starter willnot turn. Contactors, being subject to extremely highcurrent, must be maintained in the best possiblecondition. Starting contactors are either manually ormagnetically operated and are designed to be operatedfor only short periods of time.

3-43

Starter motor troubles can be traced for the most partto the commutator, brushes, or insulation. If motors areto function properly, they must be kept clean and dry.Dirt and moisture make good commutation impossible.Dirty and fouled starter motors may be caused by failureto replace the cover band, by water leakage, or by excesslubrication.

Most starter motors have a cover to protect thecommutator and windings. If you neglect to replace thecover or remove it as an aid to ventilation and cooling,dirt and water are sure to damage the equipment.

Although lubrication of bearings is essential forproper operation, excessive lubrication may lead totrouble in a starter motor. Excess lubricant in the shaftbearings may leak or be forced past the seal and foul theinsulating material, commutator, and brushes. Thelubricant prevents a good electrical contact between thebrushes and the commutator, causing the commutator tospark and heat and the brushes to burn.

Burned brushes are another possible source oftrouble if the starter motor is inoperative. Burning maybe caused by loose brush holders, improper brush springtension, a brush stuck in the holder, a dirty commutator,improper brush seating surface, or overloading thestarter.

STARTER MOTOR OPERATES BUT DOESNOT CRANK ENGINE

If the starter motor and battery are in good operatingcondition but the starter fails to crank the engine, thetrouble will usually be in the drive connection betweenthe motor and the ring gear on the flywheel. Troubles inthe drive assembly are usually in the form of brokenparts or a slipping clutch (if applicable). A slippingclutch may be the result of the engine not being free toturn or of the clutch not holding up to its rated capacity.

Even though seldom encountered, a stripped ringgear on the flywheel may be the source of trouble if thestarter motor does not turn the engine.

ENGINE CRANKS BUT FAILS TO START

Starting troubles and their causes and correctionsmay vary to some degree, depending on the particularengine. If the prescribed prestarting and startingprocedures are followed and a gasoline engine fails tostart, the source of trouble will probably be improperpriming or choking, a lack of fuel at various points inthe system, or a lack of spark at the spark plugs.

Improper priming may be either underpriming oroverpriming. Priming instructions differ, depending onthe engine. Information on priming also applies toengines equipped with chokes. A warm engine shouldnever be primed. Some engines may require no primingexcept when they are started under cold weatherconditions.

On some installations, underpriming can bechecked by the feel of the primer pump as it is operatedOn other installations, underpriming may be due toinsufficient use of the choke.

Over-priming is undesirable because it results in aflooded engine and makes starting difficult. It alsocauses excess gasoline to condense in the intakemanifolds, run down into the cylinders, wash away thelubricating oil film, and cause pistons or rings to stick

You can determine flooding by removing andinspecting a spark plug. A wet plug indicates flooding.If you find the engine to be flooded, be sure to dry outor deflood it according to prescribed instructions. Someinstallations specify that the ignition switch must be ON,while others state the switch must be OFF; therefore itis important for you to follow the engine manufacturer’sinstructions.

Improper carburetion may be the source of troubleif a gasoline engine fails to start. On some engines acheck of the fuel pressure gauge will indicate whetherlack of fuel is the cause. If the gauge shows theprescribed pressure, the trouble is not lack of fuel; if thegauge shows little or no fuel pressure, you should checkthe various parts of the delivery system to locate thefault.

In some installations, you can determine whetherthe trouble is in the gauge or in the fuel system by usingthe following procedure: (1) remove the carburetor plugnext to the fuel pressure gauge connection; and (2) usea suitable container to catch the gasoline, and operatethe pump used to build up starting fuel pressure. If fuelis reaching the carburetor, gasoline will spurt out of theopen plug hole; this indicates that the gauge isinoperative. If no fuel flows from the plug opening, thetrouble is probably in the fuel system somewherebetween the fuel tank and carburetor. Even though allinstallations do not have a fuel pressure gauge, theprocedure for checking the fuel system is much thesame.

If a wobble pump is installed to build up starting fuelpressure, you can determine whether the pump isoperating correctly by the feel and sound of the pump.If the pump feels or sounds dry, the trouble is between

3-44

the pump and the supply tanks. The trouble might becaused by a clogged fuel line strainer or by an air leakin the line. If the wobble pump is pumping, the troublemay be in the line to the engine fuel pump or in theengine fuel pump itself.

Check the fuel lines for cracks, dents, looseconnections, sharpbends, andclogging. You can removethe fuel line at the pump and use air to determine if theline is open.

Check fuel pumps for leaks at the pump gaskets orin the fuel line connections. Check fuel pump filters orsediment bowl screens for restrictions. Check the bypassfor operation. If the bypass valve is defective, replacethe fuel pump. In diaphragm-type fuel pumps, the filterbowl gasket, the diaphragm, or the valves may be thesource of trouble. Check for air leaks in the diaphragmby submerging the discharge end of the fuel line ingasoline and looking for air bubbles while cranking theengine. If the engine will run, a leaky diaphragm isindicated by gasoline leakage from the pump air vent.

Carburetor trouble may be the cause if fuel does notreach the cylinders. You can check this by removing thespark plugs and looking for moisture. If there is no traceof gasoline on the plugs, the carburetor may be out ofadjustment, the float level may be too low, or the jetsmay be clogged. If the fuel level in the carburetor floatbowl is low, the float valve is probably stuck on the seat.If the fuel level in the float is correct, yet no fuel isdelivered to the carburetor throat, the carburetor willhave to be removed, disassembled, and cleaned.

Faulty ignition system parts may be the source ofstarting difficulties. You may encounter two kinds ofignition systems-the MAGNETO type and theBATTERY type. Even though the parts of these systemsdiffer in some respects, their function is the same;namely, to produce a spark in each cylinder of the engineat exactly the proper time in relation to the position ofthe pistons and the crankshaft. Also, the system isdesigned so the sparks in all cylinders follow each otherin proper sequence.

ENGINE FAILS TO STOP

If a gasoline engine fails to stop when the ignitionswitch is turned to the OFF position, the trouble isusually caused by a faulty ignition circuit, impropertiming, the octane rating number of the fuel being toolow for the design of the engine, or the engine beingoverheated.

In a magneto-type ignition system, an open groundconnection may cause an engine to run after the ignitionswitch is turned off. When a magneto ground connectionis open, the magneto will continue to produce sparks aslong as the magneto armature magnets rotate, and theengine will continue to run. In other words, when themagneto ignition switch contact points are closed, theignition should be SHUT OFF. This is not true of thebooster coil circuit of a magneto-type system, nor of theusual battery-type ignition system. In these systems, anopen ground or open switch points prevent current flow.If the switch of a battery-type ignition system fails tostop the engine, the contact switch points have probablyremained closed.

If the ignition switch and the circuit are in goodcondition, failure to stop may be caused by overheating.If the engine is overheated, normal compressiontemperature may become high enough to ignite the fuelmixture even though no spark is being produced in thecylinders. When this happens in a gasoline engine, theengine is, in reality, operating on the diesel principle.

Normally, you will detect the symptoms ofoverheating before the temperature gets too high. Thecauses of overheating in a gasoline engine are much thesame as those for a diesel engine.

Other troubles and their symptoms, causes, andcorrections that may occur in a gasoline engine aresimilar to those found in a diesel engine. Troublesleading to the loss of rpm, irregular operation, unusualnoises, abnormal instrument indications, and excessiveconsumption or contamination of the lube oil, fuel, orwater can usually be handled in the same way forgasoline and diesel engines. Of course, there are alwaysexceptions, so it is best to consult the manufacturer’stechnical manual.

Most gasoline engines in the Navy are used by shoreactivities. Afloat, gasoline engines are used to driveportable pumps like the P-250, a piece of fire-fightingand dewatering equipment. Although pumps like theP-250 are primarily maintained by members of theDamage Controlman (DC) rating, Enginemen areinvolved to some extent in repairing or overhauling theP-250.

Before you disassemble a P-250 for repair, makesure that all the repair parts are available and on hand.When repairs are not within your ship’s force capability,you must turn the unit in to an IMA or SRF for repair.Attach an OPNAV 4790/2K (work order form) to thepump. Figure 3-45 illustrates a typical P-250 pump unit.

3-45

Figure 3-45.—A typical P-250 pump unit.

For more detailed information concerningoperation, maintenance and repair of the P-250, refer tothe NAVSEA technical manual, Firefighter PumpP-250 Mod 1, S6225-BW-MM0-010.

Some gasoline engines serve as outboard motors topower small boats. A high percentage of the motors’problems are electrical. A large number of problems arealso caused by the use of fuel with a lower octane contentthan specified by the manufacturer. To gain knowledgeabout operating, maintaining, and repairing outboardmotors, review manufacturers’ service manuals andassigned PMS publications. Most outboard motormanufacturers offer a high quality training course, freeof charge.

JACKING GEAR

The Engineman 3, NAVEDTRA 10539, introducedthe two primary types of jacking gear, the ring gear, andthe pinion assembly, and described their use. The onlymaintenance required for jacking gear is periodicinspection for wear and minor lubrication of the movingparts of the pinion assembly.

FUEL AND OIL PURIFIERS

Specific directions for operating a purifier are givenin the manufacturer’s instructions provided with the

unit. The following information is general and appliesto both the fuel and the oil purifiers.

For maximum efficiency, purifiers should beoperated at their maximum designed speed and ratedcapacity. An exception to operating a purifier at itsdesigned rated capacity is when the unit is used as aseparator with 9000 series detergent oil. Some enginesusing the 9000 series oils are exposed to large quantitiesof water. When the oil becomes contaminated withwater, it has a tendency to emulsify. The tendency toemulsify is most pronounced when the oil is new andgradually decreases during the first 50 to 75 hours ofengine operation. During this period, the purifiercapacity should be reduced to approximately 80 percentof its rated capacity.

Most oils used in Navy installations can be heatedto 180°F without damage to the oils. Prolonged heatingat higher temperatures is not recommended becausesuch oils tend to oxidize at high temperatures. Oxidationresults in rapid deterioration. In general, oil should beheated enough to produce a viscosity of approximately90 seconds Saybolt universal (90 SSU), but thetemperature should not exceed 180°F. The followingtemperatures are recommended for purifying oils in the9000 series:

3-46

Military Symbol

9110

Temperature (°F)

140

9170 160

9250 175

9500 180 MAINTENANCE OF PURIFIERS

Pressure should not be increased above normal toforce a high viscosity oil through the purifier. Instead,the viscosity should be decreased by heating the oil.Pressure in excess of that normally used to force oilthrough the purifier will result in less efficientpurification. On the other hand, a reduction in thepressure that forces the oil into the purifier will increasethe length of time the oil is under the influence ofcentrifugal force and, therefore, will tend to improveresults.

DISCHARGE RING (RING DAM)

If the oil discharged from a purifier is to be free ofwater, dirt, and sludge and if the water discharged fromthe bowl is not to be mixed with oil, the proper sizedischarge ring (ring dam) must be used. The size of thedischarge ring depends on the specific gravity of the oilbeing purified; diesel fuel oil, JP-5, and lubricating oilsall have different specific gravities and, therefore,require different sized discharge rings. While alldischarge rings have the same outside diameter, theirinside diameters vary. Ring sizes are indicated by evennumbers; the smaller the number, the smaller the ringsize. The inside diameter in millimeters is stamped oneach ring. Sizes vary in increments of 2 millimeters.Charts, provided in the manufacturers’ technicalmanuals, specify the proper ring size to be used with anoil of a given specific gravity. Generally, the ring sizeindicated on such a chart will produce satisfactory

results. If the recommended ring fails to producesatisfactory purification, you must determine the correctsize by trial and error. In general, you will obtain themost satisfactory purification of the oil when the ring isthe largest size that can be used without losing oil alongwith the discharged water.

Clean the bowl of the purifier daily according to thePMS, and carefully remove all sediment. The amount ofdirt, grit, sludge, and other foreign matter in the oil maywarrant more frequent cleaning. If you do not know theamount of foreign matter in an oil, have the purifier shutdown and examined and cleaned once each watch, ormore often if necessary. The amount of sediment foundin the bowl indicates how long the purifier may beoperated between cleaning.

Have periodic tests made to make sure the purifieris working properly. When the oil in the system is beingpurified by the batch process, tests should be made atapproximately 30-minute intervals. When thecontinuous process of purification is used, tests shouldbe made once each watch. Analysis of oil drawn fromthe purifier is the best method of determining theefficiency of the purifier. However, the clarity of thepurified oil and the amount of oil discharged with theseparated water will also indicate whether the unit isoperating satisfactorily.

SUMMARY

This chapter covered the general proceduresconcerning repairs, troubleshooting, maintenance, andoverhaul of internal combustion engines. Additionally,it covered the general maintenance of jacking gear andfuel and oil purifiers. Read and use the correctreferences, such as the manufacturers’ manuals and thePMS to operate and care for your equipment.

3-47

CHAPTER 4

SPEED CONTROLLING DEVICES

In the EN3 TRAMAN, you learned some basicinformation about the methods and the devices thatcontrol the output of the injection pumps and injectors.The purpose of these devices is to ensure control ofengine operation.

This chapter contains general information aboutmaintenance and repair of speed controlling devicesknown as governors. You should refer to the appropriatemanufacturer’s technical manuals and the maintenancerequirements (3-M) for more specific information.Woodward Diesel Engine Speed Governors Operationand Maintenance Manual, NAVSHIPS 341-5017,Marque t t e Governor Main tenance Manual ,NAVSHIPS 341-5505, and Naval Ships’ TechnicalManual, Chapter 233, “Diesel Engines,” are goodsources of information.

GOVERNORS

To control an engine means to keep it running at adesired speed, either with, or regardless of, the changesin the load carried by the engine. The degree of controlrequired depends on the following factors:

l The engine’s performance characteristics

l The type of load it drives

In diesel engines, the speed and power output isdetermined by varying the amount of fuel injected intothe cylinders to control combustion. Hydraulic andmechanical are the two principal types of governors.

HYDRAULIC GOVERNORS

This chapter will deal only with the most commontroubles that may be encountered with hydraulicgovernors. Poor regulation of speed may be due to thefaulty adjustment of the governor or to the faulty actionof an engine. Or it could be a problem with asynchronizing motor, a voltage regulator, or any pieceof equipment that has a direct bearing on the operationof the engine.

Manufacturers stated that 50 percent of all governortroubles are caused by dirty oil. For this reason, youshould take every precaution to prevent the oil frombecoming contaminated. Most hydraulic governors use

the same type of oil that is used in the engine crankcase,provided it is absolutely clean and does not foam. Youshould change the oil in the governor at regular intervals,depending upon the type of operation. But regardless ofthe operation or the preventive maintenance schedule, itmust be changed at least every 6 months. You must makesure the oil containers used to fill the governors are cleanand that only clean, new, or filtered oil is used. Youshould also check the oil level frequently to make surethe proper level is maintained and the oil does not foam.Foaming oil is usually an indication that water is presentin the oil. Water in the oil will cause serious damage tothe governor.

When a new or overhauled governor is installed,you should adjust the governor compensating needlevalve (even though it has been adjusted previously at thefactory or repair facility). This adjustment is made withthe governor controlling an engine with a load. If thisadjustment is not made, high overspeeds and lowunderspeeds after load changes will result and the returnto normal speeds will be slowed. Follow the procedurelisted in the manufacturer’s maintenance manual and thePMS.

When a governor problem is suspected, beforeperforming any maintenance or adjustments, disconnectthe governor fuel rod end from the fuel control rack andmake sure there is no binding or sticking of the fuelcontrol rack. This procedure will determine if the troubleis actually the governor.

The chart in table 4-1 lists some of the probablecauses of problems that are common to most hydraulicgovernors. This chart is for your general information,and it should not be used as a guide to troubleshoot agovernor. You should use the applicable manufacturer’sinstruction manual for troubleshooting.

The following are the definitions of some termsused in the chart:

HUNTS: Rhythmic variations of speed that can beeliminated by blocking the fuel linkage manually. Theywill reappear when returned to governor control.

SURGES: Rhythmic variations of speed of largemagnitude that can be eliminated by blocking the fuellinkage manually. They will not reappear when returned

4-1

Table 4-1.—Governor Probable Causes and Corrective Actions Chart

Problem

Engine hunts or surges

Governor rod end jiggles

Probable Cause

Compensating needle valveadjustment incorrect

Dirty oil in governor

Low oil level

Foamy oil in governor

Lost motion in engine governorlinkage or fuel pumps

Governor worn or incorrectlyadjusted

Engine misfiring

External fuel linkage sticking orbinding

Rough engine drive

Governor base not bolted downevenly

Corrective Action

Make needle valve adjustment;ensure that the opposite needle valveis closed

Drain oil; flush governor; refill

Fill to correct level with clean oil

Drain oil; refill

Repair linkage and realign pumps

Remove governor and make internalchecks for clearances according toapplicable instructions

Test and replace injectors

Disconnect fuel rack from governorand manually move linkage andprogressively disconnect fuel pumplinks until binding area is found (dirt,paint, and misalignment are the usualcauses of binding)

Check alignment of gears; inspectfor rough gear teeth; check backlashof gear

Loosen bolts; realign and secure

to governor control unless the speed adjustment of theload changes.

JIGGLES: High-frequency vibrations of thegovernor fuel rod end or engine fuel linkage. Do notconfuse jiggle with the normal regulating action of thegovernor.

When normal governor adjustments do not give thedesired response, the hydraulic governor should beremoved and you should send it to a repair activity forcleaning, overhaul, and recalibration. You should havea spare governor so that the engine can be operatedduring the governor overhaul period and other PMS thatrequire removal of the original governor.

MECHANICAL GOVERNORS

The Navy generally uses the spring-loaded In the idling speed range, control is effected by

flyball-type mechanical governors. All flyball-type centrifugal force on the two sets of large and smallmechanical governors have speed droop. This means, as flyweights, as shown in figure 4-1. This flyweight forcethe load is increased at a constant throttle setting, the acts against a light (low-speed) spring. Maximum speed

speed of the engine will drop or droop slightly, ratherthan remain constant. Consequently, mechanicalgovernors of this type are never used where absoluteconstant speeds are necessary.

Besides the spring-loaded flyball-type governors,there are several other types of mechanical governors.The two most common types are used on GM 71engines. One type, the constant-speed governor, is usedon generator sets and is designed to hold the speed ofthe engine at a predetermined operating speed. The othertype, similar in construction, is used primarily forpropulsion engines. It has a throttle plate designed sothat intermediate speeds may be obtained by manualadjustment. Notice that there is no buffer springadjustment on the constant-speed governor. Thefollowing description applies to both types of governors.

4-2

Figure 4-1.—GM mechanical governor.

control is effected by the action of the high-speed(small) flyweights acting against a heavy (high-speed)spring. See figure 4-2. If you have any questions or needmore illustrations to understand the concept of governoroperations, refer to chapter 9 of Engineman 3,NAVEDTRA 10539.

Mechanical governor faults are usually revealed inspeed variations. But not all speed variations are faultsof the governor. When abnormal speed variations

appear, you should first do the following procedures:

1. Check the load to be sure the speed changes are

not the result of load fluctuations.

2. If the load is steady, check the engine to makesure all the cylinders are firing properly.

3. Make sure there is no binding in the governormechanism or operating linkage between the governorand the engine. There should be no binding in theinjector control rack shaft or its mounting brackets. If

you find no binding anywhere and the governor still fails

Figure 4-2.—Mechanical governor control mechanism.

to control the engine properly, you may assume that thegovernor is worn or inoperative.

If the governor is the cause of improper speedvariations, it must be completely disassembled,inspected, and rebuilt or replaced. When it is necessaryto disassemble and reassemble the governor, you shouldsecure a copy of the manufacturer’s instruction book andfollow the instructions given. During reassembly of thegovernor, use only hard grease on the gasket! Under NOcircumstances should you use shellac on the gasket.Adjustment procedures for the replacement of anygovernor are listed in the manufacturer’s instructionmanual and should be followed with particular attentiongiven to the precautions listed.

OVERSPEED SAFETY DEVICES

Mechanical overspeed trips depend upon thecentrifugal forces developed by the engine and must bemaintained in good working condition. A faultyoverspeed device can endanger not only the engine butalso the personnel. The engine could explode or fly apartbecause of the uncontrolled speed.

The engine instruction manual contains informationas to the speed at which the overspeed device is designedto function. Most overspeed trips are adjustable. Beforemaking any changes in the adjustment of the overspeedtrip, you must determine the cause. If the engine did nottrip out, was it for some reason other than the action ofthe element of the overspeed trip? You should firstcheck the accuracy of the tachometer and then test the

4-3

overspeed trip. Remember that all spring tension andlinkage adjustments to an overspeed are critical.Instructions for these adjustments are found in themanufacturer’s instruction manual. You MUST followthese instructions!

Hydraulic overspeedtrips are extremely sensitive todirt. Dirt or lacquer like deposits may cause the trip tobind internally. The speed-sensitive element and allparts of the linkage and mechanisms incorporated withthe speed-sensitive element must be kept clean. Whenpainting around the engine, you must avoid allowingpaint to fall on joints, springs, pins, or other criticalpoints in the linkage.

The overspeed trip will not function properly if partsarc bent, badly worn, improperly installed, or dirty, or iftheir motion is restricted by some other part of theengine. In some situations the driveshaft of theoverspeed trip may be broken; this would preventrotation of the flyweight and the overspeed trip.Insufficient oil in the hydraulic trip may be anothersource of trouble. You should maintain a proper oil levelas specified by the instruction manual.

The following are some general procedures youshould follow to keep the overspeed safety devices inproper operation:

- Keep the overspeed trip and its linkage clean.

- Remove the source of binding.

- Replace faulty parts.

- Maintain a proper oil level in the hydraulicoverspeed trip.

- Adjust the speed-sensitive element according tothe instruction manual.

- If the trip has been damaged, replace it with aspare and completely rebuild or overhaul the damagedone according to the instruction manual.

Test overspeed trips and governor mechanisms onceeach quarter and after each major engine overhaul. Toverify if the safety device is in proper working order,overspeed the engine. When you are making this test,use a tachometer to check the speed at which theoverspeed mechanism will operate. These safetydevices should operate at the speed specified in theengine instruction manual. If this information is notavailable, the following values should be used for thetest:

l For large, slow-speed engines, the value is 107percent maximum-rated speed.

l For high-speed engines, the value is 110 percentmaximum-rated speed.

If there is any irregularity during testing, stop thetest and check the overspeed safety device and correctthe problem before continuing the test procedure.

SUMMARY

This chapter has presented several common facts inmaintenance, repair, and overhaul of speed controllingdevices. Maintenance personnel must secure theappropriate manufacturer’s instruction manual. Norepair, maintenance, or overhaul of these precisionpieces of equipment should be made until theappropriate manual is obtained. You must read,understand, and strictly follow the instructions from themanufacturer. Be sure to pay particular attention to anysafety precautions given in these instructions.

4-4

CHAPTER 5

REFRIGERATION AND AIR CONDITIONING

As an EN3, you have learned the principles ofrefrigeration and air conditioning; the components andaccessories that make up the system; and how to start,operate, and secure refrigeration and air-conditioningplants. As an EN2, you will perform routinemaintenance jobs, such as cleaning, lubricating,troubleshooting, servicing the system, using correctprocedures for leak detecting, and charging therefrigeration and air-conditioning plants. As youadvance in rate, you will be expected to have a greaterknowledge of the construction and operating principlesof refrigeration and air-conditioning plants. You will berequired to perform more complicated maintenancejobs, to make repairs as required, and to determine thecauses of inefficient plant operation and accomplish thenecessary corrective procedures. This chapter providessome general information on the construction andmaintenance of refrigeration and air-conditioningequipment and the detection and correction of operatingdifficulties.

Refer to the manufacturer’s technical manual fordetails of the plant on your ship. If you have anyquestions about the basic theory of refrigeration and airconditioning, refer to EN3, chapters 16 and 17.

R-12 REFRIGERATION SYSTEM

We will present the R-12 system as though it hadonly one evaporator, one compressor, and onecondenser. A refrigeration system may (and usuallydoes) include more than one evaporator, and it mayinclude an additional compressor and condenser units.

COMPRESSORS

Many different types and sizes of compressors areused in refrigeration and air-conditioning systems. Theyvary from the small hermetic units used in drinkingfountains and refrigerators to the large centrifugal unitsused for air conditioning.

One of the most common compressors on modemships is a high-speed unit with a variable capacity. Thiscompressor is a multicylinder, reciprocating design withan automatic device built into the compressor to controlits output. This automatic capacity control provides forcontinuous compressor operation under normal load

conditions. The capacity of the compressor is controlledby unloading and loading the cylinders. This is a verydesirable design feature of the unit. If the compressorhad to be started under a load, or with all cylindersworking, a much greater amount of torque would berequired, and it would be necessary to have a muchlarger drive motor. Also, if the compressor ran atconstant capacity or output, it would reach thelow-temperature or low-pressure limits or be constantlystarting and stopping, thereby putting excessive work onthe unit.

Unloading of the cylinders in the compressor isaccomplished by lifting the suction valves off their seatsand holding them open. This method of capacity controlunloads the cylinders completely but still allows thecompressor to work at as little as 25 percent of its ratedcapacity .

Unloader Mechanism

When the compressor is not in operation, theunloader mechanism is in the unloaded position asshown in figure 5-1. The mechanism is operated by oilpressure from the capacity control valve. The oilpressure pushes the unloader spring against the unloaderpiston. This action moves the unloader rod to the left,thereby rotating the cam rings. As the cam rings arerotated, the lifting pins are forced upward, raising thesuction valve off its seat. The suction valve is held inthis position until the compressor is started and oilpressure of approximately 30 psi is reached. At that time,the oil pressure from the capacity control valve pushesthe unloader piston back to the right against the unloaderspring. The motion transmitted through the pushrodrotates the cam ring. This lowers the lifting pins andallows the suction valve to close or operate normally andthe cylinder to become loaded (fig. 5-2). On mostcompressors the unloader is connected to the cylindersin pairs.

Capacity Control Valve

The capacity control valve (fig. 5-3) is located in thecompressor crankcase cover. The valve is actuated byoil pressure from the main oil pump. It admits or relievesoil to or from the individual unloader power elements,

5-1

Figure 5-1.—Unloader mechanism in the unloaded position.

Figure 5-2.—Unloader mechanism in the loaded position.

5-2

depending on suction or crankcase pressure. Figure 5-3 The high-pressure oil from the pump enters

shows the compressor at rest. The two cylinders chamber A of the capacity control valve. It then passes

equipped with the unloader element are unloaded and through an orifice in the top of the piston to chamber B,

will remain unloaded until the compressor is started and forcing the piston to the end of its stroke against spring

the oil pressure reaches normal operating pressure. A. When the piston of the valve is forced against spring

Figure 5-3.—Capacity control system.

5-3

A, the circular grooves that form chamber A are put incommunication with the unloader connections. Thisadmits high-pressure oil to the unloader cylinder andactuates the unloader mechanism.

A capacity control regulating valve controls oilpressure from the capacity control valve. It is connectedto the crankcase and has an oil-connecting line tochamber B of the capacity control valve. As thecrankcase or suction pressure pulls down slightly belowthe setting of the regulating valve, the regulator opensand relieves oil pressure from chamber B of the capacitycontrol valve. This permits spring A to push the capacitycontrol piston one step toward chamber B, uncoveringthe unloader connection nearest the end of the capacitycontrol valve. This relieves oil pressure from the powerelement and allows the power element spring to rotatethe cam rings and unload the cylinder.

If the suction pressure continues to drop, theregulator will relieve more oil pressure and unload morecylinders. If the heat load increases, the suction pressurewill increase, causing the regulating valve to close andload more cylinders.

MAINTENANCE

As an Engineman, maintaining the refrigeration andair-condit ioning plants may be one of yourresponsibilities. To do this, you must understand themaintenance procedures. In most instances, personnelwho are assigned to maintain refrigeration plants aregraduates of the Navy’s air-conditioning andrefrigeration school. This school teaches most operatingand maintenance procedures. However, you shouldrefer to the manufacturer’s technical manuals for thedetails of the plants on your ship.

Testing Suction and Discharge Valves

Faulty compressor valves may be indicated byeither a gradual or a sudden decrease in the normalcompressor capacity. Either the compressor will fail topump, or the suction pressure cannot be pumped downto the designed value, and the compressor will run forabnormally long intervals or continuously. You may geta rapid buildup of suction (crankcase) pressure duringan off cycle. This causes the compressor to start after avery short off-period and indicates leaking dischargevalves.

If the refrigeration plant is not operatingsatisfactory, you should first shift the compressors andthen check the operation of the plant. If the operation ofthe plant is satisfactory when the compressors have been

shifted, the trouble is in the compressor and not in thesystem.

To test the compressor discharge valves, pumpdown the compressor to 2 psig. Then stop thecompressor and quickly close the suction and dischargeline valves. If the discharge pressure drops at a rate inexcess of 3 pounds in a minute and the crankcase suctionpressure rises, this is evidence of compressor dischargevalve leakage. If you must remove the discharge valveswith the compressor pumped down, open the connectionto the discharge pressure gauge to release dischargepressure on the head. Then remove the compressor tophead and discharge valve plate. Be careful not to damagethe gaskets.

If the discharge valves are defective, replace theentire discharge valve assembly. Any attempt to repairthem would probably involve relapping and wouldrequire highly specialized equipment. Except in anemergency, such repair should never be undertakenaboard ship.

You can check the compressor internal suctionvalves for leakage by following these steps:

1. Start the compressor by using the manual controlswitch on the motor controller.

2. Close the suction line stop valve gradually toprevent violent foaming of the compressor crankcaselubricating oil charge.

3. With this stop valve closed, pump a vacuum ofapproximately 20 in.Hg. If this vacuum can be readilyobtained, the compressor suction valves are satisfactory.

Do not expect the vacuum to be maintained after thecompressor stops, because the refrigerant is beingreleased from the crankcase oil. Do not check thecompressor suction valve efficiency of operation for atleast 3 days. It may be necessary for the valves to wearin.

However, if any of the compressor suction valvesare defective, you can pump down the compressor, openit, and inspect the valves. Replace defective valves orpistons with spare assemblies.

Crankcase Seal Repairs

There are several types of crankcase seals,depending on the manufacturer. On reciprocatingcompressors, the crankshaft extends through thecompressor housing to provide a mount for the pulleywheel or flexible coupling. Now the shaft must be sealedto prevent leakage of lubricating oil and refrigerant. The

5-4

crankshaft seal is bathed in lubricating oil at a pressureequal to the suction pressure of the refrigerant. The firstindication of crankshaft seal failure is excessive oilleaking at the shaft.

When the seal must be replaced or when it showssigns of abnormal wear or damage to the runningsurfaces, a definite reason can be found for the abnormalconditions. Make an inspection to locate and correct thetrouble, or the failure will recur.

Seal failure is very often caused by faultylubrication, usually because of the condition of thecrankcase oil. A dirty or broken oil seal is generallycaused by one or both of the following conditions:

- Dirt or foreign material is in the system or systempiping. Dirt frequently enters the system at the time ofinstallation. After a period of operation, foreign materialwill accumulate in the compressor crankcase, tending toconcentrate in the oil chamber surrounding the shaftseal. When the oil contains grit, it is only a matter of timeuntil the highly finished running faces becomedamaged, causing failure of the shaft seal.

- Moisture is frequently the cause of an acidcondition of the lubricating oil. Oil in this condition willnot provide satisfactory lubrication and will causefailure of the compressor parts. Use a refrigerantdehydrator when the compressor is put into operation ifyou suspect that moisture may be a problem. Anytimeforeign material is found in the lubricating oil,thoroughly clean the entire system (piping, valves, andstrainers).

REMOVING A SHAFT SEAL.—If a shaft sealmust be removed, proceed as follows:

If the seal is broken to the extent that it permitsexcessive oil leakage, do NOT attempt to pump therefrigerant out of the compressor. If you do, aircontaining moisture will be drawn into the systemthrough the damaged seal. Moisture entering therefrigerant system may cause expansion valves tofreeze. This can cause acid formation and otherproblems. If oil is leaking excessively, close thecompressor suction and discharge valves and relieve thepressure to the atmosphere by loosening a connectionon the compressor discharge gauge line.

Next, drain the oil from the compressor crankcase.Since the oil contains refrigerant, it will foam whilebeing drained. Leave the oil drain valve or plug openwhile you are working on the seal. This ensures thatrefrigerant escaping from the oil remaining in the

crankcase will not build up pressure and blow out theseal while it is being removed.

Remove the compressor flywheel (or coupling) andcarefully remove the shaft seal assembly. If theassembly cannot be readily removed, build up a slightpressure in the compressor crankcase. To do this,slightly open the compressor suction valve. Take thenecessary precautions to support the seal and to preventit from being blown from the compressor and damaged.

INSTALLING A SHAFT SEAL.—Clean andreplace the entire seal assembly according to themanufacturer’s instructions.

Wipe the shaft clean with a linen or silk cloth; donot use a dirty or lint-bearing cloth. Be careful not totouch the bearing surfaces with your hands as youunwrap the seal. Rinse the seal in an approved solventand allow it to air-dry. (Do NOT wipe the seal dry!) Dipthe seal in clean refrigerant oil. Follow the instructionsfound in the manufacturer’s technical manual to insertthe assembly. Bolt the seal cover in place and tighten thebolts evenly. Replace the flywheel and belts or couplingand check and correct the motor and compressor shaftalignment. To test the unit for leaks, open the suctionand discharge valves and use a halide leak detector.

Evacuating the Compressor

Whenever repairs to a compressor allow anyappreciable amount of air to enter the unit, thecompressor should be evacuated after assembly iscompleted and before it is ready for operation Theproper procedure is as follows:

1. Disconnect a connection in the compressordischarge gauge line between the discharge line stopvalve and the compressor.

2. Start the compressor and let it run until thegreatest possible vacuum is obtained.

3. Stop the compressor and immediately open thesuction stop valve slightly. This will blow refrigerantthrough the compressor valves and purge the air abovethe discharge valves through the open gauge line.

4. Close the discharge gauge line and open thedischarge line stop valve.

5. Remove all oil from the exterior of thecompressor.

6. Test the compressor joints for leakage using thehalide leak detector.

5-5

Cleaning Suction Strainers

When putting a new unit into operation, you shouldclean the suction strainers after a few hours of operation.Refrigerants have a solvent action and will loosen anyforeign matter in the system. This foreign matter willeventually reach the suction strainers. After a few daysof operation, the strainers will need another cleaning.Inspect them frequently during the first few weeks ofplant operation and clean as necessary.

The suction strainers are located in the compressorhousing or in the suction piping. The procedure forcleaning the strainers is as follows:

1. Pump down the compressor.

2. Remove the strainer and inspect it for foreignmatter.

3. Dip the strainer screen in an approved solventand allow it to dry.

4. Replace the strainer and evacuate the air fromthe compressor.

5. Test the housing for leaks by wiping up all oiland then using a halide leak detector.

Maintenance Precautions

Sometimes a compressor cannot be pumped downand is damaged to the extent that it has to be opened forrepairs. If so, you should first close the suction anddischarge valves. Then allow all refrigerant in thecompressor to vent to the atmosphere through a gaugeline.

When you must remove, replace, or repair internalparts of the compressor, observe the followingprecautions:

1. Carefully disassemble and remove parts; notethe correct relative position so that errors will not bemade when you reassemble.

2. Inspect all parts that become accessible.

3. Make certain that all parts and surfaces are freeof dirt and moisture.

4. Freely apply clean compressor oil to all bearingand rubbing surfaces of parts being replaced orreinstalled.

5. If the compressor is not equipped with an oilpump, make certain that the oil dipper on the lowerconnecting rod is in the correct position for dipping oilwhen the unit is in operation.

6. Position the ends of the piston rings so thatalternate joints are on the opposite side of the piston

7. Take care not to score gasket surfaces.

8. Replace all gaskets.

9. Clean the crankcase and replace the oil.

CONDENSERS

The compressor discharge line terminates at therefrigerant condenser. In shipboard installations, thesecondensers are usually of the multipass shell-and-tubetype, with water circulating through the tubes. The tubesare expanded into grooved holes in the tube sheet tomake a tight joint between the shell and the circulatingwater. Refrigerant vapor is admitted to the shell andcondenses on the outer surfaces of the tubes.

Any air or noncondensable gases that mayaccidentally enter the refrigeration system will be drawnthrough the piping and eventually discharged into thecondenser wi th the re f r ige ran t . The a i r o rnoncondensable gases accumulated in the condenser arelighter than the refrigerant gas. They will rise to the topof the condenser when the plant is shut down. A purgevalve, for purging the refrigeration system (whennecessary), is installed at the top of the condenser or ata high point in the compressor discharge line.

Cleaning Condenser Tubes

To clean the condenser tubes properly, first drain thecooling water from the condenser. Then disconnect thewater connections and remove the condenser heads. Becareful not to damage the gaskets between the tube sheetand the waterside of the condenser heads. Inspect tubesas often as practical and clean them as necessary, usingan approved method. Use rubber plugs and an air lanceor a water lance to remove foreign deposits. You mustkeep the tube surfaces clear of particles of foreignmatter. However, you must not destroy the thinprotective coating on the inner surfaces of the tubes. Ifthe tubes become badly corroded, replace them.Replacement avoids the possibility of losing the chargeand admitting salt water to the system.

Cleaning Air-Cooled Condensers

Although the large plants are equipped withwater-cooled condensers, auxiliary units are commonlyprovided with air-cooled condensers. The use ofair-cooled condensers eliminates the necessity forcirculating water pumps and piping.

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Keep the exterior surface of the tubes and the finson an air-cooled condenser free of dirt or any matter thatmight obstruct heat flow and air circulation. The finnedsurface should be brushed clean with a stiff bristle brushas often as necessary. Low-pressure air is very useful inremoving dirt in hard-to-reach places on condensers.When installations are exposed to salt spray and rainthrough open doors or hatches, you should take steps tominimize corrosion of the exterior surfaces.

Testing For Leaks

To prevent serious loss of refrigerant through leakycondenser tubes, test the condenser for leakage byfollowing the PMS.

To test for leaky condenser tubes, drain thewaterside of the condenser. Then insert the exploringtube of the leak detector through one of the drain plugopenings. If this test indicates that Freon gas is present,you can find the exact location of the leak by followingthese steps:

1. Remove the condenser heads.

2. Clean and dry the tube sheets and the ends of thetubes.

3. Check both ends of each tube with a leakdetector. Mark any tubes that show leakage. If youcannot determine that a tube is leaking internally oraround the tube sheet joint, plug the suspected tube andagain check around the tube sheet joint. Mark theadjacent tube, if necessary, to isolate the suspected area.

4. To locate or isolate very small leaks in thecondenser tubes, hold the exploring tube at one end ofthe condenser tube for about 10 seconds to draw freshair through the tube. Repeat this procedure with all thetubes in the condenser. Allow the condenser tubes toremain plugged for 4 to 6 hours; then, remove the plugsone at a time and check each tube for leakage. If a leakytube is detected, replace the plug immediately to reducethe amount of refrigerant escaping. Make appropriaterepairs or mark and plug all leaky tubes for later repairs.

Plugging or Retubing Condensers

The general procedures for plugging or retubingcondensers can be found in Naval Ship's TechnicalManual (NSTM), Chapter 254, “Condensers, HeatExchangers, and Air Ejectors.” When plugging orretubing a specific condenser, follow the procedures inthe manufacturer’s technical manual.

THERMOSTATIC EXPANSION VALVES

The thermostatic expansion valve is essentially areducing valve between the high-pressure side and thelow-pressure side of the system. The valve is designedto proportion the rate at which the refrigerant enters thecooling coil to the rate of evaporation of the liquidrefrigerant in the coil; the amount depends, of course,on the amount of heat being removed from therefrigerated space.

When the thermostatic expansion valve is operatingproperly, the temperature at the outlet side of the valveis much lower than that at the inlet side. If thistemperature difference does not exist when the systemis in operation, the valve seat is probably dirty andclogged with foreign matter.

Once a valve is properly adjusted, furtheradjustment should not be necessary. The major troublecan usually be traced to moisture or dirt collecting at thevalve seat and orifice.

Testing and Adjustment

The thermostatic expansion valves used in mostshipboard systems can be adjusted by means of a gearand screw arrangement to maintain a superheat rangingfrom about 4°F to 12°F at the cooling coil outlet. Theproper superheat adjustment varies with the design andservice operating conditions of the valve and the designof the particular plant. Increased spring pressureincreases the degree of superheat at the coil outlet.Decreased spring pressure decreases the degree ofsuperheat at the coil outlet.

Some thermostatic expansion valves have a fixed(nonadjustable) superheat. These valves are usedprimarily in self-contained equipment where the pipingconfiguration and evaporating conditions are constant.

If expansion valves are adjusted to give a highsuperheat at the coil outlet or if the valve is stuck shut,the amount of refrigerant admitted to the cooling coilwill be reduced. With an insufficient amount ofrefrigerant, the coil will be “starved” and will operate ata reduced capacity. Also, the velocity of the refrigerantthrough the coil may not be adequate to carry oil throughthe coil. This robs the compressor crankcase andprovides a condition where slugs of lubricating oil maybe drawn back into the compressor. If the expansionvalve is adjusted for too low a degree of superheat or ifthe valve is stuck open, liquid refrigerant may floodfrom the cooling coils back into the compressor. Whenliquid refrigerant collects at a low point in the suction

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line or coil and is drawn back into the compressorintermittently in slugs, there is danger of injury to themoving parts of the compressor.

I n g e n e r a l , t h e e x p a n s i o n v a l v e s f o rair-condit ioning a n d w a t e r - c o o l i n g p l a n t s(high-temperature installations) normally are adjustedfor higher superheat than the expansion valves for coldstorage refrigeration and ship’s service store equipment(low-temperature installations).

You may not be able to adjust expansion valves tothe desired settings, or you may suspect that theexpansion valve assembly is defective and requiresreplacement. In either case, you should makeappropriate tests. First you should be sure that the liquidstrainers are clean, that the solenoid valves areoperative, and that the system is sufficiently chargedwith refrigerant.

The major pieces of equipment required forexpansion valve tests is as follows:

l A service drum of R-12 or a supply of clean, dryair at 70 to 100 psig. The service drum is used tosupply gas under pressure. The gas does not haveto be the same as that used in the thermal elementof the valve being tested.

l A high-pressure and a low-pressure gauge. Thelow-pressure gauge should be accurate and ingood condition so that the pointer does not haveany appreciable lost motion. The high-pressuregauge, while not absolutely necessary, will beuseful in showing the pressure on the inlet sideof the valve. Refrigeration plants are providedwith suitable replacement and test pressuregauges.

The procedure for testing is as follows:

1. Connect the valve inlet to the gas supply withthe high-pressure gauge attached to indicate the gaspressure to the valve. Connect the low-pressure gaugeloosely to the expansion valve outlet. The reason thelow-pressure gauge is connected loosely is to allow asmall amount of leakage through the connection.

2. Insert the expansion valve thermal element in abath of crushed ice. Do NOT attempt to perform this testwith a container full of water in which a small amountof crushed ice is floating.

3. Open the valve on either the service drum or inthe air supply line. Make certain that the gas supply issufficient to build up the pressure to at least 70 psi on

the high-pressure gauge connected in the line to thevalve inlet.

4. The expansion valve can now be adjusted. If youwant to adjust for 10°F superheat, the pressure on theoutlet gauge should be 22.5 psig. This is equivalent toan R-12 evaporating temperature of 22°F. Since the icemaintains the bulb at 32°F. the valve adjustment is for10°F superheat (difference between 32 and 22). For a5°F superheat adjustment, the valve should be adjustedto give a pressure of approximately 26.1 psig. Theremust be a small amount of leakage through thelow-pressure gauge connection while this adjustment isbeing made.

5. To determine if the valve operates smoothly, tapthe valve body lightly with a small weight. Thelow-pressure gauge needle should not jump more than1 psi.

6. Now tighten the low-pressure gauge connectionto stop the leakage at the joint and determine if theexpansion valve seats tightly. If the valve is in goodcondition, the pressure will increase a few pounds andthen either stop or build up very slowly. But with aleaking valve, the pressure will build up rapidly until itequals the inlet pressure. With externally equalizedvalves, the equalizer line must be connected to thepiping from the valve outlet to the test gauge to obtainan accurate superheat setting.

7. Again loosen the gauge to permit leakage at thegauge connection. Remove the thermal element, orcontrol bulb, from the crushed ice. Warm it with yourhands or place it in water that is at room temperature.When this is done, the pressure should increase rapidly,showing that the power element has not lost its charge.If there is no increase in pressure, the power element isdead.

8. With high pressure readings showing on bothgauges, the valve can be tested to determine if the bodyjoints or the bellows leak This can be done by using ahalide leak detector. When you perform this test, it isimportant that the body of the valve have a fairly highpressure applied to it. In addition, the gauges and otherfittings should be made up tightly at the joints toeliminate leakage at these points.

Replacement of Valves

If the expansion valve is defective, it must bereplaced. Most valves used on naval ships havereplaceable assemblies. Sometimes it is possible toreplace a faulty power element or some other part of the

5-8

valve without having to replace the entire assembly.When replacement of an expansion valve is necessary,you must replace the unit with a valve of the samecapacity and type.

ADDITIONAL SYSTEM MAINTENANCE

In addition to the maintenance of the componentspreviously described, other parts of the system will needperiodic maintenance to keep the plant operatingproperly.

Vibration may cause leakage in the piping system.This leakage may allow air and moisture to be drawn inor a loss of refrigerant charge. If this happens, the plantoperation will become erratic and inefficient, and thecause of trouble must be corrected.

CHARGING THE SYSTEM

In fo rmat ion conce rn ing the cha rg ing o frefrigeration systems may be found in NSTM, Chapter516, “Refrigeration System.” The amount of refrigerantcharge must be sufficient to maintain a liquid sealbetween the condensing and evaporating sides of thesystem. Under normal operating conditions, when thecompressor stops, the receiver of a properly chargedsystem is about 85 percent full of refrigerant. The propercharge for a specific system or unit can be found in themanufacturer’s technical manual or on the ship’sblueprints.

A refrigeration system should not be charged if ithas leaks or if you have a reason to believe the systemhas a leak. The leaks must be found and corrected.Immediately following-or during-the process ofcharging, you should carefully check the system forleaks.

A refrigeration system must have an adequatecharge of refrigerant at all times; otherwise, itsefficiency and capacity will be impaired.

PURGING THE SYSTEM

To determine if the system contains noncondensablegases, operate the system for 30 minutes. Stop thecompressor for 10 to 15 minutes, leaving all the valvesin their normal positions. Observe the pressure andtemperature as indicated on the high-pressure gauge.Read the thermometer in the liquid line, or read thetemperature of the cooling water discharge from thecondenser. Compare the temperature reading with thetemperature conversion figures shown on the dischargepressure gauge. If the temperature of the liquid leaving

the receiver is more than 5°F lower than the temperaturecorresponding to the discharge pressure, the systemshould be purged. Pump the system down and secure thecompressor; then open the purge valve on the condenser.Purge very slowly, at intervals, until the air is expelledfrom the system and the temperature difference dropsbelow 5°F.

CLEANING LIQUID LINE STRAINERS

Where a liquid line strainer is installed, it should becleaned at the same intervals as the suction strainer. If aliquid line strainer becomes clogged to the extent that itneeds cleaning, a loss of refrigeration will take place.The tubing on the outlet side of the strainer will be muchcolder than the tubing on the inlet side.

To clean the liquid line strainer, secure the receiveroutlet valve and wait a few minutes to allow any liquidin the strainer to flow to the cooling coils. Then closethe strainer outlet valve and very carefully loosen thecap that is bolted to the strainer body. (Use goggles toprotect your eyes!) When all the pressure is bled out ofthe strainer, remove the cap and lift out the strainerscreen. Clean the strainer screen with an approvedsolvent and a small brush. Reinstall the spring andscreen in the strainer body; then replace the strainer caploosely. Purge the air out of the strainer by blowingrefrigerant through it; then tighten the cap. After theassembly is complete, test the unit for leaks.

CLEANING OIL FILTERS AND STRAINERS

Compressors arranged for forced-feed lubricationhave lubricating oil strainers in the suction line of thelube-oil pump. An oil filter may be installed in the pumpdischarge line. A gradual decrease in lubricating oilpressure indicates that these units need cleaning. Thiscleaning is done in much the same manner as describedfor cleaning suction strainers.

When cleaning is necessary, drain the lubricating oilin the crankcase from the compressor. Add a new chargeof oil, equal to the amount drained, before restarting theunit. When the compressor is put back into operation,adjust the lube-oil pressure to the proper setting byadjusting the oil pressure regulator.

MAINTAINING COOLING COILS

You should inspect the cooling coils regularly andclean them as required. Defrost the cooling coils as oftenas necessary to maintain the effectiveness of the coolingsurface. Excessive buildup of frost on the cooling coils

5-9

will result in reduced capacity of the plant, lowcompressor suction pressure, and a tendency for thecompressor to short-cycle. The maximum time intervalbetween defrostings depends on such factors ascondition of door gaskets, moisture content of suppliesplaced in boxes, frequency of opening doors,atmospheric humidity, and refrigerant evaporatingtemperatures.

You should always defrost the cooling coils beforethe frost thickness reaches three-sixteenths of an inch.When defrosting the coils, be sure that you do NOT tryto scrape or break the frost off. Improper defrosting willcause serious damage to the coils.

EVACUATING AND DEHYDRATING THESYSTEM

In areas where moisture accumulation must becorrected, the system should first be cleared ofrefrigerant and air. The time required will depend uponthe size of the system and the amount of moisturepresent. It is a good engineering practice to circulateheated air through a large dehydrator system for severalhours, or as long as the dehydrator drying agent remainseffective, before proceeding with the evacuationprocess. If possible, the dehydrated air should be heatedto about 240°F.

Large dehydrators, suitable for preliminarydehydration of refrigeration systems, are usuallyavailable at naval shipyards and on board tenders andrepair ships. After the preliminary dehydration, theremaining moisture is evacuated by means of atwo-stage, high-efficiency vacuum pump having avacuum indicator. (These vacuum pumps are availableon board tenders and repair ships.)

The vacuum indicator shown in figure 5-4 consistsof an insulated test tube containing a wet-bulbthermometer with its wick immersed in distilled water.The indicator is connected in the vacuum pump suctionline. The suction line from the vacuum pump isconnected to the refrigeration system. The refrigerantcircuit should be closed to the atmosphere and thecharging connection opened to the vacuum pump.

A two-stage vacuum pump is started for operationin PARALLEL so that maximum displacement may beobtained during the initial pump-down stages. When theindicator shows a temperature of about 55°F (0.43in.Hg, absolute), the pumps are placed in SERIESoperation (where the discharge from the first step entersthe suction of the second step pump). The dehydrationprocess will produce a temperature drop of the vacuum

Figure 5-4.—Dehydrator vacuum indicator.

indicator as shown in figure 5-5. Readings will initiallyreflect ambient temperatures, then show rapidly fallingtemperatures until the water in the system starts to boil.

When most of the evaporated moisture has beenevacuated from the system, the indicator will show a

Figure 5-5.—Vacuum indicator readings plotted duringdehydration.

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decrease in temperature. When the temperature reaches35°F (0.2 in.Hg, absolute), dry air should be admittedthrough a chemical dehydrator into the system at a pointfarthest from the pump. Continue operating the pump sothe dry air will mix with and dilute any remainingmoisture. Secure the opening that feeds the dry air intothe system. Continue evacuating the system until theindicator again shows a temperature of 35°F. Thedehydration process is complete. Close the valves anddisconnect the vacuum pump.

Sometimes obtaining a temperature as low as 35°Fin the vacuum indicator will be impossible. Theprobable reasons for such a failure and the correctiveprocedures to take are as follows:

l Excess moisture in the system. The dehydrationprocedure should be conducted for longerperiods.

l Absorbed refrigerant in the lubricating oilcontained in the compressor crankcase. Removethe lubricating oil from the crankcase beforeproceeding with the dehydration process.

l Leakage of air into the system. The leak must befound and stopped. You must then repeat theprocedure required for detecting leaks in thesystem.

l Inefficient vacuum or defective vacuumindicator. The defective unit(s) should berepaired or replaced.

Immediately after each period of use or after thesystem has been opened for repairs, replace the dryingagent in the dehydrator. If a replacement cartridge is notavailable, reactivate the drying agent and use it until areplacement is available.

You can reactivate the drying agent by removingand heating it for 12 hours at a temperature of 300°F tobake out the moisture. Place the drying agent in an ovenor circulate a stream of hot air through the cartridge.Both methods are satisfactory for reactivatingcommonly used dehydrating agents such as activatedalumina or silica gel. The specific instructions furnishedby the manufacturer should be followed to reactivatespecial drying agents.

After reactivation, replace the drying agent in thedehydrator shell and seal it as quickly as possible. Thisprevents absorption of atmospheric moisture. When thedrying agent becomes fouled or saturated withlubricating oil, replace it with a fresh charge, ordehydrator cartridge, taken from a sealed container.

Remember that the dehydrators permanentlyinstalled in refrigeration systems of naval ships aredesigned to remove only the minute quantities ofmoisture unavoidably introduced into the system. Youmust be careful to prevent moisture or moisture-ladenair from entering the system.

CLEANING THE SYSTEM

Systems may accumulate dirt and scale as a resultof improper techniques used during repair or installationof the system. If such dirt is excessive and a tank-typecleaner is available, connect the cleaner to thecompessor suction strainer. When such a cleaner is notavailable, a hard, wool felt filter about five-sixteenthsinch thick should be inserted into the suction strainerscreen. Run the plant with an operator in attendance forat least 36 hours or until the system is clean. The lengthof time required for a clean system depends upon thesize and condition of the plant.

AIR-CONDITIONING SYSTEM

Most of the information presented so far applies tothe refrigeration side of a system, whether it is used fora refrigeration plant or for air conditioning. Thecompressor controls for both types of systems are nearlyidentical; however, the devices used to control spacetemperatures differ, The two-position dual control,called 2PD, is used for the automatic control of mostshipboard air-conditioning systems.

TWO-POSITION DUAL CONTROL (2PD)

This control is used on three types of systems:

Type 1. Systems employing a simple thermo-statically controlled single-pole switchto control flow of refrigerant to thecooling coil

Type 2. Systems using reheaters, employing ather- mostatic element actuating twointerlocked switches

Type 3. Systems using reheaters in the samemanner as those in type 2, with controlof humidity added where specified

The type 1 system, because of its simplicity, requireslittle explanation. The thermostat consists of atemperature-sensing element actuating a single-pole,single-throw switch. It opens and closes a magneticvalve to start and stop the flow of refrigerant-chilledwater or commercial refrigerant. This type of control is

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similar to the thermostatic control for the refrigerationplant. The type 1 system requires single-polethermostats, but type 2 and type 3 systems can usetwo-position dual controls (2PD). The cooling switchwould then be connected in the normal manner with theheating switch inoperative.

The type 2 system is most commonly used to makeliving and working spaces more habitable and forvarious types of weapons systems that require cooling.These systems often use a common cooling coil servingseveral different spaces. Since load changes seldomoccur simultaneously, electric or steam reheaters areinstalled in the cooling air ducts. The coolingthermostats of the various spaces are connected inparallel so that any one of the thermostats may open thecooling coil valve.

Suppose three spaces are being cooled by a commoncoil. Space B in figure 5-6 has a load change and spacesA and C do not. With the coil operating to take care ofspace B, these spaces would become too cold forcomfort. To prevent this condition, the thermostat wouldclose the heating switch and energize the reheaters forspaces A and C.

The type 3 system is identical to the type 2 system,except that a humidistat is wired in parallel with thethermostatic heating switch. This type of system is usedmostly in weapons and electronic spaces. Thehumidistat is set for the relative humidity desired. Inmost installations, it is only necessary to prevent thehumidity from exceeding 55 percent. Where thehumidistat is installed, an increase in temperaturebeyond the thermostat setting will close the thermostatcooling switch. An increase in relative humidity beyond

the humidistat setting will close the heating switch andenergize the reheaters.

MAINTENANCE

Proper attention to the planned maintenance systemoften exposes developing troubles in time to takecorrective action. Since most breakdowns occur at themost inopportune times, periodic checks andmaintenance will help to avoid malfunctions.

The 2PD control system can easily be checked outin a reasonably short time. The checkout should be madeat least every 3 months or more often if necessary.Inspections and checks should be made at the beginningof, and midway through, the cooling season and heatingseason.

You should inspect the sensing elements andremove any dust accumulations. Remove dust and dirtfrom thermostatic sensing elements with a soft brush.Use air to gently blow off any dust on the sensingelements in humidistats. The air will not damage theelement but will remove any problem-causing dust.

Magnetic valves should be checked for operation.Be sure that they open and close completely.

Set points of the thermostats and the humidistatsshould be checked with a calibrated thermometer and areliable humidity indicator.

When servicing the two-position control system,look for three possible sources of trouble:

l The sensing element and its associatedmechanism

Figure 5-6.—A typical air-conditioning system.

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l The magnetic valves that control the flow of DETECTING AND CORRECTING

refrigerant PROBLEMS

l The wiring system that connects the sensing A number of symptoms indicate faulty operation of

elements to the solenoids of the magnetic valves refrigeration and air-conditioning plants. Figures 5-7,

and the controller of the electric heaters 5-8, and 5-9 list some of the problems along with

Trouble

High condensing pressure.

Possible Cause Corrective Measure

Air on noncondensable gas in system. Purge air from condenser

Inlet water warm. Increase quantity of condensing water.

Insufficient water flowing through Increase quantity of water.condenser.

Condenser tubes clogged or scaled.

Too much liquid in receiver,condenser tubes submerged in liquidrefrigerant.

Clean condenser water tubes.

Draw off liquid into service cylinder.

Low condensing pressure. Too much water flowing throughcondenser.

Reduce quantity of water.

High suction pressure.

Water too cold. Reduce quantity of water.

Liquid refrigerant flooding back from Change expansion valve adjustment,evaporator. examine fastening of thermal bulb.

Leaky discharge valve. Remove head, examine valves.Replace any found defective.

Overfeeding of expansion valve. Regulate expansion valve, check bulbattachment.

Low suction pressure.

Leaky suction valve.

Restricted liquid line and expansionvalve or suction screens.

Insufficient refrigerant in system.

Too much oil circulating in system.

Remove head, examine valve andreplace if worn.

Rump down, remove, examine andclean screens,

Check for refrigerant storage.

Check for too much oil in circulation.Remove oil.

Improper adjustment of expansionvalves.

Adjust valve to give more flow.

Expansion valve power element dead Replace expansion valve poweror weak element.

Figure 5-7.—Trouble diagnosis chart.

5-13

Trouble

Compressor short cycles onlow- pressure control.

Possible Cause Corrective Measure

Low refrigerant charge. Locate and repair leaks.Charge refrigerant.

Thermal expansion valve not Adjust, repair or replace thermalfeeding properly. expansion valve.

(a) Dirty strainers. (a) Clean strainers.

(b) Moisture frozen in orifice or (b) Remove moisture or dirt (useorifice plugged with dirt. system dehydrator).

(c) Power element dead or weak (c) Replace power element.

Water flow through evaporators Remove restriction. Check water flow.restricted or stopped. Evaporator coils Clean coils or tubes.plugged, dirty, or clogged with frost.

Defective low-pressure control switch. Repair or replace low-pressure controlswitch.

Compressor runs continuously. Shortage of refrigerant. Repair leak and recharge system.

Leaking discharge valves. Replace discharge valves.

Compressor short cycles on Insufficient water flowing through Determine if water has been turnedhigh- pressure control switch. condenser, clogged condenser. off. Check for scaled or fouled

condenser.

Defective high-pressure control switch. Repair or replace high-pressurecontrol switch.

Compressor will not run. Seized compressor. Repair or replace compressor.

Cut-in point of low-pressure control Set L. P. control switch to cut-in atswitch too high. correct pressure.

High-pressure control switch does not Check discharge pressure and reset H.cut-in. P. control switch.

1. Defective switch. 1. Repair or replace switch.

2. Electric power cut off. 2. Check power supply.

3. Service or disconnect switch 3. Close switches.open.

Figure 5-8.—Trouble diagnosis chart-Continued.

5-14

Trouble

Compressor will not run(Cont’d)

Possible Cause

4. Fuses blown.

5. Over-load relays tripped.

Corrective Measure

4. Test fuses and renew if necessary.

5. Re-set relays and find cause ofoverload.

6. Low voltage. 6. Check voltage (should be within10 percent of nameplate rating).

7. Electrical motor in trouble. 7. Repair or replace motor.

8. Trouble in starting switch or 8. Close switch manually to testcontrol circuit. power supply. If OK, check control

circuit including temperature andpressure controls.

9. Compressor motor stopped by oil 9. Check oil level inpressure differential switch. crankcase. Check oil pump

pressure.

Sudden loss of oil fromcrankcase.

Capacity reduction systemfalls to unload cylinders.

Liquid refrigerant slugging back to Adjust or replace expansion valve.compressor crank case.

Hand operating stem of capacity Set hand operating stem to automaticcontrol valve not turned to automatic position.position.

Compressor continues to Pressure regulating valve not opening. Adjust or repair pressure regulatingoperate at full or partial load. valve.

Capacity reduction system Broken or leaking oil tube between Repair leak.fails to load cylinders. pump and power element.

Compressor continues to Pressure regulating valve not closing. Adjust or repair pressure regulatingoperate unloaded. valve.

Figure 5-9.—Trouble diagnosis chart-Continued.

possible causes and corrective measures. Figure 5-10also lists some of the problems, causes, and correctivemeasures and includes recommended test proceduresthat may be used to isolate the problems.

SAFETY PRECAUTIONS USED WHENHANDLING REFRIGERANTS

The following safety precautions are the minimumrequired when you are using refrigerants:

1. Two people must be present at all times while

refrigerant is being charged into a refrigeration system.

NEVER leave the area unattended while charging is in

progress.

2. Ensure that ventilation in the space is adequate

to keep the concentration of refrigerant below 1,000parts per million. If necessary, use portable blowers.

3. If refrigerant is being charged into or being

removed from a system, prohibit all nonessential

5-15

TROUBLE POSSIBLE CAUSE TEST REMEDY

Space temperature higher Bad location of thermostat Carefully read Relocate thermostat to athan thermostat setting temperature at the sensing place more representa-

element. tive of average spacetemperatre

Thermostat out of adjust- Calibrate with good ther- Clean, adjust, or replacement or sticking mometer. the thermostat

Cooling coil magnetic Test solenoid valve for Replace solenoid coil.valve not opening sticking valve Clean valve or adjust

pilots.

Space temperature lower Bad location of thermostat Test with reliable ther- Move the thermostat to athan thermostat setting (this will also affect mometer at location. better location.

cooling)

Cooling coil magneticvalve stuck in openposition

Stuck valve. Disassemble and clean.

Heating coil magnetic Test solenoid. Replace solenoid coil.valve stuck or bad solenoid Test valve. Clean the valve.

Thermostat or humidistat Sensing element fouled Examine. Clean.time constant too long, with lint and dirtcausing wide deviationfrom set point

Electric heater does not cut Controller contacts stuck Use test lamp to determine. Replace contacts, springsout or other parts as found

defective.

Electric heater does not cut Overheat protection not Place test lamp across.in reset or defective

Repair or replace.

Figure 5-10.—Trouble diagnosis chart with recommended test included.

personnel from being in or entering the space while the

refrigerant is being transferred.l You feel light-headed.

l You feel giddy.4. Locate an emergency self-contained breathing

apparatus for each person in the space to permit safe

evacuation in the event of a large accidental leak

5. When you suspect refrigerant may be present inthe atmosphere, leave the space immediately if:

l You smell something that is unusual.

l You experience shortness of breath.

l You feel a tingling sensation in your fingers ortoes.

l You suddenly start to feel warm.

l You experience rapid heartbeat,

5-16

6. Before using refrigerant, ensure that all hot work

in the space is suspended.

7. Use chemical safety goggles or a full face shieldwhile handling refrigerant.

8. Exercise care to ensure that liquid refrigerant

does not come in contact with your skin.

9. Where available, use a halide monitor with an

alarm to continuously monitor the atmosphere in the

space where refrigerant is used

10. Post a caution sign in the area to read as follows:

CAUTION

No open flame, smoking, or welding. Do not enter

without testing the air for refrigerant.

11. Establish and document emergency rescueprocedures to ensure all personnel can be safelyremoved from potentially hazardous exposures.

SUMMARY

This chapter has given you some information on theconstruction and maintenance of refrigeration andair-conditioning equipment. A helpful chart for thedetection and correction of operating difficulties wasprovided. While the chapter was not intended as asubstitute for information found in the maintenancemanuals, it should help to identify the correctprocedures to safely inspect, repair, maintain, andtroubleshoot refrigeration and air-conditioning systems.If you have any questions pertaining to performingr o u t i n e m a i n t e n a n c e o n r e f r i g e r a t i o n a n dair-conditioning plants, reread this chapter or refer toyour specific manufacturer’s manual.

5-17

CHAPTER 6

COMPRESSED AIR SYSTEMS

In the EN3 TRAMAN, we learned about the types required to supply air of adequate volume, quality, andof air compressors that an Engineman is required to pressure at the various points of applications. Thisoperate. We also learned how the air is compressed; the supply of air is measured as pounds per square inchrequirements and methods of providing oil-free air; how gauge (psig). Air compressor plants or systems aremoisture is removed from the air; and some of the safety classif ied as low-pressure (0 to 150 psig) ,precautions used when operating or working with medium-pressure (151 to 1,000 psig), or high-pressurecompressed air systems. (1,000 psig and above).

This chapter contains general information aboutmaintenance and repair of compressed air systems. Youshould refer to the appropriate manufacturer’s technicalmanuals, maintenance requirements (3-M), and variousinformation books for more specific information. NavalShips’ Technical Manual, Chapter 551, “CompressedAir Plants and Systems,” is one good source ofinformation.

Aboard Navy vessels, the A division or repairdivision is responsible for maintenance and repair ofcompressed air systems.

LOW-PRESSURE SYSTEMS

AIR SYSTEMS

Compressed air is a form of power that has manyimportant uses. An air compressor plant (fig. 6-1) is

Low-pressure (LP) systems provide compressed airup to 150 psig pressure. For branches requiring lowerpressures, pressure is usually reduced at reducingstations. The following list contains examples of airpressure requirements for LP air:

Figure 6-1.—Typical components of a compressed air system.

6-1

Laboratories 5 to 50 psig You will probably be called upon to fix some

Shops 60 to 125 psig problem on one of these stations. The three most

Laundries and dry cleaning plants 70 to 100 psigcommon problems are wet air, not enough air, or no airat all. First you must trace the system to the station and

Hospitals

Ordinary service

(tools, painting, and so forth)

20 to 50 psig

60 to 80 psig

isolate the problem. It could be just an air valve that ishalfway open, a piping leak, a malfunctioning airreducer, an empty air receiver, or an overfilled moistureseparator. Figures 6-2, 6-3, and 6-4 are maintenance

Soot blowing for boilers 80 to 125 psig requirements for LP air compressor systems.

Figure 6-2.—A maintenance index page for low-pressure air compressor systems (page 1 of 3).

6-2

Figure 6-3.—A maintenance index page for low-pressure air compressor systems (page 2 of 3).

MEDIUM-PRESSURE SYSTEMS

Medium-pressure systems provide compressed airwithin the range of 151 to 1,000 psig pressure. Thesesystems are not extensive and are generally providedwith individual compressors located near the loads.Medium-pressure systems are mainly used for thestarting of diesel engines, soot blowing of boilers and

high-temperature water (HTW) generators, andhydraulic lifts.

Some Navy vessels do not have a separate aircompressor to supply a direct medium-air pressure.Instead, compressed air from HP air systems is stored inthe user’s air flasks (banks) at high pressure. Then whenneeded, the air is routed through a pressure-reducing

6-3

Figure 6-4.—A maintenance Index page for low-pressure air compressor systems (page 3 of 3).

manifold. In this case, medium-air pressure main-

tenance requirements are coupled with the HP air

s y s t e m ’ s P M S . T r o u b l e s a n d r e p a i r s t o

medium-pressure systems are the same as the LP and

HIGH-PRESSURE SYSTEMS

These systems provide compressed air within therange of 1,000 to 6,000 psig pressure. Hazards thatincrease with higher pressures and capacities can be

HP air systems. Those medium-pressure air systems

equipped with air compressors should have a separate

preventive maintenance schedule.

minimized by using separate compressors for eachrequired pressure. Systems operating at 3,000 psig may

6-4

require small amounts of air at lower pressures, which MAINTENANCE OF LP AND HP AIRis supplied through pressure-reducing stations. DEHYDRATORS

Always use caution with HP systems! When HP airenters suddenly into pockets or dead ends, the airtemperature in the confined space increasesdramatically. If there is any combustible material in thespace and the air temperature increases to the ignitionpoint of the material, an explosion may occur.Explosions of this type may set up shock waves thattravel through the compressed air system. This travelmay cause explosions at remote points. Even a smallamount of oil residue or a small cotton thread may besufficient to cause ignition.

Follow the scheduled maintenance of LP or HP airdehydrators according to the PMS requirements. Thefollowing is a sample LP air dehydrator maintenanceschedule and is for general information only:

1. Daily:

- Check applicable power on lights, flowmeterreadings, cooling water temperatures, heatertemperatures, and outlet air temperatures for properoperation.

Some common pressure requirements for HPsystems may be as follows:

Torpedo workshop

Ammunition depot

Wind tunnels

Testing laboratories

600 to 3,000 psig

100, 750, 1,500, 2,000,and 4,500 psig

Over 3,000 psig

Up to 6,000 psig

- Note any dehydrator filter element pressuredrops for element replacement.

- Periodically blow down and clean the conden-ser water strainer.

Figures 6-5 and 6-6 show a maintenance index page(MIP) for one design and make of an HP air compressorsystem. This will give you an idea of the differences inplanned maintenance requirements between the LP air(see figs. 6-2, 6-3, and 6-4 for comparison) and HP airsystems. It is very important that the PMS you are usingare the correct ones.

- Blow down type I and type III dehydrators.Dump the valve if more than 1/2 pint of water drainsout; the automatic feature is not working.

- Check the purge pressure and the free move-ment of the purge flowmeter float of type II and type IIIdehydrators.

2. Weekly: Blow down the inlet separator,prefilter, and trap dump valve of dehydrators by openingthe manual drain valve.

3. Monthly:

You should inspect air flasks, receivers, separators,and piping for damage or external corrosion once every6 months. Enter the inspection date and results in theMaintenance and Material Management (3-M) Systemsby submitting a work request for any discrepanciesfound. You must document completion of all inspectionresults through PMS.

- Check the outlet air moisture content. The dewpoint should be below -40°F at 80 lb/in2 for both type II

2and type III dehydrators, and below 40°F at 80 lb/in fortype I dehydrators. An excessive dew point indicates amalfunction.

AIR DRYERS OR DEHYDRATORS

- Check the inlet and outlet filters and the purgefilter for the type II and type III dehydrators. Replacethe filter elements if necessary.

4. Quarterly:

- Clean the condenser water tubes.The Navy uses three types of air dehydrators for

drying LP air. These are the refrigeration (type I),desiccant (type II), and combination of bothrefrigeration and desiccant (type III). HP air applicationuses only the type III. The Navy is replacing the varioustypes of desiccant used in the fleet with activatedalumina beads in 1/8-inch diameter spheres. This typeof desiccant is also intended to reduce dust problemsproduced by the other various types. The dust causesclogged filters and other component malfunctions.

- Disassemble and clean the inlet and interstageseparators and purge the solenoid valves.

5. Annually:

- Remove and calibrate the pressure gauges.Adjust them to give maximum error 2 lb/in2 (1 percentof full scale).

- Disassemble the desiccant chambers. Cleanthe assembly of dust, oil, and dirt. Replace the desiccant

6-5

Figure 6-5.—A maintenance Index page (MIP) for one design and make of high-pressure air compressor systems (page 1 of 2).

if it is significantly powdered, burned, or discoloredwith oil carry-over.

- Remove the desiccant chamber check valves.Discard and replace them with new items. Adjustmentand repair of the dehydrators and their componentsshould be accomplished according to the appropriateequipment technical manuals.

AIR QUALITY TESTING

Air quality testing is the daily monitoring of the dryair dew point at the dehydrator’s outlet. Testing isconducted with a LP frost point indicator, MIL-I-24144.

6-6

Figure 6-6.—A maintenance index page (MIP) for one design and make of high-pressure air compressor systems (page 2 of 2).

DEHYDRATOR DEW POINT READINGS 1. LP air (type I) dehydrator’s normal dew point

This reading is taken every 4 hours of dehydratorservice. Readings verify that the dehydrator is operatingcorrectly. The normal readings of the various types ofair dehydrators are as follows:

reading is a dew point temperature reading of 40°F orlower at 80 lb/in2. This indicates that the dehydrator isdelivering an air quality within its design capability. A

reading of 50°F or higher at 80 lb/in2 indicates that thedehydrator is not working properly, and you shouldcheck the applicable technical manual.

6-7

2. A dew point temperature reading of -40°F orlower at 80 lb/in2 is normal for LP (type II and type III)dehydrators. A reading of -20°F or higher at 80 lb/inindicates that the dehydrator is not operating properly,and you should check the applicable technical manualto correct the problem.

3. For HP air dehydrators, a dew point temperaturereading of -60°F or lower at atmospheric pressure isnormal. A reading higher than -60°F at atmosphericpressure indicates that the dehydrator is not workingproperly, and you should check the technical manual forthe solution to the problem.

MAINTENANCE OF RECIPROCATINGAIR COMPRESSORS

To keep the ship’s air compressors operatingefficiently at all times, you must know what commontroubles may occur and their causes. You must knowhow to care for the air intakes; how to maintain andreplace air valves; how to take care of air cylinders andpistons; and how to adjust bearings, wrist pins, andcouplings. You must be able to maintain, troubleshoot,and repair the lubrication, cooling, control, and airsystems.

AIR INTAKES

A supply of clean, cool, dry air is essential to thesatisfactory operation of compressors. To ensure this,the air intake filters must be regularly inspected andcleaned; otherwise, the filter becomes clogged andcauses loss of capacity. A clogged air intake screen orfilter may also cause a compressor to draw oil from itsown crankcase, around rings, or through oil seals,resulting in an explosion.

Remove the filter element and clean it with a jet ofhot water or steam, or plunge it into a strong solution ofsal soda. The filter body should be drained and replaced.If the filter is the oil-wetted type, dip it in clean,medium-grade oil and allow it to drain thoroughlybefore replacing the filter in the intake. Do not usegasoline or kerosene for cleaning filters! The fumesmay collect and explode in the compressor or receiver.

Take care to prevent entrance of rain or spray intointake pipes, and provide a means for draining the intakepipe of any water that may collect. The lines should beas short and direct as possible.

For air compressors used to supply air for the divers,you must prevent the compressor from taking in exhaustgases coming from any internal combustion engines.

You must also prevent any possible intake of fumescoming from fuel tank vents, spilled oil, or gasoline.

AIR VALVES

Air inlet and discharge valves must be kept cleanand in good working order. Leaky valves are generallydirty valves, and they cause capacity loss. The valvesare removed by first loosening their setscrews orclamps, and then removing their cover plates. Eachvalve and valve unloader, if fitted, may then be liftedout. Each valve should be marked to make certain thatit is returned to the same port from which it wasremoved.

Valves removed for inspection should not be takenapart for cleaning unless their conditions make itnecessary. Dirt or carbon in valve ports can usually beremoved without taking the valve apart. This is done bysoaking the valves in kerosene, and then giving them astiff brushing or a light scraping. Valve action should betested by inserting a screwdriver through the seat ports;the valve should lift and close freely.

If it becomes necessary to disassemble the valve,note the arrangement of the various parts so that theproper relationship will be kept when the valve isreassembled. (Periodic shipboard reports indicatedamage to pistons and associated valve parts frequentlyresults from improperly assembled valves that protrudein the way of the oncoming piston.)

Before replacing air valves in a cylinder, inspect thegaskets and replace any that are damaged.Copper-covered asbestos or plain, thin copper gasketsshould be used. If these are not available, 1/16-inchcompressed-asbestos sheet gaskets may be usedtemporarily. Each valve assembly should be inserted inthe same hole from which it was removed. Since it maybe difficult, in many cases, to distinguish betweensuction or discharge valves, extreme care must be takenwhen the valves are being inserted in the cylinder. Makecertain that suction valves open TOWARD, and thedischarge valves AWAY FROM, the center of thecylinder; otherwise, serious damage or loss of capacitywill result. Then place the valve cover on the cylinder,making certain that its gasket is squarely in place; drawdown on the cover nuts evenly, and in turn, so as not totilt the cover. Tighten down the valve setscrew orclamping bolt, drawing it tight to hold the valve on itsseat. If special locknuts are not provided to seal againstleakage at the threads of the valve setscrew, a turn ofsolder or fuse wire should be placed around the screwand set down into a recess by a locking nut.

6-8

CYLINDERS AND PISTONS

The cylinders on pistons should be inspected onlyAFTER the manufacturer’s technical manual has beenconsulted. Be careful when removing heads, parti-cularly where metal-to-metal joints are involved, toprevent damage to the joint.

If replacement of piston rings is required becausethey are worn or broken, take accurate measurements ofthe cylinder liners. Standard size rings may be used inoversize cylinders if the oversize does not exceed 0.003inch per inch of cylinder diameter. The liner may alsoneed to be replaced if it is badly worn or out of round.When replacing piston rings, first fit them to the cylinderto check for proper end clearance. You can file the ends,if necessary, to make them fit. The side clearance of therings should be such that the rings will fall easily intothe piston grooves, which should be deep enough for thering thickness. Ring splits should be staggered. Afteryou assemble the piston, wire the rings tight with a softcopper wire so that they will enter the bore easily. Thiswire can be removed through the valve ports after thering has started into the cylinder bore.

When reassembling the air cylinders and heads, besure they are all drawn down evenly, especially onmultistage compressors where the heads containcylinders for third and fourth stages. Otherwise, theresult will be excess wear on the cylinders and pistons.

When a compressor piston has been replaced, thepiston end clearance must be checked. This is done byinserting a lead wire through a valve port or indicatorconnection. Jack the compressor over. When the pistonhas moved to the end of its stroke, the lead will beflattened to the exact amount of clearance. The wireshould be long enough to permit a reading near thecenter of the piston. These readings should be taken afterany adjustment or replacement of the main, crank pin,wrist pin, or crosshead bearings. Methods of adjustingthe clearances vary according to the compressor design.You should consult the manufacturer’s instructions forsuggested adjustment.

MISCELLANEOUS ADJUSTMENTS

From time to time other miscellaneous adjustmentsare required on compressors, including those pertainingto wrist pins, crosshead shoes, reduction gears,couplings, and V-belt drives. The manufacturer’stechnical manual will give you specific information forthe care, adjustment, and replacement of all fittedbearings. Refer to the manufacturer’s instructions for

detailed information on when and how to make theseadjustments.

Wrist pin bushings are replaced when necessary.This is done when they are worn to the point ofbecoming noisy. In making a replacement, be sure theoil hole in the bushing is properly lined up with the oilhole in the connecting rod. After being pressed into therod, the new bushing must be reamed.

Crosshead shoes are provided with shim or wedgeadjustment. Wear should be slight, but adjustmentshould be made when the travel of the piston rod causesa movement in the stuffing boxes.

Alignment of reduction gears and pinions should bechecked periodically, especially on a new compressor.Misalignment may be caused later by settling, straining,or springing of foundations; pipe strains on turbine-driven compressors; bearing wear; or springing due toheat from a turbine.

Flexible couplings require very little maintenancewhen they are properly lined up. Some types requireoccasional lubrication to prevent excessive wear ofsprings and bushings. A noisy coupling is an indicationthat the bushing is worn and requires replacement.

V-belt drives require adjustment for belt tension.Belts generally stretch slightly during the first fewmonths of use. A loose belt will slip on the motor pulleyand cause undue heating and wear on the belt. A tightbelt will overload the bearings. Belts should be protectedagainst oil and high temperatures. To prevent rapiddeterioration, belts should not be used at temperaturesabove 130°F. V-belts are usually installed in sets of twoor three. If a single belt is worn or deteriorated, thecomplete set should be replaced to ensure that each beltwill carry its share of the load.

LUBRICATION SYSTEM

Proper care of a compressor lubrication systemincludes the following:

- Keep the oil at a normal level in the reservoirat all times to maintain proper oil temperature.

- Change crankcase oil periodically, and at thesame time clean and flush the crankcase and clean theoil filter.

- Maintain proper lube-oil pressure by keepingthe oil pump in good working order and adjusting thebypass relief valve.

6-9

- Keep the oil cooler free from leaks (sincepressure on the water side exceeds that of the oil) toprevent oil contamination and emulsification.

- Properly adjust the lubricator for the specifiedquantity of oil feed.

COOLING SYSTEM

Proper care of a compressor cooling systemincludes the following inspections and maintenanceprocedures:

- Periodically inspect the intercoolers andaftercoolers.

- Remove collections of gummy oils or tarrysubstances from the cooler tubes by washing tube nestswith a suitable solvent and drying them thoroughlybefore reassembling.

- Correct any leakage in tube nests to preventleaks of water into the compressor while secured orleaks of air into the water side during operation.

- Inspect and clean the cylinder water jacketsperiodically with a cleaning nozzle.

When filling the cooling water system after thecompressor has been drained, open the water inletslightly to allow the water to rise slowly in the coolershells and water jackets. Vent valves fitted to the waterspaces should be opened to permit entrapped air toescape and to remove any air pockets.

CONTROL DEVICES

Because of the great variety of regulating andunloading devices used on compressors, you will have

to consult the manufacturer’s technical manual forinformation regarding the adjustment of these deviceson particular compressors.

If a control valve fails to work properly, it should betaken apart and cleaned Some valves are fitted with afilter filled with a sponge or woolen yarn to prevent

particles of dust or grit from being carried into the valvechamber. These filters remove gummy deposits from theoil used in the compressor cylinders. When repacking,use only genuine wool. Cotton will pack and stop theairflow. Relief valves are very important for safecompressor operation. They should be set as specifiedby the manufacturer and lift-tested by hand each timethe compressor is placed in operation. To check thesetting periodically, test by raising the pressure in thespaces to which they are attached.

SUMMARY

Since an Engineman may encounter so many typesof compressed air systems, air dryers, and aircompressors both ashore and aboard Navy vessels, thischapter presented only general procedures and facts. Tomaintain, repair, and overhaul specific compressed airsystems, air dryers, or reciprocating air compressors,you must refer to the manufacturer’s technical manuals.A definite preventive maintenance schedule withfrequency and assignment of responsibility is required.

You should have the manufacturer’s manual handy toestablish minimum requirements and to follow itsrecommendations for maintenance.

6-10

CHAPTER 7

LAUNDRY, MESS DECK, GALLEY, AND SCULLERYEQUIPMENT

This chapter presents some information on ways tomaintain, repair, and troubleshoot the common types ofequipment in the laundry, mess deck, galley, andscullery. Because of the differences in types ofequipment you are expected to maintain, only generalinformation is presentedin this chapter. Remember, youshould study the manufacturer’s manual that comes withthe equipment before you attempt to maintain it.Although Enginemen are not the operators of thisequipment, you as an Engineman are responsible for anyrepairs, replacements, or adjustments of this equipment.The exception is where there is a need for any electricalwork

Because you are familiar with this equipment, youcan help the operator learn to properly clean andmaintain these pieces of equipment. Laundry, messdeck, galley, and scullery equipment should haveassigned PMS requirements.

For any particular information on laundry, messdeck, galley, and scullery equipment, refer to theequipment’s technical manual or the Naval Ships’Technical Manual (NSTM), Chapter 655, “Laundry,”and Chapter 9340, “Commissary Equipment.”

LAUNDRY EQUIPMENT

All laundry equipment must be in good operatingcondition, especially on deploying ships that stay at seamost of the time. It is also important that all safetydevices that protect the equipment and operator areworking. Safety devices that are not working, or thathave been removed for any reason, must be replacedbefore they can be used.

NAVSEA S6152-B1-CAT-010 is a technical manualcatalog for Navy laundry and dry-cleaning equipment.This catalog lists standard laundry and dry-cleaningequipment identified by national stock numbers,allowance parts lists, and part numbers. You shouldobtain a copy of this catalog. Currently, the NavalSupply System supports approximately 600 differentlaundry equipment types, most of which are nowobsolete. You can help reduce this number by assisting

in the selection of the standard items described in thiscatalog.

WASHING MACHINES

You can avoid problems with washing machines ifthe operator will do the following:

- Do not overload the machine.

Strictly follow the operating instructions.

Report to the auxiliary or repair division anymalfunctioning safety device and any abnormalcondition, such as excessive vibration, leaks, ormissing parts.

Wipe all excess oil, dirt, and laundry suppliesfrom the machine at the end of each day.

Inspections

Inspect washing machines at regular intervals toensure that they work properly. If an inspection revealsadjustments or repairs are needed, make them promptly.Some of the important items to be covered in aninspection are as follows:

1.

2.

3.

4.

5.

Ensure the machine is level.

See that bolts, nuts, and screws are tight.

See that latches on cylinder doors work properly.

Make sure the thermometers are accurate.

Have an electrician check the switches to be sure

they are properly adjusted and working correctly.

6. Have an electrician check the timer to ensure it

is in working order.

7. Check water level gauges to determine if theyare correct.

8. Have an electrician check all the controls to besure they are working properly.

7-1

Maintenance, Repairs, or Overhauls

You should prevent water from entering gear

casings on washing machines. To do this, make sure all

gear gasket covers and stuffing boxes are tight.

Examine and lubricate, at frequent and regular intervals,

all the bearings and gearing. Advise the division

responsible for the equipment that any requests for

repairs and parts replacements must be submitted on

Ship’s Maintenance Action Form, OPNAV 4790/2K.

By following this procedure, you can determine what

part or parts are failing. And, you will have clear

documentation of all requested parts and repairs. You

should follow the applicable MRCs for maintenance.

TUMBLER DRYERS

A properly maintained and not overloaded tumbler

dryer will dry a load of laundry in approximately 20

minutes. If drying is not completed within this period,

you should look for the following conditions or troubles:

- Has the water from the laundry been properly

extracted?

- Is the tumbler overloaded?

- Are the lint screens clean?

- Is there enough steam pressure?

- Is the tumbler rotating in the right direction?

Figure 7-1.—A front view of a typical shipboard laundry dryer.

7-2

Figure 7-2.—A rear view of a typical shipboard laundry dryer.

Figures 7-1 and 7-2 illustrate a typical shipboardlaundry dryer. You should pay particular attention to thelocation of the parts.

Troubleshooting

Tables 7-1 and 7-2 list some common troubles,causes, and remedies on shipboard laundry dryers.These tables do not replace any procedures on yourshipboard dryer manuals, nor do they replace theprocedures specified by the equipment’s PMS.

Repairs or Overhauls

You should lubricate all dryer bearings at regularintervals according to the manufacturer’s technical

manual. Advise the division responsible for theequipment to submit the request for repairs and partsreplacements on Ship’s Maintenance Action Form,OPNAV 4790/2K. This procedure will help youdetermine parts that are failing and provide you withdocumentation of repairs. You should follow theapplicable MRCs for maintenance.

LAUNDRY PRESSES

Some ships are equipped with air-operated pressesand others with steam-operated presses. But both typesof presses use steam for heating. The trouble theoperator will most often encounter is insufficient supplyof air pressure for the air-operated presses, and notenough steam pressure for the steam-operated laundry

7-3

Table 7-1.—CommonTroubles, Causes, and Remedies on Shipboard Laundry Dryers

TROUBLE

No steam tosteam bonnet

CAUSE

Trap installedincorrectly

Supply line valveclosed

REMEDY

Check trap for inlet and outlet markings. Install trap according tomarkings.

Open valves in supply and in the return lines.

Check valveinstalled incorrectly

Strainer clogged

Check for inlet and outlet marking on check valve, and invert ifnecessary.

Remove plug and blow down strainer or remove and cleanthoroughly if heavily clogged.

Water in steamline

Steam piping Check piping per steam installation instructions.installed incorrectly

Trap not functioning Check trap for size and capacity. If dirty and sluggish cleanthoroughly or replace. Check return line for high back pressure, oranother trap charging against the trap functioning improperly.

Motors won’tstart

No power

Incorrect current

Check fuses on circuit breakers, make sure main control switch ison. Request an electrician.

Check power source. Voltage, phase, and frequency must be thesame as specified on electrical rating plate. Request an electrician.

Time offOverload relays

tripped

Turn timer clockwise to desired time setting. Rush reset buttons oncontrol box. Request an electrican.

Loose wiringConnections

Check all terminal connections. Request an electrician.

Defective startingrelay

Check coils and contacts. Request an electrician.

Fan motor only Loading door open Close door.runs

Door switch out of Adjust switch by removing cover and bending actuator lever toadjustment clear switch button 3/8” with cover in place.

Defective Door Replace switch.switch

Dryer runs nosteam to coils

Valves closed

Steam trap blocked

Check all valves in steam supply & return to make sure they areopen.

Remove and clean. Replace if defective.

presses. Both types of presses require the right amount hydrostatically tested annually as specified by the

of steam pressure for heating. You, as the manufacturer’s manual. If not specified in the

maintenanceman, must make sure safety devices are not manufacturer’s manual, test to 150 lb/sq. inch according

bypassed. All press heads and bucks should be to chapter 655 of NSTM for 1 minute.

7-4

Table 7-2.—Common Troubles, Causes, and Remedies on Shipboard Laundry Dryers-Continued

TROUBLE CAUSE REMEDY

Dryer runs, Inadequate venting Proper operation of steam dryers depends on air flow through the coils.steam passing Inadequate makeup Venting must be done with the least possible restriction. Make up airthrough coil, air opening of at least 350 sq. inches free area must be available in thedryer doesn’t Lint trap blocked vicinity of the dryer to replace the air being exhausted out by the dryer.heat. Lint traps must be kept clean.

Coil fins clogged Coil fins must be kept clean.with lint

Steam supply & Must be properly installed and adequately sized. See piping installationreturn sheet.

8-stage heat control Check for loose dampers. Adjust dampers and tighten set screw in contolhandle.

Tumbler Noisy Not level Check manual for proper leveling procedure.or Vibrating

Fan out of balance Accidental damage to the fan blade can change the dynamic balance.Damaged fans should be replaced.

Basket rubbingV-Belt sheaves

Belt

Foreign objects

Adjust basket clearances.Tighten set screws. Make sure sheaves are in proper alignment.

Adjust belt tension.

Occasionally screws, nails, etc. will hang in the basket perforations anddrag against the sweep sheets surrounding the basket. Such foreignobjects should be removed immediately.

You should lubricate all bearings, the dashpot, and of the machine. Trained personnel can avoid troublesthe air cylinder regularly as specified by themanufacturer’s manual or by the applicable MRCs.Advise the division responsible for the equipment tosubmit requests for repairs and parts replacements onShip’s Maintenance Action Form, OPNAV 4790/2K.This procedure will help you, as the maintenanceman,track the parts that are failing and provide you withdocumented repairs. The maintenance of all laundrypresses should be according to the applicable MRCs.

MESS DECK EQUIPMENT

Common mess deck equipment on most Navy shipsis either used for chilling or warming foods. For chillingfoods, there are salad bar tables, beverage dispensers,and milk dispensers. Some of the troubles that amaintenanceman may encounter on this equipment aretoo much frost buildup, not getting cold, or not workingat all. Some problems can easily be corrected orprevented by training the operator on the proper usage

by correctly loading refrigerators, properly securing thedispenser door, and using proper defrosting techniques.Improper defrosting, such as the use of a pointed objectto scale out thick frost buildup, often results in pin holeson the cooling coil and loss of refrigerant charge. If youtrain and encourage mess deck operators to practiceproper equipment use and maintenance, your job andtheirs will be easier.

For warming foods, there are electric andsteam-operated food warmers. Troubles withsteam-operated warmers are normally either not gettingenough steam pressure or not getting any steam at all.You as a maintenanceman can troubleshoot this byinspecting the steam line and checking it for leakage orrestrictions such as water in the steam line. Restrictionscan be detected by a hammering noise in the line. Whenbleeding a steam line, be sure you are well protected bywearing a face shield and thick gloves. To release anywater trapped inside the steam line, you should slowly

7-5

Figure 7-3.—Schematic drawing of a steam table.

open or lift the bleeder valve. Figure 7-3 is a typicalschematic drawing of a steam table. Notice the steamtable’s piping system in this figure.

The food service division is responsible for routinepreventive maintenance of all mess deck equipment.Any major troubleshooting, repairs, or overhauls are theresponsibility of the repair or auxiliary division. Youshould advise the division responsible to submit allrequests for repairs and parts replacements on Ship’sMaintenance Action Form, OPNAV 4790/2K.

GALLEY EQUIPMENT

Galley equipment must be maintained in a safe,sanitary, and economical way. Enginemen maintain thisequipment, and they frequently tram the food servicepersonnel on how to properly operate the equipment. Itis always a good practice to post operating instructionsnear the equipment. This will help to ensure that theoperators do not abuse the machines. You may be calledon to help inspect galley equipment. You can also helpdetermine the type of maintenance and the extent ofrepairs required to keep the equipment safe and efficient.Remember, the medical department is responsible forconducting sanitary inspections. The supplydepartment is responsible for keeping food-handlingequipment clean. And, the engineering department isresponsible for maintaining the operation of thisequipment.

REFRIGERATORS (SELF-CONTAINED)

Galley refrigerators will not have any problems ifthe user will do the following:

- Allow proper clearance in the back of therefrigerator. The refrigerator must have adistance of at least 4 inches away from thebulkhead. Any obstruction will reduce theairflow required for an air-cooled condenser.

Do not overload the refrigerator.

Properly store foods with space for aircirculation.

Follow the MRC for routine maintenance likedefrosting and cleaning.

Do not use any sharp objects like knives orscrapers when defrosting the refrigerator. This isnot an acceptable procedure for removing frostbuildup on a refrigerator.

When repairing or overhauling a refrigerator, referto the manufacturer’s manual. “Refrigeration System,”Chapter 516 of NSTM contains general procedures onhow to maintain or repair a self-contained refrigerator.Follow all the necessary safety precautions whenhandling and disposing of a refrigerant!

Figure 7-4.—An arrangement of steam-jacketed kettles.

7-6

STEAM- JACKETED KETTLES

Kettles require, as a minimum, monthly inspections.Figure 7-4 illustrates an arrangement of shipboardsteam-jacketed kettles. An annual preventivemaintenance inspection is also important. Here are afew factors to keep in mind while inspectingsteam-jacketed kettles.

When making a MONTHLY inspection, check thedraw-off faucets, valves, and piping for leaks. Checkthe steam pressure-reducing valve to ensure it is in goodcondition and is functioning properly. Lubricate thehinges of the kettle cover with mineral oil.

During the ANNUAL inspection, check each kettlefor leaks, cracks, and dents. Examine the cover, hinges,and latch for warp and alignment. Check the steampiping and the condensate piping, the valves, and thetraps for leaks and obstructions. Remove the safetyvalves; then clean, lubricate, and calibrate them beforereinstalling. Remove any rust and corrosion by using

Navy approved solvents. Other than visual inspections,each individual piece of galley equipment requires itsown type of preventive maintenance.

During each ship’s regularly scheduled overhaul,steam-jacketed kettles should be tested using thefollowing procedure:

1. Put each kettle into a cold-water pressure test of90 psi for not less than 30 minutes.

2. Check the safety valves on each kettle. Thetesting of safety valves should he covered by the PMS.In general, kettle safety valves are set to release at apressure of 45 psig.

3. Replace kettles that are cracked, badly pitted, orbulge under a pressure test.

4. Replace all malfunctioning safety valves.

Table 7-3 shows some common troubles and repairrecommendations on steam-jacketed kettles and othersteam-heated equipment.

Table 7-3.—Common Troubles and Repair Recommendations on Steam-Jacketed Kettles and Other Steam-heated Equipment

Inspection Point

Steam jacket

Steam jacket

Steam jacket

Pipe joints

Pipe joints

Control valves

Control valves

Condensate strainer

Steam trap

LaggingReducing valve

Safety valve

Covers

Drawoff valve

Symptoms

Not beating

Stays hot

Leaks

Leaks

Corrosion

Stuck open or closed

Leaks at stem

No flow

Malfunctioning

Broken or crushed

Incorrect pressure

Stuck open or liftingunder pressure

Tight operation

Leaks

Time

When noted

When noted

Monthly

Monthly

Monthly

When noted

Weekly

When noted

Every 6 months

QuarterlyWhen noted

When noted

When noted

When noted

Possible Troubles/Causes

No steam; valve stuckclosed; trap malfunctioning

Valve partly open or scoredseat

Rapid changes in temperaturecausing cracks; faulty weld

Joints made incorrectly; nottight

Leaks or condensation

No steam or too much steam;packing too tight or valvefrozen

Packing not tight enough

Restricted strainer

Parts dirty or worn

Water soaked; stepped on

Parts dirty or worn

Leaks or corrosion

Hinges dirty

Scored

Possible Corrections

Check steam supply; freestuck valve

Repair or replace valve

Raise heat slower, reweldbust or crack

Unscrew, clean and repairjoint

Repair and/or clean

Loosen packing gland or freefrozen valve stem

Tighten packing

Clean strainer

Disassemble, clean, and repair

Replace defective sections

Disassemble, clean, andrepair; clean and adjustpressure every 6 months

Replace or repair valve

Clean and lubricate binges

Resurface or replace.DO NOT REPLACE WITHREGULAR GATE VALVE

7-7

Figure 7-5.—Semiautomatic singie-tank dishwasher machine for use in and messes.

7-8

SCULLERY EQUIPMENT

You must read the manufacturer’s instruction book

for each machine and become familiar with all its

operating characteristics and its basic design. If

routinely cleaned, descaled, and properly maintained,

scullery machines will not have any problems. But

these procedures must be done on time as specified by

the planned maintenance schedule or by themanufacturer’s manual. Any necessary repairs and

parts replacement requests must be submitted by the

responsible division on Ship’s Maintenance Action

Form, OPNAV 4790/2K. Following this procedure and

using this form will provide you, as the maintenance

person, a document of repairs and parts that failed.

TROUBLESHOOTING

From time to time, you may be called upon to repair

scullery machines that have become defective. Figures

7-5 and 7-6 illustrate the types of scullery machines usedby the Navy. Some common difficulties, the usual

reasons for their occurrence, and possible remedies for

those difficulties are listed in table 7-4.

REPAIRS OR OVERHAULS

Scullery machines must be inspected by themaintenance personnel according to the PMS schedule.L i s t ed he re a re some common inspec t ions ,maintenance, repairs, or overhauls you may encounterwith these machines. You should perform the following:

1. Check the adjustment of tension on the conveyorchains if the machine is equipped with a conveyor. Ifthe chain is equipped with lugs, make sure the lugs onboth chains are directly opposite each other.

2. See that the guide sprockets are properly locatedon their shaft so that the conveyor chain will rideproperly on the track assembly.

3. Inspect the operation of the doors and make sureall the counterweights are properly attached and thedoors are held in the open position when raised.

4. Check the operation of thermometers, pressuregauges, thermostats, and automatic mixing valves orboosters.

5. Adjust the thermostat so that the machine willnot start up unless the desired temperature is reached.

6. Inspect the pump packing and adjust asnecessary to stop leakage around the pump shaft.

Figure 7-6.—Cutaway view of a double-tank automatic dishwasher.

7-9

7. Lubricate the motor and pump bearings.

8. Lubricate, as necessary, the gear reducer unit.

9. Lubricate the conveyor shaft bearings, drivemechanisms, sprocket chains, and so on.

SUMMARY

This chapter has presented some generalinformation on maintenance and repairs of laundry,mess deck, gal ley, and scullery equipment.Maintenance personnel should make use of the

10. Replace any missing lubrication fittings.

11. Inspect all steam and water valves.

12. Disassemble and inspect pumps internally forundue erosion or corrosion at least annually.

manufacturer’s technical manual, the PMS, and otherrelated NSTMs, which are furnished to all Navy ships.

Table 7-4.—Troubleshooting Chart for Scullery Machines

Trouble

Dish racks slide off chain conveyor.

Water pressure too low.

Water splashing on floor or intowrong compartment.

Rinse water temperature is lessthan 180°F.

Spot or film on eating utensils afterfinal rinse.

Probable cause

Change of tension on either chain.

Spray nozzles or slot plugged.Strainer baskets plugged. Slippedbelts on pumps.

Leaks around doors; torn curtainsor curtains not in proper position.

Insufficient heat from boosterheater.

Wash water saturated with grease.Dirty tank Weak sprays in wrongdirection. Improper detergentmixture.

Possible remedy

Reset idler sprockets to propertension on each chain.

Dismantle spray assembly. Washout piping; clean parts.Disassemble and clean strainer. Ifbelts are frayed or tom, replacethem. Adjust tension by resettingidler pulley or by moving motor onsliding base.

Realign door. Repair or replacegasket. Repair or realign curtain.Readjust spray to keep it withinlimits of tank.

Remove scale from steam coil.Correct leaking fittings. Calibrateor replace thermostat.

Stop operation and clean allEquipment. Adjust speed ofconveyor. Examine sprayequipment. Clean nozzles, spraypipes, scrap trays, and strainers.Check piping for leaks. Check tosee if valves are operating properly.Examine pump. Clean impeller ifnecesssary.

7-10

CHAPTER 8

OTHER AUXILIARY EQUIPMENT

This chapter provides general information on themaintenance and repair of a variety of auxiliarymachinery that you will be called upon to repair, replace,or adjust. Auxiliary machinery includes controllablepitch propellers, low-pressure steam drain systems,high-pressure steam drain systems, distilling plants,hydraulic systems, external hydraulics, hydraulic cargohatch covers, boat davits, bow ramp and doormachinery, elevators, conveyors, cranes, dumbwaiters,and escalators. You as an EN3 must have alreadycompleted personnel qualification standards (PQSs) onsome of this auxiliary equipment.

CONTROLLABLE PITCHPROPELLERS

This section will discuss some general facts aboutthe maintenance and repair of controllable pitchpropellers. For more information you can refer totechnical manual system-oriented instructions,Controllable Pitch Propellers, LST 1182 through LST1198, NAVSEA 0944-LP-007-1018, or MaintenanceManual for Controllable Pitch Propellers in DD-963Class, DDG-993 Class, and DD-997 Class,S9245-BF-MMM-010.

Keeping the hydraulic system clean is of the greatestimportance. During a dismantling, there is always apossibility of foreign matter entering the system. Youmust avoid any unnecessary dismantlings as long as thesystem is working satisfactorily. If the system or a parthas to be dismantled, you must be sure that all parts andpipes are clean before reassembling.

Wipe up any oil or dirt found on or near thehydraulic valve manifold, the oil distribution (O.D.)box, or the control plate assembly. Keep bilge waterlevels below the lower oil tank manhole cover. And, ifpossible, keep bilge water below the O.D. box shaftpacking glands. Check all fittings and locking devicesperiodically to be sure they have not vibrated loose.Lubricate all moving parts weekly and wipe up excessoil. Periodically check the water near the stem of theship for oil slicks that could result in oil leakage fromhub or blade seals. Very minor leaks can be detected onthe surface of the water. Follow the maintenanceaccording to the maintenance requirement cards

(MRCs). Make sure the MRCs are all tailored for yourequipment. If you find an error, you must submit afeedback report.

LOW-PRESSURE STEAM DRAINSYSTEMS

Service steam (low-pressure) drainage systemscollect the uncontaminated drains from low-pressure(below 150 psi) steam piping systems and steamequipment outside the machinery spaces. Space heatersas well as equipment used in the laundry, the tailor shop,and the galley are typical sources of drains for theservice steam drainage system. Aboard some ships,these drains discharge into the most convenientlylocated freshwater drain collecting tank. On other ships,particularly large combatant ships, such as carriers, theservice steam drains discharge into special service steamdrain collecting tanks located in the machinery spaces.The contents of the service steam drain collecting tanksare discharged to the condensate system. In addition,each tank has a gravity drain connection to thefreshwater drain collecting tank and to the bilge sumptank located in the same space.

Notice that the service steam drainage systemcollects only clean drains that are suitable for use asboiler feed. Contaminated service steam drains, such asthose from laundry presses, are discharged overboard.

Service steam drain system components consist ofvarious pipings, steam traps, valves, and flanges. In theevent you need to make repairs on this system, makesure the system is properly tagged. If needed you canrequest assistance from the Hull Technicians, who arewell trained for this job.

HIGH-PRESSURE STEAM DRAINSYSTEMS

High-pressure drainage systems generally includedrains from superheater headers, throttle valves, mainand auxiliary steam lines, steam catapults (on carriers),and other steam equipment or systems that operate atpressures of 150 psi or more. The high-pressure drainsaboard some ships lead directly into the deaerating feedtank (DFT). Aboard some newer ships, thehigh-pressure drains empty into the auxiliary exhaust

8-l

line just before the auxiliary exhaust steam enters theDFT. In either case, the high-pressure drains end up inthe DFT.

These systems have basically the same componentsas the low-pressure steam drain systems. Componentsspecifically designed for high-pressure steam and theaddition of orifices are the only major differences.Whichever system is to be repaired, the system must betagged. When dealing with repairs on both low-pressureand high-pressure steam systems, there should be acontrolled work procedure package. You should reviewthe QA manual concerning repairs on steam systems.Remember you can request assistance from thepersonnel who are trained to do the repairs. For moregeneral information concerning steam plants, readBoiler Technician 3&2, NAVEDTRA 10535-H.

DISTILLING PLANTS

This sect ion wil l deal with inspections,troubleshooting, and repairing of low-pressure steamdistilling plants. The two most common types used bythe Navy are the submerged-tube and the flash-typedistilling plants. Additionally, this section will mentionsome facts about the heat recovery type of distillingplant the Navy also uses.

SUBMERGED-TUBE PLANTS

Low-pressure submerged-tube distilling plantsdiffer from ship to ship, but the operating conditions andthe maintenance procedures are basically the same. Inalmost all instances, the personnel who stand watcheson the distilling plants are also responsible for themaintenance of the plants. When operating problems dooccur, it is the responsibility of the EN2, ENl, or ENCon duty to locate the trouble and to make the necessaryadjustments or repairs.

Distilling plant reliability and consistent operatingconditions are essential for satisfactory results. Exceptunder emergency conditions, no plant should be forcedbeyond its rated capacity. Requirements for highersteam pressures result in higher temperatures, whichwill cause more rapid scaling of the evaporator tubes.

During operation, the various elements of any plantdepend on the heat and fluid balances throughout theplant. Adjustment of any one control can producewidespread changes to these balances. For example, anincrease in the feed to the first effect will raise the liquidlevel in the first effect. More heat will be required toraise the feed to the boiling point, so that less heat willbe available for evaporation in the first-effect shell and

a smaller amount of heat will flow to the second-effecttube nest. These changes produce a new balancedcondition, and other adjustments would be required tomake the new balance satisfactory. Under suchcircumstances, overcontrolling could require manyreadjustments. The operator will always find it better tomake small adjustments, one at a time. This will allowenough time between each adjustment for all theconditions to become steady.

Causes of Low Plant Output

Failure to obtain full rated capacity is one of themost frequent problems encountered during theoperation of a distilling plant. The problem may be verydifficult to remedy since it may result from acombination of things. Adecrease in the distilling outputefficiency may result if any of these factors are not met.Full output requires the following:

1. Proper steam pressure above the orifice

a. Ample steam supply

b. Proper operation of reducing valves

2. Highest possible vacuum in the first-effect tubenest

a.

b.

c.

d.

e.

f.

No air leaks

Proper water levels in the evaporator shells

Continuously vented evaporator tube nests

Reasonably clean evaporator tube nests

(1) Continuous feed treatment

(2) Mechanically cleaned tubes

Density of brine overboard not over 1.5/32

(1) Reasonably clean overboard piping

(2) Proper valve settings

(3) Proper operation of brine pump (cleanpiping and strainers, proper speed anddirection of rotation, properly ventedpump, properly packed and sealedgland, and no air leaks in the piping)

Properly drained tube nests

(1) Proper operation of all drain regulators

(2) Proper operation of the tube nest drain

pump

3. Highest possible vacuum in the last-effect shell

a. No air leaks

8-2

b. Proper air ejector operation

(1) Clean nozzle and strainer

(2) Correct quality and quantity of steam

c. Ample flow of circulating water

(1) Clean strainer, pipeline, and tubes

(2) Proper valve settings

(3) Proper operation of the circulating

pump

d. Effective surface in the distilling condenser

(1) No undue deposits inside the tubes

(2) Proper venting of the condenser

(3) Proper operation of the condensate

pump

Steam Pressure

A distilling plant cannot maintain its full outputunless it is supplied with dry steam at the designedpressure. The orifices were constructed to pass theproper amount of steam plus about 5 psig pressure tosafely produce the designed plant output. Orificesshould be inspected annually. An orifice should bemeasured and the reading compared with the figurestamped on the plate. If necessary, the orifice should berenewed.

If the steam pressure above the orifice varies, theexact source of trouble should be located and corrected.First the weight-loaded regulating valve and then thepressure-reducing valve (if installed) should be checkedto determine whether or not each valve is operatingproperly. If they are functioning properly and thepressure cannot be maintained above the orifice, youmay assume that an insufficient amount of steam isbeing supplied to the plant.

The auxiliary exhaust steam supply for the distillingplants, after passing through the regulating valve, isusually slightly superheated because of the pressuredrop through the reducing valve and the orifice plate. Asmall amount of superheat has little or no effect on theplant operation or the prevention of scale formation.However, when live steam must be used, the installeddesuperheater spray connection should be used tocontrol the superheat. The water for desuperheatingmust be taken from the boiler feed system, preferablyfrom the first-effect tube nest drain pump. Water fordesuperheating must NEVER be taken directly from thefresh water distilled by the distilling plant.

Fluctuations in the first-effect generating steampressure and temperature cause fluctuations of pressureand temperature throughout the entire plant. Withincreased salinity of the distillate, the fluctuations maycause priming, as well as erratic water levels in theshells. These fluctuations may he eliminated by properoperation of the automatic pressure regulators in thesteam supply line.

First-Effect Tube Nest Vacuum

The range of the pressure maintained in thefirst-effect tube must be between 16 inches of mercury(in.Hg), with clean tubes, to 1 to 2 in.Hg as scale forms.The output of a submerged-tube type of distilling plantis not greatly reduced until the deposits on the tubes havecaused the vacuum to drop to about atmosphericpressure. When the first-effect tube nest vacuum is lostentirely, the reduction in output becomes very great.Assuming the reduction in vacuum is due to scale andnot to improper operating conditions, the tubes must becleaned.

Keeping the vacuum in the first-effect tube nest ashigh as possible reduces scale formation to a minimum,enabling the plant to’operate at full capacity.

A vacuum reduction that results from any factorother than deposits on tube surfaces should be correctedto reduce deposits and greatly extend the intervalsbetween cleanings. The primary factors affecting thefirst-effect tube nest vacuum are air leakage, low waterlevels in the evaporator shells, improper venting of theevaporator shells, scale or other deposits on the tubes,and improper draining of the evaporator tube nests.

Loss of vacuum resulting from deposits onevaporator tubes should be gradual. Under normalconditions, there will be no major loss of vacuum forany one day’s operation. Any sudden drop in vacuumcan be traced to causes other than scale deposits.

The generating steam circuit operates undervacuum and is subject to air leaks. Leaks from the steamside of the first-effect tube nest to the first-effect shellspace cause losses of capacity and economy. Loss ofvacuum and loss of capacity may be due to air leaks. Theair leaks may he from the atmosphere into the generatingsteam line (downstream from the orifice plate); from thefirst-effect tube nest front header; or from the first-effecttube nest drain piping. Air leaks in this part of thedistilling plant may be less noticeable than air or waterleaks elsewhere, because the effect on the plant is similarto the scaling of the tube surfaces.

8-3

Proper Water Levels Scale Deposits on Evaporator Tubes

A reduced first-effect tube nest vacuum can resultfrom low water level in any evaporator shell. On olderplants, the water levels are controlled by manuallyregulating the feed valves. On newer plants, the waterlevels are automatically controlled by weir-type feedregulators. Inability to feed the first effect is usually dueeither to scale deposits in the seawater sides of the airejector condenser and the vapor feed heater or toobstructions in the feed line. Inability to feed the secondor third effects is due to air leakage or heavy scaledeposits in the feed lines between the effects. It isimportant that you keep the gauge glass and the gaugeglass fittings free from scale and air leaks. Air leaks orscale will result in false water level indication readings.

Once the distilling plant is in operation, the feedingmust be maintained at a steady rate. A sudden rise of thewater levels or too high a water level will causecarryover of small particles of brine within the vapor(priming). Maintain the level of water in the shell at thehighest level that can be held and still prevent thecarrying over of saltwater particles within thefreshwater vapor. If this constant water level is notmaintained, scales will form rapidly on the exposed tubesurfaces.

The pressure differential between the first andsecond effects permits the second-effect feed to bedischarged into the second-effect shell. A partial or totalloss of pressure differential indicates that air leaks haveoccurred between the first-effect and second-effectshells in the two-effect distilling plants. Large air leaksbetween the first effect and second effect can be readilydetected, because the vacuum gauge for the first effectwill read approximately the same as the vacuum gaugefor the second effect. Large air leaks of this type willdisrupt the operation of the plant and must be locatedand repaired before the plant will operate properly.

Improper Venting of Evaporator Tube Nests

Improper venting of the evaporator tube nests cancause either an accumulation of air in the tubes or anexcessive loss of tube nest steam to the distillingcondenser. A loss of tube nest air or steam results in a

loss of capacity or a loss of economy. Problems of thistype usually result from improper operations, rather thanfrom material failures.

Scale deposits on evaporator tube nests have been aserious cause of operating difficulties. The rate of scaleformation is affected by the density of the brine and bythe types of solids present in the feed. Although themajor constituents of seawater (sodium chloride,magnesium chloride, and others) do not form scaleunder normal plant operating conditions, they may doso when the last-effect brine density exceeds 1.5/32. Theprimary scale-fomling constituent of seawater, calciumcarbonate, will form scale even under normal plantconditions. But, the rate of scaling depends on the brinedensity. For this reason, you must maintain thelast-effect brine density at 1.5/32.

Another method to control scale formation is by theuse of scale preventive compound. This material helpsretard scale formation and foaming in distilling plants.The only authorized distiller scale preventive compoundfor surface ships is DOD-D-24577 (SH), Distiller ScalePreventive Treatment Formulutions, available from theNavy Supply System under National Stock Number(NSN) 9G6850-00-173-7243. Ships that were notoriginally equipped with chemical injection equipmentconforming to MIL-P-21397, Chemical (For DistillingPlants Naval Shipboard Use) Proportioning Unit,should install such equipment through a ship alteration(SHIPALT). Note that all plants require 24 gallons ofsolution regardless of plant capacity. You will use 1 pintof scale preventive compound for each 4,000 gallons perday of distilling plant capacity. You must combine thetotal amount of scale preventive compound in themixing tank with enough fresh water to make 24 gallonsof solution.

WARNING

Concentrated scale preventive compoundis strongly alkaline. Avoid contact of the liquidwith skin or eyes. Wash hands thoroughly afterusing. In case of contact with eyes, flush withfresh water for at least 15 minutes and report tosick bay immediately.

Last-Effect Shell Vacuum

A vacuum of approximately 26 in.Hg should beobtained in the last-effect shell when the temperature ofseawater is 85°F. The vacuum should be higher whenthe seawater is colder. Failure to obtain a vacuum of 26in.Hg, or more, can generally be traced to one of severalfactors or a combination of these factors. It could be air

8-4

leaks, improper operation of air ejectors, insufficientflow of seawater, or ineffective use of heat transfersurface in the distilling condenser.

Air Leaks

Many distilling plant troubles are direct results ofair leaks. Air leaks in the shells of distilling plants causea loss of vacuum and capacity. You must take extremecare when making up joints, for they must be kept tight.Periodically test the joints under pressure for leaks.When the plant is in operation, use a candle flame to testall joints and parts under vacuum. When the plant issecured, you can use air pressure or soapsuds for testing.

Air leakage may also be detected by hydrostaticallytesting the various parts of the plant. You should takethe necessary precautions not to exceed the maximumlimit of the test pressure specified by the manufacturer.

Saltwater Leaks

Defective tube(s) on the heat exchangers can belocated by means of an air or a hydrostatic test. Youshould follow the recommended procedure according tothe manufacturer’s instructions.

Air Ejector

The steam pressure at the nozzle inlet of the airejector must not be less than that for which the ejectoris designed (stamped on the nameplate). Pressures at theair ejector nozzles may be 10 to 15 psig higher than theminimum specified by the manufacturer.

The primary causes of air ejector problems are lowsteam pressure, wet steam, an obstructed nozzle, or aclogged steam strainer. Problems are usually indicatedby a failure to obtain or to maintain the required vacuum.If a problem is due to low steam pressure or wet steam,you should increase the steam pressure, install adrainage trap, or devise a manual solution. A cloggednozzle or strainer must be removed and cleaned. Youshould use special reamers to clean the air ejectornozzles. You should NEVER use a sharpedged tool toclean nozzles! Improper tools will damage the nozzlesurfaces and impair the efficiency of the air ejecter.

Procedures for testing air ejectors can be found inthe manufacturer’s technical manual. In general, thesame maintenance procedures should be followed fordistilling plant air ejectors as for air ejectors for the maincondensers.

You should inspect the air ejector strainer accordingto the PMS. Failure to keep the strainer clean will causea reduced or fluctuating vacuum. When a strainer or anozzle becomes damaged, you should replace it.

Insufficient Circulating Water

An insufficient flow of circulating water is indicatedwhen the temperature of the water rises more than 20°Fwhile passing through the condensing section of thedistiller condenser. The last-effect shell pressure isdirectly dependent upon the distiller condenser vacuum.The vacuum is dependent upon the temperature andquantity of the circulating water and the properoperation of the air ejectors. Too low an overboarddischarge temperature of the distiller condensercirculating water is accompanied by efficiency losses inthe distilling plant. The overboard dischargetemperature should be kept as high as possible, withoutexceeding the desired 20°F temperature rise through thedistiller condenser. In addition, limiting the quantity ofcirculating water tends to prolong the service life of thetubes and tube sheets. When troubles occur which arenot caused by improper operating procedures, youshould inspect the condenser circulating water systemto determine the true cause of the faulty operation.

You must carry out preventive maintenanceprocedures to ensure that the circulating water pump ismaintained in good material condition. You should alsocarry out routine procedures to ensure the proper settingand maintenance of the back-pressure regulating valve.A regulating valve that is not working properly must bedisassembled and repaired before its faulty operationinterferes with the operation of the distilling plant.

You should inspect the condenser circulating watersystem pipings at regular intervals for cleanliness aswell as for scale or foreign matter. The operators of thedistilling plant shouldaccording to the PMS.

Improper Drainage

inspect and clean the strainers

If the distilling plant fails to produce the designedoutput when the pressure above the orifice is 5 psig andthe first-effect tube nest is several inches of mercury,this is an indication of improper drainage of the distillercondenser or of one of the evaporator tube nestssubsequent to the first effect. Complete flooding of theflash chamber gauge glass is also a positive indicationof improper draining of the condenser. Because the levelappears to be in the gauge glass or below is notnecessarily an indication of improper drainage. Air leaks

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at the gauge glass fittings may indicate a false liquidlevel.

Brine Density

Proper brine density should be maintained at 1.5/32.If the brine concentration is too low, there will he a lossin capacity and economy. If the brine concentration istoo high, there will an increase in the rate of scaling ofthe evaporator heating surfaces.

FLASH-TYPE DISTILLING PLANTS

Many maintenance procedures for flash-typedistilling plants are similar to the maintenanceprocedures required for submerged-tube distillingplants. Both types of plants are subject to air leakage,saltwater leakage, and malfunctioning of pumps andother auxiliary equipment.

HEAT-RECOVERY DISTILLING PLANTS

Heat-recovery distilling plants are single-effectdistilling plants with a submerged-tube heat exchanger.This heat exchanger uses heat energy contained in thejacket cooling water circulated through diesel mainpropulsion engines and ship’s service diesel generators.This unit requires no steam for air ejectors because feedis used as the motive power to operate eductors for airand brine removal To supplement the heat in the jacketcooling water when engines are running at low rates, theplant has electric heating modules and steam heaters.This ensures that the jacket cooling water will be at therequired temperature when it enters the submerged-tubeheat exchanger. The jacket water passes through all theheat exchangers (whether energized or not) to the inletof the submerged-tube bundle. Here the heat istransferred through the tubes to the feed in the boilingcompartment. The jacket water then exits the tubebundle and returns to the engine. The heat-recoverysystem is fitted with a circulating pump and anexpansion tank

Most heat-recovery distillers aboard Navy shipshave a secondary heat exchanger between the enginejacket cooling water system and the distiller unit. Thisheat exchanger isolates the engine coolant, with all itschemical additives, from the distiller. Systems nothaving this secondary heat exchanger get heat directlyfrom the engine coolant to support the distiller. This iscalled a single-loop system. A single-loop system mustbe monitored continuously to ensure that no enginecoolant leaks through the distiller submerged-tube heatexchanger. For more information on the monitoring

requirements, refer to NSTM Chapter 233, “DieselEngines.” For cleaning heat-recovery plants, follow theapplicable instructions as you would for cleaning thesubmerged-tube or the flash-type distilling plants. Formore detailed information concerning the distilling unitsthe Navy uses, refer to the manufacturer’s manual andNSTM, Chapter 531, Volumes 1, 2, and 3, “DesalinationLow-Pressure Distilling Plants.”

HYDRAULIC SYSTEMS

The overall efficiency of the hydraulic installationsused to control or drive auxiliary machines is basicallydependent upon the size, oil pressure, speed, and strokeof the hydraulic installation. The efficiency of thehydraulic speed gears and the components of the systemwill depend upon the care that is given to them. Exceptfor piping and fittings, major repairs of hydraulic gearare generally done in a naval shipyard or by themanufacturers. This section will deal primarily withtroubleshooting and preventive maintenance ofhydraulic systems, including external hydraulics.

Hydraulic transmissions are sturdy, service-provenmachines, inspected and tested with such care thatcasualties seldom occur. When casualties do occur it isusually the result of faulty assembly, installation, ormaintenance. A correctly installed hydraulic system,operated regularly and serviced with proper care, willretain its design characteristics of power, speed, andcontrol. The need for costly repair and replacement willseldom occur if the equipment has been maintainedproperly.

TROUBLESHOOTING

Troubleshooting an electrohydraulic systeminvolves the systematic elimination of the possiblecauses, one by one, until the actual cause of a casualtyis found. In attempting to locate the source of any troublein an electrohydraulic system, remember that alltroubles fit into one of three categories. It is eitherhydraulic, electrical, or mechanical. Isolating a troubleinto one of these categories is one of the main steps infinding the source of trouble.

Hydraulic Troubles

Casualties in a hydraulic system are generally theresult of low oil levels, external or internal leakage,clogged lines or fittings, or improper adjustment ofvalves and other working parts. Do NOT disassemble aunit unless you are certain that the trouble exists withinthat unit! Unnecessary disassembly may create

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conditions that lead to additional trouble, since dirt mayenter an open system.

Leaks are a frequent cause of trouble in hydraulicequipment. Generally, leaks are a result of excessivelyworn parts, abnormal and continuous vibration,excessively high operating pressures, or faulty orcareless assembly. External leaks usually have littleeffect on the operation of equipment other than a steadydraining of the oil supply. Even a small leak wastes oil,and the resulting unsightly appearance of a machine isindicative of poor maintenance procedures.

External leaks may result from improperlytightened threaded fittings; crossed threads in fittings;improperly fitted or damaged gaskets; distorted orscored sealing rings, oil seals, or packing rings; scoredsurfaces of working parts; improperly flared tube ends;or flanged joints not seating squarely.

Internal leaks usually result in unsatisfactoryoperation of the equipment. Large internal leaks aresignified by a loss of pressure and the failure ofequipment. While large internal leaks can usually belocated by installing pressure gauges in various parts ofthe equipment, the location of small leaks generallyrequires disassembly and visual inspection of the parts.Internal leaks may result from worn or scored valves,pistons, valve plates or bushings, or improperly fitted ordamaged gaskets.

The most common symptom of trouble in ahydraulic system is an unusual noise. Some noises arecharacteristics of normal operation and can bedisregarded, while others are evidence of serioustrouble. Even though the exact sound indicating aspecific trouble can be learned only through practicalexperience, the following descriptive terms will give ageneral idea of which noises are trouble warnings.

If popping and sputtering noises occur, air isentering the pump intake line. Air entering the system atthis point may be the result of too small an intake pipe,an air leak in the suction line, a low oil level in the supplytank, cold or heavy oil, or possibly the use of improperoil.

If air becomes trapped in a hydraulic system,hammering will occur in the equipment or transmissionlines. When this occurs, check for improper venting.Sometimes, a pounding or rattling noise occurs as theresult of a partial vacuum produced in the active fluidduring high-speed operation or when a heavy load isapplied. This noise may be unavoidable under theconditions stated and can be ignored if it stops whenspeed or load is reduced. If the noise persists at low

speeds or light loads, the system needs to be vented ofair. Air in a hydraulic system can also cause unevenmotion of the hydraulic motors.

When a grinding noise occurs, it can usually betraced to dry bearings, foreign matter in the oil, worn orscored parts, or overtightness of some adjustments.

The term hydraulic chatter is sometimes used toidentify noises caused by a vibrating spring-actuatedvalve, by long pipes improperly secured, by air in lines,or by binding of some part of the equipment.

Squeals or squeaks indicate that the packing is tootight around some moving part or that a high-frequencyvibration is occurring in a relief valve.

Electrical Troubles

Even though troubles occurring in electricalequipment are the responsibility of the Electrician’sMate, the Engineman can help maintain the equipmentby making a few simple checks when electrical troublesoccur. Failure to have a switch in the ON position willcause unnecessary delay in operating electricalequipment. If the switch is closed and the equipment stillfails to operate, check for blown fuses or tripped circuitbreakers. Troubles of this type are usually the result ofan overload on the equipment. If a circuit breakercontinues to cut out, the trouble may be caused bydamaged equipment, excessive binding in the hydraulictransmission lines, or faulty operation of the circuitbreaker. Check for visual indication of open or shortedleads, faulty switches, or loose connections. Do notmake repairs to the electrical equipment or system. Donot open enclosures of electrical equipment, but doreport evidence of possible electrical failure to theElectrician’s Mate.

Mechanical Troubles

When electrohydraulically driven auxiliarymachinery becomes inoperative because of amechanical failure, a check should be made. Look forimproper adjustment or misalignment of parts; shearingof pins or keys; or breakage of gearing, shafting, orlinkage. Elimination of these causes should be doneaccording to the manufacturer’s instructions for thespecific piece of equipment.

MAINTENANCE

The principal requirements necessary to keep ahydraulic transmission in satisfactory operatingcondition are regular operation, proper lubrication, and

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the required state of cleanliness of all the units and theirfluids. Regular operation of hydraulic equipmentprevents the accumulation of sludge and the freezing ofadjacent parts. Regular use also aids in preventingcorrosion. The necessity for proper lubrication andcleanliness cannot be too strongly emphasized

Detailed instructions on the maintenance of aspecific unit should be obtained from the appropriatemanufacturer’s technical manual, but the followinggeneral information will also be useful.

The Fluid System

If an inspection of an oil sample drawn from ahydraulic system reveals evidence of water, sludge, oracidity, the system must be drained, then cleaned withprescribed acid-free cleaning fluid (flushing oil), andfilled with clean hydraulic oil. A hydraulic system maybe drained and cleaned as follows:

1. Remove the permanent filters and wash them influshing oil. Then use low-pressure air for dryingpurposes. If the filters have replaceable elements, installnew elements.

2. Drain the system of old hydraulic oils ascompletely as possible.

3. Close all connections, and fill the system withacid-free cleaning fluid.

4. Start andoperate the unit under idling conditionsto fill the system thoroughly with cleaning fluid.

5. Secure the unit and allow it to stand idle for theprescribed period (usually about an hour). This periodof idleness permits the cleaning fluid to dissolve anysludge.

6. Start and operate the unit with a light load for 3to 5 minutes, unless otherwise specified. Allow theequipment to stand idle for about 15 minutes, then repeatthe whole cleaning process. Do this two or three times.

Never operate a hydraulic unit with a full load whenit is filled with cleaning fluid. Keep the operatingpressure as low as possible.

7. If time permits, allow the system to stand idlefor an additional hour following the series of shortoperating periods.

8. Drain the system of cleaning fluid. Recleanpermanent filters or, if necessary, install newreplaceable filters. Close the system, and fill it with theproper hydraulic oil.

As the system is filled, strain the hydraulic oilthrough a fine wire screen of 180 or 200 mesh. If the oilis not clean, run it through a centrifuge. You shouldprovide adequate protection against dust and moistureentering the system. Moisture should be expelled fromthe oil before it is poured into a system. Oil withnoticeable water content should be rejected orcentrifuged

When a hydraulic system is being filled, sufficienthydraulic fluid should be used to completely fill theactive parts of the mechanism, leaving no air pockets.Air valves should he opened during the filling process,so that air can escape to the oil expansion box. Be surethe valves are closed tightly after the system has beenfilled. For more information on hydraulic fluid filtration,read NSTM, Chapter 556, “Hydraulic Equipment(Power Transmission and Control).” For additionalinformation on hydraulic fluids, refer to NSTM, Chapter262, “Lubricating Oils, Greases, and Hydraulic Fluidsand Lubricating Systems.”

Pumps and Motors

Whether the pumps and motors of hydraulictransmission are of the axial or radial piston type, themaintenance procedures, as well as the operatingprinciples, are relatively the same. In general,maintenance information on other types of pumps alsoapplies to hydraulic pumps and motors. For moreinformation concerning hydraulic pumps and motors,read section 2 of NSTM, Chapter 556, “HydraulicEquipment (Power Transmission and Control).”

Neoprene is the most commonly used seal aroundthe shafts of most modern hydraulic pumps and motors,but other types of shaft packing are also used.

On some modern hydraulic transmissions, shaftstuffing box packing is of the square-braided pureasbestos type. This packing is easily removed, but youmust take care to be sure that it is not replaced too tightly.If properly installed, this packing makes a tight jointwhen you apply light pressure. If packing wears quickly,the shaft should be inspected for roughness. If a lathe isavailable, you may be able to eliminate the roughnessfrom the shaft by a finishing cut to smooth the surface.If a lathe is not available, it may be necessary to replacethe shaft. Packing should be renewed at prescribedintervals to eliminate the possibility of the packingbecoming hard and scoring the shaft. When packing isbeing replaced, make certain there is a uniformthickness around the shaft. An excess of packing on oneside of the shaft will cause breakage. Stuffing boxes

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should be packed loosely and the packing gland set uplightly to allow adequate leakage for cooling andlubrication. See NSTM, Chapter 078, “Gaskets,Packings, and Seals,” for more detailed discussion ofO-rings and other types of seals for hydraulic systemequipment.

There is very little likelihood of poor alignmentbetween the driving and driven members of a hydraulictransmission if the wedges, shims, jacking screws, oradjusting setscrews were properly set and secured whenthe connecting units were installed. However, when acasualty occurs or a unit is replaced, it is possible for theunit to become misaligned enough to cause severe stressand strain on the coupling and connected parts.Excessive misalignment should be eliminated as soonas possible by replacing any defective parts and byreadjusting the aligning devices. If this is not done, pins,bushings, and bearings will wear out too fast and willhave to be replaced frequently.

Since there is no end play to either the pump shaftor the motor shaft, flexible couplings are generally usedin hydraulic transmissions. Such couplings permitsatisfactory operation with a slight misalignment,without requiring frequent renewal of parts.

Pipings and Fittings

If properly installed, the piping and valves of ahydraulic system are seldom a source of a trouble,except for leakage. Some leaks, however, can be seriousenough to cause a reduction in the efficiency of the unit.You should make frequent inspections for leakage andtake steps to eliminate any leakage found. Guidance andrequirements for the installation, inspection, andmaintenance of piping and associated fittings arecontained in NSTM, Chapter 505, “Piping Systems,”

If leaks occur at a flanged joint in the line of ahydraulic system, tighten the flange bolts evenly, but notexcessively. If the leaks persist, use the auxiliary gearwhile the leaking flange is being refitted with copperasbestos or O-ring packing. Be sure the flange surfacesare cleaned carefully before the packing is applied.

CAUTION

Exposure to asbestos fibers is a recognizedhealth hazard. Refer to NSTM, Chapter 635,“Thermal, Fire, and Acoustic Insulation,” forsafety requirements applicable to handlingasbestos packing and gaskets.

If certain measures are taken, operation of hydraulicequipment may be continued while leakage repairs arcbeing made in some parts of the system. When the linesin an auxiliary system leak, they should be valved offfrom the main line connection to prevent leakagebetween the two systems. If leaks occur in the pumpingconnections to the three-way valves of a steering gearinstallation, the pump can be cut out with the valve, andanother pump cut in. If the three-way valves fail to cutout the leaking unit, and it becomes necessary to cut outboth pumps of a steering gear installation, the valvesmay be closed at the ram cylinder. Hydraulic systemswill work without pressure control. So by closing thevalves in the lines where they join the main piping,leaking pressure control pipes or cylinders can be cutout of the system for repairs.

Expansion lines and replenishment lines inhydraulic systems of older ships are seldom a source ofleakage or breakage, since they are not under anyappreciable pressure. However, all hydraulic lineconnections must be maintained intact. in more recentinstallations, however, replenishing lines are underpressure as much as 300 psi. In these moderninstallations, the hydraulic systems should not beoperated during the repair of these lines.

Relief valves and shuttle valves of a hydraulicsystem may also be a source of trouble. The seats ofrelief valves that are leaking should be reground. Lossof power is a symptom of a leaking relief valve. Shuttlevalves may stick and fail to cut off. This condition isevidenced either by the escape of oil from thehigh-pressure side of the line into the expansion tank orby the failure of the pressure control. When a shuttlevalve fails to operate, the stop valves should be closedand the defective valve removed and repaired.

Incorrectly adjusted needle valves can be anothersource of trouble. Needle valves that are adjusted toofine may cause the device operated by the valve to stopshort of its intended stopping point. This may happenbecause the valve adjustment allows more fluid to passthrough leakage points in the system than through thevalve. NSTM, chapter 556, provides a good source ofgeneral information concerning different types of valvesused in hydraulic systems and their maintenance.

HYDRAULIC CARGO HATCH COVERS

Cargo hatch cover opening and closing operationsare supplied by an electrohydraulic power unit. Thesystem consists of an electric motor-driven hydraulicpump mounted on a hydraulic fluid reservoir tank and

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an air-driven hydraulic intensifier. Adjacent to the powerunit is a hydraulic fluid control valve panel. Anemergency air-hydraulic pump is also provided with thesystem. Fluid pressure is transmitted to either theundogging or dogging side of the hydraulic cylinders.You must read the specific manufacturer’s manual orNAVSEA 0916-LP-018-2010, Hydraulic OperatedCargo Hatch Cover, to understand the full details of thesystem. Along with this, you should trace the system inyour ship and complete the required PQS. Duringrepairs, follow the procedures specified by the PMS.

BOAT DAVITS

Gravity davits are found on most Navy ships.Figures 8-1, 8-2, and 8-3 illustrate the types of gravitydavits that you will be maintaining.

For general information about boat davits, readBoatswain's Mate, Volume 1, NAVEDTRA 10101. You,as the maintenanceman, must also be familiar with theproper operation of the boat davit. Some commonproblems with the boat davit are rusting of parts, loss oflubrication, contaminated oil in the gearcase, and faultycentrifugal brakes. Because of the location of the boatdavit on the weather deck, the machinery is highly

exposed to sea spray, even though it is covered byprotective covering. You must lubricate the boat davitand winch after adverse weather conditions. Formaintenance and repair of the boat davit, follow thePMS assigned for this machinery. If your ship isequipped with a double-pivoted link davit and a 50-hpwinch, NAVSHIPS 0920-072-1013 providesinformation concerning maintenance instructions. Yourwork center PMS Manual 43P1, under MaintenanceIndex Page should provide you with the correctreference publications for each piece of equipment.

BOW RAMP AND DOOR MACHINERY

The ramp and door system consists of the bow ramp,bow doors, tracks, winches with their wire rope rigging,fixed and positive guidance rollers, vangs, seatingdevice, pivot post, control consoles, various interlockand limit switches, and the interlock control panels.

In time, repairs will become necessary to correct theresults of wear or to repair damage caused by variouscasualty conditions. You must know and use the correctsources of information necessary to efficientlydisassemble and reassemble the machinery. You must

Figure 8-1.—Trackway gravity davit.

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Figure 8-2.—Double-link pivoted gravity davit.

Figure 8-3.—Single-arm trackway gravity davit.

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Figure 8-4.—Aircraft carrier weapons elevator.

read and heed any of the safety precautions andwarnings like the following:

WARNING

Before starting disassembly of any piece ofequipment, be certain the power is off and theswitch is tagged. Do not re-energize any taggedcircuit until safety of doing so is definitelyestablished.

When you determine that a repair or replacement ofpart(s) will require disassembly, tag the system out.Remove any interfering guards or obstructions. To

reduce the chance of dirt and other contaminants fromgetting into the works as the parts are disassembled, youmust take the time to properly clean the machinery. Keepthe dirt out of open gear cases and be sure parts arecleaned before reassembly. If the oil becomescontaminated, drain and flush the system with light oiland refill it with proper lubricant. Water in the oil willcause rust, and dirt can act as an abrasive to wear out themachinery. You must match marked parts that could beinstalled in more than one way so that you can return themachinery parts to their original position.

Components like winches and other actuatingmachinery are covered in considerable detail by theirmanufacturer’s technical manuals. Any repairs to be

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done must be done according to the applicable technicalmanual as specified by PMS. You must complete therequired PQS for this equipment. For more detailedinformation, refer to NSTM, Chapter 584, “Stern Gates,Ramps, Bow Doors, Turntables, and Water Barriers.”Also, a copy of NAVSEA 0916-LP-018-5010,Operation Manual for Bow Ramp System (U) LST1182-1198, may be very useful.

ELEVATORS

U.S. Navy shipboard elevators are either theelectromechanical winch type or the electrohydraulicram type. Elevators are classified by their functional use.The following designations are typical of elevatorsinstalled in Navy ships:

l Cargo elevator

l Weapons elevator

l Ammunition elevator

Figure 8-5.—Auxiliary ship elevator.

l Personnel elevator

l Medical evacuation (MEDEVAC) (casualty)elevator

l Aircraft elevator

Some elevators serve several functions. Forexample, aircraft elevators are used to move weapons,cargo, personnel, and support equipment. Weaponselevators can serve as cargo elevators and can be usedto evacuate personnel casualties in a mass or medicalemergency situation. Figures 8-4, 8-5, and 8-6 illustratesome of the types of elevators aboard U.S. Navy vessels.Pay particular attention to the location of componentsand safety devices on each type of elevator.

The complexity of elevator systems is increasingand so is the degree of maintenance and trainingrequired to keep them operational. It is a must that youqualify and pass a PQS, Ordnance/Cargo Elevators,Operation/Maintenance. Only qualified personnel canwork on elevators. When doing an elevator maintenance

Figure 8-6.—Combatant (DD-963) elevator.

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procedure, comply with all the procedures specified bythe PMS.

complete system. Remember that with any electricalproblem, you will need the help of an Electrician’s Mate,who is fully trained for electrical work

CONVEYORS

The two types of conveyors the Navy uses forshipboard handling are gravity and powered. Thissection will deal with the general concepts ofmaintaining, troubleshooting, and repairing theconveyors within ship’s force capability. When workingon a conveyor, always follow the manufacturer’smanual or the PMS. For more general informationconcerning conveyors, read NSTM, Chapter 572,“Shipboard Stores and Provision Handling.” Figures8-7, 8-8, and 8-9 are examples of some conveyors theNavy uses.

The difficulties most likely to be encounteredduring the operation of powered conveyors are not dueto a malfunctioning of the mechanical equipment, but tothe electrical equipment and the related interlocks. Thefollowing list contains common conveyor troubles thatyou may experience, the probable causes, and remediesfor each of the troubles listed. The cause for improperoperation is best diagnosed with adequate testingequipment and a thorough understanding of the

Trouble

Conveyor willnot start.

Conveyor willnot hoist.

Conveyor willnot lower.

Conveyor runscontinuouslywhen set atINDEX.

Probable Cause Solution

Power fails. Determine andcorrect cause ofpower failure.

Main line fuse is Replace fuse.blown.

Selector switch Check and resetor switches are selector switches.improperly set.

Selector switch Check and resetor switches are selector switches.improperly set.Loading/unload- Repositioning platform is platform inset in horizontal either stowed orposition. decline position.

Limit switch is Adjust limitinoperative. switch to actuate

when bell crankpasses.

Figure 8-7.—Gravity conveyor.

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Figure 8-8.—Vertical conveyer, package, tray type.

For general maintenance and repair, always followthe requirements of the PMS. If the conveyor has beenout of use for some time, inspect and service it beforeuse, even if the maintenance period has not elapsed.

CRANES

Before you begin to adjust, repair, or do inspectionson a crane, the following precautions must be observedand implemented as applicable:

1. The crane to he repaired must be positioned in alocation where it will cause the least interference withother cranes or ship’s operations.

2. The boom must be placed in the stowed positionwhen work on the topping system is to be accomplished.

3. All controls must he placed in the OFF position.

4. The power supplies must be de-energized andthe power supply breaker (in the OFF position) must betagged DANGER, except as required for testing oradjustments.

5. Maintenance may be performed on energizedelectrical equipment only when specifically authorizedby the commanding officer.

6. After completion of adjustments or repairs, thecrane should not be restored to service until all guardshave been reinstalled; safety devices are reactivated;maintenance equipment is removed; and all requiredtesting is completed.

Figure 8-9.—Powered belt conveyor.

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7. Maintenance on cranes should be performedonly by formally qualified personnel, unless authorizedby an authorizing officer on a single case basis forunusual repairs.

You must do all the maintenance requirementsaccording to the instructions provided on the applicableMRCs. If the MRCs do not exist for a particular pieceof equipment, your supervisor or you should instituteinterim maintenance according to the manufacturer’srecommendations.

The following maintenance items should beincluded in the crane PMS package:

l Lubrication

l Safety inspection

l Lube oil maintenance

l Wire rope

l Brakes

l Instrumentation

l Electrical

For more genera l in fo rmat ion on c ranemaintenance, repairs, and inspections, read NSTM,Chapter 589, “Cranes.” Your ship should have a copy

of the manufacturer’s technical manual for in-depthindividualized information of your ship’s crane.

DUMBWAITERS

A dumbwaiter is a semiautomatic electro-mechanical hoist operating in a structural trunk. The carof a dumbwaiter is arranged to carry ship’s stores ofvarying weights and package sizes. Figure 8-10illustrates the parts and controlling mechanisms of adumbwaiter.

You should inspect the dumbwaiter car and hoistevery 3 months. Check the condition of the load cable(it could be a chain or wire rope cable), motor brake,friction clutches, overtravel limit devices, door interlock

control switches, and safety devices. You must followthe manufacturer’s manual or the procedures specifiedby the PMS when making repairs. You are required tocomplete a PQS for this equipment. For more generalinformation, read NSTM, Chapter 572, “ShipboardStores and Provision Handling.”

Figure 8-10.—Dumbwaiter.

ESCALATORS

Only aircraft carriers have escalators aboard, andeach aircraft carrier has two escalators. Each is chaindriven by a horizontally mounted worm gear machine.An escalator can operate in either direction and isdesigned to operate at a speed of 120 feet per minute,carrying flight personnel at the rate of 44 persons perminute. For full details of this equipment, read NAVSEA0316-LP-020-7000, Shipboard Escalators (AircraftCarriers). You must complete the required PQS for thisequipment. When making repairs, follow the necessarysafety precautions and the procedures specified by themanufacturer’s manual or the PMS.

SUMMARY

This chapter has provided you with some generalinformation on the maintenance and repair of auxiliarymachinery. For you to do your job properly, you mustbe totally familiar with each piece of machinery; you

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must complete the required PQS; and you must know maintenance and repairs. You should check yourwhere ‘to find additional information on repairs and equipment with the reference publications to make suresafety. In your work center PMS Manual 43P1, under they are the right references. If you find an error in thesethe Maintenance Index Page, each piece of equipment references, you should submit a feedback report as soonhas reference publications or publications for as possible.

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CHAPTER 9

LATHES AND LATHE MACHINING OPERATIONS

The engine lathe, its use, and its principal parts andtheir uses are knowledges and skills expected of an EN2.Although machine shop work is generally done bypersonnel in the Machinery Repairman (MR) rating,there may be times that you will find the lathe essentialto complete a repair job. This chapter will help you toidentify the engine lathe’s attachments, accessories, andtheir uses. Also, it will identify and explain differentmachining operations and the factors related tomachining operations. Of course, you will be expectedto know and to follow the safety precautions associatedwith machining operations.

There are a number of different types of lathesinstalled in the machine shops in various Navy ships.These include the engine lathe, the horizontal turretlathe, and several variations of the basic engine lathe,such as bench, toolroom, and gap lathes. All lathes,

except the vertical turret type, have one thing incommon. For all usual machining operations, theworkpiece is held and rotated about a horizontal axis,while being formed to size and shape by a cutting tool.In the vertical turret lathe, the workpiece is rotated abouta vertical axis. Of the various types of lathes, the typeyou are most likely to use is the engine lathe. Therefore,this chapter deals only with engine lathes and themachining operations you may have to perform.

NOTE: Before you attempt to operate any lathe,make sure you know how to operate it. Read all operatinginstructions supplied with the machine. Learn the locationsof the various controls and how to operate them.

ENGINE LATHE

An engine lathe similar to the one shown in figure9-1 is found in every machine shop. It is used mostly for

Figure 9-1.—Typical engine lathe.

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turning, boring, facing, and thread cutting. But it mayalso be used for drilling, reaming, knurling, grinding,spinning, and spring winding. Since you will primarilybe concerned with turning, boring, facing, and threadcutting, we will deal primarily with those operations inthis chapter.

The work held in the engine lathe can be revolvedat any one of a number of different speeds, and thecutting tool can be accurately controlled by hand orpower for longitudinal feed and crossfeed.(Longitudinal feed is the movement of the cutting toolparallel to the axis of the lathe; crossfeed is themovement of the cutting tool perpendicular to the axisof the lathe.)

Lathe size is determined by two measurements: (1)the diameter of work it will swing (turn) over the waysand (2) the length of the bed. For example, a 14-inch by6-foot lathe will swing work up to 14 inches in diameterand has a bed that is 6 feet long.

Engine lathes vary in size from small bench lathesthat have a swing of 9 inches to very large lathes forturning large diameter work such as low-pressureturbine rotors. The 16-inch lathe is the average size forgeneral purposes and is the size usually installed in shipsthat have only one lathe.

PRINCIPAL PARTS

To learn the operation of the lathe, you must befamiliar with the names and functions of the principalparts. Lathes from different manufacturers differsomewhat in construction, but all are built to performthe same general functions. As you read the descriptionof each part, find its location on the lathe in figure 9-1and the figures that follow. (For specific details offeatures of construction and operating techniques, referto the manufacturer’s technical manual for yourmachine.)

Bed and Ways

The bed is the base or foundation of the parts of thelathe. The main feature of the bed is the ways, which areformed on the bed’s upper surface and run the full lengthof the bed. The ways keep the tailstock and the carriage,which slide on them, in alignment with the headstock.

Headstock

The headstock contains the headstock spindle andthe mechanism for driving it. In the belt-driven type,shown in figure 9-2, the driving mechanism consists of

Figure 9-2.—Belt-driven type of headstock.

a motor-driven cone pulley that drives the spindle conepulley through a drive belt. The spindle can be rotatedeither directly or through back gears.

When the headstock is set up for direct drive, abull-gear pin, located under a cover to the right of thespindle pulley, connects the pulley to the spindle. Thisconnection causes the spindle to turn at the same speedas the spindle pulley.

When the headstock is set up for gear drive, thebull-gear pin is pulled out, disconnecting the spindlepulley from the spindle. This allows the spindle to turnfreely inside the spindle pulley. The back-gear lever, onthe left end of the headstock, is moved to engage theback-gear set with a gear on the end of the spindle anda gear on the end of the spindle pulley. In this drivemode, the drive belt turns the spindle pulley, which turnsthe back-gear set, which turns the spindle.

Each drive mode provides four spindle speeds, fora total of eight. The back-gear drive speeds are lessslower than the direct-drive speeds.

Tailstock

The primary purpose of the tailstock is to hold thedead center to support one end of the work being

9-2

Figure 9-3.—Side view of a carriage mounted on a bed.

machined. However, the tailstock can also be used tohold tapered shank drills, reamers, and drill chucks. Itcan be moved on the ways along the length of the bedand can be clamped in the desired position by tighteningthe tailstock clamping nut. This movement allows forthe turning of different lengths of work. The tailstockcan be adjusted laterally (front to back) to cut a taper byloosening the clamping screws at the bottom of thetailstock. (see fig. 9-1.)

Before you insert a dead center, drill, or reamer,carefully clean the tapered shank and wipe out thetapered hole of the tailstock spindle. When you holddrills or reamers in the tapered hole of the spindle, besure they are tight enough so they will not revolve. Ifyou allow them to revolve, they will score the taperedhole and destroy its accuracy.

Carriage

The carriage is the movable support for thecrossfeed slide and the compound rest. The compoundrest carries the cutting tool in the tool post. Figure 9-3shows how the carriage travels along the bed over whichit slides on the outboard ways.

The carriage has T-slots or tapped holes to use forclamping work for boring or milling. When the carriageis used for boring and milling operations, carriagemovement feeds the work to the cutting tool, which isrotated by the headstock spindle.

You can lock the carriage in any position on the bedby tightening the carriage clamp screw. But you do thisonly when you do such work as facing or parting-off,for which longitudinal feed is not required. Normallythe carriage clamp is kept in the released position.Always move the carriage by hand to be sure it is freebefore you engage its automatic feed.

Apron

The apron is attached to the front of the carriage andcontains the mechanism that controls the movement ofthe carriage and the crossslide.

Feed Rod

The feed rod transmits power to the apron to drivethe longitudinal feed and crossfeed mechanisms. Thefeed rod is driven by the spindle through a train of gears.The ratio of feed rod speed to spindle speed can be variedby using change gears to produce various rates of feed.

9-3

Figure 9-4.—Compound rest.

The rotating feed rod drives gears in the apron; thesegears in turn drive the longitudinal feed and crossfeedmechanisms through friction clutches.

Some lathes do not have a separate feed rod, but usea spline in the lead screw for the same purpose.

Lead Screw

The lead screw is used for thread cutting. It hasaccurately cut Acme threads along its length that engagethe threads of half-nuts in the apron when the half-nutsare clamped over it. The lead screw is driven by thespindle through a gear train. Therefore, the rotation ofthe lead screw bears a direct relation to the rotation ofthe spindle. When the half-nuts are engaged, thelongitudinal movement of the carriage is controlleddirectly by the spindle rotation. Consequently, thecutting tool is moved a definite distance along the workfor each revolution that the spindle makes.

Crossfeed Slide

The crossfeed slide is mounted to the top of thecarriage in a dovetail and moves on the carriage at a rightangle to the axis of the lathe. A crossfeed screw allowsthe slide to be moved toward or away from the work inaccurate increments.

Compound Rest

The compound rest (fig. 9-4), mounted on thecompound slide, provides a rigid adjustable mounting

for the cutting tool. The compound rest assembly has thefollowing principal parts:

1. The compound rest SWIVEL, which can beswung around to any desired angle and clamped inposition. It is graduated over an arc of 90° on each sideof its center position for easier setting to the angle

selected. This feature is used for machining short, steep

tapers, such as the angle on bevel gears, valve disks, andlathe centers.

2. The compound rest, or TOP SLIDE, which ismounted on the swivel section on a dovetailed slide. It

is moved by the compound rest feed screw.

Figure 9-5.—Common types of toolholders.

9-4

Figure 9-6.—Knurling and threading toolholders.

This arrangement permits feeding the tool to thework at any angle (determined by the angular setting ofthe swivel section). The graduated collars on thecrossfeed and compound rest feed screws read inthousandths of an inch for fine adjustment in regulatingthe depth of cut.

Accessories and Attachments

Accessories are the tools and equipment used inroutine lathe machining operations. Attachments arespecial fixtures that may be mounted on the lathe toexpand the use of the lathe to include taper cutting,milling, and grinding. Some of the common accessoriesand attachments are described in the followingparagraphs.

TOOL POST.—The sole purpose of the tool post isto provide a rigid support for the tool. It is mounted inthe T-slot of the compound rest. A forged tool or atoolholder is inserted in the slot in the tool post. Bytightening a setscrew, you will firmly clamp the wholeunit in place with the tool in the desired position.

TOOLHOLDERS—Some of the commontoolholders used in lathe work are illustrated in figure9-5. Notice the angles at which the tool bits are set in thevarious holders. These angles must be considered withrespect to the angles ground on the tools and the anglethat the toolholder is set with respect to the axis of thework.

Two types of toolholders that differ slightly from thecommon toolholders are those used for threading andknurling. (See fig. 9-6.)

The threading toolholder has a formed cutter whichneeds to be ground only on the top surface forsharpening. Since the thread form is accurately shaped

Figure 9-7.—Lathe tools and their applications.

over a large arc of the tool, as the surface is worn awayby grinding, the cutter can be rotated to the correctposition and secured by the setscrew.

A knurling toolholder carries two knurled rollerswhich impress their patterns on the work as it revolves.The purpose of the knurling tool is to provide aroughened surface on round metal parts, such as knobs,to give a better grip in handling. The knurled rollerscome in a variety of patterns.

ENGINE LATHE TOOLS.—Figure 9-7 shows themost popular shapes of ground lathe cutter bits and theirapplications. In the following paragraphs we willdiscuss each of the types shown.

Left-Hand Turning Tool.—This tool is ground formachining work when it is fed from left to right, asindicated in figure 9-7, view A. The cutting edge is onthe right side of the tool, and the top of the tool slopesdown away from the cutting edge.

9-5

Figure 9-8.–A. Four-Jaw chuck. B. Three-Jaw chuck.

Round-Nosed Turning Tool.–This tool is for

general-purpose machine work and is used for taking

light roughing cuts and finishing cuts. Usually, the top

of the cutter bit is ground with side rake so the tool may

be fed from right to left. Sometimes this cutter bit isground flat on top so the tool may be fed in eitherdirection (fig. 9-7, view B).

Right-Hand Turning Tool.–This is just theopposite of the left-hand turning tool and is designed tocut when it is fed from right to left (fig. 9-7, view C).The cutting edge is on the left side. This is an ideal toolfor taking roughing cuts and for all-around machinework.

Left-Hand Facing Tool.–This tool is intended forfacing on the left-hand side of the work (fig. 9-7, viewD). The direction of feed is away from the lathe center.The cutting edge is on the right-hand side of the tool,and the point of the tool is sharp to permit machining asquare corner.

Threading Tool.–The point of the threading tool isground to a 60-degree included angle for machiningV-form screw threads (fig. 9-7, view E). Usually, the topof the tool is ground flat, and there is clearance on bothsides of the tool so it will cut on both sides.

Right-Hand Facing Tool.–This tool is just theopposite of the left-hand facing tool and is intended forfacing the right end of the work and for machining theright side of a shoulder (fig. 9-7, view F).

Square-Nosed Parting (Cutoff) Tool.–Theprincipal cutting edge of this tool is on the front (fig. 9-7,view G). Both sides of the tool must have sufficientclearance to prevent binding and should be groundslightly narrower at the back than at the cutting edge.This tool is convenient for machining necks and groovesand for squaring comers and cutting off.

Boring Tool.–The boring tool (fig. 9-7, view H) isusually ground the same shape as the left-hand turning

Figure 9-9.–Draw-in collet chuck.

9-6

Figure 9-10.—Faceplate.

tool so that the cutting edge is on the right side of thecutter bit and may be fed in toward the headstock.

Inside-Threading Tool.—The inside-threadingtool (fig. 9-7, view J) has the same shape as thethreading tool in figure 9-7, view E, but it is usuallymuch smaller. Boring and inside-threading tools mayrequire larger relief angles when used in smalldiameter holes.

LATHE CHUCKS.—The lathe chuck is a devicefor holding lathe work. It is mounted on the nose ofthe spindle. The work is held by jaws which can bemoved in radial slots toward the center of the chuckto clamp down on the sides of the work. These jawsare moved in and out by screws turned by a specialchuck wrench.

The four-jaw independent lathe chuck, view A infigure 9-8, is the most practical chuck for general workThe four jaws are adjusted one at a time, making itpossible to hold work of various shapes and to adjust thecenter of the work to coincide with the axis of thespindle. The jaws are reversible.

The three-jaw universal or scroll chuck, view B infigure 9-8, can be used only for holding round orhexagonal work All three jaws move in and out togetherin one operation and bring the work on centerautomatically. This chuck is easier to operate than thefour-jaw type, but, when its parts become worn, itsaccuracy in centering cannot be relied upon. Properlubrication and constant care are necessary to ensurereliability.

The draw-in collet chuck is used to hold smallwork for machining in the lathe. It is the mostaccurate type of chuck made and is intended for

precision work. Figure 9-9 shows the partsassembled in place in the lathe spindle. The collet,which holds the work, is a split-cylinder with anoutside taper that fits into the tapered closingsleeve and screws into the threaded end of thehollow drawbar. As the handwheel is turnedclockwise, the drawbar is moved toward thehandwheel. This tightening up on the drawbar pullsthe collet back into the tapered sleeve, therebyclosing it firmly over the work and centering thework accurately and quickly. The size of the holein the collet determines the diameter of the workthe chuck can handle.

Faceplates

The faceplate is used for holding work that,because of its shape and dimensions, cannot be swungbetween centers or in a chuck. The T-slots and otheropenings on its surface provide convenient anchorsfor bolts and clamps used in securing the work to it.The faceplate is mounted on the nose of the spindle.(See fig. 9-10.)

The driving plate is similar to a small faceplateand is used mainly for driving work that is heldbetween centers. The primary difference between afaceplate and a driving plate is that a faceplate has amachined face for precision mounting, while the faceof a driving plate is left rough. When a driving plateis used, the bent tail of a dog clamped to the work isinserted into a slot in the faceplate. This transmitsrotary motion to the work.

9-7

Figure 9-11.—60-degree lathe centers.

Figure 9-12.—Lathe dogs.

Lathe Centers

The 60-degree lathe centers shown in figure 9-11provide a way to hold the work so it can be turnedaccurately on its axis. The headstock spindle center iscalled the LIVE CENTER because it revolves with thework. The tailstock center is called the DEADCENTER because it does not turn. Both live and deadcenters have shanks turned to a Morse taper to fit thetapered holes in the spindles; both have points finishedto an angle of 60°. They differ only in that the deadcenter is hardened and tempered to resist the wearingeffect of the work revolving on it. The live centerrevolves with the work and is usually left soft. The deadcenter and live center must NEVER be interchanged.(There is a groove around the hardened dead center todistinguish it from the live center.)

The centers fit snugly in the tapered holes of theheadstock and tailstock spindles. If chips, dirt, or burrsprevent a perfect fit in the spindles, the centers will notrun true.

To remove the headstock center, insert a brass rodthrough the spindle hole and tap the center to jar it loose;then pull it out with your hand. To remove the tailstockcenter, run the spindle back as far as it will go by turningthe handwheel to the left. When the end of the tailstock

Figure 9-13.—Center rest.

screw bumps the back of the center, it will force thecenter out of the tapered hole.

Lathe Dogs

Lathe dogs are used with a driving plate or faceplateto drive work being machined on centers; the frictionalcontact alone between the live center and the work is notsufficient to drive the work

The common lathe dog, shown at the left in figure9-12, is used for round work or work having a regularsection (square, hexagon, octagon). The piece to beturned is held firmly in the hole (A) by the setscrew (B).The bent tail (C) projects through a slot or hole in thedriving plate or faceplate so that when the tail revolveswith the spindle it turns the work with it. The clamp dog,illustrated at the right in figure 9-12, may be used forrectangular or irregularly shaped work. Such work isclamped between the jaws,

Center Rest

The center rest, also called the steady rest, is usedfor the following purposes:

1. To provide an intermediate support for longslender bars or shafts being machined between centers.The center rest prevents them from springing, orsagging, as a result of their otherwise unsupportedweight.

9-8

Figure 9-14.—Follower rest.

Figure 9-15.—Taper attachment.

2. To support and provide a center bearing for oneend of the work, such as a shaft, being bored or drilledfrom the end when it is too long to be supported by achuck alone. The center rest is clamped in the desiredposition on the bed and is kept aligned by the ways, asillustrated in figure 9-13. The jaws (A) must be carefullyadjusted to allow the work (B) to turn freely and at thesame time remain accurately centered on the axis of thelathe. The top half of the frame is a hinged section (C)for easier positioning without having to remove thework from the centers or to change the position of thejaws.

Follower Rest

The follower rest is used to back up small diameterwork to keep it from springing under the cutting

Figure 9-16.—Thread dial Indicator.

pressure. It can be set to either precede or follow thecutting action. As shown in figure 9-14, it is attacheddirectly to the saddle by bolts (B). The adjustable jawsbear directly on the part of the work opposite the cuttingtool.

Taper Attachment

The taper attachment, illustrated in figure 9-15, isused for turning and boring tapers. It is bolted to the backof the carriage. In operation, it is connected to the crossslide so that it moves the cross slide traversely as thecarriage moves longitudinally, thereby causing thecutting tool to move at an angle to the axis of the workto produce a taper.

The desired angle of taper is set on the guide bar ofthe attachment. The guide bar support is clamped to thelathe bed Since the cross slide is connected to a shoethat slides on this guide bar, the tool follows along a lineparallel to the guide bar and at an angle to the work axiscorresponding to the desired taper.

The operation of the taper attachment will be furtherexplained under the subject of taper work

Thread Dial Indicator

The thread dial indicator, shown in figure 9-16,eliminates the need to reverse the lathe to return thecarriage to the starting point each time a successivethreading cut is taken. The dial, which is geared to thelead screw, indicates when to clamp the half-nuts on thelead screw for the next cut.

The threading dial consists of a worm wheel whichis attached to the lower end of a shaft and meshed with

9-9

Figure 9-17.—Micrometer carriage stop.

the lead screw. On the upper end of the shaft is the dial.As the lead screw revolves, the dial is turned and thegraduations on the dial indicate points at which thehalf-nuts may be engaged.

Carriage Stop

The carriage stop can be attached to the bed at anypoint where the carriage should stop. It is used primarilyfor turning, facing, or boring duplicate parts, as iteliminates taking repeated measurements of the samedimension. In operation, the stop is set at the point wherethe feed should stop. To use the stop, just before thecarriage reaches the stopping point, shut off theautomatic feed and manually run the carriage up againstthe stop. Carriage stops are provided with or withoutmicrometer adjustment. Figure 9-17 shows amicrometer carriage stop. Clamp it on the ways in theapproximate position required, and then adjust it to theexact setting by using the micrometer adjustment. (Donot confuse this stop with the automatic carriage stopthat automatically stops the carriage by disengaging thefeed or stopping the lathe.)

MAINTENANCE

Every lathe must be maintained strictly accordingto requirements of the Maintenance and MaterialManagement (3-M) Systems. The first requirement ofmaintenance to your lathe is proper lubrication. Make ita point to oil your lathe daily where oil holes areprovided. Oil the ways daily-not only for lubrication butto protect their scraped surfaces. Oil the lead screw oftenwhile it is in use; this is necessary to preserve itsaccuracy, for a worn lead screw lacks precision in thread

cutting. Make sure the headstock is filled to the properoil level; drain the oil out and replace it when it becomesdirty or gummy. If your lathe is equipped with anautomatic oiling system for some parts, make sure allthose parts are getting oil. Make it a habit to CHECKfrequently to see that all moving parts are beinglubricated.

Before engaging the longitudinal ‘feed, be certainthat the carriage clamp screw is loose and that thecarriage can be moved by hand. Avoid running thecarriage against the headstock or tailstock while it isunder the power feed; running the carriage against theheadstock or tailstock puts an unnecessary strain on thelathe and may jam the gears.

Do not neglect the motor just because it may be outof sight; check its lubrication. If it does not run properly,notify the Electrician’s Mate who is responsible forcaring for it. He or she will cooperate with you to keepit in good condition. On lathes with a belt driven fromthe motor, avoid getting oil or grease on the belt whenyou oil the lathe or motor.

Keep your lathe clean. A clean and orderly machineis an indication of a good mechanic. Dirt and chips onthe ways, on the lead screw, and on the crossfeed screwswill cause serious wear and impair the accuracy of themachine.

NEVER put wrenches, files, or other tools on theways. If you must keep tools on the bed, use a board toprotect the finished surfaces of the ways.

NEVER use the bed or carriage as an anvil.Remember, the lathe is a precision machine, and nothingmust be allowed to destroy its accuracy.

BASIC SETUP

A knowledge of the basic setup is required if youare to become proficient in performing machine workwith a lathe. Some of these setups are considered in thefollowing sections.

Cutting Speeds and Feeds

Cutting speed is the rate at which the surface of thework passes the point of the cutting tool. It is expressedin feet per minute (fpm).

Feed is the amount the tool advances for eachrevolution of the work. It is usually expressed inthousandths of an inch per revolution of the spindle.

Cutting speeds and tool feeds are determined byvarious considerations: the hardness and toughness of

9-10

the metal being cut; the quality, shape, and sharpness ofthe cutting tool; the depth of the cut; the tendency of thework to spring away from the tool; and the strength andpower of the lathe. Since conditions vary, it is goodpractice to find out what the tool and work will standand then select the most practical and efficient speed andfeed for the finish desired.

When ROUGHING parts down to size, use thegreatest depth of cut and feed per revolution that thework, the machine, and the tool will stand at the highestpractical speed. On many pieces where tool failure is thelimiting factor in the size of the roughing cut, you maybe able to reduce the speed slightly and increase the feedto remove more metal. This will prolong tool life.Consider an example where the depth of cut is 1/4 inch,the feed 0.020 inch per revolution, and the speed 80 fpm.If the tool will not permit additional feed at this speed,you can drop the speed to 60 fpm and increase the feedto about 0.040 inch per revolution without having tooltrouble. The speed is therefore reduced 25 percent, butthe feed is increased 100 percent. Thus the actual timerequired to complete the work is less with the secondsetup.

For the FINISH TURNING OPERATION, take avery light cut, since you removed most of the stockduring the roughing cut. Use a fine feed to run at a highsurface speed. Try a 50 percent increase in speed overthe roughing speed. In some cases, the finishing speedmay be twice the roughing speed. In any event, run thework as fast as the tool will withstand to obtain themaximum speed during this operation. Be sure to use asharp tool when you are finish turning.

COOLANTS

A cutting lubricant serves two main purposes: (1) Itcools the tool by absorbing a portion of the heat andreducing the friction between the tool and the metalbeing cut. (2) It also keeps the cutting edge of the toolflushed clean.

The best lubricants to use for cutting metal mustoften be determined by experiment. Water-soluble oilis acceptable for most common metals. Specialcutting compounds containing such ingredients astallow, graphite, and lard, marketed under variousnames, are also used. But these are expensive and usedmainly in manufacturing where high cutting speedsare the rule.

Some common materials and their cuttinglubricants are as follows:

Metal

Cast iron

Lubricant

Usually worked dry

Mild steel Oil or soluble oil

Hard steel Mineral lard oil

Monel metal

Bronze

Dry (or soluble oil)

Dry (or soluble oil)

Brass Dry (or soluble oil)

Copper Dry (or soluble oil)

Babbitt Dry (or soluble oil)

Aluminum Dry (or soluble oil)

A lubricant is more important for threading than forstraight turning. Mineral lard oil is recommended forthreading the majority of metals that are used by theNavy.

CHATTER

Chatter is vibration in either the tool or the workThe finished work surface appears to have a grooved orlined finish instead of a smooth surface. The vibrationis set up by a weakness in the work, work support, tool,or tool support and is probably the most elusive thingyou will find in the entire field of machine work As ageneral rule, strengthening the various parts of the toolsupport train will help. It is also advisable to support thework by a center rest or follower rest.

The fault may be in the machine adjustments. Gibsmay be too loose; hearings may, after a long period ofheavy service, be worn; the tool may be sharpenedimproperly, and so on. If the machine is in excellentcondition, the fault may be in the tool or tool setup.Grind the tool with a point or as near a point as the finishspecified will permit; avoid a wide, round leading edgeon the tool. Reduce the overhang of the tool as much aspossible. Be sure all the gib and bearing adjustments areproperly made. See that the work receives propersupport for the cut and, above all, do not try to turn at asurface speed that is too high. Excessive speed isprobably the greatest cause of chatter. The first thing youshould do when chatter occurs is reduce the speed.

Direction of Feed

Regardless of how the work is held in the lathe, thetool should feed toward the headstock. This causes most

9-11

Figure 9-18.—Checking a center’s point with a center gauge.

of the pressure of the cut to bear on the work-holdingdevice and the spindle thrust bearings. When you mustfeed the cutting tool toward the tailstock, take lightercuts at reduced feeds. In facing, the general practice isto feed the tool from the center of the workpieceoutward.

PRELIMINARY PROCEDURES

Before starting a lathe machining operation, alwaysensure that the machine is set up properly. If the work ismounted between centers, check the alignment of thedead center and the live center and make any necessarychanges. Ensure that the toolholder and cutting tool areset at the proper height and angle. Check thework-holding accessory to ensure that the workpiece isheld securely. Use the center rest or follower rest tosupport long workpieces.

PREPARING THE CENTERS

The first step in preparing the centers is to see thatthey are accurately mounted in the headstock andtailstock spindles. The centers and the tapered holes inwhich they are fitted must be perfectly clean. Chips anddirt left on the contact surfaces prevent the bearingsurfaces from fitting perfectly. This will decrease theaccuracy of your work. Make sure that there are no burrsin the spindle hole. If you find burrs, remove them bycarefully scraping and reaming the hole with a Morsetaper reamer. Burrs will produce the same inaccuraciesas chips or dirt.

A center’s point must be finished accurately to anangle of 60°. Figure 9-18 shows the method of checkingthis angle with a center gauge. The large notch of thecenter gauge is intended for this purpose. If this testshows that the point is not perfect, you must true it inthe lathe by taking a cut over the point with thecompound rest set at 30°. You must anneal the hardenedtail center before it can be machined in this manner, oryou can grind it if a grinding attachment is available.

Figure 9-19.—Aligning lathe centers.

Figure 9-20.—Tool overhang.

CHECKING ALIGNMENT

To turn a shaft straight and true between centers, besure the centers are aligned in a plane parallel to the waysof the lathe. You can check the approximate alignmentof the centers by moving the tailstockup until the centersalmost touch and observing their relative positions asshown in figure 9-19.

To test center alignment for very accurate work, takea light cut over at each end with a micrometer and, ifreadings are found to differ, adjust the tailstockaccordingly. Repeat the procedure until alignment isobtained.

SETTING THE TOOLHOLDER AND THECUTTING TOOL

The first requirement for setting the tool is to haveit rigidly mounted on the tool post holder. Be sure thetool sets squarely in the tool post and that the setscrewis tight. Reduce overhang as much as possible to preventthe tool bit from springing during cutting. If the tool hastoo much spring, the point of the tool will catch in thework, causing chatter and damaging both the tool andthe work The distances represented by A and B in figure

9-12

Figure 9-21.—Drilling a center hole.

9-20 show the correct overhang for the tool bit and theholder.

The point of the tool must be correctly positionedon the work Place the cutting edge. slightly above thecenter for straight turning of steel and cast iron andexactly on the center for all other work To set the toolat the height desired, raise or lower the point of the toolby moving the wedge in or out of the tool post ring. Byplacing the point opposite the tailstock center point, youcan adjust the setting accurately.

HOLDING THE WORK

You cannot perform accurate work if the workpieceis improperly mounted. The requirements for propermounting are as follows:

1.

2.

3.

4.

The work center line must be accuratelycentered along the axis of the lathe spindle.

The work must be held rigidly while beingturned.

The work must NOT be sprung out of shape bythe holding device.

The work must be adequately supported againstany sagging caused by its own weight andagainst springing caused by the action of thecutting tool.

There are four general methods of holding work inthe lathe: (1) between centers, (2) on a mandrel, (3) in achuck, and (4) on a faceplate. Work may also be clampedto the carriage for boring and milling, in which case theboring bar or milling cutter is held and driven by theheadstock spindle.

Other methods of holding work to suit specialconditions are (1) one end on the live center or in a chuckand the other end supported in a center rest, and (2) oneend in a chuck and the other end on the dead center.

Holding Work Between Centers

To machine a workpiece between centers, drillcenter holes in each end to receive the lathe centers.Secure a lathe dog to the workpiece. Then mountthe work between the live and dead centers of thelathe.

CENTERING THE WORK.—To center roundstock where the ends are to be turned and must beconcentric with the unturned body, mount the work onthe head spindle in a universal chuck or a draw-in colletchuck If the work is long and too large to pass throughthe spindle, use a center rest to support one end. Mounta center drill in a drill chuck in the tailstock spindle andfeed it to the work by turning the tailstock handwheel(fig. 9-21).

For center drilling a workpiece, the combineddrill and countersink is the most practical tool.These combined drills and countersinks vary insize and the drill points also vary. Sometimes a drillpoint on one end will be 1/8 inch in diameter, andthe drill point on the opposite end will be 3/16 inchin diameter. The angle of the center drill mustalways be 60° so that the countersunk hole will fitthe angle of the lathe center point.

If a center drill is not available, center the workwith a small twist drill. Let the drill enter the worka sufficient distance on each end; then follow witha 60° countersink.

In center drilling, use a drop or two of oil on thedrill. Feed the drill slowly and carefully to preventbreaking the tip. Take extreme care when the work isheavy, because you will be less able to “feel” theproper feed of the work on the center drill.

If the center drill breaks during countersinking andpart of the broken drill remains in the work, you mustremove this part. Sometimes you can drive the brokenpiece out by a chisel or by jarring it loose, but it maystick so hard that you cannot remove it this way. Thenyou must anneal the broken part of the drill and drill itout.

We cannot overemphasize the importance ofproper center holes in the work and a correct angleon the point of the lathe centers. To do an accuratejob between centers on the lathe, you must ensurethat the center-drilled holes are the proper size anddepth and that the points of the lathe centers aretrue and accurate.

9-13

Figure 9-22.—Examples of work mounted between centers.

MOUNTING THE WORK.—Figure 9-22 showscorrect and incorrect ways to mount work betweencenters. In the correct example, the driving dog isattached to the work and held rigidly by the setscrew.The tail of the dog rests in the slot of the faceplate,without touching the bottom of the slot. The tail extendsbeyond the base of the slot so that the work rests firmlyon both the headstock center and the tailstock center.

In the incorrect example, note that the tail of the dogrests on the bottom of the slot on the faceplate at A andpulls the work away from the center’s point, as shownat B and C. This causes the work to revolveeccentrically.

In mounting work between centers for machining,be sure there is no end play between the work and thedead center. However, do not have the work held tootightly by the tailstock center. If you do, as the workrevolves, it will heat the center’s point, destroying bothitself and the center. To help prevent overheating,lubricate the tailstock center with grease or oil.

Holding Work on a Mandrel

Many parts, such as bushings, gears, collars, andpulleys, require all the finished external surfaces to runtrue with their center hole, or bore.

General practice is to finish the bore to a standardsize within the limit of the accuracy desired. Thus a3/4-inch standard bore would have a finished diameterof from 0.7495 to 0.7505 inch This variation is due toa tolerance of 0.0005 inch below and above the truestandard of exactly 0.750 inch. First drill the hole towithin a few thousandths of an inch of the finished size;then remove the remainder of the material with amachine reamer, following with a hand reamer if thelimits are extremely close.

Then press the piece on a mandrel tightly enough sothe work will not slip while being machined Clamp adog on the mandrel, which is mounted between centers.Since the mandrel surface runs true with respect to thelathe axis, the turned surfaces of the work on the mandrelwill be true with respect to the bore of the piece.

A mandrel is simply a round piece of steel ofconvenient length which has been center drilled andground true with the center holes. Commercial mandrelsare made of tool steel, hardened and ground with a slighttaper (usually 0.0005 inch per inch). This taper allowsthe standard hole in the work to vary according to theusual shop practice and still provides a drive to the workwhen the mandrel is pressed into the hole. The taper isnot great enough to distort the hole in the work Thecenter-drilled centers of the mandrel are lapped foraccuracy. The ends are turned smaller than the body ofthe mandrel and provided with flats, which give adriving surface for the lathe dog.

Holding Work in Chucks

The independent chuck and universal chuck areused more often than other work-holding devices inlathe operations. The universal chuck is used for holdingrelatively true cylindrical work when the time requiredto do the job is more important than the concentricity ofthe machined surface and the holding power of thechuck When the work is irregular in shape, must beaccurately centered, or must be held securely for heavyfeeds and depth of cuts, an independent chuck is used.

FOUR- JAW INDEPENDENT CHUCK.-Figure9-23 shows a rough cylindrical casting mounted in afour-jaw independent lathe chuck on the spindle of thelathe. Before truing the work, determine which part youwish to have turned true. To mount this casting in thechuck, proceed as follows:

1. Adjust the chuck jaws to receive the casting. Thesame point on each jaw should touch the samering on the face of the chuck If there are no

9-14

Figure 9-23.—Work mounted in a four-jaw chuck.

rings, put each jaw the same distance from theoutside edge of the body of the chuck.

2. Fasten the work in the chuck by turning theadjusting screw on jaw 1 and then on jaw 3, apair of jaws which are opposite each other. Next,tighten jaws 2 and 4.

3. At this stage the work should be held in thejaws just tightly enough so it will not fall outof the chuck while you turn it.

4. Revolve the spindle slowly by hand and, witha piece of chalk, mark the high spot (A in fig.9-23) on the work while it is revolving. Steadyyour hand on the tool post while holding thechalk.

5. Stop the spindle. Locate the high spot on thework and move the high spot toward the centerof the chuck by releasing the jaw opposite thechalk mark and tightening the one nearest themark

6. Sometimes the high spot on the work will belocated between adjacent jaws. In that case,loosen the two opposite jaws and tighten thejaws adjacent to the high spot.

THREE-JAW UNIVERSAL CHUCK.—Thethree-jaw universal or scroll chuck is made so that

all jaws move at the same time. A universal chuckwill center almost exactly at the first clamping, butafter a long period of use may develop inaccuraciesof up to 0.010 inch in centering the work. You canusually correct the inaccuracy by inserting a pieceof paper or thin shim stock between the jaw and thework on the high side.

When you chuck thin sections, be careful not toclamp the work too tightly because the work will distort.If you machine distorted work, the finished work willhave as many high spots as there are jaws, and the turnedsurface will not be true.

Care of Chucks

To preserve the accuracy of a chuck, handle itcarefully and keep it clean and free from grit. NEVERforce a chuck jaw by using a pipe as an extension on thechuck wrench.

Before mounting a chuck, remove the live centerand fill the hole with a rag to prevent chips and dirt fromgetting into the tapered hole of the spindle.

Clean and oil the threads of the chuck and thespindle nose. Dirt or chips on the threads will notallow the chuck to run true when it is screwed upto the shoulder. Screw the chuck on carefully,tightening it just enough to make it difficult toremove. Never use mechanical power to install achuck.

To remove a chuck, place a spanner wrench on thecollar of the chuck and strike a smart blow on the handleof the wrench with your hand. When you mount orremove a heavy chuck, lay a board across the bed waysto protect them; the board will support the chuck as youput it on or take it off.

The comments on mounting and removing chucksalso apply to faceplates.

Holding Work on a Faceplate

A faceplate is used for mounting work that cannotbe chucked or turned between centers because of its sizeor shape.

Work is secured to the faceplate by bolts, clamps, orany suitable clamping means. The holes and slots in thefaceplate are used for anchoring the holding bolts. Angleplates may be used to position the work at the desired

9-15

Figure 9-24.—Work clamped to an angle plate.

angle, as shown in figure 9-24. Note the counterweightadded for balance.

For work to be mounted accurately on a faceplate,the surface of the work in contact with the faceplate mustbe accurately faced. It is good practice to place a pieceof paper between the work and the faceplate to preventslipping.

Before you clamp the work securely, move it abouton the surface of the faceplate until the point to bemachined is centered accurately with the axis of thelathe. Suppose you wish to bore a hole, the center ofwhich has been laid out and marked with a prick punch.First, clamp the work to the approximate position on thefaceplate. Slide the tailstock up until the dead center justtouches the work. (NOTE: The dead center should havea sharp, true point.) Now revolve the work slowly; ifthe work is off center, the point will scribe a circle onthe work. If the work is on center, the point of the deadcenter will coincide with the prick punch mark.

Using the Center Rest and Follower Rest

Place the center rest on the ways where it will givethe greatest support to the workpiece. This is usually atabout the middle of its length.

Figure 9-25.—Work mounted in a chuck and center rest.

Ensure that the jaws of the center rest are adjustedto support the work while allowing it to turn freely.Figure 9-25 shows how a chuck and center rest are usedfor machining the end of a workpiece.

The follower rest differs from the center rest in thatit moves with the carriage and provides support againstthe forces of the cut only. Set the tool to the diameterselected, and turn a “spot” about 5/8 to 3/4 inch wide.Then adjust the follower rest jaws to the finisheddiameter to follow the tool along the entire length to beturned.

Use a thick oil on the center rest and follower restto prevent “seizing” and scoring of the workpiece.Check the jaws frequently to see that they do not becomehot. The jaws may expand slightly if they get hot,pushing the work out of alignment (when using thefollower rest) or binding (when using the center rest).

Holding Work in a Draw-In Collet Chuck

The draw-in collet chuck is used for very fine,accurate work of small diameter. Long work can bepassed through the hollow drawbar. Short work can beplaced directly into the collet from the front. The colletis tightened on the work by rotating the drawbar to theright; this draws the collet into the tapered closingsleeve. The opposite operation releases the collet.

Accurate results are obtained when the diameter ofthe work is exactly the same size as the dimensionstamped on the collet. In some cases, the diameter mayvary as much as 0.002 inch; that is, the work may be0.001 inch smaller or larger than the collet size. If thework diameter varies more than this, it will impair theaccuracy and efficiency of the collet. That is why aseparate collet should be used for each small variationor work diameter, especially if precision is desired.

9-16

Figure 9-26.—Facing a cylindrical piece.

Figure 9-27.—Facing a shoulder.

MACHINING OPERATIONS

Up to this point, you have studied the preliminarysteps leading to the performance of machine work in thelathe. You have learned how to mount the work and thetool and which tools are used for various purposes. Now,you need to consider how to use the proper tools incombination with the lathe to perform variousmachining operations.

FACING

Facing is the machining of the end surfaces andshoulders of a workpiece. In addition to squaring theends of the work, facing provides a way to cut work tolength accurately. Generally, only light cuts are requiredsince the work will have been cut to approximate lengthor rough machined to the shoulder.

Figure 9-26 shows the facing of a cylindrical piece.The work is placed between centers and driven by a dog.A right-hand side tool is used as shown. Take a light cuton the end of the work, feeding the tool (by handcrossfeed) from the center toward the outside. Take oneor two light cuts to remove enough stock to true thework Then reverse the workpiece, install the dog on thejust finished end, and face the other end to make thework the proper length. To provide an accurate basefrom which to measure, hold another rule orstraightedge on the end you faced first. Be sure there isno burr on the edge to keep the straightedge frombearing accurately on the finished end. Use a sharpscribe to mark off the dimension desired.

Figure 9-27 shows the use of a turning tool infinishing a shouldered job having a fillet corner. Take afinish cut on the small diameter. Machine the fillet with

a light cut. Then use the tool to face the work from thefillet to the outside of the work.

In facing large surfaces, lock the carriage in position,since only crossfeed is required to traverse the tool acrossthe work. With the compound rest set at 90° (parallel to theaxis of the lathe), you can use the micrometer collar to feedthe tool to the proper depth of cut.

TURNING

Turning is the machining of excess stock from theperiphery of the workpiece to reduce the diameter. Inmost lathe machining operations requiring removal oflarge amounts of stock, a series of roughing cuts is takento remove most of the excess stock Then a finishing cutis taken to accurately “size” the workpiece.

Rough Turning

When a great deal of stock is to be removed, youshould take heavy cuts to complete the job in the leastpossible time. This is called rough turning.

Select the proper tool for taking a heavy chip. Thespeed of the work and the amount of feed of the toolshould be as great as the tool will stand.

When you take a roughing cut on steel, cast iron, orany other metal that has a scale on its surface, be sure toset the tool deep enough to get under the scale in the firstcut. Unless you do, the scale on the metal will dull orbreak the point of the tool.

Rough machine the work to almost the finished size;then take careful measurements.

Bear in mind that the diameter of the work beingturned is reduced by an amount equal to twice the depthof the cuts; thus, if you desire to reduce the diameter ofa piece by 1/4 inch, you must remove 1/8 inch of metalfrom the surface.

Figure 9-28 shows the position of the tool for takinga heavy cut on large work. Set the tool so that if anything

Figure 9-28.—Position of the tool for a heavy cut.

9-17

Figure 9-29.—Machining to a shoulder.

occurs during machining to change the position of thetool, it will not dig into the work, but rather will movein the direction of the arrow-away from the work

Finish Turning

When you have rough turned the work to withinabout 1/32 inch of the finished size, take a finishing cut.A fine feed, the proper lubricant, and, above all, akeen-edged tool are necessary to produce a smoothfinish. Measure carefully to be sure you are machiningthe work to the proper dimension. Stop the lathe whenyou take measurements.

If you must finish the work to close tolerances, besure the work is not hot when you take the finish cut. Ifyou turn the workpiece to exact size when it is hot, itwill be undersize when it has cooled.

Perhaps the most difficult operation for a beginnerin machine work is to make accurate measurements. Somuch depends on the accuracy of the work that youshould make every effort to become proficient in the useof measuring instruments. You will develop a certain“feel” in the application of micrometers throughexperience alone; do not be discouraged if your firstefforts do not produce perfect results. Practice takingmicrometer measurements on pieces of knowndimensions. You will acquire skill if you are persistent.

Turning to a Shoulder

Machining to a shoulder is often done by locatingthe shoulder with a parting tool. Insert the parting toolabout 1/32 inch from the shoulder line toward the small

diameter end of the work Cut to a depth 1/32 inch largerthan the small diameter of the work. Then machine thestock by taking heavy chips up to the shoulder. Thisprocedure eliminates detailed measuring and speeds upproduction.

Figure 9-29 illustrates this method of shouldering.A parting tool has been used at P and the turning tool istaking a chip. It will be unnecessary to waste any timein taking measurements. You can devote your time torough machining until the necessary stock is removed.Then you can take a finishing cut to accuratemeasurement.

Boring

Boring is the machining of holes or any interiorcylindrical surface. The piece to be bored must have adrilled or cored hole, and the hole must be large enoughto insert the tool. The boring process merely enlarges thehole to the desired size or shape. The advantage ofboring is that a true round hole is obtained, and two ormore holes of the same or different diameters may bebored at one setting, thus ensuring absolute alignmentof the axis of the holes.

Work to be bored may be held in a chuck, bolted tothe faceplate, or bolted to the carriage. Long pieces mustbe supported at the free end in a center rest.

When the boring tool is fed into the hole of workbeing rotated on a chuck or faceplate, the process iscalled single point boring. It is the same as turningexcept that the cutting chip is taken from the inside. Thecutting edge of the boring tool resembles that of aturning tool. Boring tools may be the solid forged typeor the inserted cutter bit type.

When the work to be bored is clamped to the top ofthe carriage, a boring bar is held between centers anddriven by a dog. The work is fed to the tool by theautomatic longitudinal feed of the carriage. Three typesof boring bars are shown in figure 9-30. Note the centerholes at the ends to fit the lathe centers.

Figure 9-30, view A, shows a boring bar fitted witha fly cutter held by a headless setscrew. The othersetscrew, bearing on the end of the cutter, is for adjustingthe cutter to the work

Figure 9-30, view B, shows a boring bar fitted witha two-edged cutter held by a taper key. This is more ofa finishing or sizing cutter, as it cuts on both sides andis used for production work.

The boring bar shown in figure 9-30, view C, isfitted with a cast-iron head to adapt it for boring work

9-18

Figure 9-30.–Boring bars.

Figure 9-31.–Tapers.

of large diameter. The head is fitted with a fly cuttersimilar to the one shown in view A of figure 9-30. Thesetscrew with the tapered point adjusts the cutter to thework

TAPERS

Although you will probably have little need tomachine tapers, we have provided the followingexplanation for your basic knowledge.

A taper is the gradual decrease in the diameter of apiece of work toward one end. The amount of taper inany given length of work is found by subtracting the sizeof the small end from the size of the large end. Taper isusually expressed as the amount of taper per foot oflength or taper per inch of length. We will take twoexamples. (See fig. 9-31.)

Example l.–Find the taper per foot of a piece ofwork 2 inches long. The diameter of the small end is 1inch; the diameter of the large end is 2 inches.

The amount of taper is 2 inches minus 1 inch, whichequals 1 inch. The length of the taper is given as 2 inches.Therefore, the taper is 1 inch in 2 inches of length. In 12inches of length the taper is 6 inches. (See fig. 9-31.)

Example 2.–Find the taper per foot of a piece 6inches long. The diameter of the small end is 1 inch; thediameter of the large end is 2 inches.

The amount of taper is the same as in example 1,that is, 1 inch. However, the length of this taper is 6inches; hence the taper per foot is 1 inch times 12/6,which equals 2 inches per foot (fig. 9-31).

SAFETY PRECAUTIONS

In machining operations, always keep safety inmind, no matter how important the job is or howwell you know the machine you are operating.Listed here are some safety precautions that youMUST follow:

1. Before starting any lathe operations, alwaysprepare yourself by rolling up your shirt sleeves andremoving your watch, rings, and other jewelry thatmight become caught while you operate the machine.

2. Wear goggles or an approved face shield at alltimes whenever you operate a lathe or when you are neara lathe that is being operated.

3. Be sure the work area is clear of obstructions thatyou might fall or trip over.

4. Keep the deck area around your machine clearof oil or grease to prevent the possibility of slipping orfalling into the machine.

5. Always use assistance when handling largeworkpieces or large chucks.

6. NEVER remove chips with your bare hands.Use a stick or brush, and always stop the machine.

7. Always secure power to the machine when youtake measurements or make adjustments to the chuck.

8. Be attentive, not only to the operation of yourmachine, but also to events going on around it. NEVERpermit skylarking in the area.

9. Should it become necessary to operate the lathewhile the ship is underway, be especially safetyconscious. (Machines should be operated ONLY inrelatively calm seas.)

9-19

10. Be alert to the location of the cutting tool whileyou take measurements or make adjustments.

11. Always observe the specific safety precautionsposted for the machine you are operating.

operation of the engine lathe. Additionally, you havelearned the basic operational safety precautions. Foradditional information on the operation of the enginelathes, refer to Machinery Repairman 3 & 2,NAVEDTRA 10530-E1.

SUMMARY

In this chapter, you have learned the principal parts,the attachments and accessories, the uses and the basic

9-20

APPENDIX I

REFERENCES

CHAPTER 1

Diesel Engine, Over 400 BHP, Trend Analysis Handbook, NAVSEAS9233-C3-HBK-010/010, Naval Sea Systems Command, Washington, D.C.,June 1989.

Instrumentman 1 & C, NAVEDTRA 12202, Naval Education and Training ProgramManagement Support Activity, Pensacola, Fla., June 1990.

Military Requirements for Petty Officer First Class, NAVEDTRA 12046, NavalEducation and Training Program Management Support Activity, Pensacola,Fla., 1991.

Military Requirements for Petty Officer Second Class, NAVEDTRA 12045, NavalEducation and Training Program Management Support Activity, Pensacola,Fla., 1991.

Naval Ships, Technical Manual, NAVSEA S9086-CN-STM-030, Chapter 079,Volume 3, “Damage Control Engineering Casualty Control,” Naval Sea SystemsCommand, Washington, D.C., June 1987.

Naval Ships’ Technical Manual, NAVSEA S9086-CZ-STM-000, Chapter 090,“Inspections, Tests, Records, and Reports,” Naval Sea Systems Command,Washington, D.C., June 1984.

Naval Ships’ Technical Manual, NAVSEA S9086-GX-STM-000, Chapter 220,“Boiler Water/Feedwater,” Naval Sea Systems Command, Washington, D.C.,January 1977.

Naval Ships, Technical Manual, NAVSEA S9086-SE-STM-010, Chapter 533,“Potable Water Systems,” Naval Sea Systems Command, Washington, D.C.,January 1986.

Naval Ships’ Technical Manual, NAVSEA S9086-VD-STM-000, Chapter 631,“Preservation of Ships In-Service (Surface Preparation and Painting),” NavalSea Systems Command, Washington, D.C., April 1981.

Naval Ships, Technical Manual, NAVSEA S9086-WK-STM-000, Chapter 670,“Stowage, Handling, and Disposal of Hazardous General Use Consummables,”Naval Sea Systems Command, Washington, D.C., February 1976.

Naval Ships, Technical Manual, NAVSEA 0901-LP-480-0002, Chapter 9480,“Piping Systems,” Naval Sea Systems Command, Washington, D.C., July 1973.

Naval Ships’ Technical Manual, NAVSEA 0901-LP-581-0012, Chapter 9580,“Distilling Plants Low Pressure Submerged Tube Steam Plants,” Naval SeaSystems Command, Washington, D.C., September 1967.

Navy Occupational Safety and Health (NAVOSH) Program Manual, OPNAVINST5100.23B, Chief of Naval Operations, Washington, D.C., August 1988.

Navy Safety Precautions for Forces Afloat, OPNAVINST 5100.19A, Chief of NavalOperations, Washington, D.C., January 1983.

AI-l

Standard Organization and Regulations of the U.S. Navy, OPNAVINST 3120.32B,Chief of Naval Operations, Washington, D.C., September 1986.

CHAPTER 2

Machinery Repairman 3 & 2, NAVEDTRA 12204, Naval Education and TrainingProgram Management Support Activity, Pensacola, Fla., May 1990.

Naval Ships, Technical Manual, NAVSEA S6270-AH-MMI-010, “Diesel EngineRepair,” Naval Sea Systems Command, Washington, D.C., September 1982.

Tools and Their Uses, NAVEDTRA 10085-B2, Naval Education and TrainingProgram Management Support Activity, Pensacola, Fla., July 1988.

CHAPTER 3

Marquette Governor Manual, NAVSHIPS 341-5505 (0341-LP-550-5000), Bureauof Ships, Washington 25, D.C.

Naval Ships’ Technical Manual, NAVSEA S9086-CM-STM-006, Chapter 078,“Gaskets, Packing, and Seals,” Naval Sea Systems Command, Washington,D.C., November 1987.

Naval Ships’ Technical Manual, NAVSEA S9086-HB-STM-005, Chapter 233,“Diesel Engines,” Naval Sea Systems Command, Washington, D.C., June 1987.

Naval Ships’ Technical Manual, NAVSEA S9086-HN-STM-005, Chapter 244,“Bearings,” Naval Sea Systems Command, Washington, D.C., October 1986.

Naval Ships, Technical Manual, NAVSEA S9086-KR-STM-010, Chapter 313,“Portable Storage and Dry Batteries,” Naval Sea Systems Command,Washington, D.C., September 1990.

Naval Ships’ Technical Manual, NAVSEA S6270-AH-MMI-010, “Diesel EngineRepair,” Naval Sea Systems Command, Washington, D.C., September 1982.

U.S . Navy Diese l Eng ine Inspec tor Handbook Par t I I , NAVSEAS9233-CJ-HBK-020, Naval Sea Systems Command, Washington D.C., July1988.

Woodward Governor Manual, NAVSHIPS 341-5017 (0341-LP-501-7000), Bureauof Ships, Washington 25, D.C.

CHAPTER 4

Marquette Governor Manual, NAVSHIPS 341-5505 (0341-LP-550-5000), Bureauof Ships, Washington 25, D.C.

U.S. Navy Diesel Engine Inspector Handbook Part II , NAVSEAS9233-CJ-HBK-020, Washington, D.C., July 1988.

Woodward Governor Manual, NAVSHIPS 341-5017 (0341-LP-501-7000), Bureauof Ships, Washington 25, D.C.

CHAPTER 5

Naval Ships’ Technical Manual, NAVSEA S9086-RQ-STM-000, Chapter 510,“Ventilating, Heating, Cooling, and Air Conditioning Systems for SurfaceShips,” Naval Sea Systems Command, Washington, D.C., February 1977.

AI-2

Naval Ships’ Technical Manual, NAVSEA S9086-RW-STM-010, Chapter 516,“Refrigeration Systems,” Naval Sea Systems Command, Washington, D.C.,December 1986.

CHAPTER 6

Naval Ships’ Technical Manual, NAVSEA S9086-SY-STM-010, Chapter 551,“Compressed Air Plants and Systems,” Naval Sea Systems Command,Washington, D.C., September 1989.

CHAPTER 7

Naval Ships’ Technical Manual, NAVSEA S9086-V4-STM-000, Chapter 655,“Laundry,” Naval Sea Systems Command, Washington, D.C., May 1988.

Naval Ships’ Technical Manual, NAVSHIPS 0901-340-0001, Chapter 9340,“Commissary Equipment,” Naval Sea Systems Command, Washington, D.C.,September 1967.

CHAPTER 8

Boiler Technician 3 & 2, NAVEDTRA 10535-H, Naval Education and TrainingProgram Management Support Activity, Pensacola, Fla., 1983.

Naval Ships’ Technical Manual, NAVSEA S9086-S4-STM-000, Chapter 556,“Hydraulic Equipment (Power Transmission and Control),” Naval Sea SystemsCommand, Washington, D.C., February 1990.

Naval Ships’ Technical Manual, NAVSEA S9086-TL-STM-000, Chapter 572,“Shipboard Stores and Provision Handling,” Naval Sea Systems Command,Washington, DC., January 1985.

Naval Ships’ Technical Manual, NAVSEA S9086-T3-STM-010, Chapter 588,“Aircraft Elevators,” Naval Sea Systems Command, Washington, D.C., July1990.

Naval Ships’ Technical Manual, NAVSEA S9086-T4-STM-010, Chapter 589,“Cranes,” Naval Sea Systems Command, Washington, D.C., July 1988.

Naval Ships’ Technical Manual, NAVSEA S9086-ZN-STM-000, Chapter 772,“Cargo and Weapons Elevator,” Naval Sea Systems Command, Washington,D.C., February 1989.

Naval Ships’ Technical Manual, NAVSEA S9086-SC-FTM-010, “DesalinationLow-Pressure Distilling Plants,” Naval Sea Systems Command, Washington,D.C., August 1991.

Naval Ships Technical Manual, NAVSEA S9245-BF-MMM-010, “MaintenanceManual for Controllable Pitch Propeller in DD-963 Class, DDG-993 Class andDD-997,” Naval Sea Systems Command, Washington, D.C., November 1989.

Naval Ships’ Technical Manual, NAVSEA 0944-LP-007-1010, “System-OrientedInstructions, Controllable Pitch Propellers, LST 1182 through LST 1198,” NavalSea Systems Command, Washington D.C., January 1989.

Operation Manual for Bow Ramp System (U), LST 1182-1198, NAVSEA0916-LP-018-5010, Naval Sea Systems Command, Washington, D.C.,December 1989.

AI-3

CHAPTER 9

Machinery Repairman 3 & 2, NAVEDTRA 12204, Naval Education and TrainingProgram Management Support Activity, Pensacola, Fla., May 1990.

AI-4

APPENDIX II

UNITS OF MEASUREMENT CHARTS

AII-1

U. S. CUSTOMARY AND METRIC SYSTEMUNITS OF MEASUREMENTS

THESE PREFIXES MAY BE APPLIEDTO ALL SI UNITS

An-2

ENGLISH AND METRIC SYSTEM UNITS OF MEASUREMENTCOMMON EQUIVALENTS AND CONVERSIONS

Approximate Common Equivalents Conversions Accurate to Parts Per Million(units stated in abbreviated form)

1 inch

1 foot

1 yard1 mile **

1 square inch

1 square foot1 square yard1 acre

1 cubic inch

1 cubic foot

1 cubic yard

1 quart (lq.)1 gallon1 ounce (avdp)

1 pound (avdp)1 horsepower

1 pound per square inch

1 millimeter

1 meter1 meter

1 kilometer

1 square centimeter

1 square meter

1 square meter

1 hectare1 cubic centimeter

1 cubic meter

1 cubic meter

1 liter

1 cubic meter

1 gram1 kilogram

1 kilowatt

1 kilogram per squarecentimeter

= 25 millimeters

= 0.3 meter

= 0.9 meter= 1.6 kilometers

= 6.5 square centimeters

= 0.09 square meter= 0.8 square meter

= 0.4 hectare

= 16 cubic centimeters

= 0.03 cubic meter

= 0.8 cubic meter= 1 liter

= 0.004 cubic meter= 28 grams= 0.45 kilogram

= 0.75 kilowatt

= 0.07 kilogram per square centimeter

= 0.04 inch

= 3.3 feet= 1.1 yards

= 0.6 mile

= 0.16 square inch

= 11 square feet

= 1.2 square yards

= 2.5 acres= 0.06 cubic inch

= 35 cubic feet

= 1.3 cubic yards

= 1 quart (lq.)

= 250 gallons

= 0.035 ounces (avdp)

= 2.2 pounds (avdp)

= 1.3 horsepower

= 14.2 pounds per square inch

Number × Factor

in × 25.4

ft × 0.3048*

yd × 0.9144*

mix 1.60934in2 × 6.4516*

ft2 × 0.0929030yd2 × 0.836127

acres × 0.404686

in3 × 16.3871

ft3 × 0.0283168

yd3 × 0.764555

qt (lq.) × 0.946353

gal × 0.00378541oz (avdp) × 28.3495lb (avdp) × 0.453592

hp × 0.745700

psi × 0.0703224

mm × 0.0393701

m × 3.28084m × 1.09361

km × 0.621371

cm2 × 0.155000

m2 × 10.7639m2 × 1.19599

ha × 2.47105cm3 × 0.0610237

m3 × 35.3147

m3 × 1.30795

l × 1.05669

m3 × 264.172

g × 0.0352740

kg × 2.20462kW × 1.34102

kg/cm2 × 14.223226

= m m

= m

= m

=km= cm2

= m2

= m 2

= ha

= cm3

= m 3

= m 3

= l= m 3

= g= kg

= k W

= kg/cm2

= in

= f t

= yd=mi

= in2

= ft2

= yd2

= acres= in3

= ft3

= yd3

= qt (lq.)=gal

= oz (avdp)

= lb (avdp)

= h p= psi

**nautical mile = 1.852 kilometers *exact

AII-3

INDEX

A

Administration and training, 1-1 to 1-28

engineering casualty control, 1-23

engineering records and logs, 1-1

EOSS, 1-22

equipment and instrument tag-out, 1-10

equipment tests, 1-19

MEASURE program, 1-9

Naval Safety Center bulletins, 1-26

potable water systems, 1-20

QA, 1-26

ship-to-shop work, 1-18

watch standing, 1-25

Air and water pressure tests, 3-2

Air dryers or dehydrators, 6-5 to 6-8

air quality testing, 6-6

dehydrator dew point readings, 6-7

maintenance of LP and HP air dehydrators, 6-5

B

Bearing troubles, 3-20

Boat davits, 8-10

Bore gauges, 2-4

Borescope, 2-5

Bow ramp and door machinery, 8-10

C

Cam followers and lash adjusters, 3-12

Camshafts, inspecting and repairing, 3-13

Capacity control valve, 5-1

Centering lathe work 9-13

Charging the system, 5-9

Chatter, 9-11

Chucks, care of, 9-15

Compressors, 5-1

Condensers, 5-6

cleaning of, 5-6

plugging or retubing, 5-7

testing for leaks, 5-7

Controllable pitch propellers, 8-1

Conveyors, 8-14

Cooling coils, 5-9

Cranes, 8-15

Cylinder hone, 2-9

Cylinder safety valves, 3-39

D

Dial indicator, 2-1

crankshaft end play or thrust reading, 2-2

shaft runout, 2-1

Dial/vernier caliper, 2-2

Distilling plants, 8-2 to 8-6

flash-type distilling plants, 8-6

heat-recovery distilling plants, 8-6

submerged-tube plants, 8-2

Dumbwaiters, 8-16

Dye penetrant test, 3-2

E

Electric start malfunction, 3-27

Elevators, 8-13

Engine cannot be cranked nor barred over, 3-23

Engine cranks but fails to start, 3-27 to 3-30

clogged fuel filters, 3-28

inoperative engine governor, 3-29

inoperative overspeed safety devices, 3-30

insufficient compression, 3-29

insufficient cranking speed, 3-30

insufficient fuel supply, 3-28

INDEX-1

Engine cranks but fails to start—Continued

leakage, 3-28

timing, 3-29

transfer pumps, 3-29

Engine fails to start, 3-23 to 3-27

direct mechanical lift, 3-25

faulty air starting valves, 3-26

mechanical lift valves, 3-26

plunger-type distributor valve, 3-26

pressure-actuated valves, 3-26

rotary distributor, 3-25

Engine fails to stop, 3-45

Engine hunts or will not stop, 3-35 to 3-37

accumulation of lube oil, 3-37

fuel control racks, 3-36

leakage of fuel oil, 3-37

speed control system, 3-36

Engine lathe tools, 9-5 to 9-10

boring tool, 9-6

chucks, 9-7

faceplates, 9-7

facing tool, 9-6

inside-threading tool, 9-7

lathe centers, 9-8

round-nosed turning tool, 9-6

square-nosed parting (cutoff) tool, 9-6

taper attachment, 9-9

threading tool, 9-6

turning tool, 9-5 and 9-6

Engine overspeeds, 3-35

Engine-room casualties, 1-24

Engine stalls frequently or stops suddenly 3-30 to 3-35

blower failure, 3-33

clogged air cleaners and silencers, 3-33

defective auxiliary drive mechanisms, 3-35

improper cooling water temperature, 3-31

Engine stalls frequently or stops suddenly-Continued

insufficient intake air, 3-33

loss of compression, 3-31

misfiring, 3-31

obstruction in the combustion space, 3-35

obstruction in the exhaust system, 3-32

piston seizure, 3-35

Engine test equipment, 2-11

Engine trend analysis, 1-19

Engine will not carry a load, 3-35

Engineer’s bell book, 1-2

Engineering casual&y control, 1-23

diesel engine casualties, 1-24

engineering room casualties, 1-24

operational casualties, 1-23

Engineering handbooks, 1-26

Engineering records and logs, 1-1 to 1-3

legal engineering logs, 1-1

operating records and reports, 1-3

Engineering records and reports,

disposal of, 1-9

EOSS, 1-22

Equipment and instrument tag-out, 1-10 to 1-18

enforcement, 1-18

procedures, 1-15

tag-out logs, 1-11

Equipment tests, 1-19

engine trend analysis, 1-19

spectrographic analysis, 1-19

Escalators, 8-16

Excessive consumption of lube oil, fuel, or water, 3-43

F

Facing, 9-17

Fuel and oil purifiers, 3-46

discharge ring (ring dam), 3-47

maintenance of purifiers, 3-47

INDEX-2

G J

Galley equipment, 7-6

refrigerators (self-contained), 7-6

steam-jacketed kettles, 7-7

Governors, 4-1

hydraulic, 4-1

mechanical, 4-2

H

Holding lathe work 9-13 to 9-16

between centers, 9-13

in a draw-in collet chuck, 9-16

in chucks, 9-14

on a faceplate, 9-15

on a mandrel, 9-14

Hydraulic cargo hatch covers, 8-9

Hydraulic systems, 8-6

I

Inspecting and testing the engine frame or block, 3-1 to3-3

air and water pressure tests, 3-2

dye penetrant test, 3-2

measurements, 3-1

visual inspection, 3-1

Inspecting, maintaining, and repairing connecting rods,3-18 to 3-22

bearing troubles, 3-20

measuring bearing clearances, 3-21

repairing crankshafts and journal bearings, 3-19

Inspecting, maintaining, and replacing piston rings andpistons, 3-14 to 3-18

Inspecting, testing, and repairing cylinder heads, 3-7

Inspecting, testing, and repairing cylinder liners, 3-3

excessively worn liners, 3-4

scored cylinder liners, 3-4

Jacking gear, 3-46

L

Lathe and machining operations, 9-1 to 9-20

basic setup, 9-10

preliminary procedures, 9-12

safety precautions, 9-19

Lathe principal parts, 9-2 to 9-10

accessories and attachments, 9-5

apron, 9-3

bed and ways, 9-2

carriage, 9-3

compound rest, 9-4

crossfeed slide, 9-4

feed rod, 9-3

follower rest, 9-9

headstock, 9-2

lathe dog, 9-8

lead screw, 9-4

tailstock, 9-2

thread dial indicator, 9-9

Laundry equipment, 7-1 to 7-5

laundry presses, 7-3

tumbler dryers, 7-2

washing machines, 7-1

Liners, cracked, broken, and distorted, 3-3 to 3-6

causes, 3-6

repairs, 3-6

M

Machining operations, 9-17 to 9-19

facing, 9-17

tapers, 9-19

turning, 9-17

Maintenance of air conditioning systems, 5-4 to 5-9

cleaning suction strainers, 5-6

INDEX-3

Maintenance of air conditioning Systems—Continued

crankcase seal repairs, 5-4

evacuating the compressor, 5-5

installing a shaft seal, 5-5

purging the system, 5-9

removing a shaft seal, 5-5

testing suction and discharge valves, 5-4

Maintenance of lathes, 9-10

Maintenance of reciprocating air compressors, 6-8 to6-10

air intakes, 6-8

air valves, 6-8

control devices, 6-10

cooling system, 6-10

cylinders and pistons, 6-9

lubrication system, 6-9

MEASURE program, 1-9

Measuring bearing clearances, 3-21

Mess deck equipment, 7-5

METER card, 1-9

Micrometer, 2-3

N

Naval Safety Center bulletins, 1-26

NAVSEA publications, 1-26

Noises, engine, 3-40

O

Oil filters and strainers, cleaning of, 5-15

Operating records and reports, 1-3 to 1-9

daily boat fueling record, 1-7

diesel engine operating record 1-3

distilling plant operating record, 1-8

fuel and water report, 1-3

monthly summary, 1-3

Overspeed safety devices, 4-3

P

Pistons, 3-14 to 3-17

crown and land dragging, 3-17

excessive piston-to-liner clearance, 3-16

pins, 3-14

rings, 3-14

sleeve bearings, 3-14

Potable water systems, 1-20

Q

Quality assurance program, 1-26

assurance and essentiality, levels of, 1-27

organization of the, 1-27

program components, 1-27

R

R-l2 refrigeration system, 5-1

capacity control valve, 5-1

unloader mechanism, 5-1

Refrigeration system maintenance, 5-9 to 5-11

charging the system, 5-9

evacuating and dehydrating the system, 5-10

purging the system, 5-9

Ridge reamer, 2-8

Rocker arms and pushrods, 3-12

S

Safety precautions for handling refrigerants, 5-15

Scullery equipment, 7-9

Setting the toolholder and the cutting tool, 9-12

Ship-to-shop work, 1-18

Shop equipment, 1-26

Snap gauge, 2-4

Spectrographic analysis, 1-19

Steam drain systems, 8-1

high-pressure, 8-1

low-pressure, 8-1

INDEX-4

Sticking valves, 3-18

Strain/deflection gauge, 2-5

Stroboscope, 2-6

Submerged-tube plants, 8-2 to 8-6

air ejector, 8-5

brine density, 8-6

first-effect tube nest vacuum, 8-3

improper venting of evaporator tube nests, 8-4

last-effect shell vacuum, 8-4

proper water levels, 8-4

scale deposits on evaporator tubes, 8-4

Systems, air compressed, 6-1 to 6-5

high-pressure, 6-4

low-pressure, 6-1

medium-pressure, 6-3

T

Tag-out logs, 1-11

Tapers, 9-19

Thermostatic expansion valves, 5-7

Torque, 2-6

Training, 1-20 to 1-22

programs, 1-22

responsibilities, 1-20

safety, 1-21

Troubleshooting gasoline engines, 3-43 to 3-46

engine cranks but fails to start, 3-44

engine fails to stop, 3-45

starter does not run, 3-43

starter motor operates but does not crank engine,3-44

Troubleshooting internal-combustion engines, 3-22 to3-42

electric start malfunction, 3-27

Troubleshooting internal-combustion engines—Continued

engine cranks but fails to start, 3-27

engine hunts or will not stop, 3-35

engine overspeeds, 3-35

engine stalls frequently or stops suddenly, 3-30

engine will not carry a load, 3-35

irregular engine operation, 3-30

Turning, 9-17 to 9-19

boring, 9-18

finish turning, 9-18

rough turning, 9-17

turning to a shoulder, 9-18

Two-position dual control (2PD). 5-11

U

Unloader mechanism, 5-1

V

Valves, inspecting, testing, and repairing, 3-8 to 3-12

bent valves, 3-8

broken valve heads, 3-11

broken valve springs, 3-10

burned valves, 3-8

cam followers and lash adjusters, 3-12

loose valve seats, 3-9

pitting, 3-9

rocker arms and pushrods, 3-12

sticking valves, 3-8

weak springs, 3-8

worn valve keepers and retaining washers, 3-11

W

Watch standing, 1-25

INDEX-5

Assignment Questions

Information: The text pages that you are to study areprovided at the beginning of the assignment questions.

ASSIGNMENT 1

Textbook Assignment: "Administration and Training," chapter 1, pages l-l through 1-28.

l-l. The standard forms for the logs andrecords are prepared by the varioussystems commands and the CNO.

1. True2. False

1-2. Which of the following entries isNOT required in the EngineeringLog?

1. The total engine miles steamedfor the day

2. Any injuries to engineeringdepartment personnel

3. The amount of fuel consumed forthe day

4. Draft and displacement upongetting underway

1-3. Which of the following engineeringdepartment records must bepreserved as permanent legalrecords?

1. Engineering Log and Fuel andWater Report

2. Engineer's Bell Book andMonthly Summary

3. Engineering Log and Engineer'sBell Book

4. Machinery History and BoilerRoom Operating Record

1-4. Which of the following statementspertaining to the Engineering Logis correct?

1. Remarks must include all minorspeed changes and boilers inuse

2. Spaces are provided forrecording the total enginemiles steamed for the day anddraft and displacement upongetting underway and anchoring

3. Only erasures that are neat andthe reentries that are legibleare allowed

4. It must be prepared and signedby the senior petty officer ofthe watch only

1-5. Instructions for making entries inthe Engineering Log are containedin which of the following sources?

1. Naval Ships' Technical Manual,chapter 090

2. Type commander's directives3. Engineering Log form, NAVSHIPS

3120/2D4. All of the above

1-6. You are in charge of the entireunderway watch when Fireman Jonesslips and breaks his arm in theengine room. Where should yourecord this injury?

1. In the Monthly Summary2. In the Engineering Log3. In the Engineer's Bell Book4. All of the above

1-7. If an error is made in an entry tothe Engineering Log, what shouldyou do about the erroneous entry?

1. Erase the error and insert thecorrection

2. Line through the error once,rewrite it correctly, andinitial in the margin

3. Underline the error and enteran explanatory note in themargin

4. Circle the error and write anexplanatory note at the bottomof the page

1-8. What person is reponsible forreviewing and signing theEngineering Log each day toindicate that all entries arecomplete and accurate?

1. Petty officer of the watch2. CPO with the day's duty3. Engineer officer4. Main propulsion assistant

1

1-9. The commanding officer signs theEngineering Log on what calendarday of each month?

1. Fifth2. Tenth3. Twentieth4. Last

1-10. A new series of page numbers addedto the Engineering Log are usedstarting with the first day of each

1. month2. quarter3. fiscal year4. calendar year

1-11. No one may enter changes oradditions to the Engineering Logafter it has been signed by thecommanding officer, without firsthaving obtained permission.

1. True2. False

1-12. Which of the following statementspertaining to the Engineer's BellBook is correct?

1. Entries are made in the BellBook by the throttleman (or anassistant) as soon as an orderis received

2. It is a record of all bells,signals, and other ordersreceived by the throttleman

3. Engineer's Bell Book is a legalrecord compiled by theengineering department

4. Each of the above

1-13. If the bridge signals ahead 1/3 onthe engine order telegraph andahead 35 on the engine revolutiontelegraph, what entry should thethrottleman make in (a) column 2and (b) column 3 of the Engineer'sBell Book?

1-14. Neat corrections and erasures arepermitted in the Engineer's BellBook if they are made only by theperson required to sign the recordfor the watch and if those changesare neatly initialed in the marginof the page.

1. True2. False

1-15. The Diesel Engine OperatingRecord--All Ships (NAVSEA 9231/2)may be destroyed after what minimumlength of time??

1. 6 months2. 12 months3. 24 months4. 36 months

1-16. The Daily Fuel and Water Account ismaintained by the engineeringdepartment for which of thefollowing reasons?

1. It may be used to form thebasis of other department'sreports

2. It informs selected personnelof the appropriate water usage

3. Both 1 and 2 above4. It tells the engineer officer

the status of the ship's liquidload and forms the basis ofengineering reports submittedto the higher authority

1-17. If you are assigned to compute theamount of burnable fuel aboardship, you should consider which ofthe following factors?

1. The fuel in the service,storage, and settling tanks

2. The fuel in the service andstorage tanks only

3. The fuel above the service andstorage tank suction line

4. The fuel above the service tanksuction line only

1. (a) II; (b) 352. (a) I; (b) 2/33. (a) I; (b) 354. (a) 1/3; (b) 35

2

1-18. When computing the amount ofburnable fuel on board, all thefuel below the fuel suction line isconsidered not burnable.

1. True2. False

1-19. Which of the following engineeringdepartment records/reports must besubmitted daily to the commandingofficer?

1. Daily Boat Fueling Record2. Daily Engineering Log3. Fuel and Water Report4. Each of the above

1-20. After the Monthly Summary has beenprepared, what person must verifythe fuel received for the month?

1. The commanding officer2. The supply officer3. The type commander4. The engineer officer

1-21. Which of the following statementsis true about a ship's MonthlySummary for a given month?

1. The commanding officer signsthe copy that goes to the typecommander

2. The supply officer prepares thereport

3. The engineer officer verifiesthe fuel receipt figures

4. Each of the above

1-22. Where may you find additionalinformation regarding the use ofdefinitions and explanations in thepreparation of the Monthly Summary?

1. Chief engineer instructions2. CO instructions3. Fleet commander instructions4. Supply officer instructions

1-23. Which of the following documentsindicates the amount of fuel oil onhand as of midnight, the previousday?

1. Daily Boat Fueling Record2. Fuel and Water Report3. Fuel and Water Accounts4. Diesel Engine Operating Record

1-24. Information about engineeringrecords that must be keptpermanently is contained in whichof the following publications?

1. Naval Ships' Technical Manual,chapter 080

2. SECNAVINST P5212.5 (revised)3. NAVSHIPS 50834. NAVSHIPS 3648

1-25. The Engineering Log must beretained aboard ship for whatminimum length of time?

1. 1 year2. 2 years3. 3 years4. 4 years

1-26. If a ship is scrapped, whatdisposition is made of the ship'sEngineer's Bell Book?

1. It is destroyed2. It is sent to the nearest Naval

Records Management Center3. It is sent to NAVSHIPS4. It is sent to BUDOCKS

1-27. A NAVSEA report that has served itspurpose and is no longer useful maybe destroyed after how many months?

1. 62. 123. 184. 24

1-28. The METER card is composed of howmany parts?

1. Five2. Two3. Three4. Four

3

1-29.

1-30.

1-31.

1-32.

1-33.

1-34.

What color copy of a completedMETER card is sent to the MOCC?

1. Buff2. Pink3. White4. Green

Which of the following MEASUREreports is sent to you each monthas an inventory of all your items?

1. Format 2102. Format 3103. Format 3504. Format 802

In regards to equipment tag-outprocedures, what person isresponsible for ensuring the itembeing tagged is in the prescribedposition or condition?

1. The authorizing officer2. The person attaching the tag3. The second person4. The OOD

Checks and audits of all tag-outsare usually done at which of thefollowing times?

1. At the end of each workday2. Every Friday3. Every 2 weeks4. At the end of each quarter

When a piece of equipment fails,you must take which of thefollowing actions before repairscan begin?

1. Isolate and tag-out the pieceof equipment

2. Notify the commanding officer3. Submit OPNAV Form 4790.2Q4. Request permission from the OOD

to begin work

What person specifies the number oftag-out logs needed and theirlocation?

1. The individual force commander2. The Chief of Naval Operations3. The commanding officer4. The engineer officer

1-35.

1-36.

1-37.

1-38.

In regard to proper tag-outprocedure, what person verifies thecompleteness of the tag-out action?

1. The person initiating the tag-out

2. The authorizing officer3. The EOOW4. The second person that made an

independent check

Before starting the tag-outprocedure, the authorizing officermust obtain permission from whichof the following individuals?

1. The commanding officer2. The responsible department head3. Both 1 and 2 above4. The type commander

When repairs have been completed ona piece of equipment, which of thefollowing actions must be takenbefore it can be tested?

1. Complete the work request2. Clear the tag3. Clear the piece of equipment

from the out-of-commission log4. Warm up the system

Which of the following statementsabout label and tag enforcement isNOT correct?

1. All outstanding tags listed oneach tag-out record sheet mustbe checked to ensure they areinstalled correctly

2. Results of audits are reportedto the responsible departmenthead

3. Testing the operation of avalve or switch is authorizedas part of a routine tag-outaudit

4. Spot checks of installed tagsare conducted to ensure thetags are effective

4

1-39. Which of the following methods isused to determine if an engineneeds to be overhauled or justtemporarily shut down for simplemaintenance?

1. The current engine operatingdata is compared with theprevious operating data

2. The operating data of theengine is compared with that ofthe engine of the same type

3. The temperature of the lube oilentering the cooler is comparedto that leaving the cooler

4. The present amount of lube oilconsumption is compared withprevious lube oil consumption

1-40. What can you determine from aspectrographic analysis?

1. The extent of accelerated wearof an internal combustionengine

2. The amount of oil the engineuses per month

3. The rate of flow of coolingwater to the lube oil cooler

4. The amount of oil pressureproduced by the lube oil pump

1-41. In regard to ship-to-shop work, whois responsible for witnessing anytest required?

1. The ship QA personnel assignedto the job

2. The workcenter representativewho requested the work

3. The repair facility supervisor4. The repair facility quality

assurance representative

1-42. When the shipyard or IMA laboratoryreceives the oil samples, which ofthe following tests is/areperformed?

1. Acid test2. Physical test3. Spectrometric analysis4. Both 2 and 3 above

1-43. You are aboard a destroyerhome-ported on the West Coast andyou need additional informationconcerning trend analysis and oilspectrometric analysis. You shouldrefer to what Navy instruction?

1. OPNAVINST 43P12. COMNAVSURFLANTINST 9000.1C3. COMNAVSURFPACINST 4700.1B4. SECNAVINST P5212.5

1-44. Fresh water is not potable unlessit meets which of the followingconditions?

1. It is safe for engine operation2. It is safe for human

consumption3. It is safe for cooling systems4. It is 100 percent salt-free

1-45. Along with the engineeringdepartment, what other departmentis reponsible for the receipt,distribution, and quality testingof potable water systems?

1. Supply2. Medical3. Weapons4. Operations

1-46. In addition to technicalcompetence, which of the followingcharacteristics should you possessbefore you can teach others?

1. Ability to organize information2. Loud, strong voice3. Formal training as an

instructor4. Each of the above

1-47. Which of the following factors doesNOT help to determine theprocedures for training a newperson in engine-room operations?

1. Ship's operating schedule2. Number of experienced personnel

available3. Condition of engine-room

machinery4. Trainee's manual skill level

5

1-48. An Engineman striker who is newlyassigned to the engine room is notready for messenger duty traininguntil he or she becomes familiarwith which of the followingfactors?

1. Duties of the throttleman2. Technique of reading pressure

gauges3. Procedures of starting or

securing the main propulsionplant

4. Locations of all machinery,equipment, piping, and valves

1-49. During what part of an engine-roomwatchstander's training should atrainee learn how to take gaugereadings?

1. While learning the duties of athrottleman

2. While learning the duties of amessenger

3. After becoming proficient withthe duties of the throttleman

4. After learning to perform theduties of the throttleman

1-50. When should an Engineman striker betrained to perform the duties of athrottleman?

1. After becoming competent inadministrative requirements

2. After becoming proficient inthe duties of the messenger

3. While learning the duties ofthe messenger

4. While learning specific basicsafety precautions

1-51. Which of the following factorsshould be included in the trainingof engine-room personnel?

1. Consideration of individualdifference in the learningrates of personnel

2. Time to be spent on enginetheory before manual operation

3. Encouragement of personnel tonotice and discuss differencesin engine behavior duringoperation

4. All of the above

1-52. Which of the following factorsshould be emphasized constantlythroughout an engine-room trainingprogram?

1. Safety precautions2. Trial-and-error techniques3. Emergency repair procedures4. Machinery characteristics

1-53. What section of the PQS defines theactual duties, assignments, andresponsibilities needed forqualification?

1. Fundamentals2. Systems3. Watchstations4. Qualification Card

1-54. What section of the PQS deals withthe major working parts of theinstallation, organization, orequipment?

1. Fundamentals2. Systems3. Watchstations4. Qualification Card

1-55. What is the main purpose of theEOSS?

1. To restore plant operationafter a casualty

2. To shorten communication linesto the bridge

3. To recognize the three levelsof operation

4. To keep things going smoothlyduring confusion

1-56. Which of the following informationis contained in the EngineeringOperational Casualty Control (EOCC)subsystem?

1. Watch qualifications2. Casualty symptoms3. Casualty reporting to the type

commander4. Casualty reports to BUMED

6

1-57. What is the best form of casualtycontrol?

1. Casualty prevention2. Effective organization3. Minimizing the casualty4. Restoring the casualty

1-58. What is the best source forstudying engineering casualtycontrol?

1. The Naval Ships' TechnicalManual

2. This training manual3. The Watch, Quarter, and Station

Bill4. The EOCC procedure

1-59. All engine-room watchstanders canincrease their ability to controland prevent casualties by studyingwhich of the followingpublications?

1. The user's guide2. The EOCC manual3. The EOP manual, stage I4. The EOP manual, stage II

1-60. What is the first step you shouldtake when handling a dieselcasualty with an inoperative speedgovernor?

1. Notify the engineer officer andthe bridge and requestpermission to secure the enginefor repairs

2. Check the setting of the needlevalve

3. Check the linkage for bindingor sticking

4. Control the engine manually, ifpossible

1-61. The Quality Assurance (QA) programwas established for which of thefollowing purposes?

1. To provide personnel withinformation and guidancenecessary to administer auniform policy of maintenanceand repairs

2. To provide personnel withnecessary informationconcerning MSD reportingprocedures

3. To control casualty reportingprocedures

4. To enhance the PQS program

1-62. The QA program organization (Navy)begins with what officer(s)?

1. Type commanders2. Commanding officers3. Commander in chief of the

fleets4. QA officer

1-63. Which of the following officersprovide(s) instruction, policy, andoverall direction for theimplementation and operation of theforce QA program?

1. Commanding officers only2. Commander in chief of the

fleets3. Type commanders only4. Type commanders and commanding

officers

1-64. The quality assurance officer (QAO)is responsible to which of thefollowing officers for theorganization, administration, andexecution of the ship's QA program?

1. Type commander2. Commander in chief of the fleet3. Commanding officer4. Chief engineer

7

1-65. Which of the following duties isNOT the responsibility of thequality assurance officer?

1. Coordinating the ship's QAtraining program

2. Maintaining the ship's recordsof test and inspection reports

3. Conducting QA audits asrequired

4. Monitoring work procedure forquality assurance

1-66. Which of the following persons areassigned as the ship's qualitycontrol inspector?

1. The CO and the division officer2. The engineer officer and the

QAO3. The work center supervisor and

two others from the work center4. The 3-M coordinator and the

LCPO

1-67. Level A assurance provides which ofthe following levels of assurance?

1. The most stringent ofrestrictive verification

2. The least verification3. Limited verification4. Adequate verification

1-68. Level B assurance provides which ofthe following levels of assurance?

1. Minimum verification2. Limited verification3. The most stringent of

restrictive verification4. Adequate verification

1-69. Which of the following statementsis NOT correct about levels ofessentiality?

1.

2.

3.

4.

They are codes assigned bysupplyThey indicate the degree ofimpact on the ship's missionThey indicate the impact onpersonnel safetyThey reflect the degree ofconfidence that procurementspecifications have been met

1-70. What person implemented the systemfor periodic maintenance ofequipment requiring calibration orservicing?

1. Chief of Naval Operations2. Chief of Naval Education and

Training3. Chief of Naval Material4. Chief of Naval Personnel

8

ASSIGNMENT 2

Textbook Assignment: "Measuring and Repair Instruments" and "Internal Combustion Engines,"chapters 2 and 3, pages 2-1 through 3-23.

2-1. To ensure accuracy when measuringcrankshaft end play, you shouldtake the measurement what minimumnumber of times?

1. Five2. Two3. Three4. Four

2-2. Which of the following proceduresis the correct method to followwhen opening a micrometer?

1. Hold the frame with one handand turn the knurled sleevewith the other hand

2. Twirl the frame3. Hold the knurled sleeve with

both hands and twirl the frame4. Twirl the knurled sleeve

2-3. Which of the following statementsconcerning a bore gauge is NOTcorrect?

1. It gives a direct measurement2. It is one of the most accurate

tools for measuring a cylinderbore

3. It checks the cylinder forout-of-roundness or taper

4. It has two stationaryspring-loaded points and anadjustable point

2-4. Why must you expose the boregauge, the master ring gauge, orother tools used to preset thebore gauge, and the part to bemeasured to the same environmentbefore measuring?

1. Because it is a good practiceto have all the tools and thepart to be measured in oneplace

2. Because a temperaturedifferential may cause yourreadings to be inaccurate

3. Because by doinq so. you cancheck what else you needbefore starting a measurement

4. Because by doing so, this willgive you some time to read thebore gauge operating manual

2-5. A strain/deflection gauge is usedfor which of the followingmeasurements?

1. Crankshaft run-out2. Crankshaft end play3. Both 1 and 2 above4. Crankshaft alignment

2-6. When a strain/deflection gauge isused, readings are generally takenin how many crank positions?

1. Six2. Five3. Three4. Four

2-7. Once you have placed thedeflection gauge indicator inposition for the first reading.you do not touch the gauge untilall the required readings aretaken and recorded.

1. True2. False

9

2-8.

2-9.

2-10.

2-11.

2-12.

What is the most preferred ratio 2-13. Which of the following is NOT theof the torque multiplier? result of an improperly cooled

cylinder liner?1. 5 to 12. 2 to 13. 3 to 14. 4 to 1

1. Liner failure2. Thermal stress3. Uneven heating4. Fluctuation in rpm

If you use an extension to atorque adapter, how should thetorque applied to the part orfastener compare to the torqueindicated on the torque wrench?

2-14. Which of the following conditionsis NOT a cause for the liner to beimproperly seated?

1. It will be the same2. It will be greater3. It will be less

1. Metal chips2. Oversized liner3. Nicks or burrs4. Improper fillets

Before you begin an inspection ortest of an engine frame or block,what should you do first?

2-15. Broken piston rings will causewhich of the following problems?

1. Consult the manufacturer'smanual because specificprocedures vary with differentengines

2. Check the engine's preventivemaintenance schedule

3. Clean the outside of theengine thoroughly

4. Warm up the engine

1. Scored cylinder liners2. Connecting bearing failure3. High lube oil temperature4. High freshwater temperature

2-16. Which of the following symptoms isan indication of a scoredcylinder?

A dye penetrant test meets therequirements for quality assurancewhen it is conducted by whatperson?

1. High compression pressure2. Rapid wearing out of strainers

and liner parts3. Low compression pressure4. Cracked or broken piston rings

1. A QA inspector2. Any qualified person3. A certified nondestructive

testing technician4. A well-trained engineman

2-17. Which of the following conditionswill produce out-of-round cylinderliners?

Which of the following conditionscould indicate a crack in thecylinder liner of an engine?

1. Operating the engine at toolow a temperature

2. Defective main bearing3. Piston side thrust4. Improperly seated head

2-18. How do you determine liner wear?1. Water standing atop the

cylinder's piston after theengine is secured

2. Abnormally high coolingtemperature when the engine isoperating

3. Large amount of water in thelubricating oil

4. Each of the above

1. Take piston and linermeasurements and qet thedifference

2. Take measurements at threelevels in the liner

3. Compare wear of piston rings4. Compare compression readings

10

2-19. As a precaution against error, itis a good practice for two personsto take the liner measurement andthen compare and check anydiscrepancy between the two setsof readings.

1. True2. False

2-20. Which of the following conditionsis NOT a cause of abnormal linerwear?

1. Insufficient lubrication2. Dirt in the lube oil3. Improper starting procedure4. High cooling water temperature

2-21. Under which of the followingconditions are corrosive vaporsmost likely to condense on thecylinder liner walls of an engine?

1. While operating attemperatures exceeding normal

2. While operating with the lubeoil pressure below normal

3. While warming up after it isfirst started

4. While operating in such a waythat normal lube oil pressureis exceeded

2-22. You are removing a cylinder linerfrom an engine. When fasteningthe special liner puller to theliner studs, why must you tightenthe cap nuts by hand instead of bywrench?

1. Because the nuts cannot bereached with a wrench

2. Because the cylinder linercould be scratched with awrench

3. Because threads on both nutsand studs could be damaged bya wrench

4. Because there is some dangerthat a wrench could be left inthe cylinder liner

2-23. You are inspecting a cylinder headfor cracks. Which of thefollowing is NOT a correctprocedure to use?

1. Perform a compression test2. After bringing the piston of

each cylinder to top deadcenter. apply compressed air

3. Examine by sight or withmagnetic powder

4. Perform the hydrostatic testthat is used on awater-jacketed cylinder

2-24. The gaskets, which are usedbetween the mating surfaces of thehead and the block of an engine,give this joint which of thefollowing characteristics?

1. Acid resistance2. Protection against leakage3. Rigidity4. Correct shape

2-25. What should you do if you discovera warped or distorted cylinderhead during an inspection?

1. Machine the head to correcttolerance

2. Replace the head as soon aspossible

3. Overtorque the head tocompensate for the warpage

4. Reduce the load on the engine

2-26. Which of the following symptomsdoes NOT indicate fouling in thecombustion chambers?

1. Excessive oil pumping2. Smoky exhaust3. Loss of power4. Low compression

2-27. Which of the following valveproblems will cause a valve tohang open?

1. Burned valve2. Floating valve3. Sticking valve4. Bent valve

11

2-28. In a two-stroke cycle engine withaluminum pistons, what is themaximum wear limit for the liner?

1. 0.0015 in. per inch diameter2. 0.0025 in. per inch diameter3. 0.0030 in. per inch diameter4. 0.0050 in. per inch diameter

2-29. Which of the following conditionswill NOT cause cracks on an enginecylinder head?

1. Obstruction in the combustionspace

2. Restriction of cooling passage3. Addition of hot water to a

cold enqine4. Improperly tightened studs

2-30. What valve casualty is usuallycaused by resinous deposits leftby improper lube oil or fuel?

1. Burned valves2. Sticking valves3. Weak springs4. Bent valves

2-31. After inspecting the engine intakevalves, you discovered that thesurface of the valve head hasdamage. Which of the followingcasualties is the most probablecause?

1. It is sticking2. It has a weak spring3. It is bent4. It has a loose valve seat

2-32. Which of the following valvecasualties will cause the valve tofail to close completely?

1. A burned valve2. A valve float3. A sticking valve4. A valve that has a weak spring

2-33. Failure to properly prepare thecounterbore area before placing avalve seat insert in it will causewhat problem?

1. Uneven heat transfer betweenthe seat and the counterbore

2. Scratching of the insert3. Misalignment of the valve head

in the seat4. Loose fit of the insert in the

counterbore

2-34. When replacing a valve seatinsert, which of the followingprocedures should you follow?

1. Plan the operation so that theinsert is placed slowly andprecisely

2. Use boiling water to heat thevalve seat

3. Drive the insert down with aspecial tool

4. Shrink the valve guides orcounterbore with dry ice

2-35. Minor pits and flaws may beremoved from the valve seat bywhat method?

1. Buffing2. Hand grinding3. Insert replacement4. Rubbing with prussian blue

2-36. How are valves refaced?

1. On a lathe2. Against the valve seat3. By machine qrinding4. Each of the above

2-37. Which of the following conditionswill cause valve springs to break?

1. Compression and corrosion2. Misalignment and compression3. Corrosion and fatique4. Fatique and compression

12

2-38. Which of the following defectsdoes NOT warrant valve springreplacement?

1. Loss of 2 percent of length2. Damage to protective coating3. Hairline cracks4. Rust pits

2-39. Which of the following resultswill occur if shims are notproperly placed between a valvestem and valve stem cap?

1. Damaged valve stem cap2. Damaged or broken valve stem3. Dropped valve4. Each of the above

2-40. What is the most important factorin keeping a properly adjustedvalve actuating gear in goodcondition?

1. Minimum clearance2. Control of corrosion3. Proper materials4. Adequate lubrication

2-41. If the threads on a rocker armadjusting screw become worn, whatmust you do?

1. Replace the rocker arm, screw,and locknut

2. Replace the screw only3. Replace the screw and locknut

only4. Dress the threads on the screw

2-42. To adjust the tappet to the intakevalve of a 4-stroke cycle engine,the piston must be in whatposition?

1. On the intake stroke2. On the compression stroke3. Between the compression and

power strokes4. Between the intake and

compression strokes

2-43. What is the most frequentmaintenance requirement for rockerarms?

1. Reaming the bushings in therocker arms

2. Inspecting the rocker arm endsfor wear

3. Checking tappet clearances andlocknut tightness

4. Replacing tappet adjustingscrews and locknuts

2-44. After setting a tappet clearanceand locking the adjusting screwwith the locknut, what is yournext step?

1. Recheck the clearance2. Adjust the next tappet3. Warm the engine up and reset

the clearance4. Check the manufacturer's

manual to see if the clearanceis correct

2-45. When a lash adjuster is adequatelysupplied with oil, what will mostlikely cause it to operatenoisily?

1. Excessive clearance2. Broken parts3. Dirt,resin, or abrasive

particles4. Missing check ball or spring

2-46. Which of the following actionsshould you take to insert acamshaft into the camshaft recess?

1. Rotate it as you push it in2. Shake it up and down3. Apply grease to it4. Hit it with a sledge

2-47. Why is it necessary to scrapearound the top of a cylinder borebefore pulling the piston?

1. To remove any metal ridges andcarbon deposits

2. To increase clearance for thepiston

3. To remove abrasive particlesand gum

4. To free the piston rings

13

2-48. To scrape the top of a cylinderbore before pulling the piston,you should use which of thefollowing tools?

1. A power grinder2. A file3. A metal scraper4. An emery cloth

2-49. When using a brass drift to removea frozen piston ring, you mustavoid damaging which of thefollowing parts?

1. The ring2. The drift3. The camshaft4. The land

2-50. Piston ring gaps are measured (a)with what tool and (b) in whatlocation?

1. (a) A micrometer;(b) on the piston

2. (a) A feeler gauge;(b) in the cylinder liner

3. (a) A feeler gauge;(b) in the vise

4. (a) A micrometer;(b) in the cylinder liner

2-51. In addition to ring gap, whatother factor must you measure toensure correct ring fit?

1. Ring end gap2. Ring-to-land clearance3. Ring width4. Ring circumference

2-52. Operation of an internalcombustion engine above thespecified temperature limits mayresult in which of the followingproblems?

2-53. If the oil flow to a piston isrestricted, where will thedeposits caused by oxidation orthe oil form?

1. On the underside or the pistoncrown

2. Behind the compression rings3. On the piston walls4. On the topside of the piston

crown

2-54. You are installing a new sleevebearing. Which of the followingprocedures will make it easier toinsert the new sleeve bearing?

1. Apply plenty of grease to thebushing

2. Shrink the piston with dry ice3. Shrink the sleeve bearing with

dry ice4. Heat the sleeve bearing in the

oven

2-55. What is the primary reason pistonpin bushings are reamed?

1. To enlarge oil holes2. To obtain correct lubricating

flukes3. To obtain proper bore

clearance4. To correct oil hole

positioning

2-56. To measure the clearance between apiston pin and its bushing, whichof the following items should youuse?

1. Micrometers2. Feeler gauges3. Leads4. Prussian blue

1. Lack of lubrication of thecylinder walls

2. Low cylinder temperatures3. Increased oil viscosity4. Low oil temperatures

14

2-57. When inserting new piston pinbushings, what are the threethings you must check?

1. Alignment, clearance, andappearance

2. Cleanliness, appearance, andclearance

3. Appearance, alignment, andcleanliness

4. Cleanliness, alignment, andclearance

2-58. Crankshaft journals that exceedthe specified tolerances forout-of-roundness should berefinished by which of thefollowing means?

1. Stoning2. Grinding3. Filing4. Scraping

2-59. A rough spot or slight score on acrankshaft journal should beremoved by dressing with which ofthe following materials?

1. A fine sandpaper2. A crocus cloth3. A fine oilstone4. Both 2 and 3 above

2-60. What instrument is used to takecrankweb deflection readings?

1. A feeler gauge2. An outside micrometer3. A strain gauge4. A gauge block

2-61. Impending bearing failures may beindicated by which of thefollowing factors?

1. Lower than normal lubricatingoil pressure and temperature

2. Higher than normal lubricatingoil pressure and temperature

3. Lower than normal lube oilpressure and higher thannormal lube oil temperature

4. Higher than normal lube oilpressure and lower than normallube oil temperature

2-62. What is the recommended correctiveaction for journal bearings thathave small raised surfaces orminor pits?

1. Replace the bearing2. Stone down the raised surfaces

and fill in the pits withsolder

3. Grind the surfaces with a handgrinder

4. Smooth down the surfaces witha bearing scraper

2-63. Before installing new or restoredbearings, what should you do?

1. Wipe oil on the journalsurfaces only

2. Wipe oil on the bearingsurfaces only

3. Ensure that the surfaces areclean and place a film ofclean oil on both the journalsand bearing surfaces

4. Clean the bearings withsolvent and wipe dry

2-64. Certain information is indicatedby markings placed on each half ofthe connecting rod bearings whenthey are removed from an engine.These markings ensure that thehalves will be installed in theiroriginal positions. Which or thefollowing is an example ofsufficient and necessaryinformation being shown by amarking?

1. No. 2 cylinder2. No. 2 cylinder. upper half3. No. 2 cylinder, engine No.

3116454. Upper half, engine No. 311645

2-65. Which of the following proceduresare acceptable for tighteningconnecting rod bolts?

1. Bolt elongation and bearingcap compression

2. Bearing cap compression andslugging wrench tightening

3. Torque wrench tightening andbolt elongation

4. Slugging wrench tightening andusing a wrench extender

15

2-66. Which of the following means ofdetermining clearances will NOTleave an impression in the softbearing metal?

1. Leads2. Shim stock3. Feeler gauge4. Plastigage

2-67. Which of the following senses isNOT used by the diesel enginetroubleshooter?

1. Smell2. Sight3. Hearing4. Taste

2-68. Frequently, instruments give thefirst symptoms of trouble. Todetect a variation from normal,the troubleshooter must take whichof the following actions?

1. Memorize the specifiedengine-operating instructions

2. Report the instrument readingsto the EOOW

3. Read the instruments andrecord their indicationsregularly

4. Each of the above

2-69. Which of the following actionswill be the greatest aid indetecting minor leakage?

1. Standing watch2. Conducting material inspection3. Conducting administrative

inspection4. Conducting routine cleaning

2-70. When a diesel engine can neitherbe cranked nor barred over, whichof the following troubles is mostprobably indicated?

2-71. Which of the followinq is asymptom of excessive clearancebetween a piston and its cylinder.?

1. Piston slap2. Less oil consumption3. Minimal carbon deposits4. Each of the above

2-72. Which of the following factorscould cause piston seizure?

1. Excessive temperatures2. Excessive cooling3. Decrease in the rate of

oxidation4. Both 2 and 3 above

2-73. The best method for locatingcracks in connecting rods is withan inside micrometer.

1. True2. False

2-74. Which, if any, of the followingmeasurements, indicates that mainbearing wear has occurred?

1. Clearance between the bridgegauge and shaft

2. Variation between the measuredclearance and the clearancestamped on the bearing housing

3. Variation between last crankweb deflation and present

4. None of the above

2-75. When troubleshooting dieselengines, you should associate lackof engine power with which of thefollowing systems?

1. Lubrication2. Cooling3. Fuel4. Each of the above

1. A depleted air supply2. An open cylinder relief valve3. An improperly engaged turning

gear4. An out-of-time air-starting

motor

16

ASSIGNMENT 3

Textbook Assignment: "Internal Combustion Engines," "Speed Controlling Devices," and"Refrigeration and Air Conditioning," chapters 3, 4, and 5, pages 3-23through 5-9.

3-1. An engine cannot be cranked, but itcan be barred over. Which of thefollowing is the most probablefault?

1. Improper throttle setting2. Tripped overspeed device3. Engaged jacking gear interlock4. Seized piston

3-2. In an engine that cannot becranked, but can be barred over,which of the following systems isthe most probable source oftrouble?

1. Starting2. Fuel3. Ignition4. Lubrication

3-3. Which of the following troubles maybe detected through the scavengingair port?

1. Stuck piston rings2. Seized bearing3. Faulty air-starting

distributor4. Scored bearing

3-4. What causes most of the troubles ina direct mechanical liftair-starting system?

1. Insufficient lubrication2. Improper adjustments3. Dirt and gum deposits4. Inadequate cooling

3-5. On a rotary distributor timingmechanism, what should you use tocheck the contact between the rotorand the body?

1. Feeler gauge2. Prussian blue3. Clearance light4. Micrometer

3-6. Which of the following practicestends to reduce or eliminate theformation of gummy deposits thatcause upper and lower pistons ofpressure-activated air-startingvalves to stick in the cylinders?

1. Increasing the tension of thevalve return springs

2. Draining the storage tanks andwater traps of the air-startingsystem

3. Jacking the engine overmanually before starting tofree any valves that may bestuck

4. Decreasing the tension of thevalve return springs

3-7. If the upper piston of anair-actuated starting valve sticksbecause of gummy deposits, whataction should you take?

1. Force alcohol around thepistons

2. Blow clean hot air around thepistons

3. Put light oil or diesel fuelaround the piston and work thevalve up and down

4. Remove the piston and buff itwith jeweler's rouge

3-8. In general, what should you do if apressure-actuated air-startingvalve is not functioning properlybecause of a weak return spring?

1. Place another washer on top ofthe valve stem

2. Replace the castellated nutwith a heavier one

3. Restress the valve returnspring

4. Install a new valve returnspring

17

3-9. What is the main source of fuelpump and injection system troubles?

1. Contaminated fuel2. Improper adjustments3. Coated fuel lines4. Excessive vibration

3-10. Metal fatigue in the nipples of afuel system is usually caused bywhich of the following factors?

1. Leakage2. High injection pressure3. Vibration4. Erosion

3-11. What are the two main causes ofleakage in fuel tanks?

1. Corrosion and excessive fuelline pressure

2. Metal fatigue and improperwelds

3. Vibration and metal fatigue4. Clogged fuel lines and

corrosion

3-12. Which of the following problems islikely to cause failure of a dieselengine mechanical governor?

1. Faulty oil seals2. Bound control linkage3. Defective cold starting valve4. Low oil level

3-13. Which of the following actions willcause the overspeed safety deviceof an engine to become inoperative?

1. Trying to start the engine withlow air-starting pressure

2. Tripping the deviceaccidentally while trying tostart the engine

3. Shutting off the fuel supplyafter starting the engine

4. Shutting off the air supplyafter starting the engine

3-14. Most diesel engines are equippedwith a special means of cutting offtheir air or fuel supply in anemergency. In which of thefollowing situations would thespecial means be used?

1. Engine cannot be cranked orbarred over

2. Parts of the exhaust system areobstructed

3. Fuel oil injection system isnot properly timed

4. Overspeed safety device doesnot operate when speed becomesexcessive

3-15. Slow cranking of a cold dieselengine may be caused by the use ofwhich of the following substances?

1. Detergent lube oil2. High viscosity lube oil3. Centrifuged lube oil4. Low viscosity lube oil

3-16. What diesel engine system is likelyto be at fault if a cylindermisfires regularly?

1. Lubrication2. Fuel3. Exhaust4. Ignition

3-17. A cylinder compression leak isindicated when the pressure in aparticular cylinder of an enginesignals which of the followingconditions?

1. It is much higher than thepressure in the other cylinders

2. It is much lower than thepressure in the other cylinders

3. It fluctuates from normal tomuch below specified pressure

4. It fluctuates from normal tomuch above specified pressure

18

3-18. If the water in the cooling systemof a diesel emergency generatoroverheats because the thermostatfails to function, what correctiveaction should you take?

1. Clean the bellows of theelement

2. Adjust the tension of theregulator spring

3. Clean the freshwater cooler4. Replace the thermostat

3-19. In the Fulton-Sylphon automatictemperature regulator, what happensif you decrease the spring tension?

1. The velocity of the coolingwater decreases

2. The temperature range of theregulator increases

3. The temperature range of theregulator decreases

4. The velocity of the coolingwater increases

3-20. Which of the following troubles inthe engine exhaust system willcause back pressure?

1. Obstruction in the combustionspace

2. Thermostat failure3. Restricted exhaust4. Restricted oil filter

3-21. After being cleaned, most oilbath-type engine air cleanersshould be refilled to what level?

1. To the full mark2. Slightly above the full mark3. To the halfway mark4. Slightly less than the halfway

mark

3-22. Which of the following conditionscan damage the turbine blading of aturbocharger?

1. Foreign objects2. Bearing failure3. Overspeeding4. Each of the above

3-23. Which of the following conditionswill NOT cause scoring of blowerparts?

1. Dirty lube oil2. Worn gears3. Improper timing4. Improper end clearance

3-24. How can you determine whetherblower rotor gears are wornexcessively?

1. Measure the clearance betweenthe leading and the trailingedges of the rotor lobes

2. Measure the backlash of thegear set

3. Measure the clearance betweenthe rotor lobes and the casing

4. Check the timing of the rotors

3-25. Which of the following conditionsis a major contributing factor todiesel engine power loss, startingfailure, and frequent stalling?

1. High cooling water temperature2. Faulty operation of the

governor3. Improperly engaged jacking gear4. Faulty air-starting distributor

3-26. If you are checking an engine for astuck fuel control rack, whatshould you do immediately afterdisconnecting the linkage to thegovernor?

1. Visually inspect the rack2. Try to move the rack by hand3. Test the return springs4. Clean the removed rack

3-27. A leaking fuel injector may causean engine to

1. stop2. overheat3. operate better4. continue to operate when you

attempt to shut it down

19

3-28. Under which of the followingconditions will a properlyoperating engine governor fail tohave any control over a suddenincrease in speed?

1. Injector leakage duringoperation

2. Sudden drawing of lube oil intothe cylinders from the air box

3. Manifold explosion due toexcessive accumulation of oil

4. Inoperative cylinder reliefvalve due to a stuck spring

3-29. Before installing a new blower oilseal, what must you do to the oilseal first?

1. Wash it in a detergent2. Spray it with paraffin3. Blow some air through it4. Soak it in clean, light lube

oil

3-30. What must you do to an improperlyoperating safety valve when it isremoved from an engine cylinder?

1. Reset the spring tension2. Replace the shear pin3. Machine and lap the valve4. Replace it with a new one

3-31. If the exhaust ports of an enginebecome clogged during operation,which of the following conditionsis a possible result?

1. High exhaust temperatures2. Overheating of the engine3. Popping of the cylinder safety

valves4. Each of the above

3-32. When cleaning the cylinder ports ofan engine, you can prevent carbonfrom entering the cylinder byperforming which of the followingactions?

1. Using a vacuum cleaner whilebrushing off the carbon

2. Jacking the engine over to aposition that the piston blocksthe port

3. Covering the inside of thecylinder

4. Brushing off the carbon awayfrom the cylinder direction

3-33. What kind of noise will most likelybe coming from an engine operatingwith a broken engine part?

1. Rattling2. Clicking3. Pounding4. Knocking

3-34. The color of the exhaust smoke ofan engine can NOT be used as an aidin which of the followingcircumstances?

1. Troubleshooting2. Testing for fuel contamination3. Determining engine performance4. Determining serious engine

troubles

3-35. An explosion may occur if acigarette is lit near a storagebattery because of the presence of

1. hydrogen gas2. carbon monoxide3. sulphuric acid4. gasoline fumes

3-36. Failure of a gasoline enginestarting motor to run may be causedby corroded, loose, or burnedbattery terminals.

1. True2. False

20

3-37. When the starting motor of agasoline engine turns but fails tocrank the engine, the trouble isusually found in the

1. drive assembly2. engine timing3. fuel system4. ignition system

3-38. Which of the following problems canresult from overpriming a gasolineengine?

1. An overheated engine2. An inoperative fuel pressure

gauge3. Stuck piston rings4. Corroded piston crowns

3-39. You are checking for trouble in afuel system that has a wobble pump.If the pump feels or sounds dry,where is the trouble probablylocated?

1. In the carburetor2. In the line to the fuel pump3. In the fuel pump4. Between the fuel pump and the

supply tanks

3-40. If a gasoline engine with abattery-type ignition system failsto stop, what is the most likelycause?

1. The switch contact points areopen

2. The ground connection is open3. The switch contact points are

closed4. The battery terminals are

burned

3-41. Oil purifiers are designed to givemaximum efficiency when you operatethe purifier at what limits?

1. Minimum speed2. A speed determined by

prevailing conditions3. A speed between minimum and

maximum and below the ratedcapacity

4. Maximum designed speed andrated capacity

3-42. Most oil used by the Navy can beheated to what maximum temperaturewithout damaging the oil?

1. 195°F2. 190°F3. 185°F4. 180°F

3-43. When the military symbol 9250 lubeoil is to be purified, it should beheated to what specifictemperature?

1. 140°F2. 160°F3. 175°F4. 180°F

3-44. The size of the discharge ring usedin a purifier is determined bywhich of the following factors?

1. Viscosity of the oil2. Moisture content of the oil3. Sediment content of the oil4. Specific gravity of the oil

3-45. What is the best method ofdetermining the efficiency of apurifier?

1. Oil clarity check2. Oil analysis3. Batch process4. Bowl sediment check

3-46. Which of the following correctivemeasures should you use to reducethe number of engine governordifficulties?

1. Reduce the engine speed2. Increase the engine load3. Use clean oil4. Adjust the fuel linkage

3-47. When installing a new or overhauledgovernor, which of the followinggovernor components should youadjust?

1. Governor linkage2. Compensating needle valve3. Speed adjusting screw4. Speeder spring

21

3-48. When the governor compensatingneedle valve is correctly adjusted,the engine will behave in which ofthe following manners during loadchanges?

1. Maintain low underspeeds2. Maintain high overspeeds3. Return slowly to normal speeds4. Return quickly to normal speeds

3-49. An increase in load for anyconstant throttle setting of amechanical governor will beaccompanied by a decrease in

1. engine speed2. spring length3. fuel pressure4. oil temperature

3-50. The mechanical governor controlsthe engine maximum speed when thecentrifugal force of both sets offlyweights act against which of thefollowing parts?

1. The buffer spring2. The light spring3. The heavy spring4. Each of the above

3-51. Which of the following is NOT acause of improper speed fluctuationof an engine equipped with amechanical governor?

1. Constantly changing loads2. Misfiring engine cylinders3. A binding governor linkage4. High lube oil temperature

3-52. When you are in the process ofassembling a governor, which of thefollowing materials is recommendedfor use on the sealing gasket?

1. Shellac2. Hard grease3. Soft grease4. Lube oil

3-53. An overspeed trip will stop adiesel engine that is equipped witha speed governor when the regularspeed governor fails to performwhich of the following actions?

1. Limit the load on the engine2. Keep the engine within its

maximum designed limit3. Adjust to higher engine loads4. Reduce engine hunt

3-54. A broken drive shaft of a hydraulicoverspeed trip will causeuncontrolled engine speed becausethe flyweights would

1. disconnect from the shaft2. remain in the distended

position3. cease to exert centrifugal

force4. increase in rotative speed

3-55. What controls the output of ahigh-speed refrigerationcompressor?

1. The box temperature2. The loading and unloading of

compressor cylinders3. The low-pressure switch4. The solenoid valve

IN ANSWERING QUESTION 3-56, REFER TOFIGURE 5-3 OF THE TEXTBOOK.

3-56. What will happen when an increasein oil pump pressure causes thepiston of the capacity controlvalve to move against spring A?

1. More cylinders will becomeloaded and the compressoroutput will increase

2. More cylinders will becomeunloaded and the compressoroutput will decrease

3. The regulating valves willrelieve the oil pressure

4. The compressor output willremain the same

22

3-57. A refrigerant compressor has beenoverhauled. What is the first stepyou should take to remove the airfrom the compressor?

1. Disconnect the connection inthe discharged gauge linebetween the stop valve and thecompressor

2. Disconnect the connection onthe compressor suction line

3. Start the compressor and let itrun until a vacuum is obtained

4. Remove all oil from thecompressor crankcase

3-58. You are trying to locate therefrigeration purge valve. Mostlikely you can find the valve inwhich of the following locations?

1. At the bottom of the condenser2. At the top of the condenser3. At the midsection of the

condenser4. On the condenser gauge line

3-59. In which of the following areaswould air that enters arefrigeration plant tend tocollect?

1. Upper part of the receiver2. Upper part of the condenser3. Inlet end of the condenser4. Downstream end of the cooling

coil

3-60. In a refrigeration system, what isthe purpose of the purge valve?

1. To take out unpleasant fumesfrom the refrigerant

2. To vent off excess refrigerantduring an emergency

3. To remove any air that mayaccumulate in the system

4. To permit the opening of therefrigeration system forcleaning and inspecting

3-61. On an air-cooled condenser, theexterior surfaces of the tubes andfins are dirty and restricting aircirculation. Which of thefollowing items should you use toclean these surfaces?

1. Jets of steam2. Hot-water lances3. Compressed-air lances4. Stiff-bristled brushes

3-62. You are testing the condenser tubesfor leakage. Why do you hold theexploring tube of the leak detectorat one end of each condenser tubefor about 10 seconds before drivinga cork into each end of the tube?

1. To dry the tube heads2. To detect the presence of R-123. To draw fresh air through the

tube4. To vaporize any water left in

the tube

3-63. You are attempting to locate leaksin a refrigeration condenser.Before continuing the tests, youshould allow the condenser toremain idle for what minimum periodof time after all tubes in thesuspected section have been corked?

1. 2 to 4 hr2. 4 to 6 hr3. 6 to 8 hr4. 8 to 10 hr

3-64. When the thermostatic valve isoperating properly, how does thetemperature at the outlet side ofthe valve compare with thetemperature at the inlet side?

1. The temperature is lower at theoutlet side

2. The temperature is lower at theinlet side

3. The temperature isapproximately the same at theoutlet and the inlet sides

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3-65. Which of the following factors cancause a thermostatic expansionvalve to operate improperly?

1. A collection of dirt on thecontrol bulb

2. A collection of Freon at thevalve seat

3. A collection of dirt at thevalve orifice

4. Each of the above

3-66. As a rule, about how many degreesof superheat are picked up by therefrigerant vapor before it leavesthe cooling coil?

1. Between 4°F and 12°F2. Between 15°F and 20°F3. Between 30°F and 38°F4. Between 45°F and 50°F

3-67. In a refrigerant plant, liquidrefrigerant may flood back to thecompressor from the evaporator ifthe thermostatic expansion valve isin which of the followingsituations?

1. Stuck shut2. Adjusted for too high a degree

of superheat at the outlet3. Adjusted for too low a degree

of superheat at the outlet

3-68. If you suspect that the expansionvalve assembly requiresreplacement, which of the followingconditions should be met beforemaking an expansion valve test?

1. The liquid strainers should becleaned

2. The solenoid valves should beoperational

3. The system should besufficiently charged

4. All of the above

3-69. A service drum that is used fortesting an expansion valve shouldcontain which of the followinggases?

3-70. You are testing the thermostaticexpansion valve of a refrigerationplant. When should you immerse thethermal element in a bath ofcrushed ice?

1. Before the valve inlet isattached to the gas source

2. After the high-pressure andlow-pressure gauges have beenconnected

3. Before the high-pressure gaugeis connected to the valveoutlet

4. After the valve on the airsupply line has been opened

3-71. A thermostatic expansion valve isset for 5°F of superheat. Whatshould be the outlet pressure onthe gauge?

1. 16.1 psig2. 22.5 psiq3. 26.1 psig4. 32.5 psiq

3-72. Which of the following operatingconditions is an indication thatthe expansion valve is seatingproperly?

1. Pressure stops increasing aftera few pounds

2. Pressure will build up slowly3. Both 1 and 2 above4. Pressure increases rapidly and

equals the inlet pressure

3-73. You have removed the ice packingfrom the control bulb. Which ofthe following outlet pressureconditions indicates that the valveis operating properly?

1. The pressure does not change2. The pressure decreases rapidly3. The pressure decreases a few

pounds and then stabilizes4. The pressure increases rapidly

1. Pressurized R-122. Wet compressed air3. Oxygen gas4. Each of the above

24

3-74. Under normal operating conditions,the receiver of a properly chargedrefrigeration system should be atwhat level when the compressorstops?

1. 25 percent full2. 50 percent full3. 85 percent full4. 100 percent full

3-75. Which of the following actionsshould you take before tighteningthe cap on a cleaned liquid linestrainer?

1. Test the strainer for leaks2. Open the strainer outlet valve3. Purge the air out of the

strainer4. Replace the strainer screen

spring

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ASSIGNMENT 4

Textbook Assignment: "Refrigeration and Air Conditioning," "Compressed Air Systems,""Laundry, Mess Decks, Galley, and Scullery Equipment," "OtherAuxiliary Equipment," and "Lathe and Machining Operations," chapters5 through 9, pages 5-9 through 9-20.

4-1. Which of the following conditionsmay be caused by excessive buildupof frost on the cooling coils?

1. Low suction pressure2. High suction pressure3. Low suction temperature4. High condensing pressure

4-2. The maximum time between defrostingof the cooling coils depends onwhich of the following factors?

1. Amount of refrigerant in thesystem

2. Moisture content of thesupplies placed in the box

3. Amount of heat to be removed4. All of the above

4-3. You must defrost the cooling coilsbefore the frost reaches whatmaximum thickness?

1. 1/8 inch2. 3/16 inch3. 1/4 inch4. 5/16 inch

IN ANSWERING QUESTION 4-4, REFER TO FIGURE5-4 OF THE TEXTBOOK.

4-4. Approximately how many inches ofmercury represent the difference intemperature between points B and D?

1. 0.200 inch absolute2. 0.232 inch absolute3. 0.436 inch absolute4. 0.640 inch absolute

4-5. While you are evacuating anddehydrating a refrigeration system,the vacuum indicator fails toattain 35°F. Which of thefollowing conditions may be thecause of this failure?

1. Lack of lubricating oil in thecompressor crankcase

2. Lack of moisture in the system3. Presence of R-12 in the

lubricating oil4. Each of the above

4-6. To be properly reactivated,dehydrating agents should be heated(a) at what specific temperatureand (b) for what approximate lengthof time?

1. (a) 200°F; (b) 12 hr2. (a) 300°F; (b) 12 hr3. (a) 400°F; (b) 6 hr4. (a) 500°F; (b) 6 hr

4-7. If you do not have a tank-typecleaner, you can clean an R-12system by which of the followingmethods?

1. By flushing boiling waterthrough the system three times

2. By blowing hot air through thesystem for 24 hours

3. By inserting a hard, wool feltfilter in the suction strainerscreen and operating the plant

4. Each of the above methods

4-8. On the two-position, dual control(2PD), which of the followingsystem types uses one commoncooling coil to service severaldifferent spaces?

1. 12. 23. 3

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4-9. What technique must you use toclean the sensing elements in thehumidistats?

1. Use of a soft brush2. Use of gently blown air3. Use of a spray of soap and

water solution4. Use of a hard brush

4-10. To correct a low condensingpressure in an operatingrefrigeration system, you shouldperform which of the followingactions?

1. Reduce the water supply2. Increase the water pressure3. Clean the valves and the valve

seats4. Adjust the high-pressure cutout

switch

4-11. Insufficient refrigerant in arefrigeration plant may cause whichof the following problems?

1. High discharge pressure2. Low suction pressure3. Frosting of the crankcase4. High temperature of the

overboard water

4-12. Which of the following actionsshould you take to correct a lowcondensing pressure in arefrigeration system?

1. Add refrigerant2. Purge the condenser3. Increase the compressor speed4. Adjust the thermostatic

expansion valve

4-13. In an R-12 refrigeration plant, acompressor runs continuously. Whatis the probable cause?

1. An open solenoid valve switch2. An inadequate supply of

refrigerant3. Clogged condenser tubes4. An excess of liquid refrigerant

4-14. Which of the following symptomsindicates that an inadequate supplyof water is passing through thecondenser of a refrigeration plant?

1. Excessively low temperature ofthe overboard water and lowdischarge pressure

2. High suction pressure and hightemperature of the suction line

3. High condensing pressure andcompressor short cycling on thehigh-pressure switch

4. High suction line temperatureand high discharge pressure

4-15. The cut-in point is set too high onthe low-pressure control switch ofan R-12 refrigeration system. Howwill this effect the functioning ofthe compressor?

1. It will short cycle2. It will not operate3. It will operate unloaded4. It will operate continuously

4-16. Which of the following conditionsis probably caused by liquidrefrigerant slugging back to thecompressor crankcase of arefrigeration system?

1. Bubbles in the refrigerant2. A sudden loss of oil from the

crankcase3. The compressor continues to

operate unloaded4. Failure of oil to return to the

compressor crankcase

4-17. Aboard Navy ships, in which of thefollowing situations would you mostlikely use MP air?

1. To clean machinery2. To start diesel engines3. To operate pneumatic tools4. Each of the above

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4-18. What type of air dehydrator is usedto reduce dust problems produced bythe other various types?

1. Refrigeration (type I)2. Desiccant (type II)3. Activated alumina beads4. Combination refrigeration and

desiccant (type III)

4-19. Which of the following statementsis correct about the dehydrator dewpoint readings?

1. They are taken only to verifysuspected operational problems

2. They are taken every 8 hours ofdehydrator service

3. They are taken as required bythe PMS

4. They are taken every 4 hours ofdehydrator service

4-20. Which of the following statementsdescribes the recommendedprocedures for cleaning anoil-wetted filter element that wasremoved from a compressor intake?

1. Clean with gasoline orkerosene, dip in lightweightoil, and drain excess oil

2. Clean with steam or strong salsoda solution, dip in cleanmedium viscosity oil, and drainexcess oil

3. Clean with a jet of hot water,dip in kerosene, and drainexcess kerosene

4. Clean with kerosene, drainexcess kerosene, dip in mediumviscosity oil. and drain excessoil

4-21. Leakage through the dischargevalves of an air compressor isusually caused by which of thefollowing factors?

1. Dirt in the valves2. Moisture in the air3. Overcompression of air in the

cylinders4. Insufficient compression of air

in the cylinders

4-22. Carbonized air compressor valvesshould be cleaned by soaking themin which of the following solvents?

1. Gasoline2. Solution of kerosene and

mineral oil3. Kerosene only4. Strong soda solution

4-23. When you are inserting valves in acompressor cylinder, in which ofthe following directions should the(a) discharge valves and (b)suction valves open?

1. (a)(b)

2. (a)

(b)3. (a)

(b)

4. (a)

(b)

Toward the center;away from the centerAway from the center of thecylinder;toward the centerToward the center of thecylinder;toward the center of thecylinderAway from the center of thecylinder;away from the center of thecylinder

4-24. What material is used to repack thefilter of air compressor controlvalves?

1. Wool2. Cotton3. Linen4. Nylon

4-25. Which of the following valves of acompressed air system is vital forits safe operation?

1. Control2. Discharge3. Suction4. Relief

4-26. Which of the following checks isNOT a requirement during aninspection of a washing machine?

1. Test for correct steam pressure2. See that the bolts, nuts, and

screws are tight3. Ensure the machine is level4. See that the latches on the

cylinder doors work properly

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4-27. A well-maintained and properly usedtumbler will dry a load of laundryin what minimum amount of time?

1. 10 minutes2. 20 minutes3. 30 minutes4. 40 minutes

4-28. Steam kettles safety valves are setto release at what pressure?

1. 15 psig2. 25 psig3. 35 psig4. 45 psig

4-29. Varied operating conditions of thedistilling plants are a primarycause of which of the followingproblems?

1. Changes in feed level2. Scaling of evaporator tubes3. Improper liquid level in the

first-effect tube nest4. Excessive steam pressure

4-30. You are making adjustments ondistilling plant controls to bringheat and fluid conditions intobalance. Which of the followingtechniques should you use?

1. Adjust all controlssimultaneously

2. Adjust all heat controls one ata time and quickly

3. Adjust controls one at a timeand in small adjustments

4. Adjust each control at10-minute intervals

4-31. Which of the following factors isNOT likely to cause a decrease inthe distilling plant's efficiency?

1. Air leaks in the first-effecttube nest

2. Low vacuum in the last-effectshell

3. Dirty circulating waterstrainer

4. No undue deposits inside thetubes

4-32. You should inspect distilling plantsteam orifices a minimum of howoften?

1. Monthly2. Twice a year3. Annually4. At each overhaul

4-33. From which of the following sourcesshould you take water to be used todesuperheat live steam?

1. The first-effect tube nestdrain pump

2. The second-effect tube nestdrain pump

3. The freshwater supply4. The steam feed system

4-34. Fluctuations in the first-effectsteam pressure and temperature willcause similar fluctuations in whichof the following parts of theplant?

1. The second-effect shell only2. The steam supply line only3. The water levels only4. The entire plant

4-35. When you keep the vacuum in thefirst-effect tube nest of adistilling plant as high aspossible, you will reduce which ofthe following factors?

1. The amount of brine pumpedoverboard

2. The pressure rate of the steamlines

3. The rate of evaporator tubescaling

4. The rate of distillateformation

4-36. When you cannot feed water into thefirst-effect tube nest of adistilling plant, you should lookfor which of the following causes?

1. Scale deposits in the airejector

2. Scale deposits in the vaporfeed heater

3. Obstructions in the feed line4. Each of the above

29

4-37. Once the distilling plant is inoperation, which of the followingproblems is/are likely to causepriming?

1. A sudden rise of the waterlevel

2. A water level that is too high3. Both 1 and 2 above4. A sudden drop in the water

level

4-38. The vacuum gauge readings arenearly identical on the first- andsecond-effect shells of adistilling plant. What is the mostlikely cause?

1. Air leaks between the first andsecond effect

2. Equally low water levels inboth effects

3. Equally high water levels inboth effects

4. Obstructions in the flowbetween the first and secondeffects

4-39. Improper venting of evaporator tubenests can cause which of thefollowing problems?

1. Condensation of steam in thevapor feed heater

2. Accumulation of air in thetubes

3. Excessive increase of tube neststeam to the distillingcondenser

4. Excessive increase of scaledeposits on the evaporator tubenest

4-40. How much scale preventive compoundis needed for each 4,000 gallonsper day of distilling plantcapacity?

1. 1.0 pint2. 2.0 pints3. 3.0 pints4. 1.5 pints

4-41. You have an air leak in thedistilling plant last-effect shelland the watch stander has beenoperating the air ejectorsimproperly. These conditions canproduce which of the followingvacuum readings in the last-effectshell?

1. 34 in.Hg2. 30 in.Hg3. 26 in.Hg4. 10 in.Hg

4-42. When a distilling plant is inoperation, which of the followingvacuum tests should you use onjoints?

1. Candle flame2. Air pressure3. Soapsuds4. Hydrostatic

4-43. You must clean air ejector nozzleswith which of the following tools?

1. Special reamer2. Rat-tail file3. Sharp scraper4. Metal hole brush

4-44. The temperature of circulatingwater has exceeded the allowable20°F as it passes through thedistiller condenser. You know thatthis situation is not normal. Whataction should you take first?

1. Clean the air ejectors2. Inspect the condenser

circulating water systems3. Check for improper operating

procedures4. Reset the back pressure-

regulating valve

30

4-45. Which of the following indicatorssuggest(s) improper drainage of thedistiller condenser?

1. The flash chamber gauge line isflooded

2. The first-effect tube nestvacuum is several inches ofmercury

3. The plant does not produce thedesigned output when theorifice is 5 psig

4. Each of the above

4-46. All sources of troubles inelectrohydraulic systems fit intoone of three categories. Which ofthe following is NOT a category?

1. Hydraulic2. Cooling3. Electrical4. Mechanical

4-47. What is the recommended method forlocating small internal leaks inhydraulic systems?

1. Use magnetic flux2. Install pressure gauges3. Listen for identifying sounds4. Visually inspect the

disassembled parts

4-48. A popping or sputtering noise in ahydraulic system indicates which ofthe following conditions?

1. An oil leak in the pressureline

2. An air leak in the pressureline

3. An air leak in the suction line4. An air pocket in the cylinder

4-49. Which of the following conditionsshould you suspect if a pounding orrattling noise occurs in ahydraulic system?

1. Overtight adjustment of parts2. Defective spring-activated

valve3. Improperly adjusted relief

valve4. Overloaded system or high-speed

operation

4-50. Foreign matter in the oil of ahydraulic transmission usuallycauses which of the following typesof noise?

1. Rattling2. Popping3. Squealing4. Grinding

4-51. When a squealing or squeaking noiseoccurs in a hydraulic system, it isusually caused by which of thefollowing conditions?

1. Wiped bearings2. Air pocket in the cylinder3. Overtight packing around moving

parts4. Overloaded system during high-

speed operation

4-52. What should you, as an Engineman,do upon discovering a faultyoperation of a circuit breaker of ahydraulic system?

1. Repair the circuit breaker2. Check for excessive binding in

the electric motor3. Replace any damaged equipment

in the plant4. Report the condition to the

Electrician's Mate

4-53. If a hydraulic system is left toidle for a long period of time,which of the following difficultiesmight you expect to develop?

1. Misalignment of linkage2. Accumulation of sludge3. External leakage4. Internal leakage

4-54. What is the purpose of securing ahydraulic system for 1 hour afterfilling it with clean oil?

1. To permit the settling offoreign matter

2. To dissolve the sludge3. To permit the venting of air4. To dissolve corrosive deposits

31

4-55. Which of the following actions is apart of the procedure for cleaninga hydraulic system?

1. Allow the system to remain idlefor 15 minutes after operatingit with a light load for 4minutes

2. Operate the system for 1 hourwhile it is filled withcleaning fluid

3. Operate the system at highpressure while it is filledwith cleaning fluid

4. Dilute the old hydraulic oilwith cleaning fluid and operatethe system for 15 minutes, thenallow the system to remain idlefor about 5 minutes

4-56. You are replenishing the hydraulicsystem with oil. What strainershould you use with the oil?

1. A cheese cloth2. An aluminum filter3. A 200-mesh wire screen4. A 400-mesh wire screen

4-57. If you are filling a hydraulicsystem and notice water in the oil,which of the following actionsshould you take?

1. Centrifuge the oil or reject it2. Run the oil through a 180-mesh

wire screen3. Heat the oil to permit the

water to evaporate4. Allow the oil to stand until

the water settles to the bottom

4-58. What material is used to form theshaft seal of most modern hydraulicpumps?

1. Rubber2. Neoprene3. Asbestos4. Flax

4-59. Which of the following conditionscan cause the packing of a shaftstuffing box to wear out quickly?

1. Hard packing2. Rough shaft3. Shaft deflection4. Excessive packing

4-60. What is the main purpose of packinga shaft packing gland uniformly andlightly?

1. To allow for cooling andlubrication

2. To prevent scoring of the shaft3. To prevent leakage of seawater4. To prevent binding of the shaft

4-61. A routine inspection revealed aleak in the line of a hydraulicsystem at a flanged joint. If theleak persists after you havetightened the bolts evenly, whatcorrective action should you takenext?

1. Replace the flange2. Install new packing3. Inspect the fluids for

contaminants4. Install square-braided asbestos

packing

4-62. The relief valve in a hydraulicsystem leaks. What should you doto the valve seat?

1. Reface it2. Replace it3. Regrind it4. Fit the valve with a seat

insert

4-63. The selector switch on the conveyoris improperly set. Which of thefollowing troubles is most likelyto occur?

1. Conveyor will not start2. Conveyor will not hoist3. Conveyor will run continuously4. Conveyor will not lower

32

4-64. The engine lathe in a machine shopshould NOT be used for which of thefollowing jobs?

1. Turning and boring2. Facing and thread cutting3. Drilling and grinding4. Bending and shaping

4-65. In ships with a one latheallowance, what is usually the sizeof the lathe?

1. 14 in.2. 16 in.3. 18 in.4. 20 in.

4-66. When an engine lathe is used formilling, the workpiece is usuallymounted on which of the followinglathe parts?

1. Headstock2. Tailstock spindle3. Carriage4. Faceplate

4-67. On an engine lathe, which of thefollowing operations is usuallyperformed with the carriage lockedin position?

1. Turning2. Facing3. Boring4. Drilling

4-68. Gears in the apron of an enginelathe are driven by which of thefollowing lathe parts?

1. Control rod2. Lead rod3. Reverse rod4. Feed rod

4-69. Which of the following cutter bitsis sometimes ground flat on top soit may be fed in both directions?

4-70. What type of lathe chuck can beused to automatically center roundworkpieces of many sizes?

1. Scroll chuck2. 4-jaw chuck3. Standard collet chuck4. Hexagonal collet chuck

4-71. A carriage stop may be used on anengine lathe to eliminate the needfor which of the following actions?

1. Individual measurements ofduplicate parts

2. Manually shutting off theautomatic feed

3. Setup measurements madedirectly on the workpiece

4. Variable rates of feed across aworkpiece

4-72. Which of the following lubricantsis to be used for general machinework on brass or Monel rods?

1. Mineral lard oil2. Turpentine3. Soluble oil4. White lead

4-73. What lathe accessory is used formounting odd-shaped workpieces thatcannot be turned between centers?

1. Mandrel2. 3-jaw chuck3. Collet chuck4. Faceplate

4-74. A depth of cut of 0.040 inchreduces the diameter of a latheworkpiece by what measurement?

1. 0.020 in.2. 0.040 in.3. 0.080 in.4. 0.120 in.

1. Left-hand turning tool2. Right-hand facing tool3. Square-nosed parting tool4. Round-nosed turning tool

33

4-75. Shoulders are commonly located witha parting tool to eliminate theneed for which of the followingsteps?

1. Using a pointed turning tool2. Facing the shoulder3. Cutting a fillet4. Measuring during the rough

turning

34