NEMA SM23-1991.pdf

NEMA Standards Publication No. SM 23-1991 (R1997, R2002)

Steam Turbines for Mechanical Drive Service

Published by:

National Electrical Manufacturers Association 1300 North 17th Street, Suite 1847 Rosslyn, VA 22209

O Copyright 2002 by the National Electrical Manufacturers Association. All rights including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the international and Pan American Copyright Conventions.

Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMA Licensee=Defense Contract Mgmt Command/5935922100

Not for Resale, 09/18/2006 02:36:51 MDTNo reproduction or networking permitted without license from IHS

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NOTICE AND DISCLAIMER

The information in this publication was considered technically sound by the consensus of persons engaged in the development and approval of the document at the time it was developed, Consensus does not necessarily mean that there is unanimous agreement among every person participating in the development of this document.

The National Electrical Manufacturers Association (NEMA) standards and guideline publications, of which the document contained herein is one, are developed through a voluntary consensus standards development process. This process brings together volunteers and/or seeks out the views of persons who have an interest in the topic covered by this publication. While NEMA administers the process and establishes rules to promote fairness in the development of consensus, it does not write the document and it does not independently test, evaluate, or verify the accuracy or completeness of any information or the soundness of any judgments contained in its standards and guideline publications.

NEMA disclaims liability for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, application, or reliance on this document. NEMA disclaims and makes no guaranty or warranty, express or implied, as to the accuracy or completeness of any information published herein, and disclaims and makes no warranty that the information in this document will fulfill any of your particular purposes or needs. NEMA does not undertake to guarantee the performance of any individual manufacturer or seller’s products or services by virtue of this standard or guide.

In publishing and making this document available, NEMA is not undertaking to render professional or other services for or on behalf of any person or entity, nor is NEMA undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstances. Information and other standards on the topic covered by this publication may be available from other sources, which the user may wish to consult for additional views or information not covered by this publication.

O

NEMA has no power, nor does it undertake to police or enforce compliance with the contents of this document. NEMA does not certify, test, or inspect products, designs, or installations for safety or health purposes. Any certification or other statement of compliance with any health or safety-related information in this document shall not be attributable to NEMA and is solely the responsibility of the certifier or maker of the statement.



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NEMA SM 23



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NEMA Standards Publication No. SM 23-1991 (R1997)

Steam Tuhines for Mechanical Dive Service

Published by:

National Electrical Manufacturers Association 1300 North 17th Street, Suite i 847 Rosslyn, VA 22209

Q Copyright 1997 by the National Electrical Manufacturers Association. All rights including translation into other bnguages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the International and Pan American Copyright Conventions.



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STQ-NEMA SM 23-ENGL 1991 6470247 0524297 714 m

TABLE OF CONTENTS

FOREwom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RefaencedSEancbrrds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Definithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

sectm2 CONSTRUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ' I ) p e s o f S t e a m T . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CiassiñedbyExhaustcaiditiasis .............................. . N- Tiabmc ..................................

CoadensingTUrbinc ................................... classified by Number of Stages and Coam1 Valves ....................

SingleValveSingieSEagC'Iirrbint ............................ Single Vaive Muuistege Mine ............................. Multi* sil@ stage mine ............................ Muitivaive Muitisiage'ïixòine .............................

C i a s s i ñ d b y ~ N e e d s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . controlled (Alumtic) Exeraction Turbine ....................... NoncwtrolletiExtractiosi nlrbhw ............................ CmmUed InQiCtim (Mixdnesslire) M e ..................... InductimExtractionTirrbine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SteamIIiabinecctUl~ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Turbinecasmg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SteamInletEndseCtion ................................. ExhaustEI?dstction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Irlemedia& sactiw ...................................

SteamRing ......................................... StatiomyReveEngBladcs ................................ Diciphragm ......................................... sw. nlrbirbe ........................................

ImpuIseStage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . shaftseals .........................................

casingshaftseals ..................................... Intemagestlaftseals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ThnistBearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AntitÌiCtianBearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RotorAssembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . wheels@iscs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shroud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

COnmhgDevi~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ExtemalcontrolDevice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . WamingDeVice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . REFERENCED STANDARDS AND DEPlNlïïONS .................... Sectkn 1

Noacontrolled Induction 'linbine ............................

Steam Chest (GOV~IIKN vahe Body) ............................ Nozzles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . StationaryRevczsingCham~ ..............................

ReactianS tage ......................................

BearingHousing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RacüaiBcarings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Biades(Buckets) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Handvalve@) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RotectiveDevice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PiSc i ii 1 1 1 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5



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plr sectlocr2

Sentinel W h g Valve ................................... 5 soleplate(s) .......................................... 5

Basephte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 FeatmsandAccessan ?es ................................... 6

BasicFeaMesaQd- ............................... 6 OptiOnalFeaMesandAccessorics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 c o n t r o n e d ~ ~ a n d c o n t r o l l e d ~ ?Itrrbines . . . . . . . . . . . . . . . . . 7 Ncmwntroiled Exüacîh Turbhes ............................. 7 Nonconp.olled Inductiai Ilabines ............................. 7

?IiirbineRating ......................................... 7 power ............................................ 7 speed ............................................ 7

Ratedspeed ....................................... 7 Maximum continwus speed .............................. 7

N d Power end Speed and Steam Caiditions ..................... 7 Stcamconditiaas: ...................................... 7

MinimwnSteam(hKiibS ............................... 7 MaximumStcamconditions .............................. 7 MinimumEnergystcamccmditions .......................... 7 Inlets teampressure ................................... 7 ExhaiistSteampressUre ................................. 8 Extraction Steam Rressiire ................................ 8 Induction Steam Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Inlet Steam Tempemure .................................. 8 ExhaustSteamT~ perame ............................... 8 Extiaction SteamTemperatrae .............................. 8 Lndpctim Steam Tempgatme .............................. 8 Maximum Mowable Working Pressures and Teanptmtms . . . . . . . . . . . . . . 8 DualSteamconditions ................................. 8 VauiationsinSteamconditions ............................. 8 Flow Limits for an Automatic Exaaction ? M i h e . . . . . . . . . . . . . . . . . . . 9 HowrjmitpforanInductionTurbine .......................... 9

Units of Measurement for Absolute and Gauge Pressure . . . . . . . . . . . . 9 Thermodynamic?Iienns .................................... 9

SteamRateS ......................................... 9 I TheOretidSteamRate ................................. 9

ActualsteamRates ................................... 10 GuaranteedSteamRate ................................. 10

?Iiirbineconnectiais ...................................... 10 outputshaftExte~ .................................. 10 S t e a m c o h u s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 AuxiliaryconnectionS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

LlbiClUb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 NonpFessure?lSpeLubncation (Single stage lbbines) . . . . . . . . . . . . . . . . . . 10

oil Lulnicztred sleeve Beanngs (HarizwEal Tiirbines) . . . . . . . . . . . . . . . . . 10 G?ease or oillubricatad Antiniction Bearings ..................... 10

p r e s s u r e ? l s l p e o i l L u ~ ............................... 11 InProduction ....................................... 11 Oilnrmpr ........................................ 11 oilReservoir ....................................... 11 oilcooler ........................................ 11 OilFdt~zs ......................................... 11



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STD-NEMA SM 23-ENGL L99L b470247 0524299 597 =

section2 piping and Instnunentation ...............................

nwisons for the Esrvin>nment ................................ Eaclosufe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exposwe to Nanrral Elements ............................... Exposure to Abnonnal Ahnœphedic conditioas ......................

GeneraiRequiremeats ..................................... PltsSureandTempemmRanges ............................. vi’bration ..........................................

Singlestageïùrbim .................................. M d t i s t a g e ï ù r b ~ ...................................

clitwspeeds. L ................................... NameplateData .......................................

Sedkn 3 CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GoveaningSystem .......................................

SpeedGOm ar .......................................

GOvmorconmlled WVe(S) ............................... Servomom System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Speedcbangetlype ...................................

speedchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Speed Govaning System classification . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SpeedRange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Maximums @Rise .................................... speedvariation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DeadBand ........................................ stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Speed Regulation. Steady State .............................. steamPressurecaritrd ....................................

PressureRegUlatingSysíea~ ................................ PressureRegUlatw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control MechaniSn ..................................... nessUre Controlled Wves ................................. pressurechanger ...................................... SteadyStatePxess~mRe guûuion ..............................

PressureReguiatioai C. ............................ stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pressure control perfamilmce ...............................

Compensated coatrol System ................................. Electronic Governing System .................................

Basic Features ........................................ Accessones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Control Primiries ..................................... Control of inâuctim or Extracoon ............................ Missing Signai Detection Featrae ............................ SensorRedundancy ................................... OverSpeeaTnp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Genexal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Automatic S t a t Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Multivariable Govexnor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CoatmlMeChanism .....................................

E x t e m a l C d D e v i w .................................. RemoteSetPoint Qpe .................................. Valve Actuating- ..................................

. 11 12 12 12 12 12 12 12 12 12 13 13 17 17 17 17 17 17 17 17 17 17 17 17 17 18 18 18 18 18 18 ZQ m m 20 20 20

A) 21 21 21 21 21 21 21 21 22 22 22 22 22

m



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STD.NEMA Sf l 23-ENGL 1991 m b470247 0524300 039

s e c t h 4 PRûïECTiON ......................................... BasicFeaûues .........................................

UanUalTrip ......................................... Overspeed'LtipSystem ................................... OverspeedScnsingD ................................. n i p s peed .......................................... nipvalve .......................................... Combined 'Ltip and Ihrottlt Valve ............................. overspeednipsystemsetting ...............................

secSIon5 FACIDRYTESTING ..................................... 'Iiirbine .............................................

HydroTd .......................................... NoLoadRUnmngTesc ...................................

Sectbn6 SOUNDPñESSUREJEVELS ................................ Gtaeral . ............................................ swnd€3essweLev& ..................................... soSmd~LevelMtasuremcntprocedme ........................ Camction for BacLgrwnd Noise ............................... souadResolution ....................................... Instnuneats ........................................... S d A ü e n d o n .......................................

sectm7 PRapARATI0NFORS"TANDSTORAGE .................... S h i j l p i D g R e ~ ...................................... Shipneat ............................................ W i t and Storage of Equipmeat ..............................

sectkn8 INSTALLAIION ....................................... In-tion ........................................... SupervisionOfIaseallation ...................................

steam Inlet and Exhaust Piping ............................... C i e a m n g o f ~ S t e a m P i p i n g .............................

SteamPipingS ystems ..................................... I n e t i o n ......................................... The Piping noblem as Applied to ?brbines Fbms Due to Stearn Pressure ............................... Fbms Due to Temperatwe .................................. Farces Due to Dead Weight ................................. AuowaMe Fœces and Moments on Sttam Turbines ....................

DrainPiping .......................................... IÆak-ofli ........................................... Fuil-FiowReii &Device .................................... CoUptingAlignmcnt ...................................... Grwting ............................................ FlushingûiiSystem ...................................... In-tim ..........................................

........................................... Fouudation .........................................

........................

............................ seCtrOn9 OPERATONANDMAINTENANCE

operatioa ............................................ Noncondensin ' g 'hbine opetatian of aMultisrage condensia . g'Ihrbine 'I)pical SEertmg Seqaence fima Steam nirbine ........................ Maintlmance ..........................................

Intluduction .........................................

. . . . . . . . . .

p.pc 23 23 23 23 23 23 23 23 23 25 25 25 25 27 n 27 27 28 28 28 29 31 31 31 31 33 33 33 33 33 33 34 36 36 36 36 38 40 41 42 42 42 44 44 44 51 51 51 51 51 51 51



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STDmNEUA SU 23-ENGL 1991 6470247 0524303 T75

pige SeCtknS

UitemalWaterWashing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 steamhinty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Sacth10 INQUIRYGUIDE.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67



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STD * N E M A SU 23-ENGL L99L 9 6470247 052430il 7 D l W

Foreword Ilhis standard has been developed by the Steam "wbiine Section of NEMA. In its preparation

andrevision, considaation bas been given to the work of other organizations. such as the American National Standards institute, the American Peuoleum institute, the American Boiler Manufacturas Association, and the Amencan . SoCiety of Mechanical Engineers, striving toward the deveiopment ofstandards,anddtishaebygiventoaii whosesiandardsmayhavebeenh~~inthepreparatian of this publication.

nK purpose of this standard f a singie stage and multistage mechanid drive steam turbines is to faciiitate the appiication of the.se turbines by engineers, users, aad conuactas, to promote ecwomieS m driving rotalhg mechanical equipment, and to assist in the proper seiection and app~ofthedifferingmechantcal designs of turbines.

NEMA Standards P u b l i a SM 23-1991 revises and SupeISedes the NEMA Standards Publi- Cation Steam Turbines for Me~hanical z)rive S e M e , SM 23-1985.

User needs have been considertd throughout the development of this standard. Proposed M recommmded revisions should be submitted to:

Vice Resident, Engineering Depamnent NationalEiecaicalManufacturersAssociation 2101 L S l E a Nw, suite 300 Washnigton,DC 20037 (202) 457-8400

1



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STD-NEMA SU 23-ENGL L99L b470247 0524303 848

ii



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STD-NEMA SM 23-ENGL 2992 6470247 0524304 784

Section 1 REFERENCED STANDARDS AND DEFINITIONS

AmtriamNationolStandandsInstitute 1430 Broadway

NewYork,NY 10018

S1.4-1983 s1.11-1%

ANSUASME B 16.1-1989 B16.5-1988 B1.20.1-1983 B31.1-1989

Spcjficprion for Soundikwl Meters Spe@hations for Octave-Bad, Fractional Octaw-Band Anolog Md DìgM Füms

Can Iron Pipe Flanges mid Flanged Fìttings, Class 25,125,250 anàW piPC F b g e s and Flrurged F&gs General Purpose Pipe ThrecuFr (Inch) PowcrPìpìng

J h t Ililrinnfactprors Association 25 North Broadway -,NY 10591

The S t a d a d sf the IIqmsion Joìnt Matu#actmrs AssocirrtiOn (1980) (198s Addendum).

Riuiont-An -t deviarian in SM caiceaoicityiodicattdbytheoatputofaprmimityprobc whichisduetovariatiaas in the electrical condllctivjty œ magnetiCpopertiesOfthtobsavedshaftsraface.

volume of steam bappad betweem the turbine and a trip valve ur notmew Valve.

atspeedsgreaterthan the first lateral c r i h i speed. Hmting-Tñe oscillation of speed or other c011PD)led

pamnmx above and below the mean vaiue. An MsEable coaditioll.

smecontainingcompentsof the turbinebypressip1pag with water. ïntemaiWaterW~g-Aproceduremwhichsteam

having a high percentage of moisture is hjecteä into the tuhine for the pinpose of removhg water soiuble &posits from the tirrbine blades and aozzles.

EntrrippedEwrgy-'Ibe~whichcemainsintk

FhibleShriPt-Ashaftwhichisintendedfmapera0ioa

Hydno --A test fm leairs and mtegrity 0fthepn~-



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SM 23-1991 Page 2

STDmNEMA SM 23-ENGL 1991 W b470247 O524305 bLO

Laterpl C r i h l Speeds-The speeds at Which the ~ITI- plitude of die iaterai vibration of a machine rotar due to shaft rotation I.each their maximum due.

Proximity Probe-A non-contacting device which eiecîronidy measures the position or displacement mo- tion of an obsexveú surface relative to the probe position. Purge A i r 4 method of seaihg in which air (or ineat

gas) is bid into the seal ar housing to maintain a slight positivep.essrireandthuspreventtheentranceofcoaruuni- nants.

ResiSEnace lkmperaîure Detector (RTD)-A device for d g temperature in which the eíwhicai resis- tance of tbe &vice changes with mperaiure.

Respoase The-'ib time required to m v e r to the d y suue operating value afterasudden change in bad.

Service Factor-ïhe factor by which the maximum power capability of a device exceeds its rated m.

SpeeiTied Conditions-Specified conditiolls are aU customer d e f d power, speed and steam conditions at which the turbine must operate.

Steam liirbine-A prime mover which converts the thermal energy of steam directly into mechanical energy of d o n . Stiff Shaft-A shaft which will not be operated during

n o d circumstancesat speeds greater than the nrst lareral criticalspeed.

Therm0coupl-A &vice for Sensing temperatures in which a pair of dissimilar conductors are pined at two pints so that an electromotive force is developed by thermoeiectric effects when the junctions are at merent temperature.

NEMAStandard 130-91.



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STD*NEMA SM 23-ENGL 1991 b470247 0524306 557

SM 23-1991 Page 3

Section 2 CONSTRUCTION

21 TYPES OF STEAM TURBINES

2.1.1 clsssified by Exhaust conditkns

2.1.1 .I NO"DPISING TURBINE A noncondengng turbine is a steam turbine designed to

aperate with an exhaust steam pressureequal to ur greatex tbanatmospkricpressure.

NEMA- 11-13-1969.

21.12 CONDENSING TURBINE Am- turbine is a sream Wine designed to

operatewithanexhauststeampressurebelowamia6p~c P=-=

2 1 2 CWslfîedbyNunberofStegesand

NEMAStandard 1-30-91.

Cœlwvahrea

2.1 2.1 SINGLE VALVE -LE STAGE TURBINE A singie valve single stage turbine is a steam airbine

which has one govmor conmiled valve and one stage.

2.1 2.2 SINGLE VALVE MULTISTAGE TURBINE A single valve multistage turbine is a steam trirbine

which has one govmor conaoued valve and two or more stagts,

2.1 9.3 MULTIVALVE SINGLE STAGE TURBINE A mdtidve Agie stage turbine, is a steam turbine

wbich has two or m a t governorcontmkd vaives and one stage.

NEMA- 6-21-1979.

NEMASEendard 6-21-1979.

NEMA spnd9id 6-21 -1979.

2.1 9.4 YULTIVALVE MuLTWTAOE TURBPIE Amuitivaive muitistage turbine is asteam uxbine which

has two ar more governar Caimlled valves and two OT

-stages-

215 C ~ b y P F o c e s S N e e b s


2.1 3.1 m D (AWWAC) EXTRACTION TURBINE

A controlled (automatic) extraction turbine is a steam turbme which has an opening(s) in the turbme casing for the extraction of steam and which is provided with means far directly reguiacing the flow of steam to the turbine stages following the extraction opening for the purpose of mmiiing extraction pressure.

NEMAStandaid 6-21-1979.

2.1 3.2 N O " T R 0 U D EXTRACTlûN TURBYSE A nonconmiied exnaction turbine is a steam trrranC

which has an opening(s) in the turbine casing for thc extraction of steam but which does not have means fa cantrolling the presswe of the extracted steam.

NEMA SIPndard 6-21-1979.

2.1.3.3 NO"TR0LLED IN- TuRBWE A I1oI1contTdled mduction turbine is a steam Mbine

which has an opening(s) in the airbine casing fainductioa of steam but which does not have means for CQltlDUiilie the pressureof the inducted steam.

NEMA S W d d 11-14-1W.

2.1 6 4 m D INWCTION (m PRESSURE) mBWE

A controlled induction (mixed pressiire) turbine is a steam turbine which is povided with sepíirate inlccs far steam at two pressures and has an automatic device f a conb.olling the flow of steam to the turbine stages following the induction opening.

2.1.3.5 INDUCTION EXTRACT" TURBINE An induction exmtion Mbinc is one which combincs

the fatum of extraction (controlled ar nanconmikd) with the features of induction.

2.2 STEAM TURBINE COMPûNENTS

NEMA stendprd 6-21-1979.

NEMA standerd 6-21-19B.

2 2 1 nirblnecaslng A turóine casing is the enclom which sumomis tbc

rotating element of the turbine and supports the statim steamparts.CasingsshallbeaxiallysplitJadiauysplifa a combination thereof.

he turbine casing W be divideaintotwourmon sections as follows:

NEMA Standard 6-21-19B.

2.2.1.1 STEAM INLR END SECTION

which contains the higher pressure steam.

2.2.1.2 EXHAUST END SECTION The exhaust end section is that partion of the cssing

which contains the exhaust connection and the steam at exhaust conditions. It shaü also contain the low pressnn stage(s) of a multistage turbine.

The steam inletend section is that portion of the riffpinn

NEMAStandard 6-21-197W.

NEMA Standard 6-12-1979.



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www.bzfxw.com

STD-NEMA SM 23-ENGL L99L H 6470247 0524307 493

SM 23-1991 page4

2.2.8.1.1 Aptsure impulse ur Rateau stage coLIsi8t8 d smionmy expnshx~ nozzíe(s) and one row of rotatiag bkides.

2.2.8.1.2 A velocity-compoanded impuise or Curtis stageconsistsofstationaryexpansionnozzle(s)Imdtwoa more rows of rotating blades.

2.2.8.13 A v e l o c i t y ~ p u n i d e d i m p u i s e ~ ~ s i a g e umsists of Srationary expansion nozzie(s), am? IOW at rotatiogbladesandoneormorereversingchambas.

TbepressmdropacrossaRateanstageisreiativelybw inwmpoaisontothepssmdmpacmsaCmtis~.

Authorized E n g W n g l t l h n a h 6-21-1070.

2.2.8.2 R~CTION STAGE A reaction stage consists of stationary expanSion

nozzie(s)discharginghighvelocitysteamjetsaitherotat- ingblades.Apressuredropoccursinboththesiatioaary and rotating elements.

229 shaftseals

2.28.1 CASING SHAFT SEALS Casingshaftsealsminimizetheleakageofsteamoutof

uie casing dong tbe shaft.

rhe entnuice of air into the casing dong the ShaR *yare aaraaged fur the admifipimi of steam at a canstant low

NEMAStandard ô-21-107B.

For condensing turbines, seals are arranged to jxemt

pressmcand low mperalme. NEMAStandard 6-21-1979.

INTERSTAQE SHAFT SEALS

Interstage shaft seals minimize the leakage of steam h g the shaft between stages m amuitisfage mrbh

NEMAStandaid 6-21-1979.

2.2.10 Beerlngtlouslng Abearing housing Coataias andsupputs abeariagfs)

andisequippedwithseaistopreventlcíücageofdaodttie entnince of m o h , dust, and foreign matmi&.

NEMA- 6-21-1970.

2.2.11 ûmtln(Y

2.2.11.1 RADIAL BURINOS Raclialbearingsarebearings Which s u p p a r t t b e ~

elementinhorimtalshaftbirbines.Iheyareofihtsl~~, tilting pord mantifriction type. In verticat tmbrnes, these bearings tnri;sllv positiOn the mtar assembly.

NEMAStandrurl6-21-1970.

2.2.11 9 T H R W BEARINGS Thrust bearings rn m g s which trammitthe axid

thrust of the rotatllig dement to the beaping bousmg and maintain the axial position of the mux assenibly m the



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S T D - N E M A SM Z3-ENGL I99L W b470247 0524308 32T m

casing. They m of the antifrictm, laad, ar scgmeniai tutuigpadtypt.

NEMASWdaid 6-21-1939.

2.2.113 ANTFRICTION BURIN08 Antiúictim bearings stmuid have a minimum rating life

of3 yearsa25 o0Ohours w h e n a p e r a t e d ~ ~ a t maxgnumtblUStdradislloadsaodat~speed.

Authorized Engheeiing Inkrmillion 6-21-1979. The rating life is tbe number of houisatcunstant speed

tbat9ûperctntofagroupofidcnticalbearhgswiiiopcratc befcxe the fitaeviâe-nce of fatigue devebps.

kthomed E n g i i n g Inbnnaakn 6-21-1979.

2.2.12 RotorA88etnbly "be r~ot assembly is the rotllting elemnt of the turbine

whichinclubesaiîpartsattachedtotheshaft,excludiugthc caipling(S) unless coupling is integral Witb the shaft.

NEMA- 621-1979.

2.2.13 W h 0 d s m ) wheels arediscs which are inmgrai witb,orñxcdto, the

~ieshaftandoawhichbladesaremounted,orinwwhich bladesorbuclrmsaremachined.

NEMA- 6-21-1979.

2.2.16 HandW0(S) A hand vaive@) is the valve which isalates steam flow

to a gmup afnozzle(s) to pennit e&cient apetriton at redmtdpowerawithdualsteamconditionsHaudvalvalves can be either manuaily condied or arbomated and are used on singie valve turòines oniy.

2217 PmtecthreDeVice

NEMA SiaKliUd 6-21-1979.

Apotective device is one which, alone oras p?* Qf a sy9iem,respondsinsomepredetemiinedmannerto,~sor- malconditionsaoendllig theopewtion ofthe unitorsys- tem towhichit is connected.

NEMA Standard 6-21-1979.

SM 23-1991 Page 5

2.2.18 ConadllngDeVice

icaliy initiates action of a system which caaerols a(MnB1 apaationofthetiirame.

2219 ExtemalcontrdDwlce An extanal control deviœ is an element which is E-

sponsive to signais other than turbine spaad, ie., flow, presswe, -,and soforth,dacis toconirol the fbw of steam to the turbiDe. u shalt be pnemwid Y* mecbanidy, hydraulically. or electricany actuated fiom the signal sollfcc to position the governor vaive@). (Ref- mmœ Section 3.1.6.)

Acoatrolliag device is OM which manidly

NEMA- 11-13-1968.

NEMAStandard 6-21-19'19.

2220 WamlngDeVlce A warning de* is one which, by visiõle or auáiblc

means, or both, indicates that an abnomai apefatingum- ditionexiscs,

2.2.21 Sentlnel Wamlng Valve A sentiael waming valve is a pressure warning device

whichopenswhaithesteampressurerisestoapredeter- mined 1eveLThedeVice shaü dischge tothe atmosphere andshallbesolocatedasto be plainly visible&

For condcaskig tl&K%% it shall be set at 5 psig 135 kFa(gauge)]. For noocondensing mines the minimm

maximnm exhaust steam pftssuR, Whichever is greater.

following applications:

NEMAStandard6-21-1879.

seüing shall beeither 10 percent or 10 psi (ïOLpa) above

A sentinci warning vaive is not recoaimended for the

locatiais where the discbarge of steam to the am+ sphaeisobjcctionable,hamdousorpmhibkdbyhw

NEMA standard 6-21-1979.

- a i n e s which utmd volatile gase^

- Mbineswhicbareanangedforauiomaticworunat-

hir these applicaliom, an alteniate wanimg device œ mded start-up

optionai trip device is iecommended.

2.222 s o w w s )

Authorued Enginwing Information 1-91.

A soleplate(s) is a machined fiat steel piate(s) or cast- ing(~) for mounting of the equipment supports and far biting and grouting to the foundatiar.

2.223 ûmapiate Abaseplate is a fabricated of cast continuws structure

having machined pads for mounting of the equipment and for bolting and grouting to the foundation.


NEMASQndard 11-13-lQ69.



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S T D -NEMA Sfl 23-ENGL

2.3 FEATURESANDACCESSORIES

m 6470247 05243ûq 266

9. Insulation for the high tempemm section of tht Wine to limit exposed siirfaoe temperatme to 16pF (74OC) or other tempemture specified by the P-.

10. Steampresswegaugestoindi~inletsteam,~ ring, nrststage,dexhauststenimpressure.

11. Coupling between the turóine and driven machine (normaiiy fumhhed by the m8nufacturea of the dnven equipment).

12. coiipling guard SuppOIted frwi tbe baseglate oc adjacent bealing housmg(s). Tbe couplmg guard shouldbecasilyremovableandbe~ientlyrigid

resuuofnaïmalt!odilycaitsctbypersonnel.Wbco continuauslylubaicatedcouplragsare~the coupiing guard œ housing should be fitted so that oil leaks will bepmted.

13. GlandleakageevacUatingappIiratus whendiegland casngdesignrequiresitsuse.

14. Tachometer of the vibaatuig mai, machanical, ‘ a r e~type;iodicatiagspeedsfroniabovethcûip speed to M o w the minimum aperatiag speed. Th- chometers shall be suitaóle for the specifmed eavi- Ionment.

15. Supemhry instniments to monitor such as vibration, axial shaft movement, tempemtms, etc.

16. Shaftgroundingdevicetocarrytogromdanysíatic

romandwhichmayotherwisebuildtoLevelswhich ddâamageturbhcbearings.

17. Rotor turning gear togeUier with driving maus, engagement and äisengagement feaiures, and lube oil pressure interlocks to permit slow turning of the mtorsystemonstatt-upandsbutdown.

trip valve which provides a means far 18. AlbusSm quick and positive shutoíf of admjssion stcam f a emegencY tnppuig.

19. Nonretuni valve(s) for blocking ihe revme flow of s t e a m f k o m ~ i n t o t h e t u r b m e t h r o u g h ~ orextractioaopenings.

20. Redmiantoverspeedtrip. 21. Exhaustreliefvalveornrptriredisctopre~over

piessrning of the exhaust end section (see Sectim 8.7).

22. Vacuumbreakertoadmitairiatotheexhau9tam nections d a condensing turbiue in cmk to reduce coastdowntime.

to withsiand deflection and plevent rubbing as a

charge which might be developed on the hirane

. .

Additbd items may be availsble. Authorized E n g i i t q ~ infamaiion 1-1.

2 s ControlledEXttadknandmled krdudknmrblnes

Conwlleü exmaion, ccmtrolled indoction, and um- mlled induction exmction turb8nes &ail include basic



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features W i n items 1 thrwgh 6ofU.1, together Witti those lisied in 23.3.1 through 23.3.4.

2.33.1 Controlled extraction turbhm shall bave apre+ 8utt regdath8 SySteB for mtroiiing mt pssm of the extracted ste9m by regulaiing the fbw of steam to the turbine stages fallowing the extracth opening(s). Anon- return valve br the extraction apallng(s), which is also actpated by the ovaspetd tip system. is nquind far installationintheexoactimsteamline(s).

2.3.3.2 controlled mduction turbines Shan imve apes- me regdating sysrem for cantrolling tticpm5urcof the imjucth steam toregulate t h e b w ofsteam tothe turbine stagesfoiìowingthein&ctionopening.Atripvaivewbi& isalsoactuatedby theoverspeedmpsystemisnquired fnrinstallaaon . intheinductionsttamk.

233.3 Dependmg on the source of induction steam, the usashould consider the need for a steam ssainer in t i i s

AumaiEed Engineering Infornietion 11-14-1985.

2.3.3.4 Controlled extraction turbines and controlled induction turbines shall have a multivariable miml system

uiatingsystemaadthespeedgovemingsystem.

chdethecombinationofthefcxegoingitems.

NEMA- 190-1991.

h e to protect the loweapressure stages of me turbine.

which provibes interconnectiOn die pressiut rCg-

2.335 conaroued inductim ~rtractioa trabines shall in-

NEMA- 11-14-1085.

23A ~ ~ E x t r a c t b n T i a M n e r Nonccmmiiedextnictionturbinessballincludetbbasc

feaaacsiistedinitemsl througIi60f2~.1,togctfrtr~ith mwisecmnvatve(s) far the extraction opening(s). 'he quantity and lomion of nomearni valves are tobedetermhl bythe t r i rb incman~basedonent rappedaiergy ~redimdaacypolicy.

NEMAStandard 130-1991.

2.3.5 N~ l ledk i$uáknni ib l I l@S NoaiconmIIed induction turbines shaü inchide the basic

feahaeslistBdinit«nS 1 tl1rough6of23.1,togetheswirb a trip vaive@) for the induction opening(s).

NEMA- 11-14-1985.

2.4 TURBINE RATING

2A.i Power Rated power is the maximum specifiedpower output of

the~ine.Itismeasuredattheoutpitshaftofthearrbine. NEMA Standard 6-21-1979.

SM 23-1991 page 7

242 speed 2.4.2.1 RATED SPW

Ratcdspeedisthespeedcanesponduig * toratedpowa. It is measiaed at the output shaft of the turbíw, is expressed in rievdutioas per minute, and is quai to M less than m8ximm ~ u o u s speed.

2.4.2.2 W u u Com~uous SPEED Maximum conhinuous speed is the highest specifiad

speed at whicb a turbine can be operatcd continwusly pwidedproperovaspeed~goverwr- - a r e iastalled and operatianal.

2 ~ 3 NomralPower,SpeedandSteam

hJ- power, m and - cooditionsaretbost c a i d i t i o n s f w a d m d ~ a a d a t w b i c h r h e s t e a m ratcwillbeguafan~

U A S î ~ C o n d i t l o n s

2.4.4.1 WNuW STW C û t d m Minimum steam ~ t i ~ a r e thelowest inlet stcam

pressure and tempemm and lowestexhaustprcssm to which theturbineissubjectedincontinuwSopaatiOa.

NEMA standprd 6-21-1979.

NEMA- 621-1979.

corabns

NEMA- 6-21-1979.

NEMA stadard 6-21-1979.

2.4.4.2 M A # ~ ~ ~ ~ T E A ~ ~ ~ N ~ T K I N ~ Maximum steam CDnditiOIls am thehighest inlet steam

pitssrrre and imperature and exhausspIesllm to Whicb the tiirbmeis subjectedincaltinuousopaation.

NEMA- 621-1979.

2.4.4.3 Wuuu E N m v Smw Mïn i Inm~geamcondi t i .M ls iue tbe~ in l t t

steam presswe and t e m m and the highest CxImust pmsm at which the turbine is requucd to produœ a specinedpower~speed

2.4.4.4 hLET STEAM PRESSüRE uiietsteampressiire is the pressureof the steam supplied

totk tUrbii.Jtis m«wred at the $tcf3m inlet conncctim of the airbine and is e x m a s a gauge piessure.


2.4A.5 EXHAUST STEAM PRESSURE Exhaust steam pressure is the pressure of the steam

system to which the turbine exhausts. It is measured at the exhaust connection of the turbine and is expressed as a gauge pressure far n- ' airbineSandasanab- solute pressrrre for condensing tuhines.




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STD.NEMA SM 23-ENGL 1971 D b470247 0524311 9L4

2.4.4.6 ExtRAcT#))J STEAM PRESSURE Extraction steam pmsm is the pressine of the steam

extracted from the turbine. it is measuredat theextraction wnnecticm of the turbine, and is expressedas a gauge P===

2.4.4.7 hwCnON STEAM PRESSURE

NEMA-6-21-1979.

Inductionsteam~isthepIessureofthesecoadary steam supplied to the Wine. it is measureâatthe induc- tionconnectian of thetrirbineand is expressedasagauge p#rsiae.

2.4.4.8 INLET STEAM TEMPERATURE

NEMASEandaid 6-21-1979.

Inlet steam tempeniture is the total teIn- of the steam supplied to the turbine. It is nreasiired at thesteam in le tcmnect ionof the turb ineandisex~inde~ Fatireobeit~indegrces CeW.


2.4.4.9 EXHAUST STEAM TEMPERATURE luhapststeam temperame is the totai t e m m of the

steam cxhartpted from the tinrbine. It is r n d at the cxhailst CoMectiOn of the tuxbine and is expresd m degrees Fahrenheit or in degrees Celsius.

NEMAStanderd 6-21-1979.

2.4.4.10 WRACl" STEAM TEMPERATURE Exaaction steam temperatureisthetotalteInperatureof

the steam extracteü from the turbine. It is measuredat the exixmirn connection of the tintiineandis eJtpressedin äegrees Fahrenheit or m degrees Celsius.

NEMASEendaid 6-21-1979.

244.11 1NDUCTK))II STEAM TENPERATURE Uiductioosteamtempenimreisthetotalm~of

t h e ~ s t e a l n ~ W t o t h e ~ Itislmasmtd at the iiiduction connectim of die turbine and is expressed in de- Fahrenheitor in Celsius.

NEMASEandaidô-21-1979.

2.4.4.13 DUAL Srrrun CûNMl"S Dual steam conditians are two ofmmcombin8tons of

iniet steam pressme, inlet steam tempenitine, or exhaust -pressure.

2.4.4.14 VARIAl"S IN STEAM CCXJüITlONS The Iatíng, capability, steam flow, speed re-, and

pressme control shall be basedon operation at maximum stcam unuütions as defined m 2.4.42. Steam Mbiaes shall be capable of operating under the


followingvariatioasininletpressureandm~but p e ? f ~ s h a l l n o t n e c e s s a r i l * y bem accardance with thestandaadsestab~foroperatmgatmaximumsteam conditions.continuousopetatiaiatotherthanmaximum steam conditioI1s shaü require review by the turbiw manufacturer.

2.4.4.14.1 VARUTKJNS FROU hhXUuU INLET STEAM


PRESSURE The turbine shali be capable of operating without dam-

ageat less than the guaranteedsteam flow tothe Mbine with average Wet pressure of 105 percent of maximum idet steam pressure. (This pemisible variation recog- n i z e s t h e ~ i n p r e s s u r e w i t h ~ i n s t e a m f l O W encountered in operahion.) The inlet steam pxsure shall average not more than

maximum pressiire over any 12 month opedug period,

maximumpressurein maintainingtheseaverages,e;xcept Theinlttsteamprwsureshailnotexceed 110perccmd

during a b d COilClitioI1S. During abmnmal cosiditim, the steam paessare at the

tiirbineinletconnection - shallbepermitredtoexdmax- h u m pressure briefly by as much as 2ûpesent, butîhe aggre@e drnation of such swings beyond 1M percent of maximum pssure shallnot exceed 12hwrsper 12mondi operatingpenod.

NEMA- 6-21-19m.

2.4.4.14.2 VARIATIONS FROU WXiNUM INLET STHM mPERAlURE

Theinietsteamtempeniturestœüaveragenotmorethan maximum tempexatme over any 12 month operatmg pe riod. In maintaining this average, the tempemm shall not

exceedmaximum tempemureby nme than 1fl(8oc) exceptduringabnnmalcoaditions.Duringabaonnalcoo- ditions, the tempcratiae shall not exceed maximum tern- perature by m m dian m(14Oc) fwojmathgperiods



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~ - ~

STD-NEMA SI 23-ENGL L77L H 6470247 0524312 850

SM 23-1991 page9

h2-theenthalpyofsteamatwrhaustsLeam paeasiiredinitialenaopy.

NEMA s&idard ô-21-197Q.

2.5.1.2 AcniAL STEAM RA-

26.1.2.1 TURBINE - -TE îùrbinesmunrateisthequaatityofrmctsteamnqairad

by the tlirbioe per miit of power outpit, lneasmdattbt ouiput shaft ofthe tmbme. It is d y e- in pounds ofsteamperhorstpower-hour(orinkilogremsa€steem pa kilowatt-hour).

2.51 -2.2 TURBINE GEAR STEAM WlE Whenagearisprovidedòytheturbineman~,tht

required by the turbine gear set per unit of power outpiit, measured at the output shaft of the! gear. It is &y

turbine gear steam rate is the quantity of inlet weam



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STDeNEMA SM 23-ENGL 3993 M b470247 0524333 797

SM 23-1991 Page 10

eqxessed mpoundsof steam pet harsepower-hour (or in kil~0fsteampexkilowa#-hour.

NEMAStendardô-21-1979.

2.5.1.3 GUARANTEED STEAM RATE' Theguarauteed steam rate is thesteam rate which will

not be exceeded When the turbine isoperaredat w)rmal power, speed. and steam condkions.

2.6 TURM"CO"ECTK)NS

NEMAStenderd 6-21-1979.

u 1 o u t p u t s h a f f ~

26.1.1 Omput shaft cxtensionS shall be Spatable for a cyimdrical coupling bore and provided with a keyway(& tapaed ooupling bom with a keyway(s), tapered for a hydraulic fít, or ntted with an hie!@ coupling hub.

2.6.1 2 When a tapered shaft extension with keyway(s) is speciüed, the taper, wupiing hub, andmupiing nut shaü

areavailablefarshaflextenshs frwi 2 inches m 5 inches.

N E M A W 11-14-1985.

be in accardance wirb Figure 2-1. NEMA taper diameteSS

NEMA- 11-14-1985.

2.6.1.3 if cyhdrical shaft Cxtension is specfied, it is ncommended that the cwpling-to-shaft fit be an inmfer- ence fit

NEMA- 11-14-1985.

26.1.4 When a hydraulic fit coupling is specified, the mountiug method should be reviewed with the turbine lnallllfimmr.

2.6.1.5 Recommended use of one and two keys and keyways is as shown in Tbble 2-1.

Authœiæd Enginwring Intomiobon * 11-14-1986.

2&2 SteamComecUons 'Iiirbmeflangedsteam C o n n e c t i o n s shallbe facedand

drilled for bolting to flanges which arem accordance with ANSUASME B16.1 or B16.5. CastiNnlflaagecOM~nsshallbeflatfaced The thickness of cast iron exhaust flanged connections

under 1 0 m c h e s ( 2 s o m m ) i n d ~ b e n o t l e s s m Class 25û of ANSUASME B 16.1.

Singie vaive single stage hariuwall Ysplitcasingan- bines shall have steam cannections m the bwexhaifdthe trnbiae. connections for making up topipenot0ver2

inches in diametex (So mm nominal diamtter) shall have


intenial taper threads conforming to ANSI/ASME B 1.20.1-1983.

NEMAStandard 11-14-1@8!5.

26.3 ArorlllaryConneUtons AuxiliarycotlIlectiomthataredireadedshallconf~to

ANSVASME B120.1-1983. W y , these are a d e ring prtssure gauge - - , drain Co- fat casingandsteamchest,casingsealingglandsandbeariqg h ~ ~ , c o o l i n g ~ , v a l v e ~ l ~ ~ , a n d ~ f f o r i h .

2.7 LUBRICATKIN

2.7.1 NûiìpressueType kibrîcation (Singie

2.7.1.1 OIL LUBRlCATEû SLEEVE BWüNûS

NEMA- 11-14-1086.

s te ( leWW)

a

b.

C.

(tiomzomL~~meB) LU~~WOII Should be prended by oil l h ~ ilar means. Beating housings should be large enough to peanit solidsor water m d e to the bottarn and should haw a dtain connection at the lowest point, oil fiil fittings, and an oil level indicam.

. F ~ i l i h f o r c d i n g shouldbeprovided~hcn ne^- essary to assure the proper oil temperahrre. nie cooling water should be supplied at a temperame not exceeding 90%(32Oc).

Sim-

2.7.1.2 GREASE OR OIL LLJBíUCAEû A N i F H C " BEAWNGS

Gmse-lubricated autifriction bearings should be regreaseable ~II die kid. Grease fittings should ex- tendtotheoutsideoftheniachiaetopermitregreas- ingduringopemion. Means should be provided far venting grease lutNi- cated bearings to pment the buildup of pnssure within the housing. Faciütiesforcoolingshouldbeprovidedwbennec- essary to assure the proper lubricant tempemme. The cooling water shouid be suppiied at a temperature not exceeding 909: (32Oc).

27.2 Pressum tLpe Oil Lubrlcatiûiì

2.7.2.1 ~ O D U C T I û N It is recognized that there is awidevariation in turbine

Szesandapplicaths which makes it impracticai to have one recommended lubrication systcm ckign. However,



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STD.NEMA SM 2 3 - E N G L 1991 H 6470247 0 5 2 4 3 1 4 623

the foilowing diouidserve wagenaal design guide tothe o e a f u r ~ h i s r a q u i r e m e n t s .

27292 OILPWPS

272.2.1 A main oil pump drive^ from the turbine shaft ar a seperately driven pump to provi& oil for lubrication aadgovemingshouldbepm4de.d.

272.2.2 Anauxiliaryoilpumpforuseduringthc start-

by bic design ? whan qecihd. niiS pump should be powaedbyadiffemismceofeaagythanthemainoil pimp.AprrssurtsensingdeviceshouMbeprovidedfcx

pmsmeintbcmainsystemdmpsbebwapredetermined valm For a Mbinedriven auxiliary oil pump, the turbine

8bOdd d m to all of the @pli* pvisim of diese sltmd&L

272.3 OILRESERVOIR

u p ? s h p t - Q w n p e M d s h w l d b e ~ w h e n r e q ~

aptomatically sfming the ruailiary oil pump when the oil

A samate ail ~ ~ S U V O ~ T should have a

a c.

d

t.

f.

2.7204 oLcoolar(s)

empuame oftbc oil supplied to the bcaringsatamaxi- mimi d 120°F (49oc), with a maximum woling water tmrpaaaarc mx excealhg 90°F (32OC). It should have a fwl ingfáC~ofO.~l on the wataside fopcoaliag towel water anã afouling faaor asncommendcd by the manu- nicMafarothtrcoolingwate?sources.'Ibemo~sbould be suitable fora working pressme of notkss than 75 psig [517 kPa (gauge)] m the w w side. Singkartwin~kmmaybeused.Eechcoolershould

be capable of operatioa at a pressure quai to or peat ter tima the nlief valve setting of positive displacement oil pumps or ofth maxllnum shutoff dischargepressiae of ca~trifugal oil pumps. M coolets should be piped in paraüci with acontintmus flow transfer valve to pert., ,i the traas6er of oil from one cooler to the ocher without inter- rupting the oil flow. Each cooler should be sized for the

The oii coola should be capable of maimhhg the

SM 23-1991 Page 11

total cooling loadandshouidbearrangedandventedf? maintaining eitha cooler with the Wire in ojmation.

2.7.2.5 OIL FILTER(S) Single or twin oil tilters may be used. Afiltafs) shoptd

be capable of nmving panicles iarger than 25 micmns. When the film is clean, the pmsurc drop sbould not exceed 5 Pgi (35 kPa) atdesign t a n m a a d flow. Tiviu fílters should be piped in paraiicl witha con- fkw transfer valve to permit the transfa of oil fiom 011c filta t o t h e o c h a w i t b u t ~ ' g the oil flow. Each nUa should be sized fm the total oil flow end sbaild bc U- ranged aad vented for lminmining uthu filtawirh tbe tiirbineinoperation.Acommontrsasfavalvemaybt~ fortheoilfílteIsaQdcoolas.m?íl~cartridgeshouldbe camsion nesisauu. Filter cases should be suitable for opaationatapressurenotlesstbanthcreiidvahn~ oftbepmitivedispiacementoilpumpsoratthemaximum shut off discharge pressiire of cenhifugal oil pump.

2.7.2.6 RPNû AND INSTRWEWTAT"

2.7.2.6.1 Pressure sensitive devices sboahl be prwidad forea&prtssurclevel(forwrampie,oii h&tokarings, discharge 6rom oil pumps, befase and afta fílta(s) and c ~ n h ~ l oil). Means should be pwidad fm BII ai-liee main~asappropriaie.

Authorired Engineering Inforniafion ll-lClOBs.

2.7.2.6.2 if bearing mctal thenwconples ot #Il)s arc not pviâcâ, tben thamometers should be povidad for

be provi&d before and after oil d e r @ ) . Thermowells should b e p v i d d in the piping f a t h e m ofthCr- m e t e r repiacemait while oniine.Tbenmweias shouki begaSfilledOrcrnrosion-resistantbimetalliCtypc.

Authorioed Engineering In- 11-14-1985.

2.7.2.6.3 An oil sight flow indicatm wbui spccifiaì shouldbe provided m the oil return from each öcaring housing where thedesign permis

Authofbd Engineering Infotmaütm 11-14-1985.

2.7.2.6.4 A pressiire regulam or relief vaive should be providedto maintain the oil pressure level(s).

2.7.2.6.5 Afterfabricafim,piping shauldbecleanedd passivated by mechanical an4or chemical means.

Authomed EngVieering I n h i i o n 6-21-1879,

2.8 PROVISIONS FOR THE ENVIRONhENT

2.8.1 Encksure Steam turbines shouíd pfembly be installed in en-

ciosedareas.Thee?Fe!&tsofundseMceconditi~may

oilwtlet fromcachbesring housing.Tbemiametasmay

AuthonzedEngtnear ing I~ * 11-14-10Bti.



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STD-NEMA SM 23-ENGL 3991 b470247 0524335 5bT m

SM 23-1 991 Paga 12

be mi@ted by the use of one or moxe of the measmes bescribed in 2.82 and 2.83.

Authobd Engineefing Infonnetkn 11-14-1985.

2m E x p o r i u r e t o N a á i f a l ~ in general, d exposed surfaces should be potected

against rusting by apaotectivecoatiag or paint after instal- hion of the unit. Enposed workiqg parts which affect aperation d the unit such as govexnor, govexnor ïinkage, fuiuum pomts, Valve stems. and imilw elements should b e ~ a g a i a s t ~ g i s t u i g b y the useof comwion resis- tantmatenalS.

Equipment having nonpressure lubricated bearings sbouldbedcsignedtopvcntîhetnaruiceof *

dust, and fmign mamiais to the governing s y x bearinghai9ngs.

aning systans, or both, shouldbepruwtedas bilowx

both, should be protected against the entrance of water or foreign materials by proper seaiing devices. The points to

sidarelements.Tbereservoirshouiáóeprovi&xiwirha ventwithanairñiîerandcarnectionstofacuitsteremovd of water.

2.8.2.2 In addition to the foregoing protective measum,

trires will be less than 4û?F (4%)

EqpipntnthaMig~l&iCaboihydrauEicgov-

2.82.1 The lULni- system 09 goveanar system, 09

beprotectedinchideallcofinectuwis - orapeningstotbeoil Eale€Voir, goveznor. gBromotor, bearing housings, and

tbe following should be included when ambient ttmpezg-

1.

2

3.

4.

5.

Far use durhg down times,drains sbaild vi&d whe€e water can colkctforall steam,d, and waterlines, the turbme casing and steam chest, and the oil aad water si& of the oil coolex. Pneumatic "blow down- may benectssary m someiostances. Aheater for the ail mservoir. Ifaa electric heater is specineditmustbeofawifncicntlylowwaadeasity topmt coking of lkoil An auxiliary pump may be reqiiired to eosure oil CircUlatBon for unitonn heating. An enclosure or bood witb venting to cover the govemùlg system may be provided, and heating shouklbe supplied toprevent icing. The amount and type of enclosure and heating wiii be governed by localconditions. Protection against fieeziag for instnuaen Band d P i @ & mine manufacturer shouid identay those lines ~resuat-protectionoypa.asa.

AuthobdEngineeMgInfomiehon 11-14-1985.

2.û.3 Exposu~toAb110mialAtm0spheric oondltkns

if possible, the turbine should be located away froin damaging fuma and vapars, or abrasive, magnetic ai metallic dust. If this is not pnictical, the atmospheric candirioas should be called to the aaention of the manu- factufft. Suitable materials or protective coatings may be requiredtoansetthecomisiveeffectsofthefumes.When necessary, purge air connections on bearing housings, glaad cases, and govemm should be provided.

Auth#ired EnQnWring Infonnaoion 11-14-1s.

2.9 GENERAL REQUIREMENTS

2.9.1 PmssureanâTemperaaireRanges Sieam turbines shouid be designed and proportioned far

operationatmaximumsteamconditions.Genedpressnre and tempexatme ranges ¿ut síÍown in Figure 2-2. The ranges are general, accmding to tempeam&xsure cambinations at which pomt material or design changes, OrbOth,~~berequired.

Authorlled Engineering Information 6-21-1978.

2.9.2 Vlbratlon The vibmion of the turbine rotar (double ampïitude)

within thespecifíedoperating speedrange as measuredon thesprfacedtheshaftadjacenttotheradialbeaaingsshall be m accadance with the foilowing:

2.9.2.1 SINGLE STAGE TURBINES The maximum permissible w i o n shaü be not peatex

than 2.0 mils for speeds 4ooo rpm and lower, or 1.5 mils for speeds 4001 rpm and higher.


2.9.2.2 MULTISTAGE TüRBINES The maximum permissi'ble vibratian shall be inaccar-

daace with Figure 2-2. The absolute values for vibrath levels above 3ooo rpm can be derived from the following formule

1-M

Shaft mechanid and electrid runout sbaii be determined by slow rolling the rotor in its bearings while measming the Nwut witb a proximity probe. if it can be demaisoatedthatmtcbanid&electncalnmoutis~- ent, this shaü be added to the abwaòle vibration level op toamaximum 25 peacent of thedioweddoubleampiitude v i ¡ or 25 mils, whichever is greater.

NEMAStendard 6-21-1978.



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S TD-NEMA SM 23-ENGL 1771 6470247 05243Lb 4Tb

SM 23-1991 Page 13

not have the specified margins betweem the apaating speadsand~speeds.ïnthiscasetheturbinedesigna should Catculanerotor response to unbalance. The prime caisiderationisseasitivitytom~

Authorired Enghming Inlonnation 6-21-1985.

2.9.4 NAMEPUTEDATA

tiabiae nameplale: 1. Manufacainr'snameandbcatioa 2 SaialnumW 3. - 4. Ratedborsepower 5. Ratedspeed 6. Maximuminletste9mpressure 7. Maximmillletsteamtunpenitiite 8. Maximumexhauststeampressure 9. M a M m u m e x ~ ~ p r t s s u r e ( i f ~

blc) 10. Tripspeed 11. Maximum continuous speed (ifdifímnt fim rated

rg6ed). 12 Fim lataal critical speed 13. purchaser's equipmeat item number (when speci-

fied).

nie following minimum data StlfJu be given on the




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STD-NEMA SM 23-ENGL 1993 m 6470247 0524337 332 m

L

f t + '

I

I CIE



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STD-NEMA SU 23-ENGL 1991 6470247 0524318 279

SM 23-1991 Page 15

RPM. THOUSANDS

Figure 2-2 MAXIMUM PERMISSIBLE SHAFT VIBRATION



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SM 23-1991 Page 16

Table 2-1 RECOMMENDED KEY FITS

(up to & including) 1-50 2

250 3

350 4

450 5

550 6

650 7

7.50 8 9 10

Twokeys may be used in any c89e.

40 50 65 75 90 100 115 125 140 150 165 180 190 rn 230 w )

Table 24 GENERAL PRESSURE AND TEMPERATURE RANGES



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STDI N E M A SU 2 3 - E N G L 199L b470247 0524320 927

SM 23-1991 Page 17

steam 00 cnm the turbine. nie pilotvaivecoatrois tbc flow of highpnssme fluid to the power cylink. This flow d highpressmfluidcausesthepistonmthepowcrcyinda to move in rcspaise to the signai h m thegovanœar conQo1mechasiism.

81.6 Extemalcontrol-'

deaibedbebw:

3.1.6.1 SPEED CHANGER TYPE

NEMA- 612-1986.

Extanal calm1 devices shall be me of thne Eypcs

-mchangatypeis- dirtcts,iaDothe governing system which in hun positions the gomar coatrolled vaivt(s). The govenoat shall be !Aaxcd to providethe9pecinedadjustaöiespecúrange.

3.1.6.2 ReuOlESET Popsr TYPE ?be remote set poiat type is mcorparated dinxtly mio

thegovanmgsystemwhichinmposi~tbegovam ancudfd valvc(S). Tbc gwawr shall be 8ekctcd to provide the specincd adjustable ranges fœ aîi watroiüng patameta9

3.1 4 3 VALVE ACTlJAlWû TYPE Tbe valveacluating typeissepame h n l ttlegovanœ.

'ïñe extaaal signai acts to positiaa e i tk tbe gmaacr coamiied valve@) or a separate liac mounted valve In thiscase.tbe govemxacts oniy asa speeâhiting @e emergeacy)goveniar.

3.1.7 speed changer

NEMA- 11-14-1985.

Thespeed changa is a device fwcbging the setting 0fthegoverningsy~withinthe~ifiedspeedrange while the turbineis in aperation.

3.2 SPEU) GOVERNING SYSTEM

NEhkStrvidard 6-12-1885.

CLASSIFICATION SpeedgoYeaningsystemS s h a l l b e c ~ a s s h o w n m

Tablt 3-1. NEMA standatd 6-12-1985.



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STD.NEMA SN 23-ENGL 3993 m b470247 0524324 863 m

SM 23-1 991 Page 18

TWb 3-1 SPEED GOVERNING SYSTEM CLASSIFICATION

A 10 0.75 13* B 6 0.50 7* C 4 0.25 7* D 0.50 O Z 7*

~ ~~~~ ~~

* niese Maximum speed Rise Percent values can be achievedunderthef~wi43conditians: a Govemor system is adjusted fop maximum sensitiv-

ity. b. Rotational inertia of the equipment is relatively

iargeforthepowerrating. c. Steam mditions produce a relatively low theoreti-

calsteamrate. Agowrnor system in seMce which meets ali the foliow-

ingwnd.itionsshallbecapableofiimiîingspeedtoprevent overspeed trip when load is suddedy reduced from rateú to zero: a nie driven machine is synchronous perator. b. Thegovernorsystemisoperatinginamodeinwhich

it m á s to demand for electrical power. c. niesteamturbinehasaninletpressureofatleast

150 psig i1035 kPa (gauge)]. d. Tbsteamturbineexîmuastoaccm&~.

-Range Speed range, expressed as a percentage of rated speed,

is the specined range of opeming speedsbeiow or above rated ,$xx!d, or both, for which the governor shall be d j d e when the tucbh is Operatmg nnder the control o f ~ ~ g o v e a n o r .

3.22 8bximunSpeedRlse The maxjrnum speed rise expressedasa percentage of

ratedspeed,isthemaximummomentaryincxeaseinspeed which is obtaineü when the turbine is dcveiopmg rated power output atnited speed and the bad is suddenly and unnpletelyreducedtozeao.

NEMAStanclard 6-12-1985.

Maximum speed rise (%) =

1.

2.

3.

when the steam mditiom (inlet inlet tem- and exhaust pressrire) 8Ic set at rated valuesandheidconstant When the speed changer is adjusted to give rated speed with rated power OUlpUL When any exteanai conmldeviœisrenderedinop- erative and blocked in the open positfon so as to offexnoresaictionstothefreefiow of steam tothe goveanar controlled valve(s).

--

(See Figure 3-1 for agraphic repmentation of speed rise charactexistics of a Class D govenior.)

32.3 speedvariation Speed variaiion, expressed as a percentage of rated

speed, is the total magnitude of speed change or fluctuations h m the speed setting unäer the steady state cadi- tiom given in 33.4. 'Lhe speed change is dehedas the difíemœ m speed variation between the governiag system in Operation and the goveZnmg system biocked tobe inoperative,withalloiherconditionswnstant, Sjmdvari- &an includes dead band and sustained osciiiati~

Speed variation (+ a) =

2xratedspeed (See Figure 3-2 for graphic npresenratiai of speed

variation charactaistics of a Class D governor.)

3.23 DEADBAND Deadband is the totai magnia>dtof thechange in steady

state speed within which there is no &ring measiirable change in the position of the governor conmilexi vaive@). It is a measure of the speed gweming system insensitivity and is expressed in percent of xated speed

9.232 SrMiUn Sîabiíity is theability of the speedgoveming system to

position the goveniar conmlied valve@) so that a sustained osciliath of sped or of enezgy input to the turbine isnotproducedbythespeedgovemingsystemchniag operation under sustaid load demand or following a change to a new sustained load demand.

324 Speed Regulation, steady State Speed regdation, expnxsed as a percentage of rated

speed,is the change in gli5t8ined speed when thepower output of the turbine is gradually changed fmn rated power oulput to zen, power outpit mider the following steady state conditions:



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S T D - N E M A SI 23-ENGL L99L b470247 0524322 7 T T

SM 23-1991 Page 19

107%

100.0%

O w w a tß

O

2 5 9

t

i I I I I I 1 I I I I

J LOU) ' 100%

Figure 3-1 SPEU) RISE NEMA CLASS D GOVERNOR

Figure 3-2 SPEED VARIATION NEMA CLASS D GOVERNOR



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STD.NEMA SM 23-ENGL 1991 m b470247 0524323 636 = SM 23-1991 Page 20

P

I O 1oOY LOAD

flgure3-3 ’

STEADY STATE SPEED REGULATION NEMA CLASS D GOVERNOR

3.3.5 PmssunChanger Thepressurechangerisadevicebymeansofwûichthe

setting of the pressure regdating system maybe changed for the piirpose of aajusting the p m s m of the exhaust staun or ofthe extraction or mduction steam whiie the turbme is m @on.

3.3.6 SteaiyStatePressureRegulation


Far controlid extraction or conmiled induction type

in sustained extraction or induction pressure when, with identical settings of all parrs of thespeed governing systtm and of the presswe reguiating system(s), the exmxtmn ‘ a iaductian flow is gradually changed from rated flow Io zero flow. Fornoncondensmg ’ turbioesprovidedwithexhauscpres-

sureregdatas, the steady s r a t e p r e s s u r e r e ~ is the change in sustained exhaustpmsure when. with identical seüings of ail parts of the speed govemiag system and through tbe action ofthe p r t s m r r e m , the powa outputofthesteamtucbineispduaüyreduced6romrateú power output to zero power outpit.

turbines, the steady stare ~ ~ g u l a t i O n i s t h e C h a n g e




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STD-NEMA SM 23-ENGL 1991 b470247 0524324 5 7 2 M

3.3.6.1 PRESSURE REGULA^

iacreases with decrease in steani flow.

3.3.7 Stablltty Stabiîity is the capabiiity of the pessure regulating

system(s) to position the pressurt controlled vaIve(s) so that sustained oscillations of the coaadled pressrno(s) ar theeaxzgy~puttothesteamturbincarenotproducedby the pressrire regulating SY-m drnmg m m undfx mstaimîfiow demands or fauowing achange to another value of sustained flow dtmand.

For Ihe pirpose of this standad ~ ~ i l . l a t i ~ ~ b Y ~ p r e s s u r e r e g u l a t i a g s y s t e n i O f - pressurtar of encrgy inpt are definedas the dinaence b c t w c c n t h o s e e ~ w i t h t h e p r e s 9 u r e r e ~ s y s t e m in semicc and thme existing with thepressrinregularing system blocked or inaperstve.

338 Pressum~rolperformanee A Class D goveniOring system (see 3.2) shall exhibit the

following characteristics when u t i h ú in a com- conml system:

w . 1 changeinsuseainedspeedshallbe196maximum for any sustamed change in flow within limits of 5% and 95% of maximum inductionor exmuion fbw guaranteed forthatload.

Rcssueregulation iscoasideredpositivewhcnprtssure

NEMASEandard6-12-1985.

NEW-6-12-1985.

NEMA- 11-14-1985.

3.3.8.2 Steady state plessare regdation shall be 0.5 psi (35 kpa) maximm or496 of ratedexbaust, extrauion.n

whichever is larger. indmion plesule wtpressed m psig oc kPa (absolue);

N E W S U d d 11-14-1985.

3.3.8.3 sustained 0Scillat.i~ of canttolled pressure, wiien aprating at C O I I S E B ~ ~ flow demaad op foiiowing a change to another canstant flow, Shan notcxcetdoa psi (1.7 kPa) ar 2% of thecon~fledpnsnireexptssed in psi ob kPa (absolute); whichever is larger.

334.4 s ~ o s c i l l a t i ~ o f e i a e r g y i n p u ~ w h e n o p

NEMA- 11-14-1985.

&gatconstant flow demand or foilowing achange to a n o r h e r ~ t f i o w , s h a U n o t e ~ 4 % ofratedpcwer.

338.5 The range of adjustment for ptsmre change(s) shaü pennit adjustment of exhaust, extraction, or iaduc- tion pressure betweem f5 p i g (35 kPa) M f10% of the coamlled pressure expressed in psi or kFa (absolute); whichever is iarger.

NEMA- 11-14-1û8!j.

SM 23-1991 Page 21

3.4 COMPENSATED CONTROLSYSTEM Acompcrisatedcontral system is one which is proviâd

with intaconneciions between its conml mechanisms so that the action dthe speed governar or of the pressure qdator (s) also directly actuates the Othet control mech- anism.

3.5 ELEC”K= GOVERNING SVSTEM

3.5.1 BaslcFeatures An electronic govanhg system shaü include the foilow-

ingbasiccompooeprs: 1 Sensorswhichmeasureanoperat8igparamctaof

the turbineai system, andpoduce electricsipah.

2 Agovamx which compares -(s) fnw dic sea- gor(s) witb the seiectcd set point(s) and padeces a Qgnal(s)fobthevalveactuator(s)tomaintainsystem Parametebs-

3. An actuam@) whicb positions the valve(s) directly or though a a m l nucbamm * i n I e s p s e t o h gov=SiEm.

one or mon of following parameters shallbecxxumlld

a. speed

c. othersforspecificapplicatiom.

NEMASEandaid6-21-1979.

bythegovemingsystem:

b. Eachinduct ion/exaact ion~

NEMASE8ndard 11-14-1985.

332-

a e p e n d i n g o n r a t i n g a o d ~

u . 1 CONTROLP~ES Asignal selectmmay be incorporated intbegOVUIIOrt0

aüowthegovenwrrtoreceivesignalsfromse.veralscnsus and tochoose the signal, which wiii result in thc piopa valveopening.

Any paramm may be primary which the governing as constant during IK)iTmBI operation. Sy- -

Any panunetex could be secondary which is i g n d as lcQg asitisbelow the preset value.

3.599 CONTROLOF INDUCTION OR E X T R A m The governor may be designed to control the low pres-

surevahrt(s) daninductim urextlxtion mine in con- junctian wiíh the high pressure nive(~) . in this case, the governar wnmls the flow to maintain the steam pressure at each controlled extraction or induction opening while simuuaneously controlling speed when necessary for the appiication.

The following are accessories which may be selected,

. .



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STDmNEMA SM 23-ENGL L991 6470247 0524325 409

Agoveniar with h i s capability incorporates featUtes to adjust aii the ccmtroiied valves in mponse to a change in any controlled parameters.


3.5.23 MISSHG SIGNAL DRECllON FEAtLIRE nie missing signai &tecrion feature monitors all input

signahandaetaminesif they are in the cmect range. Any signai that is out of range shwld cause immediate action by the electmiic govexnor to enSure safe operation of the tmbine, and should cause an alami indication.

3.52.4 SENSOAREDUNDANCV

8.5.2.5 OVU1SPEEDTmP

vided in addition to the primary trip. nie overspeed trip feature in the governor can be pro-

3.5.26 other demonic governor accessories may be available.

3.5.3 GENERAL Caw shouid be talren in each installation to provide for

adequate wiring. in addition, elecmnic governors and

INPUTS

theirassociafedWiringshouldbepro~fmnheat,weat and induced signais Local codes and area classif- should be con-

Whenmi~basedturbinecontrolsystemsIrre provided which interface with plant distributed control systems, there may be some overlap of control loops and confusion regarding inpuWoutputs. in these cases the pni chaser and the vendor should mutually agree upon scapt and responsibility spiiL Extemal selpoints can come íknn the piant DCS but the turbine control loop should be suppiieü by the Wine manufacturer.

A typid eiec&onic governor schematic is shown m Figure 34.

3.6 AUTOMATIC START CONTROLS Automatic start controls are avaiiabie for turbine and

driven machine. nie Wine manufacturer should te m- suited for recommended equipment and pnicediires

Auaionred~neeringInfonnabon * 6-12-1mS.


Figure 34 ELECTRONIC GOVERNOR FOR PUMP OR COMPRESSOR CONTROL



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4 1 BASICFEATURES Thefollowmgfeaturesandaccessoriesarenecessaryfar

the proper functioning of equipment and safety of operation:

11.1 Ananugill@

device to ciose h û i p valve or hip and throttic valve. Each turbine shall be pvided with amanual tripping

NEMASEandard 612-1985.

4.12 ~ M p s y s t e m Theoverspeed trip system shall besparkpioofandshall

include the overspeed sensing &vice, linkage. and a (rip valveora combined trip and bottle valve sepatate from the spceü governor conmiled valve@).

NEMA- 11-14-1985.

A13 overspeedsensingDevlce

action to close the trip valve at apmkammd -speed

41A mspeed

ansing device is set

The ovaspeed smsing device mc1Udes those elements which are direcily responsive to speed and which initiate

NEMA standard 621-1979.

Tbt trip speed is the speed at which the overspeed


SM 23-1991 Page 23

Section 4 PROTECTION

41.6 Comblned mp and mmle mive Thecambineatrip, and throttle valve is separate fmm the

govelnor controlled valve@) and is closed (tripped) m response to the action of the overspeed sensing &vicc, other safety &vices or manuai trip device. ?his vaive pennits manual ttirottling of steam to the turbine.


4.197 overspeed m h g The tnp speedseauigs shown inTable4-1 shall be above

the speedreacbeddue to the maximum speedrisecharac- Eeristic of the govetning system to avoid tripping the turbine on sudden loss of load.

when design or application of driven equipment re- quires trip speeds other than those shown in Thble4-1, the

NEMA Standd 6-12-1985.

trip speed should be specified. Authohcl Engineering Infomiation 6-21-1979.

Table 4-1 TRIP SPEED SEmNGS

A B

115 110

C 110 D 110

41.5 TñpVahre "be hip vaive is separate from the goveanor conmiied

vaive@) and isclosed (tripped) in response to the action of

UaiIripdeVice. theoverspbedscnsingdcvice,othasaf~&~orman- *An vrluaueinpe<rmidmuiminii ContinLKnM Ipœd.

NEMA- 6-21-1079.



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~ ~

STD-NEMA SM 2 3 - E N G L 1991 W b470247 052i1327 281

Sectlon 5 FACTORY TESTING

S.1 TURBiNE 1. Qiecknerieraloperatioa

6.1.1 1.

2

3.

~ ~ i e x b a u s t ~ ~ h s t e a r n or hydro testcd at a minimum of25 pi [172 kPa 0 1 .

NEMA- 11-14-1085.

Wa!exj&~ts, coils, or d e m shall be hyärottsted to 1.5 times thespecifiedcooluigwaœr~,but notkman115psip93kPa(gauge)].

NEMA SkldWd 6-21-1979.

pressirre(s) shall be maintained for a m of 15

when no extemai leaLs from îbe item under test are observed,

millUteS.TbeteStShallbeamsidaed~

NEMA SEandard 6-21-1879.

5.12 No Lond Running Test

Previous page is blank.

- ~~



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STD*NEMA SM 23-ENGL 199L II 6470247 0524328 IL6 H

SM 23-1991 Page 27

Sedon 6 SOUND PRESSURE LEVELS

occurring atratedpowerand speedandmaximum steam amditions, are shown m ïàble 6.1.

TaMe 6-í Sound Pressure Levels

45-90 90-180 1-355 355-710 710-1400 1400-2800 2800-5600 MoO-llu10 OVeralldBA

63 125 250 500 lo00 2Ooo 4OOo 8Ooo ...

98 94 91 89 89 89 89 89 93

106 98 97 92 90 90 90 90 95

For arrbmemoimtedon asteeibasepiate.abdonea&ii- tioaaidecibeltotabul8tcdval~.

Actnai swnd pre9sure levels may not equaî maximum t a b w valm for all fíequewy bands. o v d dBAis* therefore* less than the sum of individual values.

6.3 SOUND PRESSURE LEVU MEASUREMENT

Sound presswe levels shall be measiindin accordrmce with Ameaican N a t i d Standard S5.1. Section 7.0, as it

Acoilstical penamanCe is based on a sound prtssure level which is &pendent on acoustical c b & x i s t k s of the space m which the unit operam. AU m d soumi levels are assumed to be in k ! d s p k d - netfleldar semi-revaberant field which has r00m m t iarge empgh so as to not significantiy ef?ezt m ä pressum levebatîhcmeasiiriagpoint.

A six decibel drop off in SOWICI pressure levei per distance douòling in each octave band of inmesr, as the microphoaeismoved~eachmeasurementlocationm aii direaionSamund the machine.regardlessof distanCC, indicates approximate free fieid conditjolls. Corrections must be made f?environment whea the drop Onis less than su decibels.

Authorized Engiuieenng Infwmation &21-1979.

PROCEDURE

i!Japplicable,Eammamd * asfallows:

Previous page is blank. Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMA Licensee=Defense Contract Mgmt Command/5935922100


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SM 23-1991 page 28

All ¡3Ound--readings shallbercaorded as sound pressme pls in decibels at refereace pressure of two times 10' Newton per square meter.

Ausoraid~readingsshallbemadewitbanoctave baad meter set for slow respanserecording visual average

minus 2dBAovetall shall be murded.

of maclings. F l d g m i s e le* equal to arhigkdian plus oc

' L b e ~ s h a l l b e p r o t t c t e d n o m e x t e r n a l d i s - tmbing mfluences (vibnitian, aircunents,alldelec~ of magnetic fields) which may affectreadings.

Miaophoae locations shall be approximately, but not less than, aae meter from any sound sotme being mea- d a n d a t a heigbt 1.5 meters above the fioor. Care shall be talrcn to avoid a poBitiai at the nodal point of standing wave. (hie set ofreadings skould bed that is requaed if tbemicrophoneissoposi t ioaed.~seotenceis~- izedEnghe&gW¿xmation.)ThcpaBitionofthemicm phane fmmeesirring kkgmund ambient sound and total swndshanbeidentical.

ô.4 CORRECTION FOR BACKGRWND NûlSE

NEMASEendard6-21-1979.

rvm!memats oftiirbiae sound plesSun levels should

els. Levels at each iocatim should exceed background levels by at least tea decibels in each octave band If the dinereaceùetweenmeasuredsoundîevelandbacirground soundkvelislessthanthree&cibelsingivenoctave-nd, vatid eq- sound level in that bad cannot be deter-

rection factor should be subtmcw fnwn the measured sound levek

be WHWWI far ambient baclrgtouad m d press~re lev-

mineb. when thc m-is -, t w a ~ ~ -

Decibeloorrection~=

- 3 4-5 6-2 loandover 3 2 1 O

cori9ideratonshould~begiiventoef6ectsof~ msonnd somes, such as piping anddriven equipment, w e a m l ~ o r ~ e f m n v a i v e s a n d p i p i n g . How- ever, swndlevels from these somcesmay be 80 clase to leveis from the turbine that a meaninghil meatmment will be difncnlt or impossible unless s&ep are taken to isdatedietnrbine. Itmaybepossibletoaccomplishchis by inanlnting all Piping, using acoustic barners as appw pllate, and cowring some sound sources with lead blau- kets.

Aumorired E n g M n g Infamalion 6-21-1979.

6.5 SWNûRESOLUTION Ikromeasuremeatsoftenmustbeaddedtodeîerminethe

cunbined mise level of s e v d sources or wibtracted to

find the noise output of one particular sou~ce in a noisy envimment. However, noise measurements cannot be addedm subsracted directly. Rather,measuremauscau be canbined wirb a coirection number. The CQzeCtioll num- bers obtained from * i 6-1 and 6-2 areappoximate. However, the graphic results are East and sufficiently ac- curareformosteagineaiagapplications. The currection numbex is based on the dif6erence m

amplitude of two sormds - whether the sounds ale beiqg a d d e d o i ~ b t r a c t e d . W h ~ s o n n d s ~ ~ t b e ~ - rion number is added to the higher level Far example, 80

SUBTRACTING BACKGROUND NOISE

3 4 5 6 7 8 9 1 0 DIFFERENCE BETWEEN TOTAL SOUND

AND BACKGROUND NOISE (dB)

Figure bl CORRECTION FOR BACKGROUND NOISE

and 86 decibel sound levels diffa in amplitude by six decibels. a dinerencethat yieiäsacxmctm * m l m k o f l frwn F-6-1. Thus, totai sound level is 87 deciLòels.

w h e n ~ n o i s e i s s u b t r a c t e d b r o m t i r e t o t a l somid lcvek the Lxmwtmn ' numóerissubtractedals0.k example, a 90 decibel backgod noise and a 97 dezibel total sound level difíer m amplitude by seven decibels, a dif€- that yields acmectum numberoflfr0nif;igUr 6-2 'Thnsthem~level without theba&gmmd noiseis %decibels.

6.6 INSTRUMENTS Sound pressure levels should be measund by meam of

a sound level meter which meets the requkments of American Naticmal Standard S 1.4. Afull-octave&andsoundanalyzex,rneeting therequire-

men& of Ameriwn Nationai Standard 51.11, should be

S o U d

Authomed E n g i i w Informatian 6-21-1979.

USed~conjimctionWiththesoumdlevel~teatOmeaSme



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STD-NEMA Sf l 23-ENGL 1991 6470247 0524330 87b

ADDING TWO SOUNDS

SM 23-1991 Page 29

Insfmments, including microphones, should receive an acoustic check an overaU calibration before and after every swnd pressure level test.

Authorired Engineering Information 621-1979.

6.7 SOUND AmNUATION It is recommended that acoustic81 treatment for turbines

and similar machinery be applied after instailation of the equipment and ensuing piant operation. Facm which &ea sound levels are many and varied and may not be associated as closely with the machinery itself as with steam velocities in piping and other sound sources.

After instailation and operaton has commenced, an ovexall piant sound levei can be established and corrective measures Ealren to isolate the major sound producing por- tions of the process.

Authorized Engineering information 6-21-1979.

O 1 2 3 4 5 6 7 8 9 1 0

DIFFERENCE BETWEEN SOUNDS (dB)

Flgure 62 SMIND RESûLUI"



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SM 23-1991 Page 31

Section 7 PREPARATION FOR SHIPMENT AND STORAGE

7.1 SHPPING PREPARATION nit turbine and ail scparate parts shall be properly

taggodandidentified At ttit timeof shipment,aiieqoscdnonmachinedsur-

faces shall be protected widl OpLe coiitof shop paintaad coatingorcovaiagorboth Aiiexpastdmachincdsur- k c s a n d oiiIiaparvoH.iateriors shall be protected with a nist pvenmtive. All ojmlìngs shall be jllugged oc cov- aad. llleinteIioroftheártbineshallbesaitablytFeaud toprcvcntnist

tiooal protection and packaging. Ocean freight or extended storage shall require aãdi-

Theppamionassumesthas~ewillbesoarrangd tbattheequipncntwillbeprotectedagainstloss,~on andwtathadamage.

ki(h0rlled Engineering Infomiawn . 11-14-1985.

7.2 SHIPMENT The purchaser* since he has the most wmpîete knowl-

edge of local conditions, should specify the delivery point rind provide infamiadon on the method of handting tothe pointddelivery.

Thcmanufacairashouîduseshippmgmethodsandship p a r t s i n t h e s e q ~ r e q ~ f œ ~ y i n s t a l l a r m n - a w l

blies c r ~ p n m to shipment.

protact the equipment if die ins- isdehyed.

NEMASEandard 11-14-1885.

i&dfydl~sbipmeri tsbymarkingindiv idua~~~-

Themanufacaurersshouldspccifythe~pfcpB- retiOnandproteCtivecoatingSthatsbouldbeprwidedto

The purchaser should advise the mandacturer of thc unladmg facilities available and whether skids will be newsaryformllinglargeassemblìesintopoStion.

Authonred Engineering Infarmath 11-14-1985.

7.3 RECEIPT AND STMIAGE OF EQUIPMENT Upon receipt, the purchaser should check ail equipment

for darnagt which may have o c c d in transit. Any damageorshortagcsshouidbereportedimmediatelytothe tninsportatioacompanyandacopyofthereport- tothemanufactuta. AH material should be checked against the manu-

immediately to themanufácturer. The equipment should at aü times be storedin a clean,

noncorrosive atmosphere and protected against loss, weather,damage, and fareig0 materials such as dust, sand, a d so forth indoor starage where constant ternpawe ismauitained at a levei which wiil p v m t condcz1sBtiQ1 is preferred. The purchaser should seek the manufacturer’s advice if storage conditions are other than thc above.

Specialattention and cureshould be given to thesmage

B e h --up, the oil orpnxemtive usedin the bearing housingshouldbeflushedoutandrepiacedwirhc~ lubricatmg oil of the recommended type. Grease lubri-

Prior to start up, forced lubrication systems should be

Aulhonzed EngineerKig Infomiation 11-14-1885.

fsctraer’s packiug liss and my discrepancies repoml

. .

ofpartshavmgexposedmachinedsurfaces.

cated bearings may require lubrication prior to start-up.

checkedforproperoperation.



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STD-NEMA SM 23-ENGL 1791 b470247 0524332 649

SM 23-7997 Page 33

Sectlon 8 INSTALLATION

ai INTRO DU^ TbetmbineshauMbeiilptnllulmaccardencewithrwF

ommendationsandinsmictions * ispuedbydrcmanufac-

The m f o m i a t i o n c o n ~ i n Section 8ispovided to asgist~prirchasaarhiscontractatintbepropahandliog gndinmiliahrn * 0fmtcbamcaldriveweamtiabmes.There &e m i y vatiabies mvohrcd mtheaquipnent funiished methodofshiplaent,andtypcsofiir9rallntinn.uierefore,it is not feesi'ble to detail step-by-step proCadurW.

Auihairod Enginwring Infomath 11-13-1969.

It is f c c o m m a that the man-'S representa- tive faqwise theia9iallationof the tmbiac. The mstatltt- tion procedure should be in accordance with recammndatiaisandiartnictim~bythemanufac- turcrutham drawings arbyoibeameans. Sucb piocb

Lwiskmy iImauion and commissionmg of the eqwp

pauyqualifiedlabor,incl~qpalinedsupervisim,is requiredfoapmpetirldhtm ' ,scastupand~m.

ánt

82 SUPERVISION OFINSTAUATION

dares are arranged and planned to obtain the most

ment.

-Engineering- * 6-21-1079.

83 INsTALmnoN propermazallatiaa i saec t sparyfm~ir ;ay opera-

tion.* nsershOuldprovidean adequate fauidation to maintain alignment and sbould install piping to minimize txtanalf~andmomentsonmeMbiae.

S f i k n t space andnecessary openings in the founda-

insWahn of theequ'ipment Suitablcqmiqs should be puviäcd in the building to admit the quipmew me purchaser should provide sufncient space raound the quipmalt for savicmg, including the ripace formwing the rotor and setting down îhe upper half of the turôine

Authorized Engineersiq Infomiation 11-14-1985. casing.

tionsandkiuding !aluCtun shaildbe pwided for the

8.3.1 FOUndatlOn Foundations should be sufficiently heavy and rigid to

farm a permauentiy nonwarpmg smictinie. The manufacturez should íiunisb dimensional drawings

to enabíe the purchasez to design a suitable foundation of

"he fwndation sûouldbe designed so that it WU absorb to a large extent the vibrath of die unit installed on it.

hire by means of spacers (felt, coak, and so fortii) so that outsi& vibration will notbetransmioed tothe foundation.

ample~~ands trengthfor theequip~tspec i6ed .

nefouadabon - shouldbeisolated~thebuildingstnic-

~

Inlet 175 53 175 53 Exhaust 250 76 450 137

Induction 175 53 175 53 Extraction 250 76 250 76

-

8.3.3 Cleaning af Tutt~ne Steam pping Asourceofcleansteam,free~foreignparticles,must

be provided to the inlet of the turbine connecaons * .The Station piping and the boiler system should be cleaned in



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STD-NEMA SM 23-ENGL L991 I 6470247 0524333 585

SM 23-1991 Page 34

~withthepoceduressubsequentlywiggestedin

steam Mowingisfequiredforall main steam, seal and adnussion piping before the steam turbii is put into aperation. steam Mowing greatly reduces potealtial dam-

steambbwingisbestachievedbyrepeatedbeatingand coalingwhichwin~altwiateeiqiensaiandcoanaction intkpipingwhichwinhelpbasenpipe~. Itisforthis ~thattheMowdownshouidbeatfullpns9ureand terrpwratiae for several minutes to allow the pipc to get as ~ t o o p e ! x s & ~ ~ a s y o s s i b l e . n i e p I p i n g s h o u l d beallowedtoco0lbef~stastuigthenextMowdown.

A m i n i m u m o f t h r e e b b W S S h O U l d b e ~ a n d ~ subsequentblowsshouldiiseapolishedstedwgetatdiecnd oftheMowdowniinetoactasanindicatiaiofckantmess ~shouldbepolishedonbodisi&stoobiaindoublie usage.AnewEargetshoutdbeitsedfareachttSandcheEsrget compand toanew one untiitheyqpearto bethesame. See

ïùepurchasershouldprovidetemporarypiphgrequlled for the blowdown. It is always advisable to blow to atmos- phereoutsidethestationinanareawberesteamarperticles wouldnotinjurepersonnelaraffectequipnentnitpblow piping must be iarge enough to develop a mass velocity head in the permanent piping at ieast equal to thatdevd- oped during full load Operation. Blowdown lines should be installed with adequate anchors toprevent pipe whip ping oc damage. "he trip throttle valve and stramer must be removedandall valves in the main healer should be wideopen. The following procedm should be used for sizing the

temporary Mow down line: Since the forcemaparticle is proportional tothe mass

veiociry head of the fluid, it appears reasonable that the mass velocity head cieveiojxd during die Mowing cycle must be at leastequai to that developed during full &ad operation. 'ibis should rake care of most hose pieces. However, a time Eactor is involved; no one can be sure how long it takes pipe scale to loosen up, ar such things as

d e r to assure the avaiiability of clean steam.

. .

age to the turbim by weid beads and pipe slag.

Figure8-1f~~~ggesedtargetinstal)atim.

pieces of welding rod to work their way ttuuugh the pipelhesandsupeitieaterlllbes.

calculationscan be made to show how much flow and what drum pressure am necessary foranassumed temporary pìpe size to a c b a mass velocity head during cleaning quai to that attainedduring fuii loadoperatiai, based M the followinn:

1.

2

3.

AS I nrst atten+, assume that tfie velocity at the pipe exit to atmosphere during blowdown is sonic, and that the pressure, Ppjllstinsidlediepipattht exit is u) psi. Tomake this assumpion, it is neccs- ssay that all ofthe flow ateas in &he System be equal to, 01 larger than, the dischargeam. Estimate the steam conditions (piessiae, enthalpy) at the boiler outla expected during steam blowdown. Fnim tbecurve~inFigure8-2read~ma~~ flow function, F3o. Calculate the massfl<lw, Qcl as follows

Q c = F30xAp where Aphthe area of the pipe at discharge m.3.

It isnecessary to dculate the presslm drop through the temporary and permanent piping to amive at a boiler pmsure. Refa to Figure û-3. 'ibis curve shauldbe used todetennine rhe pressure dropnear the discharge endofthetempmrypiping, since the velocity is near sonic and an ordinary dculaiim of pressiiredrap due to friction does not^^.



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~~ -

S T D * N E M A SM 23-ENGL L99L 6470247 0524334 411

O 1 2 3 4

%'

Figure û4 PRESSURE DISTRIBUTK)N NEAR M E END OF A PIPE DISCHARGING STEAM

AT SONIC VELoclfv in applying Figure 8-3, assume as a ñrst hial thatL is

ing the equivalent length of elbows, tees, etc. in the tem-

porary system. calculate the 5 anci aiter the curve in F m 8-3 and thus calculate P, the ptsamat thc distance Lfran the exist. Note that if-& thewmpmry pipe is

more than 5, use a sharterL which wiü makc? equaî 5

wtm+ is gnater tiun 5, the pressure drop isa straight-

line frmction of L and can be caicuiaied by the conventional method. Then calculate, by conventional

the piping from point Lfrom the exit to the boiler outlet, thus arriving at the boiler outlet prrssiire, Pc.

4. Next, caîcuiate the cleaning farce ratio at the boiler

enthalpy. This mio compares the mass-velocity head during cleaning with dut developed c&uing nomial fuii-load operation. nie cleaning facc ratio is expressed by:

dietotalequivalentIcngthofthetempararypiping,niclud-

FL D

andusecoxmpdm * g P/Pp to CalculatePat the shorts L.

straight-line methods, the press~re drop due to friction in

outlet, using the calculated Pc and the expected

where: Qc = calculatedflowdiiRngcltanllig,lb/hr Qmu =maximumloIdflm,lb/hr

5.

SM 23-1991 Page 35

(Pv~ = pressure-specifÏÌ volume product during

(P-) = pressure at maximum load flow at boiler outlet, psia

(Pc) = presslire during cleaning at boiler outlet, psia

( P V ~ = pssure-specific volume product at maximm load flow at boiler outlet,

Ifthisxatio,R, is less than are and the steam velocity inthesupeheatertubesislessthan twice theabw- able, divi& the pnssure assumeû inside pipe exit, Pp, by this ratio and repeat the above process. Thus, the required flow andgressures for equivalent cleaning forces can be deteamined. îhereby estabMing the required sizes for the temporary Mowpip. Note that for a discharge pressure different than 30 psi, the flow function is

cleaning at boiler ouuet, ft3/in2

ft3/in2

The~ofthetemporarypipeisamostimportantfactor. nie use d a iarger pipe wiU result in lesser flows and lesser pressure h e i s required for the same cleaning farce. The size effect is poportional to the ratio of diameters to the fourth pow. In no case, however, should the temporary pipe have a greater flow area than the permanent piping. Pressure readings during blowdown should be taken at

the inltt u) the stop valves andas close as possible to the Mowclown Pipe discharge. The lauer connection should be made ata convenient location, but not less than 20 diameters fran the discharge end of the blowpipe in order to obtain a stable pressure Feading. These readings will help substantiate the calculated boiler pressure and pipe Szes selected for the blowdown operation.

Afdi size Mock valve, safeiy iocated, shouldbe used to perform die blow. Adequate pham communication between the boiler mom and the operaror at the blow down valve must be established This might also be backed up by a system of visuai communication, such as indicating lights, since phone communication may become difficult due to the high no& level at the blowdown valve. An anangrnent should also be made to record the pressure readings at the various siations simultaneously through proper communications.

When performing the blav, the blow down vaive should fystbe cracked so as to get a graduai warming of all the steam lines. When the lines are adequately warmed up, open the blow down valve all the way as fast as possible. When the boiler pressure has dropped to approximately 150 pSi [lo35 kpa (gauge)], close the blow Qwn valve

psi [69û kPa (gauge)]. ~~ysothattheboilerpressuredoesnotdropbelow 100



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STD-NEMA SM 23-EWGL L77L W 6470247 0524335 358 H

Steam seal piping or any other lines that might bring steam to theanbinemustbebiown down. Weldspatierand other foreign matenal that may becontained wiîhin the steam seal piping can cio appreciable damage to both the steam seal packing and the turbine shaft. Thetefare, it is prudent to direCr as much attention to the cieaning of this piping as has been stated for main steam lines.

It is imporiant that uie blowing apeiatiOn be conducted after ail of the field weiding is completed Allliough Mt the turbine manufacturer’s responsibility, it is a good pac- tiœ to have a service supervisor witness at least the finai blow down.

It is left to the customer’s discK&on to determine the most practical method of cleaning íktoiy prefabrid lines which may become con lmhaledin ihe field nKst linesstiouldbecleanedandgivenseveralgoodbbwspr¡or to final assembly. FOI short runs which cannotbebiown down, mechanical cleaning may be adequate. Lints id- mg from the turbine to the customer’s steam lines sbould also be blown Out for the best interests of the custame.

Authonted Erigheerhrg Infomiation ll-14-lg85.

8.4 SMMPIPINGSYSTEMS

8.4.1 Intmductbn Reactions of piping systems connecteü to steam au-

bines, if of sufficient magnitude, will result m d i g n - ment of the turbine sufñcient to cause rough operation and sarious mechanical damage. Steam turbines have been very Carefdy designed to provide for thermal expaeon and, at the same tllne, maintain close aügnmeat betwecn the tlubine rotating and stationary parts, and also the ~ineanddrivenequipnent.mpvisimfortlubii rbennai expansions by necessity limits theallowable values of forcesand manen& applied tothe Qrrbine stnicture by the piping c o ~ ~ c t e d to it.

It is the purpose here to briefiy discuss piping arrange- ments and recammend fiangeloedinglimitationsimposed on steam turbines by piping. This infonnatbn is presented as an aid to the user and is not intended as aselfcaitaid thesisonpíping. The recornrnendahns to be discussed h u i d provide

aibwable d u e s of forces and momeats at the turbb connectionsfor steam iníet,exaaction,andexhaustpiping.

It is not caisidered necessapy to supply values far aux- iitarypiping such as steam íeakoff, hhkating o& and coolingwater,but even so, this adhrypiping sbaild also be designed such that tubine expansioSi is not restramad.

Authorized bgimririg Infwmation 6-21-1979.

8.4.2 ThePipingProblemssAppliedioWnes one of die firstcxmidediaas in designing any piping

system isto keep the StreSJes in the pipe within the limits of ANSI/ASME B31.1 and/or any local codes that may be appiicabîe. In generaì, the jipisdicaion dsuch authanties

stops at the W i inlet and exhaustconnectioasuother apenings al the machine to which external piping systems connect.

In ader to keep the strains due to faces aad bending matnentsonthe~ineoonnections,iaciu~gtheweight ofthepipe,withinrecommenäe.dlimits,diepipingsystem

ment match moments at the connections to the turbine and toveqîarge forcesat the turbine suppom.

desigashouldbe~hthatresoaintssindíitMomafmove-

.. The faces in piping sys&m tauieroperatingcondutons can be giouped into three Classes: those due to stean l==-’temperatiireanddeadweight.

8A3 FoiicesDueioOPressum niesealemOStcOmmanl~associatedWithbwprtssue

andvacuum iineswhereexpansionjointsareof&nusedto provide flexibility. If an expansion pint is impmpedy used, it may cam a pipe reactjon greater dmn îhe one which it issupposed toeliminate. An uriffsalctedexpm- Sion pint will cause an axial uuust equal to tbe effective ana ofthe bellows times the intend pfesslm The magnitude ofthese forces may be geater than the limits forme

it is found that expansion joints ale required, die standad of the Expansion Joint Manufacturws Association should becmsulled.

The following figures and paragraphs represent typical installauons - andareofferedonlyasguide& Figure 8-4 showsanexpansionjoint m apressure lint.

T h e a x i a l t h n i s t ~ t h e e x p a r i s i o n p i n t t e n d s t o ~ Lhe~ineandtheelbaw.Topreventthis,dieelbowshould haveanahchortokeepitfnnnmoving.”ñt?turbineshaild atsoabsorbthisthrnstand,mdoingso,becanes8nasichor. m fœce al the Mbme may be greater tbaa can be allowed. In general,this mebiod shouldbediscouage& Figure84 shows the SamepipingarrangemmtasngiPe

8-4 except for the atkiition of tie rods on the expansian pint. nie tie rodspvent the elongation of the joint and taketheaUalcreatedbythein~pressunofdie

The tie rods eliminate any axial flexibility, but tbewt is still fïexibie in shear; that is, the fianges may m

-fngineerkigi- * 6-21-1979.

exhaust flange. In &to have the iowest reaction when

expansionpint soit is n o t m i t t e d & b aabiaeflange.

p a r a l l e l p l a n e s . ’ I b e b C a t i O n O f t h i S ~ O f ~ h ~ ~ s h w l d b e s u c h ~ m o v e m e m o f d i e p i p i n g p i s s ~ ~ sionjointmsheainsteadoftensionocaimpessia

Fii8-6isanarrang~~tfiequentlyiised,hawigtie rods as indicated for 1yn1condeilsing aperation. This IIC- langement should prevent ally duustdue to mtemalpes- sure of Ihe expansion pint 6rom being transnrtted * t o b exhaiistaangeandretairistheaxiztlflexibuitydditjaitIt may be used for either VBCUIIIII oc pnsure savicc (by suitable arangementoftheIods).



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S T D-NEMA SM 23-ENGL 1791 b470247 052433b 294

SM 23-1991 Page 37

l i TURBINE

mgUr8 84 UNRESTRAINED EXPANSION JOINT

(May Impose an unacceptable thrust forœ on the turbine.)

ANCHOR

Figure &5 ////////) EXPANSION JOINT TIE RODS - -. .

(Flexible in shear only)

Fígute 8-7 shows a suggested anangement far a andens- ing~widlEin”iip”exhaust.Duetothelargecxhaust piPeSiZen<rmallY~te€edOncandetmn - g-k exhaustpipingmayberelativelystin,dan~jomt StioUMbeiisedat some point to take care of t h d expansion. An umestricted expansionPrnt placed at the exhaust fiange of the turbine may exert an upward or lifting force on dit turbine flange which in many cases is excessive.

Figure 8-7 p v i h the necessary flexibility to take care

iifting force on the turbine. The expansion joint is in shear which is the preferred use. The reîatively smaü vertical expansion may compress one p i t and elongate the other whichcausesasmdireactionaaly andmaybe wellwithin the turbine fìange limits

Authorized Engineering Infomation 6-21-1979.

of themial expansiai without impsing any UnIl-



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STD*NEMA SM 23-ENGL 1991 W 6470247 0524337 120

sh4 23-1991 page 38

Figure 8 4 EXPANSION JOINT wmi TiE RODS FOR NONCONDENSING OPERATION

(Proviaes awlel fiexlblllty without Imposing thnist on the tu*ine.)

Figure 8-7 EXPANSION JOINT Wmi TIE RODS FOR CONDENSING OPERATION Wil" "UP" EXHAUST

(Provlâes veitical flexibility without bnposlng thrust on the tu&lne.) 8AA Fo~cesDuetoTTemperature if a pipe is COMtected to some point as Am Figure 8-8,

and hestheamfígurath shown by the soiid tine, it may assiimetheappmmak ' pOmtioashownbythedashline when heated to a higher temperature, pmviäing no restraint is offeredby point B. If both pomîs AandB are rigid points which may not

wwc, the pipemay assumeashapesimuartothathwn by thedashbe mFigure 8-9 whai heated.



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~

STDeNEMA Sfl 23-ENGL L99L 6470247 0524338 Ob7 m

A

/////////// A



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STD.NEMA SM 23-ENGL L99L 6470247 0524339 TT3 W

Table 8-2 Temperature Ranges for Forces and Moments

'Ihe btrbine manufmurershonldbe coI1sulted toassure that the turbine car^ withstand forces and moments which wiU be imposed by Cdd-spning piping in the cald condi- h.

8.4.5 FoicesDuetoDeadWeigM nie dead weight of the pipmg should be ea~tireiy sup

pmcdbypipehangersorsupports. Therearebasically two

necesSay*=- ted expansion joint is used

Auihorired Engineering Information 6-21-1979.

types Of -rigid and mg. Rigid supports

Rigid supportsmay be usedto limit die movement ofaihe to prevent excessive deflection at any point. A rigid sup-

the pipe to move away from the support On the two types of rigid mpports shown in figue

8-12, the rise of the turbine CoNKctiOn due to temperatrire

would have to suppat the weight of the pipe. nie expansion of the vertical mn of pipe would relieve the pipe hanger of its ioad so the Mbine would again have to suppattheweightofthepipe.

portisnotsatisfactoPywherethennalexpansionmaycause

may lift the base elbow from the support so the tiabine

Figure 8-12 DEAD WEIGHT SUPPORT

If an expansion joint with restraint ''ngtierodsisused, either a rigid pipe hanger or a bitse elbow with a siidhg oc rolling contact surface may be used as shown m fim 8-13.

When the thrust due toan expansionjoint is less than the exhaust flange limits and no resminhg tie rods are used, the pipe shwld have an anchor as shown in Figure 8-14. Since this condition rarely exists, it is better to use the pn?fdarrange.mentsas shown in figure 8-13 andelimi- nate as mpch pipe reaction aspossiilerather rhanjust siay withinthelimits.

dead weight when there is thermai expsion to be considered. nie movement of the pipe may change the spring tension or compression a smaü amount, and the banger loadings snaii amount, but may not remove the id fmm the banger. Pubiished manuals oc1 pipe design p r o v i d e infonnatim on hangerspacing togivepoper suppost Ia

spnnghangersorsupports are best suited to carry the

additiontothis,itmaybefoundnecessarytoaddadditioaal



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- ~

STD-NEMA SM 23-ENGL 1991 6470247 0524340 715

Fy t

SM 23-1991 Page 41

/' /

/

/'

///

Figure 8-13 DEAD WEIGHT SUPPORT Wi lH RESTRAINED

WPANSION JOINT

Figure &14 DEAD WEIGHT SUPPORT WiTH UNRE-

STRAINED MPANSION JOINT sqpnts or mweexisting supports ifresonant vibration appearsinthepiping.

Aspring support should not be used to appose the titrust ofanexpansianjoint Whcnthepnssureisnmovedh the line, the sping support may exma force the same as the expansion joint ally m ihe opposite direction.

w b i g i n e e m g - ' 6-21-1979.

8.4.6 AlkWable Fomes and Moments on Steam Turbines

'Ibefœcesandmantntsachgonstcamairbinesduem thesteam inlet,entraction,andexhaustconnectionsshould be limited by the following:

8.4.6.1 nie totai resutmt force and totai resuitant moment im posedon thetucbimat any connection shwldnot exceed the values per Limit 1.

(Limit 1) 3FR + MR i;5oODe

Where: FR = Resuitant fme (pounds) at the CM-

W h e r e u n r e s e a u i e d ' expansion joinis are used except on vertical down exhausts Full vacuum load isallowedon Vertical down exhaust flanges. It is not included

nection. mis includes pessure forces

as part of the piping load frwn Figrire 8-15: FR=- MR = Resultant moment (foot-pads) at Lhe connecth

from Figure 8-15 MR= ~ M ? + M ~ ~ + M ? De = Nominal pipe sizeof ihe conne~tion in inches ~p

to eight inches in diameter. For sizes greater than this, use a vaiue of

De = 3

VERTICAL

I l l z+ I

1

Figure 8-1 5 COMPONENTS OF FORCES AND MOMENTS

ON TURBINE CONSTRUCTION. POSiTiVE Mo- MENTS ROTATE COUNTERCLOCKWISE WHEN

VIEWED LOOKING INTO POSITIVE FORCES

8.4.6.2 The combined iiesdtants of the fmes and moments of the inlet, extraction, and exhaust connections, resolved at the centerlines of the exhaust conndon should not exceed the vaiues per Limit 2. a. These resultant should not exceed:

2 F c + hfc I =OD, Where:

(Limit 2)



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STD.NEMA SM 23-ENGL 1971 I 6470247 0524343 b5L

Combined resultant of inlet, extraction, and exhaust fcuces, in poiincis. Combined resuIcBnt of inlet, extract&, and exhaust momeum, and moments resulting 6rom fon!es, in poond-feet Diameser (in inches) of a circular opening equal tothe total aleas oftheinle& exlrac- tion,aaäexhaust~gsuptoamiue of 9 inches in áiame€er. For values beyond this. use a value of Dcquai to:

~ a s d e ~ b y a p p l i c a b e c o d e s a u d ~ b a d = ia.

Authorized Engineering Infomiatkn 11-14-1985.

8.4.6.5 See Sample problems 8 4 ûB and 8C for exam- ples of how these f m and momat limitations are qplied toturbineinstallati0 - 0 s .

85 DRAINPIPING IndividualdrainpipmgshOuldbe~withsbiiton

valvesortraps. Authorired a nee ring Lnf#maEkn 11-14-1985.

8.ô LEAK-OFFS L e a k 4 should be piped dhxtly to an Opern i idn

ventedto theatmosphexe w i b o u t v a h r e s o r ~ a to a combsue recway system. The pipe sixmid be adequately sized to avoid pmsure bdäup.

AuthociredEngineeiinqInformatian . 11-14-1965.

8.7 FULLFLOW REUEF VALVE Thetnrbinecasingaadmtanalpartsshdbcp.otected

a~texcesSivep.essinrebytheinstallaaon ' of afuü-fíow relief valve. The relief valve is connected into tht piping system between the aubiueexhaustconnectieo and the nrst shutd valve. niis relief valve should not be coa- fused with the sentbel warning valve whichwhcn sup pli& is maunteú on the Mbine casing. The full-flow relief device should be provided by the

user aspart of the piping mstallation which iswrtanal to the tulbme. In COILdtLIsm * g appiicaoioar, a fan-flow dicf valve or nipun disc may be pm&d as plin of the c-œthttiirbiat.

The size of the rn-h device diaildbe such that it w i l l e x h a u s t t o t h e a t m ~ t h e ~ m n < I p a n s i t y o f

(as- . bytheáabinemanufrictunr)whidi w i u p a s s t h r o u g h t h e ~ ~ w i t h m a x m n i m i i n i t i a l

For condensrn * g sabines, the full-flow * device

(¿3allge)l. Fot exlmtion Mbines ur back-- tuhiDe& the

fall-flow relief device shopldapen at 10 psi om) Q 10 ~t(whichcvcrisgrtaoa)abovetbemaxmiunwrtasc- tion~armaxmiumexhaastpresnnie.Therew device shalt give full relief atm mae thsn 10 pacent abovethe"start-to-open" pcwsure. ïfthehigh-~-pessweorhighextractimorIiriminnirn

~tripisfirmishedthereucfdevicepiesarresshopld

steamconditions.

should give full relief at no more than 10 psi POkni

braised 5 ppi 135 &(gaugc)l a n d t h C b i @ - ~ j ~ ~ + s r ~ e trip should be set at the above sure.



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STDaNEf lA SM 23-ENGL L991 m b470247 0524342 598 m

SM 23-1991 page 43

2 2 3 3 4 4 4 4 4 4 4 4 4 6 6 6 6 6 6 6 8 8 8 8 8 8 8 8 10 10 10 10 10 10 10 10 12 12 12 12 12 12 16 16 16 16

6 8 6 8 8 10 12 16 18 20 24 30 36 12 16 18 20 2A 30 36 12 16 18 20 24 30 36 48 12 16 18 20 2r) 30 36 48 18 20 2.4 U)

36 48 24 30 36 48

316 412 335 427 447 480 511 575 607 640 706 804 .904 524 585 616 648 712 810 908 540 5981 628 659 722 817 915 1111 560 614 643 673 733 827 923 1117 661 689 747 839 932 1125 781 867 957 1143

791 1031 839 1068 1118 1199

1437 1518 1600 1764 2011 2259 1309 1462

1620 1781 2025

1351 495 1571 1648 1804 2044 2287

1401 1536 1608 1682 1833 2068 2307 2793 1651 1722 1868 2096 2331 2812 1952 2167 2391 2858

1277

in1

mi

2n8

632 825 671 854 894 959 1022 1150 1215 1280 1411 1609 1807 1047 1170 1232 1296 1425

1817 1M1 11% 1257 1318 1443 1635 1829 2222 1121 1229 1286 1345 1467 1654 1845 2234 1321 1377 1494 167î 1865 2249 1561 1733 1913 2287

1620

1581 2062

2136 2236 2398 2554 2874 3037 3200 3528 4022 4518 2618 2924 3081 3240 3562 4050 4541 2702 2991 3141 3295 3608 4087 4573 5555 2802 3072 3216 3363 3667 4135 4614 5586 3303 3444 3736 4193 4662 5623 3904 4333 4783 57 16

1677

791 1031 839 1068 1118 1199

1437 1518 1600 1764 2011 2259 1309 1462 1541 16u) 178 1 A125 2271 1351 1495 1571 1648 1804 2044 2287 2778 1401 1536 1608 1682 1833 2068 23û7 2793 1651 1722 1868 20% 233 1 2812 1952 2167 2391 2858

1277

791 1031 839 1068 1118 1199 1277 1437 1518 1600 1764 m11 2259 1309 1462 1541 1620 1781 2Q25 2271 1351 14% 1571 1648 1804 2044 2287

1401 1536 1608 1682 1833 u168 2307 2793 1651 1722 1868 2096 233 1 2812 1952 2167 2391 2858

2718



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STD.NEMA Sf l 23-ENGL L99L bY70247 0524343 4 2 4 IFI

SM 23-1991 Page 44

~shauldbenoairpocketsinthegrout.Aftertbegront is dry, connect the piping, fúlly tighten the foundatim bolts, and recheck me aiignment.

Amixtureof cement and h e sand isnormaüy usedas grout, 'ihm are other mateaals availabie which bave proven tmxcssM. Care mustbeexcrciseüin tbe used matajals whicb expami while setting, as they may OVQ expaad and prescrit mare of a problem tban mven~onai materials such as cement and sand, which have atendency

8-16 a d 8-17 -t typicai

Aulhailled Engineering 1- 11-14-1oe5.

When a foxwd-feed lubrication system is provided, flushing of the iubricatbn system should be perfarmed prior to the initial start-up in accordance with the m a n ~ s r e c o m m e n d a t i o n s .

Authorized Engimefing Infomatiori 11-14-1985.

8.10.1 mushing oil shoold be compatiile with the finai airbiae oil.

to shtmk d&hdy. i l s a a h s d a r e ~ t e d o n l y as guide&)

aio FLUSHING OIL SYSTEM

aios oil should be circulated tbmgh the entire system as long as necessary to remove or to flush parrialate matter back tothe oil reservoir. Aperiodic checkof theoil filtas or temporary screens should m e as a guide to detenninewtien meoil isclean.

Authorized Engineemg Inforniath 11-14-1985.



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S T D - N E M A SM 23-ENGL 1991 = 6470247 0524344 360

SM 23-1991 Page 45

I

3 1

7

1. Support Foot 2. Mounting Pad 3. Baseplate 4. Anchor Bolt 5. Anchor Nut 6. Shims 7. Foundation

Figm 8-16 BASEPLATE MOUNTED TURBINE AND DRIVEN EWIPMENT



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STDINEMA SM 23-ENGL L99L H 6470247 05243q5 2T7

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/ / 1. 2. 3. 4. 5. 6. 7.

Support Foot Soie plate Hold-down Bolt Anchor Bolt Anchor Nut Shims Foundation

Figure 8-17 SOLEPLATE MOUNTED TURBINE AND DRIVEN EQUIPMENT



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-

STD-NEMA SM 23-ENGL 1791 6470247 0524346 133 m

SM 23-1991 Page 47

mleproMem8A ALLOWABLE FORCES AND MOMENTS ON STEAM TURBINES

ExhaustFíange &= -11Olb Fy= -25olb &= +180lb I&= +XI0 lbft My= +ux) lbft &= +350lb-ft check to see if these farces and moma@ are w i t h

NEMAguidclinea 1. ~ R E S U L T A N T f ~ d m o m c a t s ONINDI-

VIDUAL FLANGES against Limit 1. paragrriph 8.4.6.1.

~=~(40)2+(-100)2+(-70)z = 128 lb

ExbaustFiange F~=~(-110)~+(-250)~+(180)'= 327 ib

2

(31027) + 680 5 (soo)(8) 1661 S4ooois true so forces aadmom«itsoa the inlet flangeare within acœptable limits f a exhaust && Check combined R E S U . M f o r a aad moment ON THE ?'U..ZNE Limit 2, Parap& 8.4.62.a. Fx= 40-110= -7Olb F y -100 - 250 = -350 Ib Fz= - 70 + 180 t +110 lb I&= 200+500=+700Ib-ft M y s 150+300=+450bft &e - l m + 350 = +230 lbft F&70)z+(-350)z+(110)2-= 373 lb F~~(700)z+(450)2+(230)2 = 863 lb-ft Nominai inlet Flange Area = m2 = 1257 ir?

4 N o m i n a i ~ F l 8 n g c A r e a . : m2 = 50.27 Si2

4 Totai Fiange Area = 1257 + 50.27 = 6284 in2 Dc= = 8.%in.(Nocozrectiori

x ntedtdbwvalues 9 m. aad Smaller.)

Allowpbk Foroes and Moments Fx= 50&= 447lb F y = 125&= 11181b Fz=loO&s 8Wlb &= 250&=2236bft My 125 Dc = 1118 lû-ft &= 125Dc= 1118lû-ft Magnitu~oftheactualforcesandmomentscaicuiateù

in Part 2 of this problem are lower than the allowable magnitudescalculatedabove. Therefaile.thecornponen~~ of rhe combined farce and moments on the turbine are WithinNEMAgUidelines.

Resultsfrompipts 1,2,&3 of this problem show that forces and moments imposed by the piping system are WithinallNEMAgUidelines.



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STD.NEMA S I 23-ENGL L97L 6470247 0524347 07T

SM 23-1991 Page 48

Sample Problem 88 ALLOWABLE FORCES AND MOMENTS ON STEAM TURBINES

A condensing turbine has a 6 inch side inlet and an 36 inch down exhaust. Analysis of the steam piping system pqxsed for the turbine has determined that the components dthe forces and moments imposed on the iniet and exhaustflanges(cxcludingfarceontheexhaust~~due IoprrssureforcesinttKumesaained * expansionjointinthe exhaust line.) wil l be 8s tabulated below.

Inlet Fiange Fr= +901b

Fz= + m l b Mx= -350 lb-ft My= +200 lb-ft Mz= +150 Ib-ft

Fy= -1zolb

ExhaustFlange Fx= O F y = -250lb FE = O Mx= O My= O &= O Bellows area far the expansion joint (obtained from

expansion joint manufacturer) is 1030 square inches. Resure f m &vel@ by full vacuum in the expan-

(1030 in3 = 15,141 Ib sionpintis:

(14.7 This is additional force in the -Y direction. Check to see if thest forces and moments are within

1. ~ k ~ U L T ~ f ~ ~ d r n ~ e n t s 0 N ~ ~ I - VIDUAL FLANGES against Limit 1, Paragraph 8.4.4 1.

NEMAguidelines.

inlet Flange F~=~(!W)2+(-1S0)2+(200)'= 266 lb M~=d(-350)~+(+C200)~+(150)~ = 430 lb-ft & =

(3)(266) + 430 5 (500)(6) 1228 S3ûûû is true so facesand momentson the inlet flange are within NEMA guidelines.

6 inches (No correction needed for flanges 8" and smaller.)

3FR+mS500& Limit1

ExhaustFìange FR excluding presswe force =

MR = d(0)2+(o,2+(O)2'= O ib d(0)2+(-250)2+(O)2 = 250 lb

De = (16+36)= 17.33 inches 3

(3)(2!50) + O 500 (17.33)

750 S8665istniesoforcesand momentsoathecx- haustfiangearewithinNEMAguidelines. 2 Checkcombined RESJLTANTfacesandm~meat

ON THE TURBINE against Limit 2, Pamgmph 8.4.6.2.a

Fx= W+O= 901b Fy = -150 - w)= 400 Ib Fz= 200+0=200lb Mx = -350 + O = -350 lb-ft My= 2OO+O=ux)lb-ft I&= 150+0=15OIb-ft

F&O)2+(400)z+(2Ml)2 = 456 Ib &d(-350)2+(200)2+(1S0)2= 430 îb-fi

. Nominai inlet Fiange Area = m2 = 28.3 in2

NominalExhaust Fiange Area = zQ&hJ2 = 1017.9 in2

4 Total Flange Area = 23.3 + 1017.9 = 1046.2 ia

4

3.

Dc = i-3 = 18.166 in.

2Fc+Mc525oDc Limit2 (2) (456) +4301250(18.166) 1342s 4542 is me so the resultant forces and moments are within NEMA guiWines. Check the COMPONENTS of the cunbined foi.ces and moments ON THE lU. .LVE against values calculated per Paragraph 8.4.6.2.b.

3

From calculations in part 2, ik = 18.166 in.

AUowable Forces and Momenis Fx= 50Dc= 908lb Mx= w)Dc=4541Ib-ft Fy=125Dc=2271lb My= 125Dc=2271lb-ft Fz= 100Dc= 18171b &= 125&=2271bft Magnicudesoftheactuaifonwaad~cntscalailated

in Part 2 of this problem are lower than the dowable magnitudes calculated above. 'brefore, the cum-



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STD-NEMA SM 23-ENGL 1971 b470247 0524348 TOb 9

SM 23-1991 Page 49

of Ik canbined fotces and Inomem on the turbine are WilhinNEhwgindClimes

4. aiecktoralforœmthetiabineexhaustfìange against h e limit pes jtaragrapb 8.4.6.3. paragraph 8.4.6.3 statts that fame on the exhaust flangc should not exceed 15-112 times the nominai Cxhaustarea (i5-w) (1017.9 in5 = i s m ~b

Total force on the exhaust fhnge is the vector total of pressme farce from iheexparrsionjoint and the faces caicukd with force excluded.

Results from parts 1.2.3 and4 ofthispmblm show that forces and moments imposed by the piping system are within ail NEMA guideiines.

Total farce = -15,141 - w)= -15391 Ib



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STD-NEMA SM 23-ENGL L99L M 6470247 0524347 742

Sample Problem 8C ALLOWABLE FORCES AND MOMENTS FOR A

TURBINE WITH FOUR EXTRACTION OPENINGS

Strofoprneei Ara of opeahlp Equivalent Diameter = 153.04 Eiches (UI 1-1 ms<ruuc~-) Equivalent Dhmem must be corrected when value ex-

Inlet 14 153.94 ceeds9inches EXamiQn#l 10 78.54 . Dc = = 57.01 inches

* Extraction#2 8 Extraction#3 16

50.26 201.06

3 Calculate maximum allowable forces and moments Fx = 50(57.01) = 2851 lb

ExtracrionM 30 706.86 Fy= 125(57.01)= 71261b 5701 lb Fz = 100 (57.01) =

My = 125 (57.01) = Mz = 125 (57.01) =

Mx = 250 (57.01) = 14253 lb-ft E;xhaust 148 17203.40 Fmd the diameter ofa circular opening equal to the total 7126 lb-ft

7126 lb-ft 8ceB

Equivalent Diameter = 4I 133.W78 .54+50.26+20 1.W7ûó .86+1'1203.40)

It



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S TD*NEMA SM 23-ENGL 1991 b470247 0524350 bb4

SM 23-1991 Page 51

-Section 9 OPERATION AND MNNTENANCE

9.1 INTRODUCTION 9.4 TYPICAL STARTING SEQUENCE FOR A To ensure that the turbine receives tbe cae and artention

necessary and d for this type of equipment, specific iastnictionswithrespecttostartingup,shuaingdown,and 2. Sfartcoolingwater.

in the instruction manual fumisbed with the airbine. 4. Startsteamsealsystem.

STEAM TURBINE 1. Open exhaust shut off valve.

routine operation shouid be provided by the mufacturet 3. Startlubri&onoilsyStem. ~

Authtnized Engineering k\fom\rmon . 11-14-1985. 5. Opmcasedrains.

1.

2.

3. 4.

5.

6.

7.

8.

9.

6. S& or m e t aip valve. 7. crack open isolating valve.

9. Slowly upen isolating valve und governor Eakts control (observe manufacturer’s instructions re nard inn critical^.

9s opmnoN The following should be @ven careful consideration by 8. Aüowcasingtoheatup.

hopaator: The steam supplied to the turbine should be free of debris. To ensure maximum protection, steam lines shouid be blown prior to Starting. l h e steam turbine operator shouldbe aware of the hazards associated with ccmtaminatioa of the p m cess steam with agents which p r o m o t e stress

Avoid slugs of water and unduly wet steam. Avoid great or sudden fluctuations in pressure and

proMbeanadequatesuppiyofcleanwaterfreef?om acid or scale forming impurities for oil mlers, air cooïexs and the gïand ccmdensing system. Provide lubricating oil of proper quality and

Maintain a log of aperating conditions, including steam inia pressures and t e m m stage pressures, oii pressures, exhaust pres~ures, whition, and 50 fimdi. This is im-t in predicting and scheduling inspection outages. Check trip valves or trip and throttle valve for Oper- ation.

sim Cracking.

temperamre of steam supply.

characwtics, including initial flushing change.

----- c h e c k o v e a s p e e d t r i p a t ~ e intervals.

10. Check auxiliary oil pumps. Aurhwued Engineering Iníurmebjon 11-14-1985.

9.3 NONCONDENSING TURBINE OPERA..N OF A MULTlsTAGE CONDENSING TURBINE

Noncondensing operation of a multistage condensing turbine is not recommended unies approved by the man- ufiumnx. High exhaust pressme and temperanne can cause last stage blade flutter, Casing distortion and damage and misalignment with driven machines. An mcrease m exhaust temperature and pressure may also af€ect pipiig farces. (See piping f o a calcuiationS given in Section 8.)

Authorized Engineering Information 11-14-1985.

10. h y &en isoladng ;alve. 11. Adjust governor speed. 12. closecasingdrains. 13. Monitor turbine operation untii stable operation is

achieved

9.5 MAINTENANCE

Authorized Engineering Information 11-14-1985.

9.5.1 Introduction inspection and &ce should follow manuf~auw’s

ioseuCtions. Frequency of inspection and degree of thor- oughnessmay vary a n d a have tobe determhed by the mainteamce personnel: The foilowing is a typical maintenance program: Daily 1. V i y inspect turbine for extemai damage and

leaks. 2 Check oil level in resewoir and governor. 3. Check for unusual vibration and noise levels. 4. Check oil temperature and press&. weekly 1. Check operation of auxiliary oil pump, if applicable. 2. Check operation of ail shut down devices. 3. Check that shafts are fite of oil or grease. 4. Exmise the tnp valve. Monthly 1. Check overspeed governor. 2 Check foundation bolts for tighmess. 3. Checkoiìandñlter. AMU~IY Shut down the turbine and perfom the following: 1. Remove and clean steam strainer. 2. Check shaft seals fa wear. 3. Check thrust bearing end piay. 4. Remove sentinel warning valve and check for

proper operation.



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S T D a N E M A Sfl 23-ENGL L99L

SM 23-1991 Paga 52

5.

6.

7. 8.

9.

b b470247 0524353 5T0 9

berter to prevent tbe bu&i up of sotids than to bave to removedepositsaf'tertheybavefonnexL

AuihorizedEngineehgInfomiabon . 11-14-1985.

9.7 STEAMPURITY Steam nub& users should be a m ob the hazards

associated with contamination of tbe steam by agents which migûtproniote stms cQnDGLos1 crackiag. solids baiM up. e€osirm, and corroaioa. conmmiaan@ wichris sodium, bydroxicks. chIodes, sulfates. copper. Itab and sjlicacesmay result inshoateaedturbineiifeand faihaed iutunalpar&s of the turbine. Since it is not possible to prescnbc the &grce of

that s teamniró ine~canto lera tem coa- order to achieve the iong life expected of intemal turbine canponcnts,onlyg~gui&lin~caIlbeoffd

F a r s m a l l l o w ~ a p p l i c a t i o n s , ~ m a y a p e r - ate taisfactorily on steam havingpnity limitssetby the

see =le A m e & m l 3 o i l e r ~ ~ ~ 9-1.

Auhized~neeringinfomiaiiar . 11-14-1985.

. .

. .



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STD-NEMA SM 23-ENGL L77L 6470247 0524352 437 W

SM 23-1991 Page 53

Table 9-1 WATERTUBE BOILERS RECOMMENDED BOILER WATER UMil'S

AND ASSOCIATED STMM PURITY AT STEADY WATE FULL LOAD OPERATION DRUM TYPE BOILERS

0-300 0-2068 700-3500 140-700 15 0.2 - 1.0 3014% 2069-3103 600-uxx) 12O-600 10 0.2 - 1.0 451-600 3104-4137 5002500 1CNMM 8 0.2 - 1.0 60 1-79 4138-5171 #)(11OOO 40-m 3 0.1 -05 751-900 5172-6206 150- 750 30-150 2 0.1 -05 901-1Ooo 6207-6895 125- 625 25-125 1 0.1 - 05

Table 9-2 SEAM PURITY- LIMITS

conductivity- Micn>mhoslcm at Z0C

Dnun ûnce dirough

SiO, ppb. max Fe, ppb, m a Cu, e, max Na+K,ppb,-

Up to 800 psi [5516kPa (gauge)] 801 to 1450 psi 15517 to 9998 kPa(gauge)] 1451 to 2400 psi [9999 to 16548 kPa(gauge)] Over 24Oû psi [over 16548 kPa(gauge)]

0.3 0.2 20 20 3

20 10 5 3

1 .o 0.5 50 50 10

20 10 5 3



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S T D g N E M A SM 23-ENGL 1791 I 6470247 0524353 373

SM23-1991 pases

Section 10 INQUIRY GUIDE

(Authorized Engineering Information)

Job No. Item No. inquiry order No. pinrchase Chder No.

Revisim

Sk. No. Required: savice Driven Equip. GearYesJNo ManuEacMa Model



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sM23-1991 Page 56

mut Mamifactunr'sstandard



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STD*NEMA Sf l 23-ENGL 1991 6470247 0524355 L 4 b

SM23-1991 Page 57

Factory Tests

Hydo test No-load running test

DynamiCbalancerotor

site utilities cooling w8t#: NOM Fresh Brackish coding wata: other Tempcracure- - Electrid supply: ddc

Conml(s) volts phase Hz Motaro volts phase Hz

Air Supply pressiire

Site Environment

Elevation Ambient tempexatwe Maximm Minimm

Environment Rdection at Site (S or i ) Enclosed SheltfXd outdooa other For monthss!crragepriortowartup S = Storage I = Installation

Remarks

Drawings and Data to be Supplied certifiedoutlinedrawings Recommendedspanpamlist Instnicdonbooks No. other



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MA



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Documents

NEMA SM23-1991.pdf