Zenith® Pumps

Installation,Care andMaintenance

ZenithPolymerExtrusionGear Pumps

PEP-II SeriesGear Pumps

Zenith® Pumps

2

Thoroughly read and understand this entire manual before installation and operation of pump.

Benefits

Specifications Capacities: 0.16 to 750 cc/rev.

Operating Speed: 10 - 90 rpm on most extrusion processes depending upon process parameters

Differential Pressure: Up to 5,000 psi (345 bar)

Body Pressure: 10,000 psi (690 bar).

Temperature: To 645° F (340° C),(950° F maximum with special fasteners and seals).

In 1926, Zenith Pumps was approachedby the synthetic fiber industry to design apump to provide a precise, pulseless, andrepeatable flow and assure better qualitycontrol.

Since then, Zenith has providedpumps for virtually every polymer utilizedin the plastics extrusion industry. Over theyears, Zenith has continually developedand improved its pump designs to meetthe stringent demands made by newpolymers and new processes.

Zenith Pumps' line of PEP-II polymerextrusion pumps has a unique positivedisplacement design, which provides con-sistent, accurate polymer delivery undervarying extruder output conditions ofpressure, temperature and viscosity.These virtually pulseless gear pumps arethe ideal interface between the extruderand the die of extrusion systems, and pro-vide a homogeneous melt at increasedthroughputs and tighter gauge tolerances.

For years, polymer processors have utilizedgear-pump-assisted extrusion to solvecritical issues in the diverse plasticsindustry.

The Zenith gear pump optimizes theextrusion process by allowing the screwto melt and homogenize the polymer. Asthe pump generates the needed pressure,it relieves the extruder of work; therefore,reducing heat from the shear, lowering thetorque required, and eliminating surging.All this optimizes the performance of theextruder and offers the following benefits:• Improved Dimensional Stability—

Effectively isolates the die fromupstream fluctuations.

• Controlled Melt Quality—Regulatesthe extruder back pressure while itreduces residence time, stabilizes theplasticating action, and lowers melttemperature.

• Increased Production—Provides veryhigh efficiency regardless of its pres-sure building requirement.

• Reduced Raw Material Usage—Provides a narrower finished productgauge variation.

• Eliminates Surging and Screw Beat—Effectively handles problems causedby melt density or extruder parameters.

• Increased Extruder Flexibility—Allows varying process conditionssuch as higher regrind levels, tempera-tures, pressures, etc.

• Crowned Root Gear Design—Reduces shear internal to the pump,lowering the temperature and increasingthe production rate per power required.

• Streamlined Operation and Start-up—Closed-loop controls provide easyoperator interface.

• Extended Extruder Life—Reduceswork required by the extruder such aspressure and torque.

• Lower Operational Costs—Providesa more efficient method of conveying,eliminating material giveaway, andincreasing production per pound ofextrudate, etc.

Zenith® Pumps and The Extrusion Process

Design

Zenith Pumps can handle all your extrusion pumping applications including additive injection for on-line compounding of tackifiers, colorants, stabilizers, etc.

3

ZENITH ADDITIVE

INJECTIONSYSTEM

ELECTRICHEAT PLATE

PUMP TEMPERATURE

INLETPRESSURE

DISCHARGEPRESSURE

ZENITH PEP-II PUMP

CHANGER

PP T

EXTRUDER

The PEP-II pump is constructed of twogears rotating in mesh within a closely fit-ted housing that is comprised of threeplates. The center, or gear plate, fitsclosely around the outside diameter of themetering gears and bearings. The frontand rear, or cover plates, sandwich thecenter plate and restrict axial movementof the gears and bearings. In capacitiesof 5 cc/rev and larger, the driving gear ismanufactured integral with the drive shaft,and the driven gear is machined integralwith its shaft. In capacities of 3.0 cc/revand below, the gears are keyed to theirrespective shafts. In all capacities theshafts are supported by “D” shaped bearings which fit into the center plate. Incapacities of 40 cc/rev and above, thesebearings are located by two screws whichpass through the cover plates. In capacitiesof 20 cc/rev and below, the bearings arekeyed to each other for accurate location.

Each cover plate is secured to thecenter plate by 10 screws (6 screws forbelow 5 cc/rev). Each side of the centerplate has a circular port in the center of abolt circle for the mounting of adapterflanges that fit the pump to your equiment.Threaded holes are provided on the topand bottom of the center plate for themounting of heat plates and for themounting of the pump to its stand.Thermocouple wells (1/8-27 NPT) arelocated on the body of the pump.

A Zenith Rheoseal assembly securedto each cover plate (front cover plate onlyon 3.0 cc/rev and below) prevents leakage

around the shaft, using both dynamic andstatic types of sealing mechanisms. ARheoseal consists of a helical groove onthe inner diameter, a cooling jacket and astatic, backup seal counter bore andgland. These spiral grooves allow theRheoseal to act as a screw-type pump.As the fluid attempts to leave the gearpump, the shaft's rotary motion forces thefluid into the grooves. This creates a pres-sure greater than the pressure forcingpolymer out of the pump, thus returningthe polymer back towards the pump.Since the rotary motion is required of theshaft, two other static types of seals areemployed on the Rheoseal—a springenergized lip-seal or a packing sealsecured by the gland. Also a flushingcooling jacket surrounds a portion of thegrooved seal. Use of the cooling jacketmay be required for effective sealing if theviscosity is below 1,000 poise at processconditions. If used, water passing throughthe housing cools the polymer, increasingthe effectiveness of the seal's pumpingaction. A thermocouple well is provided in the seal housing to allow for measuringthe temperature close to the region wheresealing actually occurs.

A complete line of accessories isavailable and includes heating plates(electric, oil and steam), adapter flanges,mounting blocks and pump drive systemscomplete with power package controlsand process controls. Please contactZenith or your local Zenith representativefor further information.

PEP-II Pump0.16-3 cc/rev

ITEM QTY PART MATERIAL

1 1 FRONT PLATE TOOL STEEL2 1 CENTER PLATE TOOL STEEL3 1 REAR PLATE TOOL STEEL4 1 DRIVE SHAFT TOOL STEEL5 1 ARBOR TOOL STEEL6 2 METERING GEAR TOOL STEEL8 2 KEY, GEAR9 2 BEARING TOOL STEEL10 2 BEARING TOOL STEEL11 1 RHEOSEAL STAINLESS13 1 SEAL PLATE STAINLESS14 1 LIP SEAL FILLED PTFE15 6 SOCKET HEAD BOLT ALLOY16 4 SOCKET HEAD BOLT ALLOY17 4 SOCKET HEAD BOLT ALLOY18 2 METAL C-RING, PORTS19 2 KEY, D-BEARING20 1 KEY, EXTERNAL

PUMP PUMP DIMENSIONS MAX APPROXCAPACITY A B C D E F G H I J TORQUE WEIGHT

0.16 3.000 3.000 2.860 1.400 2.400 1.960 0.750 1/4 1.500 0.125 80 90.3 3.000 3.000 2.860 1.400 2.400 1.960 0.750 1/4 1.500 0.125 80 90.6 3.000 3.000 2.860 1.400 2.400 1.960 0.750 1/4 1.500 0.250 195 91.2 3.000 3.000 3.650 1.400 2.400 1.960 0.750 5/16 2.500 0.750 410 91.8 3.000 3.000 3.650 1.400 2.400 1.960 0.750 5/16 2.500 0.750 410 93.0 3.000 3.000 3.650 1.400 2.400 1.960 0.750 5/16 2.500 1.000 600 9

CC/REV PUMP DIMENSIONS ARE IN INCHES IN-LBS LBS

Materials Of Construction Diagram And Chart

Diagram 2 Chart 2

Chart 1

Dimensional Data Chart

Diagram 1

Dimensional Diagram

4

ITEM QTY PART MATERIAL

1 1 DRIVING GEAR SHAFT TOOL STEEL2 1 DRIVEN GEAR SHAFT TOOL STEEL3 1 CENTER PLATE TOOL STEEL4 2 COVER PLATE 41406 2 BEARING TOOL STEEL7 2 BEARING TOOL STEEL14 2 SEAL PLATE STAINLESS16 2 LIP SEAL FILLED PTFE17 20 SOCKET HEAD BOLT ALLOY18 8 SOCKET HEAD BOLT ALLOY20 2 RHEOSEAL STAINLESS21 8 SOCKET HEAD CAP SCREW ALLOY22 2 METAL C-RING, SEALS23 2 METAL C-RING, PORTS NOT SHOWN

Materials Of Construction Diagram And Chart

Dimensional Diagram

PUMP PUMP DIMENSIONS MAX APPROX CAPACITY A B C D E F G H I J TORQUE WEIGHT

5 3.250 3.250 3.250 1.125 2.875 2.125 0.500 1/4 1.875 0.750 1225 1010 4.000 4.000 4.000 1.188 3.375 2.615 0.625 5/16 2.344 1.000 2085 1820 4.750 5.000 5.000 1.188 3.750 3.300 0.750 3/8 2.813 1.250 3250 3440 5.750 6.000 6.250 1.188 4.438 4.000 1.000 7/16 3.531 1.500 6750 61

100 8.000 8.250 8.250 1.750 5.438 5.458 1.250 5/8 4.688 2.188 12100 150175 9.500 9.750 9.880 1.813 6.375 6.475 1.500 3/4 5.750 2.625 22400 260300 11.250 12.000 12.500 2.375 8.063 8.000 2.000 7/8 7.063 3.000 50600 480750 14.750 15.750 16.500 3.000 10.000 10.542 2.500 1 1/8 9.688 4.250 116600 1100

CC/REV PUMP DIMENSIONS ARE IN INCHES IN-LBS LBS

Dimensional Data Chart

Diagram 3

5

Chart 3

PEP-II Pump5-750 cc/rev

Chart 4Diagram 4

Operation

6

Installation

Polymer enters the PEP-II pump on thesuction side where shaft rotation exposesgear tooth volumes between the gearteeth. Polymer fills these spaces and istransported to the discharge side wherethe gear teeth mesh together, decreasingthe gear tooth volumes and displacing thepolymer. Due to the precision tolerancesand close clearances within the rotatingspaces, very high pressures can beachieved at the pump discharge withextremely high volumetric efficiencies.

As PEP-II pumps rely on the meteredpolymer for lubrication of internal bearingsurfaces, the operating speed is designedto be from 10 to 90 rpm on most extrusionprocesses depending on process parame-ters. Do not allow the pump to run dryor attempt to pump poor lubricating

fluids such as water or solvent. Whenhigh-viscosity fluids are used, more timeis required to fill the tooth volumes. As aresult, the inlet pressure must beincreased or the gears must rotate at aslower speed to ensure complete volumefilling. Proper speed and inlet pressuremust always be maintained to preventcavitation and to ensure proper lubrication.

Slip can occur across the sides of the gears from the high-pressure sideto the low-pressure side. The amount ofslip depends on four factors: polymer viscosity, speed, differential pressure and pump clearances. Under reasonablystable operating conditions, slip is repeat-able and predictable, and pump operationcan be adjusted to compensate.

Pumps should be carefully unpacked tomake sure that the shipment is complete.If any items are missing or damaged, thefreight carrier and Zenith should be noti-fied immediately.

To prepare the pump for use:1) Where required, install the heat

plates as follows. Zenith-supplied heatplates are machined to tolerances thateliminate the need for heat transfer cement.All bolts used should be lubricated withhigh-temperature thread lubricant such as DAG Dispersion 154, Felpro C-100 orequivalent.

2) Place the top heat plate on thepump, then place the insulation jacket ontop of the heat plate. Install and tightenthe bolts, taking care not to crack theinsulation block.

3) Repeat for the bottom plate, notingthat bottom heat plate mounting bolts aretypically used to mount the pump to itsmounting block.

4) Place the supplied metal O-ringsinto the counterbores in the pump ports,and attach the inlet and discharge portingflanges with lubricated screws. Replacethe O-rings after each use. Torque downthe screws in a crisscross pattern, takingthem first to 1/4 the recommended torquevalue, then to 1/2, to 3/4 and finally totheir full recommended torque value asshown on the table on page 10. If theflanges are not supplied by Zenith, make

certain that their mating faces are flat,with no pilots that protrude into the pump.Check that the pump rotates freely byturning the shaft with your hand.

5) The pump drive shaft should beconnected to the motor drive assemblywith a flexible coupling, a double universaljoint shaft or an appropriate Zenith SJMCcoupling. Side loading on the pump shaftis to be avoided at all costs.

6) If water is used for sealing, connecteither 1/8-27 or 1/4-18 NPT fittings to theRheoseal and turn on the water. Be sureto avoid excessive cooling, or damage tothe pump may occur.

7) Turn on the pump heaters. A 250° Ftemperature rise per hour is recommendedfor cold starts. No attempt should bemade to start the pump until the entirepump is at operating temperature. Coldstarts are the most common cause ofpump failure.

On start-up, a small amount of moltenpolymer should be introduced into thepump by slowly rotating (less than 5 rpm)the pump by hand to ensure that thepump is free turning and well lubricated.With sufficient inlet pressure, the pumpcan then be started at a very slow speed,with discharge pressure low enough tomaintain low loading. When operating satisfactorily, the pump and system maynow be gradually brought up to normalprocess speeds and pressures.

Cleaning,Inspection,Repair andService

7

Disassembly

After removal from the system, the assem-bled pump can be cleaned by placing itin a suitable furnace (i.e. vacuum oven,fluidized bed, etc.) and slowly increasingthe temperature to 800-850° F in no lessthan two hours. Special care should betaken to avoid flashing of the polymer.Control of temperature is essential as it ispossible to draw back the hardness of thesteel and affect dimensional stability if thepump is overheated. The time to com-pletely carbonize the polymer is three totwelve hours, depending on the polymer,temperature, pump size and furnace load.

The pump must be gradually cooledto room temperature (no forced cooling or quenching), then disassembled andcleaned as instructed in the following section. Close adherence to these instruc-tions should be maintained for maximumpump life and performance.

It is recommended that pump usersinstitute a program of dimensional inspec-tion of critical parts in order to keep main-tenance and operating costs at a minimum.By noting the performance of a pumpimmediately before removing it from serviceand correlating the performance to meas-ured component wear, the user canestablish the maximum wear limits for thepump’s critical components. Further, hecan predict the service life of the pump,and schedule his downtime accordingly.

After a pump has been disassembled,

all parts should be carefully inspected fornicks, burrs, scoring or other signs ofwear. The side plates, D-bearings (andsides of the gears on the 3.0 cc/rev andsmaller pumps) can be hand blocked on600 grit paper, and any nick or burrs andother sharp edges very lightly touchedwith an Arkansas stone.

Note: After cleaning, all seals, O-ringsand fasteners must be discarded.

CAUTION: As the thickness relation-ship between metering gears, center plate and D-bearings is critical to meteringperformance, care should be taken thatthese parts are only polished and that no metal is removed. Lapping of thesecomponents should not be done underany circumstances.

As with any other Zenith pumps, PEP-IIpumps may be returned to Zenith forcomplete rehabilitation as necessary. Thisprocedure may be desirable if only a fewpumps are involved. If a large number ofpumps are to be maintained at the user’splant, it may be worthwhile to have keymaintenance personnel attend a mainte-nance seminar at the Zenith factory to viewthe manufacturing, gauging and assemblytechniques involved in producing thePEP-II pump. In addition, Zenith alsooffers a contract service program. Pleasecontact Zenith for further information onthese services.

These instructions should be thoroughlyread and understood before starting dis-assembly.

General instructions that should beobserved to ensure correct disassemblyof the pump are as follows:

• If the pump is to be disassembledon a regular basis, set up a room with aseparate clean area with all the toolsrequired for disassembly, reassembly andstorage.

• During disassembly, note the loca-tion and orientation of all parts to ensureproper reassembly.

• Use a soft-jawed vise to hold thepump during disassembly.

When maintenance is required, referto the exploded view and disassemble thepump as follows:

CAUTION: Careful handling of the partsis imperative. Do not drop or allow partsto strike each other. The slightest nick orburr can cause difficulty in reassembly andmay cause further damage to the pump.

1) Clearly mark which side of thepump is the inlet port and drive input side.

2) Remove the screws securing theRheoseal seal plate cover to the sealhousing and remove the cover.

3) Remove the screws securing theRheoseal seal housing to the cover plateand withdraw the housing from the coverplate and shaft, taking care not to dam-age the drive shaft. After removal of theseal housing, disassemble and clean theRheoseal housings either mechanically orchemically (always replace the O-rings).

4) Carefully pry out and discard thelipseals at this time, taking care not todamage the seal countersink in the hous-ing, as damage here could cause polymerleakage at start-up.

5) Loosen and remove the D-bearingretainer screws (40 cc/rev and aboveonly).

6) Loosen all cover plate screws oneturn, then back them out and removethem from the pump. Remove each cover

Disassemblycontinued

8

D-Bearing OrientationSchematic

plate and set aside in a safe place to pre-vent damage. At this point, make certainto note the orientation of the groove on therear of each bearing with respect to theinlet port. They MUST be reassembled inthe same way as disassembled; that is,they must point toward the inlet port, orsevere pump damage may result whenthe pump is started.WARNING: (Read before steps 7 & 8)Extreme caution must be exercised whenremoving the gear shafts and bearing. Forthe 40 cc/rev and above capacity pumps,which have two (2) tapped holes in the D-bearing faces, an optional disassemblymethod is possible. If the gear shaft andtwo D-bearings will not slide out as acomplete assembly after tapping with asoft-faced hammer, it is recommendedthat a gear puller tool be used to extractthe individual D-bearings from each sideof the gear shafts. If these still exhibitforce, soaking in a lubricating (penetrat-ing) oil will help the disassembly.

For 20 cc/rev and smaller capa-cities, there are no tapped holes in theD-bearing faces to be utilized. The gearshaft and D-bearings must be removed as a complete assembly. Again, soakingthe parts in lubricating (penetrating) oil or other non-damaging solution will helpease the disassembly. Do not force theparts out one side with a hammer or arbor press.

7) Slide the gear shafts and bearingsout of the center plate. They will not comeout separately as the gear teeth will notclear the bearings. Take extreme care notto nick or ding the gear teeth or the edgesof the bearings. If they will not slide outeasily, use a hammer with a plastic or softbrass head to gently tap them out. DONOT use a steel-headed hammer.Alternate taps on the shafts until the partsslide clear. Separate the two shaft/bearingassemblies, taking care not to lose thekeys in the 10 cc/rev and smaller pumps.There are no keys in the 20 cc/rev andlarger pumps.

8) Slide the bearings from the shafts,again taking extreme care not to damage the gear teeth, bearing edges or theshafts. If the bearings will not slide easilyfrom the shaft (due to residual polymer),use a plastic or soft brass-headed ham-mer and a soft drift (NOT steel) to gentlytap the bearings free. Do not pry them offwith a screwdriver or other tool as thismay damage the gear teeth. Identifywhich shaft the bearings came from, andset them aside in a safe place.

9) On the 3 cc/rev and smaller, slide the gears from their shafts and remove the keys from the shaft.

Reassembly

9

These instructions should be thoroughlyread and understood before startingreassembly.

General instructions that should beobserved to ensure correct reassembly of the pump are as follows:

• Using a solvent such astrichloroethane or chloroethene Nu, clean all parts that are to be used in thereassembled pump.WARNING: Use extreme care when usingany solvent. Prolonged contact with theliquid or inhalation of the vapor can causeserious health problems.

• During and between each of theassembly steps, manually turn themetering gears to ensure that they arefree turning. If binding occurs at any timeduring assembly, determine the causeand correct it before proceeding further. A tiny nick, burr or foreign particle canextensively damage a valuable part ifallowed to remain. Never use excessiveforce in assembling or turning a pump. Ifproperly aligned, the pieces will fit easilyinto the plate, and the drive shaft will turnfreely. All seals, O-rings and fastenersmust be replaced with new parts priorto assembly.

• Use a soft-jawed vise to hold thepump during reassembly.

• Before installing screws, lubricatetheir threads with DAG Dispersion 154,Felpro C-100, or similar heat-resistantlubricant, and torque to prescribed valuesas shown on the table on page 10.

1) On 3.0 cc/rev and smaller pumps,place a gear key on each shaft and slideeach gear onto its shaft, engaging the key.

2) Slide the gear shafts into the centerplate, taking care not to damage the gearteeth. On 3.0 cc/rev and smaller pumps,note that each shaft has a larger diameterend. These larger ends must be on oppo-site sides of the pump for the bearinggrooves to align properly.

3) Gently slide the gear shafts so thatthe rear ends of the shafts protrude fromthe rear of the center plate. On the 3.0cc/rev and smaller pumps, take care notto slide the shafts out of the gears andallow the keys to drop out of the shafts.

4) Slide a bearing onto the drive shaft,taking special care to select a bearingwith the proper groove configuration (andwith the proper ID on the 3.0 cc/rev andsmaller pumps). Slide the matching bear-ing onto the driven shaft, taking care toselect a bearing with the proper groove

configuration. Set the flats on the circum-ference of the bearings against eachother, and gently slide the bearings andshafts into the center plate. Slide them farenough through the center plate to allowthe drive shaft to protrude out on the frontside and allow the front bearings to beinstalled. See D-bearing orientationschematic on page 8.

5) Install the front bearings in thesame manner as the rear bearings, andslide the bearings and shafts back intothe center plate so that the gears areroughly in the center of the center plate.

6) For the 20 cc/rev and smallerpumps, the bearings should be allowed toprotrude very slightly above the face ofthe center plate before the cover platesare installed. This will allow the bearingsto fit flush against the cover plates asthere are no bearing screws on thesesmaller pumps. For 20 cc/rev and smallerpumps, insert the bearing locating keyson each side.

7) At this point make certain againthat there is no foreign matter on the facesof the cover plates or on the faces of thecenter plate. An accidental smudge ofthread lubricant can cause the smallpumps to bind.

8) Place the front cover plate on thepump (and center on pump), checkingone more time that the configuration of thebearing grooves is correctly oriented forthe inlet and discharge ports of the pump.Insert the lubricated cover plate screwsinto the pump and tighten them fingertight only. Repeat for the rear cover plate.

9) On the 40 cc/rev and larger pumps,insert the bearing retainer screws andtighten them finger tight at this time.

10 Torque down the cover platescrews in a crisscross pattern, takingthem first to 1/4 the recommended torquevalue, then to 1/2, to 3/4 and finally totheir full recommended torque value.

11) Torque down the bearing retainerscrews in the same manner as the coverplate screws. (Install C-Rings if applicable.)

12) Fit the Rheoseal seal housing tothe shaft. Loosely install but do not torquedown the seal housing screws, as this willallow the lip seal to properly center thehousing.

13) Install the lip seals, using thespecial Zenith installation tools as followsto prevent damaging the seal. Install thelip seals with the open face toward thebody of the pump. Slide the installation

Size (UNC Recommended Alloy Steel) Torque (in-lbs)

1/2-13 922

9/16-12 1,331

5/8-11 1,836

3/4-10 3,257

7/8-9 5,800

1-8 8,000

1 1/8-7 12,000

10

Reassemblycontinued

Bolt TorqueSize (UNC Recommended Alloy Steel) Torque (in-lbs)

#8-32 30

#10-24 43

#10-32 49 (UNF thread)

1/4-20 103

5/16-18 213

3/8-18 378

7/16-14 605

PEP-II ISO View

Clockwise rotation, pressure building pump shown (standard).

ring on the shaft with the ID taperingtoward the pump. On the drive shaft ends,fit the bullnose on the end of the shaft.Work the seal gently over the end of thebullnose and down the shaft, as any dam-age could cause polymer leakage afterstart-up. Ease the seal into the wide endof the installation ring and, using thepressing tool, gently press the lip seal intothe Rheoseal housing. Do not attempt topress on the lip seal with screwdriver orother pointed object, as this will damagethe seal. Do not press the lip seal all theway into its cavity. Instead, allow it to protrude slightly so that it will be correctlyseated by the seal cover. Carefullyremove the special Zenith tools.

14) Slide the seal cover over the shaftuntil it rests on the protruding lip seal.Align the screw holes in the cover withthose in the housing and insert thescrews. Tighten them evenly in a criss-cross pattern so that the seal is slowlypressed into the seal housing. When thecover is touching the housing all the wayaround, remove the seal cover and torquethe seal housing bolts down. Reinstall theseal cover on the shaft and torque itdown. In reinstalling the pump, be certainto follow the instructions given in theInstallation section of this manual.

11

Troubleshooting

Parts Replacement

When ordering replacement parts, please be sure to include the following information:1) Pump model number2) Part number (12-digit) and description3) Quantity4) Shipping instructionsOrder parts from your local Zenith representative or direct from Zenith.

Trouble Probable Cause Remedy

Pump will not turn 1) Low pump Check thermocouple and control temperature loop for proper setting/operation.

Allow sufficient heat-up time.

2) Drive malfunction Verify drive is powered. Check to assure all alarm circuits are clear.Check drive motor current and speed settings. Check all drive couplings.

3) Process conditions changed Check process conditions for

proper melt temperature, pres-sures, viscosities and materials.

4) Entrained particle Disassemble and clean pump; replace any damaged parts.

5) Possible internal damages Disassemble and clean pump;

replace damaged parts. Consult factory.

Excessive seal assembly leakage 1) Worn lip seal Replace lip seals.

2) Incorrect water flow Monitor and adjust water flow to provide correct sealing temperature.

3) Clogged Rheoseal Disassemble two-piece sealchannel housing and inspect.

Reduced pump efficiency 1) Worn gear(s) Replace worn gear.

2) Worn bearings Replace worn bearings.

3) Process conditions Consult factory for clearance changed recommendations on new

process conditions.

FAILURE, IMPROPER SELECTION OR IMPROPER USE OF THE PRODUCTS AND/OR SYSTEMS DESCRIBED

HEREIN OR RELATED ITEMS CAN CAUSE DEATH, PERSONAL INJURY AND PROPERTY DAMAGE.

This document and other information from Zenith Pumps, itssubsidiaries and authorized distributors provide product and/orsystem options for further investigation by users having technicalexpertise. It is important that you analyze all aspects of your application and review the information concerningthe product or system in the current product catalog. Due to thevariety of operating conditions and applications for these productsor systems, the user, through its own analysis and testing, is solelyresponsible for making the �nal selection of the products and systems and assuring that all performance, safety and warningrequirements of the application are met.

The products described herein, including without limitation, product features, speci�cations, designs, availability and pricing, are subject to change by Zenith Pumps and its subsidiaries at any time without notice.

WARNING

© Copyright 1992 Zenith Pumps PEP C&M 10/04

Zenith® Pumps1710 Airport Road

Monroe, NC 28110Phone: 704-289-6511 • Fax: 704-289-9273

zenithpumps@colfaxcorp.com • www.zenithpumps.comA Colfax Buisiness Unit

ISO 9001: 2000 Registered