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NEMA SM 23

YRIGHT National Electrical Manufacturers Associationensed by Information Handling Services

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NEMA Standards PublicationNo. SM 23-1991 (R1997)Steam Tuhines for Mechanical Dive Service

Published by:National Electrical Manufacturers Association1300 North 17th Street, Suite i 47Rosslyn, VA 22209

Q Copyright 1997by the National Electrical Manufacturers Association. All rights includingtranslation into other bnguages, reserved under the Universal Copyright Convention, the BerneConvention for the Protectionof Literaryand Artistic Works, and the International and PanAmerican Copyright Conventions.


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~~. S T Q - N E M A S M 2 3 - E N G L 1991 6470247 0524297 714 m

TABLEOF CONTENTSFOREwom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .RefaencedSEancbrrds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Definithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .sectm2 CONSTRUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .' I ) p e s o f S t e a m T . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CiassiedbyExhaustcaiditiasis............................... N Tiabmc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CoadensingTUrbinc ...................................classifiedby Numberof Stagesand Coam1Valves . . . . . . . . . . . . . . . . . . . .SingleValveSingieSEagC'Iirrbint ............................Single Vaive MuuistegeMine .............................Multi* sil@ stagemine . . . . . . . . . . . . . . . . . . . . . . . . . . . .Muitivaive Muitisiage'ixine . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

C i a s s i d b y ~ N e e d s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .controlled (Alumtic)ExeractionTurbine .......................NoncwtrolletiExtractiosi nlrbhw . . . . . . . . . . . . . . . . . . . . . . . . . . . .CmmUed InQiCtim (Mixdnesslire)M e ....................InductimExtractionTirrbine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SteamII iab inecctUl~ts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Turbinecasmg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SteamInletEndseCtion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ExhaustEI?dstction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Irlemedia&sactiw ...................................

SteamRing .........................................StatiomyReveEngBladcs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Diciphragm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .sw. lrbirbe ........................................ImpuIseStage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .shaftseals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .casingshaftseals .....................................Intemagestlaftseals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ThnistBearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .AntitiCtianBearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .RotorAssembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .wheels@iscs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Shroud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .COnmhgDevi~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ExtemalcontrolDevice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .WamingDeVice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .REFERENCEDSTANDARDS AN D DEPlNlONS ....................ectkn1

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

Steam Chest (GOV~IIKNaheBody) . . . . . . . . . . . . . . . . . . . . . . . . . . . .Nozzles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .StationaryRevczsingCham~ ..............................

ReactianS age ......................................BearingHousing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RacaiBcarings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

PiSciii11133333333333333333333444444444444444455555555555


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plrsectlocr2 SentinelW h g alve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5soleplate(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Basephte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6FeatmsandAccessan es ................................... 6BasicFeaMesaQd- ............................... 6OptiOnalFeaMesandAccessorics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6c o n t r o n e d ~ ~ a n d c o n t r o l l e d ~Itrrbines . . . . . . . . . . . . . . . . . 7Ncmwntroiled Exach Turbhes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Nonconp.olled InductiaiIlabines ............................. 7IiirbineRating......................................... 7power ............................................ 7speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Ratedspeed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Maximum continwus peed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7N d ower end Speedand SteamCaiditions . . . . . . . . . . . . . . . . . . . . . 7Stcamconditiaas: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7MinimwnSteam(hKiibS ............................... 7MaximumStcamconditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7MinimumEnergystcamccmditions . . . . . . . . . . . . . . . . . . . . . . . . . . 7Inlets eampressure ................................... 7ExhaiistSteampressUre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Extraction Steam Rressiire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Induction Steam Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Inlet Steam Tempemure . . . . . . . . . . . .. . . . . . . . . . . .. . . . . . . . . . 8ExhaustSteamT~erame ............................... 8Extiaction SteamTemperatrae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8LndpctimSteamTempgatme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Maximum MowableWorkingPressuresandTeanptmtms . . . . . . . . . . . . . . 8DualSteamconditions ................................. 8VauiationsinSteamconditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Flow LimitsforanAutomatic Exaaction M i h e . . . . . . . . . . . . . . . . . . . 9HowrjmitpforanInductionTurbine. . . . . . . . . . . . . . . . . . . . . . . . . . 9Units of MeasurementforAbsolute and GaugePressure . . . . . . . . . . . . 9ThermodynamicIienns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9SteamRateS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

I TheOretidSteamRate ................................. 9ActualsteamRates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10GuaranteedSteamRate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Iiirbineconnectiais ..................................... 10outputshaftExte~. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10S t e a m c o h u s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10AuxiliaryconnectionS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10LlbiClUb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10NonpFessurelSpeLubncation (Single stage lbbines) . . . . . . . . . . . . . . . . . . 10

oilLulnicztredsleeveBeanngs(HarizwEalTiirbines) . . . . . . . . . . . . . . . . . 10G?easeoroillubricatadAntinictionBearings ..................... 10p r e s s u r e l s l p e o i l L u ~ ............................... 11InProduction ....................................... 11Oilnrmpr ........................................ 11oilReservoir ....................................... 11oilcooler ........................................ 11OilFdt~zs ........................................ 11

YRIGHT National Electrical Manufacturers Association

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.S T D - N E M A SM 23-ENGL L99L b470247 0524299 5 9 7 =section2 piping andInstnunentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .nwisonsfor heEsrvin>nment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Eaclosufe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Exposwe toNanrral Elements ...............................Exposure toAbnonnalAhnphedicconditioas . . . . . . . . . . . . . . . . . . . . . .GeneraiRequiremeats .....................................PltsSureandTempemmRanges . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vibration . . . . . . . . . . .. . . . . . . . . . . . .. . . . . . . . . . . .. . . . . .Singlestagerbim ..................................M d t i s t a g e r b ~...................................clitwspeeds.L ..................................NameplateData .......................................Sedkn 3 CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .GoveaningSystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Sp eed GOm r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .GOv morcon mlled WVe(S) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ServomomSystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Speedcbangetlype . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .speedchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SpeedGovaning System classification . . . . . . . . . . . . . . . . . . . . . . . . . . . .SpeedRange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Maximums@Rise . . . . . . . . . . .. . . . . . . . . . . . .. . . . . . . . . . . .speedvariation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DeadBand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Speed Regulation. Steady State ..............................steamPressurecaritrd ....................................PressureRegUlatingSysea~. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .PressureRegUlatw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ControlMechaniSn .....................................nessUre ControlledWves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pressurechanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SteadyStatePxess~mReuuion ..............................PressureReguiatioaiC............................stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pressure controlperfamilmce ...............................Compensatedcoatrol System .................................Electronic Governing System .................................Basic Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Accessones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ControlPrimiries .....................................Controlof inuctimorExtracoon ............................Missing Signai Detection Featrae . . . . . . . . . . . . . . . . . . . . . . . . . . . .SensorRedundancy ...................................OverSpeeaTnp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Genexal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Automatic S t a t Conmk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Multivariable Govexnor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CoatmlMeChanism . . . . . . . . . . . .. . . . . . . . . . . .. . . . . . . . . . . ..E x t e m a l C d D e v i w ..................................

RemoteSetPointQpe ..................................Valve Actuating- ..................................

.11121212121212121212131317171717171717171717171717181818181818ZQmm202020A)21212121212121212222222222

m


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STD.NEMA S f l 23-ENGL 1991 m b 4 7 0 2 4 7 0524300 039

s e c t h 4 PRECTiON . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . ..BasicFeaues .........................................UanUalTrip .........................................Overspeed'LtipSystem ...................................O v e r s p e e d S c n s i n g D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .n i p s eed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .nipvalve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Combined Ltipand IhrottltValve . . . . . . . . . . . . . . . . . . . . . . . . . . . . .overspeednipsystemsetting ...............................secSIon5 FACIDRYTESTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .'Iiirbine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .HydroTd ..........................................NoLoadRUnmngTesc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Sectbn6 SOUNDPESSUREJEVELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Gtaeral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .swnd3essweLev& .....................................s o S m d ~ L e v e l M t a s u r e m c n t p r o c e d m e .......................CamctionforBacLgrwndNoise ...............................

souadResolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Instnuneats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .S d A e n o n .......................................sectm7 PRapARATI0NFORS"TANDSTORAGE . . . . . . . . . . . . . . . . . . . .S h i j l p i D g R e ~. . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . .Shipneat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .W i t ndStorage of Equipmeat ..............................sectkn8 INSTALLAIION .......................................In-tion ...........................................SupervisionOfIaseallation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .steam Inletand ExhaustPiping...............................C i e a m n g o f ~ S t e a m P i p i n g . . . . . . . . . . . . . . . . . . . . . . . . . . . .SteamPipingSystems .....................................I n e t i o n .........................................ThePiping noblemasApplied to?brbinesF3nwDue to StearnPressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F3nwDue toTemperatwe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .FarcesDue oDead Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .AuowaMe FcesandMoments onSttamTurbines ....................DrainPiping ..........................................Iak-ofli ...........................................Fuil-FiowReii&Device ....................................CoUptingAlignmcnt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Grwting ............................................FlushingiiSystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .In-tim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

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

............................eCtrOn9 OPERATONANDMAINTENANCEoperatioa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Noncondensing hbine opetatianofaMultisragecondensiag'Ihrbine'I)picalSEertmgSeqaence imaSteamnirbine ........................Maintlmance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Intluduction .........................................

. . . . . . . . . .

p.pc2323232323232323232525252527n27272828282931313131333333333333343636363638404142424244444451515151515151


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S T D m N E U A SU 23-ENGL 1991 6470247 0524303 T 7 5

pigeSeCtknS UitemalWaterWashing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52steamhinty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52Sacth10 INQUIRYGUIDE.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67


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S T D * N E M A S U 23-ENGL L99L 9 6470247 052430il 7 D l W

ForewordIlhisstandard has been developed by the Steam "urbi= Section of NEMA. In its preparationandrevision,considaation as been givento he work ofother organizations, such as heAmericanNational Standards nstitute, theAmericanPeuoleum institute, the AmericanBoiler Manufacturas

Association, and the Amencan SoCiety of Mechanical Engineers, striving toward the deveiopmentofstandards,anddtishaebygiventoaii whosesiandardsmayhavebeenh~~inthepreparatianof this publication.'%e purpose of this standard f a ingiestage and multistage mechanid drive steam turbines isto faciiitate the appiication of the.se turbines by engineers, users, aad conuactas, to promoteecwomieS m driving rotalhg mechanical equipment, and to assist in the proper seiection andapp~ofthedifferingmechantcal esignsof turbines.NEMA Standards P u b l i aSM23-1991revisesand SupeISedestheNEMA StandardsPubli-CationSteam Turbines or Me~hanical )rive S e M e , SM 23-1985.User needs have been considertd throughout the development of this standard. Proposedorrecommmdedrevisionsshould be submittedto:ViceResident,Engineering DepamnentNationalEiecaicalManufacturersAssociation2101 L S l E aNw,uite 300Washnigton,DC 20037(202)457-8400

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S T D - N E M A SU 23-ENGL L99L b 4 7 0 2 4 7 0524303 848

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S T D - N E M A SM 23-ENGL 2 9 9 2 6470247 0524304 784

Section 1REFERENCEDSTANDARDS AND DEFINITIONS

AmtriamNationolStandandsInstitute1430BroadwayNewYork,NY 10018S1.4-1983s1.11-1%ANSUASMEB16.1-1989B16.5-1988B1.20.1-1983B31.1-1989

Spcjficprion or SoundikwlMetersSpe@hations for Octave-Bad, Fractional Octaw-Band Anolog MdD g M FmsCan ron Pipe Flangesmid Flanged Fttings,Class25,125,250anWpiPC F b g e s and Flrurged F&gsGeneralPurpose Pipe ThrecuFr (Inch)PowcrPpng

J h t lilrinnfactprorsAssociation25 North Broadway-,NY 10591The S t a d a d sf he IIqmsion Jont Matu#actmrs AssocirrtiOn (1980)(198sAddendum).

Riuiont-An -t deviarian inSMcaiceaoicityiodicattdbytheoatputofaprmimityprobcwhichisduetovariatiaas in theelectricalcondllctivjtymagnetiCpopertiesOfthtobsavedshaftsraface.volume of steam bappad betweem the turbine and a tripvalve ur notmew Valve.atspeedsgreaterthan he first ateralc r i h i speed.

Hmting-Te oscillationof speed or other c011PD)ledpamnmx above andbelow the mean vaiue. An MsEablecoaditioll.smecontainingcompentsof he turbinebypressip1pagwith water.ntemaiWaterW~g-Aproceduremwhichsteamhaving a high percentage of moisture is hjecte into thetuhineforthe inposeofremovhgwater soiuble&positsfrom the tirrbineblades andaozzles.

Entrr ippedEwrgy- ' Ibe~ whichcemains in tk

FhibleShriPt-Ashaftwhichisintendedfmapera0ioa

Hydno --A test fm leairs and mtegrity 0 f t h e p n ~ -


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SM 23-1991Page 2

S T D m N E M A SM 23-ENGL 1991 W b 4 7 0 2 4 7 O524305 bLO

Laterpl C r i h lSpeeds-The speedsat Which then-plitude of die iaterai vibration of a machine rotardue toshaft rotationI.each their maximum due.Proximity Probe-A non-contacting device whiche ieconidy measures the position ordisplacementmo-tion of an obsexve surfacerelativeto the probe position.PurgeA i r 4 method of seaihgin which air (or ineatgas) isbidinto the seal ar housingto maintain a slightpositivep.essrireandthuspreventtheentranceofcoaruuni-nants.ResiSEnace lkmperaure Detector (RTD)-A devicefor d g emperature in which the ewhicai resis-tanceof tbe&vice changeswith mperaure.Response Time-* time required to ncover to thed y uue operatingvalue afterasudden change in bad.Service Factor-he factor by which the maximumpowercapabilityof a device exceedsits ratedm.

SpeeiTied Conditions-Specified conditiolls are aUcustomex d e f d power, speed and steam conditions atwhich the turbine mustoperate.Steam liirbine-A prime mover which converts thethermal energy of steam directly intomechanical energyof d o n .StiffShaft-A shaft which will not be operatedduringn o d ircumstancesatspeeds reater hanthe nrstlareralcriticalspeed.Therm0coupl-A &vice for Sensing temperatures inwhich a pair of dissimilar conductors are pined at twopints so that an electromotive force is deveiaped bythermoeiectric effects when the junctions are at merenttemperature. NEMAStandard130-91.


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S T D * N E M A SM 23-ENGL 1991 b470247 0524306 5 5 7

SM23-1991Page3Section 2CONSTRUCTION

21 TYPES OF STEAM TURBINES2.1.1 clsssified by Exhaustconditkns2.1.1 .I NO"DPISING TURBINEA noncondengng turbine isa steam turbinedesigned toaperatewith an exhauststeampressureequal tourgreatextbanatmospkricpressure. NEMA- 11-13-1969.21.12 CONDENSINGTURBINEA m - turbine is a sream Wine designed tooperatewithanexhauststeampressurebelowamia6p~cP=-=2 12 CWslfedbyNunberofStegesand

NEMAStandard1-30-91.Clwvahrea

2.1 2.1 SINGLE VALVE -LE STAGE TURBINEA s ingie valve single stage turbine is a steam airbinewhich hasonegovmor conmiled valveand one stage.2.12.2 SINGLEVALVEMULTISTAGEURBINEA single valve multistage turbine is a steam trirbinewhich has onegovmorconaouedvalveand woormorestagts,2.1 9.3 MULTIVALVEINGLESTAGE TURBINEA m d t i d v e Agie stage turbine, is a steam turbinewbichhas two orm a t governorcontmkdvaivesandonestage.

NEMA- 6-21-1979.

NEMASEendard 6-21-1979.

NEMA spnd9id6-211979.2.19.4 YULTIVALVEuLTWTAOE TURBPIEAmuitivaivemuitistageturbineisasteamuxbinewhichhas two ar more governarCaimlled valves and two OT-stages-

215 C ~ b y P F o c e s S N e e b sNEMAStandard6-21-1979.

2.13.1 m D AWWAC) EXTRACTIONTURBINEA controlled (automatic) extraction turbine is a steamturbmewhich has an opening(s) in the turbme casingfortheextractionof steam and which isprovided with meansfar directly reguiacing the flow of steam to the turbinestages followingtheextraction opening for thepurpose ofmmiiingextractionpressure. NEMAStandaid 6-21-1979.

2.13.2 N O " T R 0 U D EXTRACTlN TURBYSEA nonconmiied exnaction turbine is a steam trrranCwhich has an opening(s) in the turbine casing for thcextraction of steam but which does not have means facantrollingthepresswe of the extracted steam.NEMA SIPndard6-21-1979.2.1.3.3 NO"TR0LLED IN TuRBWEA I1oI1contTdled mduction turbine is a steam Mbinewhichhasan opening(s) in theairbinecasingfainductioaof steam but which does not have means for CQltlDUiiliethe pressureof the inductedsteam.NEMA S W d d 11-14-1W.2.16 4 m D NWCTION(mPRESSURE)mBWE

A controlled induction (mixed pressiire) turbine is asteam turbine which is povided with sepirate inlccs farsteam at two pressures and has an automatic device f aconb.olling theflow of steam to he turbinestages follow-ing he inductionopening.2.1.3.5 INDUCTIONEXTRACT" TURBINEAn induction exmtion Mbinc is one which combincsthe fatum of extraction (controlled ar nanconmikd)with thefeaturesof induction.2.2 STEAM TURBINE COMPNENTS

NEMA stendprd6-21-1979.

NEMA tanderd6-21-19B.

2 2 1 nirblnecaslngA turine casing is the en cl om which sumomis tbc

rotating elementof the turbine and supports hes t a t imsteamparts.CasingsshallbeaxiallysplitJadiauysplifaa combination thereof.he turbine casing W be divideaintotwourmonsectionsas follows: NEMA Standard6-21-19B.2.2.1.1 STEAM INLR ENDSECTIONwhichcontains he higherpressuresteam.2.2.1.2 EXHAUSTENDSECTIONThe exhaust end section is that partion of the cssingwhich contains the exhaust connection and the steam atexhaustconditions. t shaalso contain the low pressnnstage(s) of a multistage turbine.

The steam inletend section is thatportion of the riffpinnNEMAStandard6-21-197W.

NEMA Standard6-12-1979.


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S T D - N E M A SM 23-ENGL L99L H 6470247 0524307 493SM 23-1991page4

2.2.8.1.1 A p t s u r e impulse urRateau stagecoLIsi8t8dsmionmy expnshx~nozze(s) and one row of rotatiagbkides.2.2.8.1.2 A velocity-compoanded impuise or Curtisstageconsistsofstationaryexpansionnozzle(s)Imdtwoamorerows of rotatingblades.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 eumsists of Srationary expansion nozzie(s), am?IOW atrotatiogbladesandoneormorereversingchambas.TbepressmdropacrossaRateanstageisreiativelybwinwmpoaisontothepssmdmpacmsaCmtis~.Authorized E n g W n g t l h n a h -21-1070.2.2.8.2 R ~ C T I O NTAGEA reaction stage consists of stationary expanSionnozzie(s)discharginghighvelocitysteamjetsaitherotat-ingblades.Apressuredropoccursinboththesiatioaaryand rotatingelements.229 shaftseals2.28.1 CASING SHAFTSEALSCasingshaftsealsminimizetheleakageofsteamoutofuie casingdong tbe shaft.rheentnuiceofairinto hecasingdongtheShaR yareaaraaged fur the admifipimi of steam at a canstant low

NEMAStandard-21-107B.

For condensing turbines,seals arearranged to jxemtpressmcand ow mperalme.

NEMAStandard6-21-1979.INTERSTAQESHAFT SEALS

Interstage shaft seals minimize the leakage of steamh g he haftbetweenstagesm amuitisfagemrbhNEMAStandaid 6-21-1979.2.2.10 Beerlngtlouslng

Abearing housing Coataias andsupputs abeariagfs)andisequippedwithseaistopreventlccageofdaodttieentninceof m o h , ust,and foreign matmi&.NEMA- 6-21-1970.2.2.11 mtln(Y2.2.11.1 RADIAL BURINOSRaclialbearingsarebearingsW hic h s u p p a r t t b e ~elementinhorimtalshaftbirbines.Iheyareofihtsl~~,tiltingpordmantifrictiontype. In verticat tmbrnes, hesebearingstnri;sllv positiOn themtar assembly.NEMAStandrurl6-21-1970.2.2.11 9 T H R W BEARINGSThrust bearings rn m g s hich trammitthe axidthrustof the rotatlligdement to thebeapingbousmg andmaintain the axialposition of themux assenibly m the


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S T D - N E M A SM Z3-ENGL I99L W b470247 0524308 3 2 T m

casing. They m of the antifrictm, laad, ar scgmeniaitutuigpadtypt. NEMASWdaid 6-21-1939.2.2.113 ANTFRICTION BURIN08htiictimbearingsstmuidhave a minimumratinglifeof3yearsa25 o0Ohoursw h e n a p e r a t e d ~ ~ a tmaxgnumtb lUStdrad i s ll oadsaodat~ speed .Authorized EngheeiingInkrmillion6-21-1979.The ating life is tbenumberof houisatcunstantspeedtbat9perctntofagroupofidcnticalbearhgswiiiopcratcbefcxe the fitaevie-nce of fatiguedevebps.kthomed E n g i i n g nbnnaakn6-21-1979.2.2.12 RotorA88etnbly

"ber ~ o tssemblyis therotlltingelemntof the urbinewhichinclubesaipartsattachedtotheshaft,excludiugthcca ipl ing(S) unlesscouplingis integralWitb the shaft.NEMA- 621-1979.2.2.13 W h 0 d s m )

wheelsarediscs which are nmgrai witb,orxcdto, the~ieshaftandoawhichbladesaremounted,orinwwhichbladesorbuclrmsaremachined. NEMA- 6-21-1979.

2.2.16 H a n d W 0 ( S )A hand vaive@) is the valve which isalates steam flow

to a group afnozzle(s) to pennit e&cient apetriton atredmtdpowerawithdualsteamconditionsHaudvalvalvescan be either manuaily c o n d i e d or arbomated and areused on singie valve turinesoniy.2217 PmtecthreDeVice NEMA

SiaKliUd6-21-1979.

Apotective device is one which, alone 0185 p?* Qf asy9iem,respondsinsomepredetemiinedmannerto,~sor-malconditionsaoendllig theopewtionofthe unitorsys-tem towhichit is connected. NEMAStandard6-21-1979.

SM 23-1991Page 52.2.18 ConadllngDeViceicaliy initiatesaction of a system which caaerols a(MnB1apaationofthetiirame.2219 ExtemalcontrdDwlceAn extanal control devi is an element which isE-sponsive to signais other than turbine spaad, ie., flow,presswe, -,and soforth,dacis toconirolthefbw of steam to the turbiDe. u shalt be pnemwid *mecbanidy, hydraulically.or electricany actuated fiomthe signal sollfcc to position he governorvaive@). (Ref-m m Sectim3.1.6.)

Acoatrolliagdevice isOM which manidlyNEMA- 11-13-1968.

NEMAStandard 6-21-19'19.2220 WamlngDeVlceA warning de* is one which,by visile or auibkmeans, orboth, indicatesthat an abnomai apefatingum-ditionexiscs,2.2.21 SentlnelWamlng ValveA sentiael Warning valve is a pressure warning devicewhichopenswhaithesteampressurerisestoapredeter-mined1eveLThedeVicesha dischge totheatmosphereandshallbesolocatedasto be plainly visible&For condcaskig tl&K%% it shall be set at 5 psig 135kFa(gauge)]. For noocondensingmnes the minimmmaximnmexhaust steam pftssuR,Whicheveris greater.followingapplications:

NEMAStandard6-21-1879.

seing shallbeeither10percentor 10psi (OLpa) boveA sentinciwarning vaive is not recoaimended for the

locatiais where thediscbarge of steam to theam+sphaeisobjcctionable,hamdousorpmhibkdbyhw

NEMAstandard 6-21-1979.

- a i n e swhichutmd volatile gase^- Mbineswhicbareanangedforauiomaticworunat-hir these applicaliom,an alteniate wanimg devicemdedstart-up

optionai ripdeviceis iecommended.2.222 s o w w s )

Authorued EnginwingInformation1-91.

A soleplate(s) isa machined fiat steel piate(s) or cast-ing(~)or mounting of the equipment supports and farbiting and grouting to the foundatiar.2.223 mapiate

Abaseplate is a fabricated of castcontinuwsstructurehavingmachuiedpads for mountingof he equipmentandforbolting and groutingto the foundation.

NEMAStandard 11-13-1689.

NEMASQndard 11-13-lQ69.


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S T D -NEMA Sf l 23-ENGL

2.3 FEATURESANDACCESSORIES

m 6470247 05243q 266

9. Insulation for the high tempemm section of thtWine to limit exposed siirfaoe temperatme to16pF(74OC) orother tempemture specified by theP10. S t e a m p r e s s w e g a u g e s t o i n d i ~ i n l e t s t e a m , ~ring, nrststage,dexhauststenimpressure.11. Coupling between the turineand driven machine(normaiiy fumhhed by the m8nufacturea of thednvenequipment).12. coiipling guard SuppOIted frwi tbe baseglate ocadjacent bealing housmg(s). Tbe couplmg guardshouldbecasilyremovableandbe~ientlyrigidresuuofnamalt!odilycaitsctbypersonnel.Wbcocont inuaus ly luba ica tedcoup lragsare~ thecoupiing guard housing should be fitted so thatoi l leakswillbepmted.13. GlandleakageevacUatingappIiratuswhendieglandcasngdesignrequiresitsuse.14. Tachometer of the vibaatuig mai, machanical,a re~type;iodicatiagspeedsfroniabovethcipspeed to M o w he minimumaperatiag speed. Th-chometers shall be suitale for the specifmed eavi-Ionment.15. Supemhry instniments to monitor such as vibra-tion, axial shaftmovement,tempemtms, etc.16. ShaftgroundingdevicetocarrytogromdanysaticromandwhichmayotherwisebuildtoLevelswhichddamageturbhcbearings.17. Rotor turning gear togeUier with driving maus,engagementand isengagementfeaiures, and lubeoil pressureinterlocksto permitslow turningof themtorsystemonstatt-upandsbutdown.trip valve which provides a means far8. AlbusSmquick and positive shutof of admjssion stcam f aemegencY tnppuig.19. Nonretunivalve(s) forblocking iherevme flow ofs 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~overpiessrningof the exhaust end section (see Sectim8.7).22. Vacuumbreakertoadmitairiatotheexhau9tamnectionsd a ondensing turbiuein cmk toreducecoastdowntime.

to withsiand deflection and plevent rubbing as a

charge which might be developed on the hirane

. .

Additbd items may be availsble.AuthorizedE n g i i t q ~nfamaiion 1-12 s ControlledEXttadknandmledkrdudknmrblnes

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


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features W i n tems 1 thrwgh6ofU.1, together Wittithose lisied n 23.3.1 through 23.3.4.2.33.1 Controlled extraction turbhm shallbave apre+8utt regdath8SySteB formtroiiing mtpssm of theextracted ste9m by regulaiing the fbw f steam to theturbinestages fallowing the extracth opening(s). Anon-return valve hr the extraction aPallng(s), which is alsoactpated by the ovaspetd t i p system. is nquind farinstallationintheexoactimsteamline(s).2.3.3.2 controlled mduction turbinesShan mve apmsme regdating sysrem for cantrollingtticpm5urcof theimjucth steam toregulatet h e b w ofsteam tothe urbinestagesfoiowingthein&ctionopening.Atripvaivewbi&isalsoactuatedby theoverspeedmpsystemisnquiredfnrinstallaaonintheinductionsttamk.233.3 Dependmgon hesourceof induction steam, theusashould consider the need for a steam ssainer in this

AumaiEed EngineeringInfornietion 11-14-1985.2.3.3.4 Controlledextraction turbinesand controlledin-duction turbinesshall have a multivariableconic01 systemuiatingsystemaadthespeedgovemingsystem.

chdethecombinationofthefcxegoingitems.

NEMA- 190-1991.

h e o protect the loweapressurestages of me urbine.

which provibesinterconnectiOn diepressiutrCg-2.335 conaroued n d u c t i ~ ~ ~rtractioarabines hall in-

NEMA- 11-14-1085.23A ~ ~ E x t r a c t b n T i a M n e rNonccmmiiedextnictionturbinessballincludetbbascfeaaacsiistedinitemsl througIi60f2~.1,togctfrtr~ithmwisecmnvatve(s)farthe xtractionopening(s). 'he quan-tity and lomion of nomearnivalvesare tobedetermhlb y t h e t r i r b i n c m a n ~ b a s e d o n e n t r ap p e d a i e r g y~redimdaacypol icy . NEMAStandard 130-1991.

2.3.5 N ~ l l e d k i $ u k n n i i b l I l @ SNoaiconmIIed induction turbinessha inchide he basic

feahaeslistBdinitnS1tl1rough6of23.1,togetheswirba trip vaive@)for he induction opening(s).NEMA- 11-14-1985.2.4 TURBINERATING2A.i PowerRatedpower is the maximum specifiedpower outputofthe~ine.Itismeasuredattheoutpitshaftofthearrbine.NEMA Standard6-21-1979.

SM23-1991page 7242 speed2.4.2.1 RATED SPEED

Ratcdspeedisthespeedcanesponduig toratedpowa.It is measiaed at the output shaft of the turbw, is ex-pressed in rievdutioas per minute, and is quai toM essthanm8ximm~ u o u speed.2.4.2.2 MAxrruw CWn~uousPEEDMaxmum conhinuous speed is the highest specifiadspeed at whicb a turbine can be operatcd continwuslypwidedproperovaspeed~goverwr- - a r eiastalledand operatianal.2 ~ 3 omralPower,SpeedandSteamhJ- power,m and- ooditionsaretbostc 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 mratcwillbeguafan~U A S~Condi t lons

2.4.4.1 W N ~ MTW C~N~ITWWMinmum steam ~ t i ~ a r ehelowest inlet stcampressure and tempemm and lowestexhaustprcssm towhich theturbineissubjectedincontinuwSopaatiOa.

NEMA tandprd6-21-1979.

NEMA- 621-1979.

corabns

NEMA- 6-21-1979.

NEMAstadard 6-21-1979.2.4.4.2 M A # ~ ~ ~ T E A ~ ~ ~ N ~ T K I N ~Maximum steam CDnditiOIlsam thehighest inlet steampitssrrreand imperature and exhausspIesllm to Whicbthe tiirbmeis subjectedincaltinuousopaation.NEMA- 621-1979.2.4.4.3 MNINUNNERQVTEAY CONDITIONSM n i I n m ~ g e a m c o n d i t i . M l s i u e t b e ~ i n l t tsteam presswe and t e m m nd the highest CxImustpmsm at which the turbine is requucd to produ asp e c in e d p o w e r ~sp e e d2.4.4.4 hLETSTEAM PRESSREuiietsteampressiires thepressureof thesteam suppliedto tk tUrbii.Jtis mwredat the $tcf3minlet conncctimof the airbineand is e x m a s gauge piessure.NEMAStandard6-21-1979.2.4A.5 EXHAUST STEAM PRESSUREExhaust steam pressure is the pressure of the steamsystem towhich the turbine exhausts. t is measuredat theexhaust connectionof the turbine and is expressed as agauge pressure farn ' airbineSandasanab-solute pressrrre forcondensing uhines.NEMAStandard6-21-1979.


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STD.NEMA S M 23-ENGL 1971 D b 4 7 0 2 4 7 0524311 9L4

2.4.4.6 ExtRAcT#))JSTEAM PRESSUREExtraction steam pmsm is the pressine of the steamextractedfrom the urbine. it ismeasuredat theextractionwnnecticm of the turbine, and is expressedas a gaugeP===2.4.4.7 hwCnON STEAM PRESSURE

NEMA-6-21-1979.

Inductionsteam~isthepIessureofthesecoadarysteam supplied to theWine. t ismeasureattheinduc-tionconnectian of thetrirbineandisexpressedasagaugep#rsiae.

2.4.4.8 INLET STEAM TEMPERATURENEMASEandaid 6-21-1979.

Inletsteam tempeniture is the total teIn- of thesteam suppliedto the turbine. It is nreasiiredat thesteami n l e t cmnect ionof the turb ineandi sex~ inde~Fatireobeit~indegrcesCeW.NEMAStandard 6-21-1979.2.4.4.9 EXHAUSTSTEAM TEMPERATUREluhapststeam emperameisthe totait e m m fthesteam cxhartpted from the tinrbine. It is r n d t thecxhailst CoMectiOn of the tuxbine and is expresd mdegreesFahrenheitor in degreesCelsius.NEMAStanderd 6-21-1979.2.4.4.10 WRACl" STEAM TEMPERATUREExaaction steam temperatureisthetotalteInperatureofthesteam extracte from the turbine. It ismeasuredattheexixmirn connection of the tintiineandis eJtpressedinegreesFahrenheitorm degreesCelsius.NEMASEendaid6-21-1979.244.11 1NDUCTK))IISTEAM TENPERATUREU i d u c t i o o s t e a m t e m p e n i m r e i s t h e t o t a l m ~ o ft h e ~ s t e a l n ~ W t o t h e ~tislmasmtdat theiiiductionconnectimof die urbine and isexpressedin de- Fahrenheitor in Celsius.NEMASEandaid-21-1979.

2.4.4.13 DUAL Srrrun CNMl"SDual steam conditiansare wo ofmmcombin8tons ofiniet steam pressme, inlet steam tempenitine,or exhaust-pressure.2.4.4.14 VARIAl"S IN STEAM CCXJITlONSThe Iatng,capability, steam flow,speed re andpressme control shall be basedonoperation at maximumstcamunutionsasdefinedm 2.4.42.SteamMbiaesshall be capable ofoperating under he

NEMAStandard 6-21-1979.

followingvariatioasininletpressureandm~butp e ? f ~ s h a l l n o t n e c e s s a r i ly bem accardance withthestandaadsestab~foroperatmgatmaximumsteamconditions.continuousopetatiaiatotherthanmaximumsteam conditioI1s sharequirereview by the turbiwman-ufacturer.2.4.4.14.1 VARUTKJNSFROU hhXUuU NLETSTEAM


PRESSUREThe urbine shalibe capableof operating without dam-ageat less than the guaranteedsteam flow tothe Mbinewith average Wet pressureof 105 percent of maximumidet 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 Wencountered n operahion.)The nlet steam pxsure shall average not more thanmaximum pressiireover any 12 month opedugperiod,

maximumpressurein maintainingtheseaverages,e;xceptTheinlttsteamprwsureshailnotexceed 10perccmd

during a b d OilClitioI1S.During abmnmalcosiditim, the steam paessare at thetiirbineinletconnectionshallbepermitredtoexdmax-h u m pressure briefly by as much as 2pesent, butheaggre@e drnationof such swingsbeyond 1M percent ofmaximump s s u r e shallnotexceed12hwrsper 12mondioperatingpenod. NEMA- 6-21-19m.2.4.4.14.2 VARIATIONSFROU WXiNUM INLETSTHMm P E R A l U R ETheinietsteamtempeniturestaveragenotmorethan

maximum tempexatme over any 12 month operatmgperiod.In maintaining this average, the tempemm shall notexceedmaximum tempemureby nme than 1f l ( 8oc )exceptduringabnnmalcoaditions.Duringabaonnalcoo-ditions,the tempcratiae shall not exceed maximum tern-peratureby m m ianm ( 1 4 O c ) fwojmathgperiods


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SM 23-1991page9

h2-theenthalpyofsteamatwrhaustsLeampaeasiiredinitialenaopy.NEMA &idard -21-197Q.2.5.1.2 AcniAL STEAMRA-26.1.2.1 TURBINE-TErbinesmunrateisthequaatityofrmctsteamnqairadby the tlirbioeper miit ofpower outpit, lneasmdattbtouiputshaftofthe tmbme.Itisd y inpoundsofsteamperhorstpower-hour(orinkilogremsasteempa ilowatt-hour).2.51 -2.2 TURBINEGEAR TEAM WlEWhenagearisprovidedytheturbineman~, thtrequiredby the turbinegear set per unit of power outpiit,measured at the output shaft of the!gear. It is &yturbine gear steam rate is the quantity of inlet weam


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S T D e N E M A S M 23-ENGL 3 9 9 3 M b 4 7 0 2 4 7 0524333 797

SM 23-1991Page 10eqxessedmpoundsofsteam pet harsepower-hour(or ink i l ~ 0 f s t e a m p e x k i l o w a # - h o u r .NEMAStendard-21-1979.2.5.1.3 GUARANTEED STEAM RATE'Theguarauteedsteam rate is thesteam ratewhich willnot be exceeded When the turbine isoperaredatw)rmalpower, 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 acyimdricalcouplingbore and provided with a keyway(&tapaed ooupling bom with a keyway(s), tapered for ahydraulic ft, ornttedwithan hie!@coupling hub.2.6.12 When a tapered shaft extension with keyway(s)isspecied, he taper, wupiinghub, andmupiingnutshaareavailablefarshaflextenshsfrwi inchesm 5 inches.

N E M A W 1-14-1985.

be inaccardancewirb Figure 2-1. NEMA aper diameteSSNEMA- 11-14-1985.

2.6.1.3 if cyhdrical shaft Cxtension is specfied, t isncommendedthat thecwpling-to-shaft it be an inmfer-ence fit NEMA- 11-14-1985.26.1.4 When a hydraulic fit coupling is specified, hemountiug method should be reviewed with the turbinelnallllfimmr.2.6.1.5 Recommended use of one and two keys andkeyways isasshown in Tbble 2-1.Authid Enginwring Intomiobon11-14-1986.2&2 SteamComecUons

'Iiirbmeflangedsteam Conn e c t i o n s shallbe facedanddrilled or bolting toflangeswhicharem accordancewithANSUASME B16.1 orB16.5.CastiNnlflaagecOM~nsshallbeflatfacedThe thicknessof cast iron exhaust flanged connectionsunder 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

Class25ofANSUASME B 6.1.Singie vaive single stage hariuwallYsplitcasingan-bines hallhave steamcannectionsm thebwexhaifdthetrnbiae.connections formakingup topipenot0ver2inches indiametex (So m m nominaldiamtter) shall have


intenial taper threads conforming to ANSI/ASMEB .20.1-1983. NEMAStandard 11-14-1@8!5.26.3 ArorlllaryConneUtonsAuxiliarycotlIlectiomthataredireadedshallconf~toANSVASMEB120.1-1983. W y , hese are a d ering prtssure gauge-, drain Co fatcasingandsteamchest,casingsealingglandsandbeariqgh ~ ~ , c o o l i n g ~ , v a l v e ~ l ~ ~ , a n d ~ f f o2.7 LUBRICATKIN2.7.1 NipressueTypekibrcation Singie2.7.1.1 OIL LUBRlCATESLEEVEBWNS

NEMA- 11-14-1086.

s t e ( l e W W )

ab.

C.

(tiomzomL~~meB)LU~~WOI Ihouldbe prendedby oill h ~ilarmeans.Beatinghousings should be arge enough topeanitsolidsor water m d e o the bottarn and shouldhaw a dtain connectionat the lowest point, oil fiilfittings, and an oil level indicam.. F ~ i l i h f o r c d i n ghouldbeprovided~hcnne^-essary to assure the proper oil temperahrre. niecooling water should be supplied at a temperamenot exceeding 90%(32Oc).

Sim-

2.7.1.2 GREASER OIL LLJBUCAEA N i F H C "BEAWNGSGmse-lubricated autifriction bearings should beregreaseable~IIiekid. Grease ittings should ex-tendtotheoutsideoftheniachiaetopermitregreas-ingduringopemion.Means should beprovided arventing grease lutNi-cated bearings to pment the buildup of pnssurewithin the housing.Facitiesforcoolingshouldbeprovidedwbennec-essary to assure the proper lubricant tempemme.Thecooling water shouidbe suppiied at a tempera-turenot exceeding909: (32Oc).

27.2 PressumtLpeOil Lubrlcatii2.7.2.1 ~ O D U C T I NIt is recognized that there s awidevariationin turbineSzesandapplicaths which makes it impracticaitohaveone recommended ubrication systcm ck ign. 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 oilowingdiouidservewagenaal designguide totheo e a f u r ~ h i s r a q u i r e m e n t s .27292 OILPWPS272.2.1 A main oilpump driva from the turbine shaftara seperately driven pump to provi& oil for lubricationaadgovemingshouldbepm4de.d.272.2.2 Anauxiliaryoilpumpforuseduringthc tart-by bic design whan qecihd. niiS pump should bepowaedbyadiffemismceofeaagythanthemainoilpimp.AprrssurtsensingdeviceshouMbeprovidedfcxpmsmeintbcmainsystemdmpsbebwapredeterminedvalmFor a Mbinedriven auxiliary oil pump, the turbine8bOddd m o all of the@pli* pvisim ofdiesesltmd&L272.3 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 sfmingthe ruailiary oilpump when the oil

A samateail ~ ~ S U V O ~ Thouldhaveaac.dt.f.

2.7204 oLcoolar(s)empuame oftbc oil suppliedto the bcaringsatamaxi-mimi d 120F (49oc), with a maximum woling watertmrpaaaarcm x excealhg90F (32OC). It shouldhave afwl ing fC~ofO.~ ln he wataside fopcoaliag towelwater an afouling faaorasncommendcdby the manu-nicMafarothtrcoolingwatesources.'Ibemo~sbouldbe suitablefora workingpressmeof notkss than 75 psig[517 kPa gauge)] m the w w ide.Singkartwin~kmmaybeused.Eechcoolershouldbe capable of operatioa at a pressure q u a i to or peat tertima the nlief valve setting of positive displacementoilpumpsor ofth maxllnum shutoff dischargepressiaeofca~trifugalil pumps.M coolets should be piped inparaciwith acontintmus low transfervalvetopert . ,,ihetraas6erofoil from one cooler to he ocher without inter-rupting theoil flow. Each cooler should be sized for the

The oii coola hould be capable of ma imhhg the

SM 23-1991Page 11total cooling loadandshouidbearrangedandventedfmaintaining eithacooler with theWire in ojmation.2.7.2.5 OILFILTER(S)Single or twin oil tiltersmay be used. Afiltafs) shoptdbe capable of nmving panicles argerthan25 micmns.When the film is clean, the pmsurc drop sbould notexceed5 Pgi 35 kPa) tdesign t a n m a a d low.Tiviufltersshould be piped inparaiicl witha con- fkwtransfervalvetopermit the transfa of oil fiom 011c filtat o t h e o c h a w i t b u t ~g the oil flow. Each nUashould be sized fm the otal oil flow end sbaild bc U-ranged aad vented for lminmining uthu f i l tawirh tbetiirbineinoperation.Acommontrsasfavalvemaybt~fortheoilflteIsaQdcoolas.ml~cartridgeshouldbecamsion nesisauu. Filter cases should be suitable foropaationatapressurenotlesstbanthcrei idvahn~oftbepmitivedispiacementoilpumpsoratthemaximumshutoff ischarge pressiireof cenhifugal oil pump.2.7.2.6 RPNAND INSTRWEWTAT"2.7.2.6.1 Pressuresensitive devices sboahlbe prwidadforea&prtssurclevel(forwrampie,oiih&tokarings,discharge 6rom oil pumps,befase and afta flta(s) andc ~ n h ~ lil). Means should be pwidad fm BII ai-lieem a i n ~ a s a p p r o p r i a i e .AuthoriredEngineering Inforniafionll-lClOBs.2.7.2.6.2 if bearing mctal thenwconplesot#Il)s arcnot pvic, tben thamometers hould be povidad forbe provi&dbefore and after oil d e r @ ) . Thermowellsshould b e p v i d d in thepiping f a h e m fthCr-m e t e r epiacemaitwhileoniine.TbenmweiasshoukibegaSfilledOrcrnrosion-resistantbimetalliCtypc.AuthorioedEngineeringIn- 11-14-1985.2.7.2.6.3 An oil sight flow indicatm wbui spccifiashouldbe p r o v id e d m the oil return from each caringhousing where thedesign permisAuthofbd Engineering Infotmatm 11-14-1985.2.7.2.6.4 A pressiireregulam or relief vaive should beprovidedto maintain the oil pressure evel(s).2.7.2.6.5 Afterfabricafim,pipingshauldbecleaneddpassivated by mechanical an4or chemical means.Authomed EngVieering I n h i i o n 6-21-1879,2.8 PROVISIONSFOR THE ENVIRONhENT2.8.1 EncksureSteam turbines shoud pfembly be installed in en-ciosedareas.TheeFe!&tsofundseMceconditi~may

oilwtlet fromcachbesringhousing.Tbemiametasmay

AuthonzedEng tnear ing I~11-14-10Bti.


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S T D - N E M A S M 23-ENGL 3991 b 4 7 0 2 4 7 0524335 5bT m

SM23-1991Paga 12bemi@ted by the use of one or moxe of the measmesbescribed in2.82 and2.83.Authobd Engineefing Infonnetkn 11-14-1985.2m E x p o r i u r e t o N a i f a l ~in general, d xposed surfaces should be potectedagainst usting by apaotectivecoatiagorpaintafter instal-hion of the unit. Enposed workiqg parts which affectaperationd heunit such asgovexnor, govexnor inkage,fuiuum pomts, Valve stems, nd imilwelements shouldb e ~ a g a i a s t ~ g i s t u i g b yhe useofcomwion esis-tantmatenalS.Equipment having nonpressure lubricated bearingssbouldbedcsignedtopvcnthetnaruiceof *

dust,and fmign mamiaisto the governing s y xbearinghai9ngs.aning systans,orboth, shouldbepruwtedasWowxboth, should be protected againstthe entranceof waterorforeign materials by proper seaiing devices. The points tosidarelements.Tbereservoirshouieprovi&xiwirhaventwithanairierandcarnectionstofacuitsteremovdof water.2.8.2.2 in addition tothe oregoingprotectivemeasum,tureswillbe lessthan4?F (4%)

EqpipntnthaMig~l&iCaboihydrauEicgov-2.82.1 The ULni- system 09 goveanar system, 09

beprotectedinchideallcofinectuwisorapeningstotbeoilEaleVoir, goveznor. gBromotor bearing housings, and

tbe ollowing shouldbe includedwhen ambientttmpezg-1.

2

3.

4.5.

Far use durhg down times,drains sbaildvi&d wheewater cancolkctforalls team,d , andwaterlines, he turbme casingand steam chest, andthe oil aad water si& of the oil coolex.Pneumatic"blowdown- may benectssarym someiostances.Aheaterfor the ail mxrvoir.Ifaa electricheater isspecineditmustbeofawifncicntlylowwaadeasitytopmtcokingoflkoilAn uxiliarypumpmaybe reqiiired to eosure oil CircUlatBon for unitonnheating.An enclosure or bood with venting to cover thegovemlg system may be provided,and heatingshouklbesuppliedtoprevent icing.The mountandtype of enclosureand heating wii i be governedbylocalconditions.Protection against fieeziag for instnuaenBandd P i @ &mine manufacturer shouid identay those lines~resuat-protectionoypa.asa.AuthobdEngineeMgInfomiehon 11-14-1985.

2..3 Exposu~toAb~mialAtmosphericoondltknsif possible, the turbine should be located away froin

damaging fuma nd vapars, or abrasive, magnetic aimetallic dust. If this is not pnictical, the atmosphericcandirioasshouldbe called to the aaentionof themanu-factufft. Suitablematerialsor protective coatingsmay berequiredtoansetthecomisiveeffectsofthefumes.Whennecessary, purge air connections on bearing housings,glaad cases, nd govemmshould be provided.Auth#ired EnQnWring Infonnaoion 11-14-1s.2.9 GENERALREQUIREMENTS2.9.1 PmssuteanTemperaaireRanges

Sieam turbinesshouidbe designed andproportioned aroperationatmaximumsteamconditions.Genedpressnreand tempexatme ranges utsown in Figure 2-2. Theranges are general, accmding to tempeam&xsurecambinationsat which pomt materialordesign changes,OrbOth,~~berequired.Authorlled Engineeringnformation6-21-1978.2.9.2 VlbratlonThe vibmion of the turbine rotar (double ampitude)within thespecifedoperating peedrangeasmeasuredonthesprfacedtheshaftadjacenttotheradialbeaaingsshallbe m accadancewith the foilowing:2.9.2.1 SINOLE STAGEURBINESThe maximum permissiblew i o n habe not peatexthan2.0 mils for speeds 4ooo rpm and ower,or 1.5 milsfor speeds4001qnnandhigher.NEMAStandard11-10-1985.2.9.2.2 MULTISTAGE TRBINESThe maximum permissi'ble vibratian shall be in--daace withFigure2-2. The absolute values for vibrathlevels above3ooo pm can be derived from thefollowingformule 1M

Shaft mechanid and electrid runout sbaii be deter-mined by slow rolling the rotor in its bearings whilemeasmingtheNwut with a proximitypmbe. if it can bedemaisoatedthatmtcbanid&electncalnmoutis~-ent,thissha be added o theabwale vibration leveluptoamaximum25peacentof thedioweddoubleampiitudev i r25mils, whicheverisgreater.NEMAStendard6-21-1978.


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S T D - N E M A SM 23-ENGL 1771 6470247 05243Lb 4Tb

SM 23-1991Page 13not have the specified margins betweem the apaatingspeadsand~speeds.nthiscasetheturbinedesignashould Catculanerotor response to unbalance. Theprimecaisiderationisseasitivitytom~AuthoriredEnghming Inlonnation6-21-1985.2.9.4 NAMEPUTEDATAtiabiaenameplale:1. Manufacainr'snameandbcatioa2 Sai a l numW3.-. Ratedborsepower5. Ratedspeed6. Maximuminletste9mpressure7. Maximmillletsteamtunpenitiite

8. Maximumexhauststeampressure9. M a M m u m e x ~ ~ p r t s s u r e ( i f ~blc)10. Tripspeed11. Maximum continuous peed (ifdifmnt fim ratedrg6ed).12Fmlataalcritical speed13. purchaser'sequipmeat 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+ '

II CIE


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ST D-NEMA S U 23-ENGL 1991 6470247 0524318 2 7 9

SM 23-1991Page 15

RPM. THOUSANDSFigure2-2MAXIMUM PERMISSIBLESHAFT VIBRATION


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SM 23-1991Page 16Table2-1RECOMMENDEDKEY FITS

(up to & including) 1-502250335044505550665077.508910

Twokeys may be used in any c89e.

4050657590100115125140150165180190rn230w )

Table24GENERAL PRESSURE AND TEMPERATURE RANGES


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S T D I N E M A SU 2 3 - E N G L 199L b 4 7 0 2 4 7 0524320 9 2 7SM 23-1991Page 17

steam 0 cnm he turbine.niepilotvaivecoatroisbcflowof highpnssme fluid to thepower cylink. This flowdhighpressmfluidcausesthepistonmthepowcrcyindato move in rcspaise to the signai h m hegovanarconQo1mechasiism.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,iaDothegoverning system which in hun positions the g o m a rcoatrolled vaivt(s). The govenoat shall be !Aaxcd toprovidethe9pecinedadjustaiespecrange.3.1.6.2 ReuOlESETPopsrTYPE?be remote set poiat type is mcorparated dinxtly miothegovanmgsystemwhichinmposi~tbegovamancudfd valvc(S). Tbc gwawr shall be 8ekctcd toprovide the specincd adjustableranges faiwatroingpatameta93.14 3 ALVE ACTlJAlW TYPE

Tbe valveacluatingtypeissepame h n l tlegovan.'e extaaal signai acts to positiaa e i t k tbe gmaacrcoamiiedvalve@) or a separate liac mounted valve Inthiscase.tbe govemxactsoniy asa speehiting@ eemergeacy)goveniar.

3.1.7 speed changerNEMA- 11-14-1985.

Thespeedchanga isa device fwcbging the setting0 f th e g o v e r n in g sy ~w i th in th e ~ i f i e d sp e e d r a n g ewhile the turbineisin aperation.3.2 SPEU) GOVERNING SYSTEM

NEhkStrvidard 6-12-1885.

CLASSIFICATIONSpeedgoYeaningsystemSs h a l l b e c ~ a s s h o w n mTablt3-1. NEMA standatd 6-12-1985.


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STD.NEMA SN 23-ENGL 3993 m b 4 7 0 2 4 7 0 5 2 4 3 2 4 8 6 3 mSM23-1991Page 18

TWb 3-1SPEED GOVERNING SYSTEMCLASSIFICATION

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 beachievedunderthef~wi43conditians:a Governorsystem isadjustedfopmaximum sensitiv-ity.b. Rotational inertia of the equipment is relativelyiargeforthepowerrating.c. Steammditionsproduce a relatively low theoreti-calsteamrate.Agovernor systeminseMcewhichmeetsali thefoliow-ingwnd.itionsshallbecapableofiimiingspeedtopreventoverspeed trip when load is suddedy reduced from rateto zero:a nie driven machine is s y n c b u s perator.b. Thegovernorsystemisoperatinginamodeinwhichit ~ p o n sodemandfor electricalpower.c. niesteamturbinehasaninletpressureofatleast150psig i1035kPa (gauge)].d. Tbsteamturbineexmuastoaccm&~.

-RangeSpeed ange, expressed as a percentageof rated speed,isthe specined range of opeming speedsbeioworaboverated ,$NA,r both, for which the governor shall bed j d e henthe ucbh isOperatmgnnderthe controlo f ~ ~ g o v e a n o r .3.22 8bximunSpeedRlseThem8ximmspeed rise expressedasa percentage ofratedspeed,isthemaximummomentaryincxeaseinspeedwhich is obtainewhen the turbine is dcveiopmg ratedpower outputatnited speed and the bad is suddenly andunnpletelyreducedtozeao.

NEMAStanclard 6-12-1985.

Maximum speed rise (%) =

1.

2.3.

when the steam mditiom (inlet inlettem- and exhaust pressrire) 8Ic set at ratedvaluesandheidconstantWhen the speed changer is adjusted to give ratedspeed with ratedpowerOUlpULWhen any exteanaiconmldeviisrenderedinop-erative and blocked in the open positfon so as tooffexnoresaictionstothefreefiowof steam tothegoveanarcontrolledvalve(s).

-(SeeFigure3-1 oragraphicrepmentationofspeed risecharactexisticsof a ClassD ovenior.)

32.3 speedvariationSpeed variaiion, expressed as a percentage of ratedspeed, is the totalmagnitudeof speed change or fluctua-t ions h m he speed setting uner the steady state cadi-tiom given in 33.4. Lhe speed change is dehedas thedifem m speed variation between the governiag sys-

tem n Operationand he goveZnmg system biocked tobeinoperative,withalloherconditionswnstan~peedvari-&an includesdead band and sustainedoscii iati~Speed variation (+a)

2xratedspeed(See Figure 3-2 or graphic npresenratiai of speedvariation charactaisticsof a ClassD overnor.)3.23 DEADBAND

Deadbandisthetotaimagnia>dtof hechange in steadystate speed withinwhich there s no &ring measiirablechange in thepositionof thegovernorconmilexivaive@).It isa measure of the speed gweming system insensitivityand s expressed in percentof xatedspeed9.232 SrMiUnStabilityis theability of thespeedgoveming system toposition the goveniar conmlied valve@)so that a sus-tainedosciliath of sped or ofenezgy input tothe urbineisnotproducedbythespeedgovemingsystemchniagoperation under sustaid load demand or following achange to anew sustainedload demand.324 Speed Regulation,steady StateSpeed regdation, expnxsexl as a percentage of ratedspeed,is the change in gli5t8ined speed when thepowaoutput of the turbine is gradually changed fmn atedpower oulput to zen, power outpit mider the followingsteady state conditions:


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S T D - N E M A SI 23-ENGL L99L b 4 7 0 2 4 7 0524322 7 T T

SM 23-1991Page 19107%

100.0%

Owt

O

2 5 9

t

iIIIII1IIIIJLOU) ' 100%

Figure3-1SPEU) RISE NEMACLASS D GOVERNOR

Figure3-2SPEED VARIATION NEMACLASSD GOVERNOR


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STD.NEMA SM 23-ENGL 1991 m b470247 0524323 636 =SM 23-1991Page20

P

IO 1oOYLOADflgure3-3 STEADY STATE SPEED REGULATION NEMACLASS D GOVERNOR3.3.5 PmssunChangerThepressurechangerisadevicebymeansofwichthesetting ofthepressure regdatingsystem maybe changedfor the piirpose of aajusting the p m s m of the exhauststeam or ofthe extraction or mduction steam whiie theturbme ism @on.3.3.6 SteaiyStatePressureRegulation


Far controlid extraction or conmiled induction typein sustained extraction or induction pressure when, withidenticalsettingsofa l lparrsof thespeedgoverningsysttmand of thepresswereguiating system(s), theexmxtmn aiaductian low is gradually changed from rated flow Iozero flow.Fornoncondensmgturbioesprovidedwithexhauscpres-sureregdatas,thesteady s r a t e p r e s s u r e r e ~s thechangein sustainedexhaustpmsurewhen. with identicalseings of ai l parts of the speed govemiag system andthrough tbe action ofthe p r t s m r r e m , thepowaoutputofthesteamtucbineispduayreduced6romratepower outputto zero power outpit.

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



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S T D - N E M A SM 23-ENGL 1991 b 4 7 0 2 4 7 0524324 5 7 2 M

3.3.6.1 PRESSURE REGULA^iacreaseswith decrease n steani flow.3.3.7 Stablltty

Stabiity is the capabiiity of the pessure regulatingsystem(s) to position the pressurt controlledvaIve(s) sothatsustainedoscillationsof the coaadledpressrno(s) artheeaxzgy~puttothesteamturbincarenotproducedbythepressrireregulating SY-m drnmg m m ndfxmstaimfiowdemands or fauowing achange to anothervalue 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 -pressurtarof encrgy i n p t are definedas the dinaenceb 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 minsemicc and hme existing with thepressrinregularingsystem blockedor inaperstve.338 Pressum~rolperformaneeA ClassD oveniOringsystem (see 3.2) shallexhibit thefollowing characteristics when u t i h n a com-conml system:w . 1 changeinsuseainedspeedshallbe196maximumfor any sustamed change in flowwithin limits of 5%and95% f maximum inductionorexmuion bw guaranteedforthatload.

Rcssueregulation scoasideredpositivewhcnprtssureNEMASEandard6-12-1985.

NEW-6-12-1985.

NEMA- 11-14-1985.3.3.8.2 Steady state plessare regdation shall be 0.5 psi(35 pa) maximmor496 of ratedexbaust,extrauion.nwhichever 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~ f canttolled pressure,wiien aprating at C O I I S E B ~ ~low demaad op foiiowing achange to another canstantflow, Shan notcxcetdoa psi(1.7 kPa)ar2%of thecon~fledpnsnireexptssednpsiob 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 toa n o r h e r ~ t f i o w , s h a U n o t e ~ 4 %fratedpcwer.338.5 The range of adjustment for ptsmre change(s)sha pennit adjustment of exhaust, extraction,or iaduc-tion pressure betweem f5 p i g (35 kPa)M f10% of thecoamlled pressure expressed in psi or kFa (absolute);whichever is iarger. NEMA- 11-14-18!j.

SM 23-1991Page 213.4 COMPENSATED CONTROLSYSTEM

Acompcrisatedcontralsystem isonewhich isprovidwith intaconneciions between its conml mechanismssothat the action dthe speed governar or of the pressureq d ato r (s ) alsodirectly actuates the Othetcontrolmech-anism.3.5 ELECK= GOVERNING SVSTEM3.5.1 BaslcFeatures

An electronicgovanhgsystemsha ncludethe foilow-ingbasiccompooeprs:1 Sensorswhichmeasureanoperat8igparamctaofthe turbineai system, andpoduceelectricsipah.2 Agovamx which compares - fnw ic sea-gor(s) witb theseiectcd setpoint(s) and padeces aQgnal(s)fobthevalveactuator(s)tomaintainsystem

Parametebs-3. An actuam@)whicb positionsthe valve(s) directlyor thougha a m l nucbammi n I e s p s e t o hgov=SiEm.oneormonof followingparametersshallbecxxumlld

a. speedc. othersforspecificapplicatiom.

NEMASEandaid6-21-1979.

bythegovemingsystem:b. E a c h i n d u c t i o n / e x a a c t i o n ~

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 C O N T R O L P ~ E SAsignal selectmmay be incorporated intbegOVUIIOrt0aowthegovenwrrtoreceivesignalsfromse.veralscnsusand tochoose the signal, which wiii result in thc piopavalveopening.Any paramm may be primary which the governingas constant during IK)iTmBIoperation.y- -ny panunetex could be secondary which is i g n d slcQgasitisbelow the preset value.3.599 CONTROLOF INDUCTIONOR E X T R A m

The governor may be designed o control the low pres-surevahrt(s)daninductim urextlxtionmine incon-junctian wih the high pressure n i v e ( ~ ) .n this case, hegovernar wnmls the flow tomaintain the steam pressureat each controlledextraction or induction opening whilesimuuaneously controllingspeed when necessary for theappiication.

The following are accessories which may be selected,

. .


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S T D m N E M A SM 23-ENGL L991 6470247 0 5 2 4 3 2 5 409

Agoveniarwith this capability incorporatesfeatUtes toadjustaii the ccmtroiied valves inmponse to a change inany controlledparameters. NEMAStandard1-1-1991.3.5.23 MISSHG SIGNAL DRECllONFEAtLIREniemissing signai &tecrion feature monitors all inputsignahandaetaminesifhey are in thecmectrange. Anysignai that is out of range shwld cause immediate actionby the electmiicgovexnorto enSuresafe operationof thetmbine, nd shouldcausean alami indication.3.52.4 SENSORREDUNDANCY8.5.2.5 OVU1SPEEDTmPvided in additiontotheprimary trip.nie overspeed rip feature in the governor can be pro-

3.5.26 other demonic governor accessories m a y beavailable.3.5.3 GENERALCaFeshouidbe talren n each installation to provide foradequate wiring. in addition, elecmnic governors and

INPUTS

theirassociafedWiringshouldbepro~fmnheat,weatand inducedsignais Local codes and area classif-should be con-W h e n m i ~ b a s e d t u r b i n e c o n t r o l s y s t e m s I r r eprovided which interface with plant distributed controlsystems, there may be some overlap of control loopsandconfusionregardinginpuWoutputs.in hese casesthepnichaser and thevendor should mutually agree upon scaptand responsibility spiiL Extemal selpointscancome knnthe piant DCS but the turbine control loop should besupplied by he Wine manufacturer.A typid eiec&onicgovernor schematic is shown mFigure 34.3.6 AUTOMATIC STARTCONTROLSAutomatic start controls are avaiiabie for turbine anddriven machine.nieWine manufacturer shouldtem-suited for recommendedequipment and pnicediiresAuaionred~neeringInfonnabon6-12-1mS.


Figure3 4ELECTRONICGOVERNOR FOR PUMPOR COMPRESSOR CONTROL


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4 1 BASICFEATURESThefollowmgfeaturesandaccessoriesarenecessaryfartheproperfunctioning ofequipmentand safety of opera-tion:11.1 Ananugill@device tocioseh i pvalveor trip and hrotticvalve.Each turbine shall be pvided with amanual trippingNEMASEandard612-1985.4.12 ~ M p s y s t e mTheoverspeedtrip system shall besparkpioofandshallinclude the overspeedsensing&vice, linkage. and a (ripvalveora combined trip and bottle valve sepatate romthespce governor conmiled valve@).NEMA- 11-14-1985.A13 overspeedsensingDevlce

action toclose the trip valve at a p m k a m m dspeed41A mspeedansingdevice is set

The ovaspeed smsing device mc1Udes those elementswhich are directly responsive to speed and which initiateNEMA standard621-1979.

Tbt trip speed is the speed at which the overspeedNEMAStandard6-21-1979.

SM 23-1991Page 23Section4PROTECTION

41.6 Comblnedmp andmmlemiveThecambineatrip,andthrottlevalve isseparatefrom hegovelnor controlled valve@)and is closed (tripped) mresponse to the action of the overspeed sensing &vicc,other safety &vices or manuai trip device. ?his vaivepennitsmanual ttirottling ofsteam tothe turbine.NEMAstandard6-21-1978.4.197 overspeed m h gThe np speedseauigsshowninTable4-1 hallbeabovethe speedreacbeddueto themaximum speedrkcharac-Eeristic of the govetning system to avoid tripping theturbine on suddenlossof load.when design or application of driven equipment re-quires trip speedsotherthanthoseshowninThble4-1,the

NEMA Standd 6-12-1985.trip speed should be specified.Authohcl EngineeringInfomiation6-21-1979.

Table 4-1TRIPSPEEDSEmNGS

AB

115110C 110D 11041.5 TpVahre"be trip vaive is separate from thegovernorconmiiedvaivc(s) and sclosed(tripped) inresponseto heactionof

UaiIripdeVice.theoverspbedscnsingdcvice ,o thasaf~&~orman-*An rluaueinpe

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~

S T D - N E M A S M 2 3 - E N G L 1991 W b 4 7 0 2 4 7 052i1327 281

Sectlon 5FACTORY TESTINGS.1 TURBiNE 1. Qiecknerieraloperatioa6.1.1

1.

2

3.

~ ~ i e x b a u s t ~ ~ h s t e a r nor hydro testcd at a minimumof25 pi [172 kPa0 1 . NEMA- 11-14-1085.Wa!exj&~ts, coils,or d e m hall be hyrottstedto1.5 times thespecifiedcooluigwar~,butnotkman115psip93kPa(gauge)].NEMA Sk l dWd 6-21-1979.pressirre(s) shallbemaintained for a m f 15when no extemaileaLs rom be item under testareobserved,m i l l U t e S . T b e t e S t S h a l l b e a m s i d a e d ~

NEMASEandard6-21-1879.5.12 No LondRunning Test

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S T D * N E M A S M 23-ENGL 199L II 6470247 0524328 IL6 H

SM 23-1991Page 27Sedon 6SOUND PRESSURE LEVELS

occurring atratedpowerandspeedandmaximum steamamditions,are shownm ble6.1.

TaMe6-SoundPressureLevels

45-9090-1801-355355-710710-14001400-28002800-5600MoO-llu10OVeralldBA

63125250500lo002Ooo4OOo8Ooo...

989491898989898993

1069897929090909095

For arrbmemoimtedonasteeibasepiate.abdonea&ii-tioaaidecibeltotabul8tcdval~.Actmi swnd pre9sure evels may not equa maximumt a b w valm foral l fequewy bands.o v d BAis*therefore*ess than thesum of individual values.6.3 SOUNDPRESSURELEVUMEASUREMENT

Soundpresswe levels shallbe measiindin accordrmcewith American N a t i d StandardS5.1. Section 7.0,as tAcoilstical penamanCe is based on a sound prtssurelevelwhich is &pendent on acousticalc b & x i s t k softhe space m which the unit operam. AU m d oumilevels are assumed to be in k ! d s p k d netfleldarsemi-revaberant field which has r00m m t argeempgh so as to not significantiy efeztm ressumlevebathcmeasiiriagpoint.A six decibel drop off in SOWICI pressure levei per dis-tance douling in each octave band of inmesr, as themicrophoaeismoved~eachmeasurementlocationmaii direaionSamund he machine.regardlessof distanCC,indicatesapproximate free fieid conditjolls.Correctionsmust be made fenvironment wbea the drop Onis lessthansudecibels.

Authorized Engiuieenng Infwmation&21-1979.PROCEDURE

i!Japplicable,Eammamd asfallows:

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ensed by Information Handling Services

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SM 23-1991page 28All 3Ound--readings shallbercaordedassoundpressmepls in decibels at refereace pressure of twotimes 10' Newton per square meter.Ausoraid~readingsshallbemadewitbanoctavebaadmetersetforslow respanserecording isualaverage

minus2dBAovetall shall bemurded.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 -tmbingmfluences(vibnitian,aircunents,alldelec~ fmagneticfields) which may affectreadings.Miaophoae locations shall be approximately,but notless than,aaemeter from any sound sotme being mea-d a n d a t a heigbt 1.5metersabove he fioor.Care hallbe talrcn toavoid a poBitiaiat the nodal point of standingwave. (hie set ofreadingsskouldbed that is requaediftbemicrophoneissopos i t ioaed.~seotenceis~-izedEnghe&gWxmation.)ThcpaBitionofthemicmphanefmmeesirringkkgmundambientsoundand otalswndshanbeidentical.4 CORRECTION FOR BACKGRWND NlSE

NEMASEendard6-21-1979.

rvm!memats oftiirbiaesound plesSun levels shouldels. Levels at each iocatim should exceed backgroundlevelsby at least tea decibels n each octaveband If thedinereaceetweenmeasuredsoundevelandbacirgroundsoundkvelislessthanthree&cibelsingivenoctave-nd,vatide sound level in that b a d cannotbe deter-rection factor should be subtmcw fnwn the measuredsound levek

be WHWWI far ambient baclrgtouadm d ress~reev-

mineb.when thcm-is -, t w a ~ ~ -D e c i b e l o o r r e c t i o n ~ =

- 4-5 6 - 2 loandover3 2 1 Oc o r i 9 i d e r a t o n s h o u l d ~ b e g i i v e n t o e f 6 e c t s o f ~msonnd somes, such aspiping anddrivenequipment,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 .ow-

ever, swndlevels from these somcesmaybe 80 clase toleveis from the turbine that a meaninghil meatmmentwi l l be difncnlt or impossible unless s&epre taken toisdatedietnrbine. Itmaybepossibletoaccomplishchisby inanlnting allPiping, usingacoustic barnersasappwpllate, and cowring ome sound sources with lead blau-kets. Aumorired E n g M n g nfamalion6-21-1979.6.5 SWNRESOLUTIONIkromeasuremeatsoftenmustbeaddedtodeerminethecunbinedmise level of s e v d sources or wibtracted to

find the noise output of one particular sou~ce n a noisyenvimment. However, noise measurements cannot beaddedmsubsracteddirectly. Rather,measuremauscaubecanbined wirb a coirectionnumber. heCQzeCtiollnum-bers obtained from * i -1and 6-2 areappoximate.However, the graphic resultsare East and sufficientlyac-curareformosteagineaiagapplications.The currection numbex is based on the dif6erence mamplitude of two sormds whether the sounds ale beiqga 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 ~rionnumberisadded to thehigherlevelFar example, 80

SUBTRACTING BACKGROUND NOISE

3 4 5 6 7 8 9 1 0DIFFERENCE BETWEENTOTAL SOUNDAND BACKGROUND NOISE(dB)

FigureblCORRECTION FOR BACKGROUND NOISEand 86 decibel sound levels diffa in amplitude by sixdecibels. dinerencethat y ie i s ac xm c tm m l m k o f lfrwnF-6-1. Thus, otai sound level is 87 deciLels.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 lsomid lcvek the Lxmwtmnnumerissubtractedals0.kexample, a90 ecibelbackgodnoiseand a 97dezibeltotal sound level diferm amplitudeby seven decibels,adif- thatyieldsacmectum numberoflfr0nif;igUr6-2 T h n s t h e m ~ l e v e l ithouttheba&gmmd noiseis%decibels.6.6 INSTRUMENTS

Sound pressurelevels shouldbe measundby meam ofa sound level meter which meets the requkments ofAmerican Naticmal Standard S .4.Afull-octave&andsoundanalyzex,rneetingherequire-men& of Ameriwn Nationai Standard 51.11, should beS o U d

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

USed~conjimctionWiththesoumdlevel~teatOmeaSme


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S T D - N E M A S f l 2 3 - E N G L 1991 6470247 0524330 87bADDING TWO SOUNDS

SM 23-1991Page 29Insfmments, including microphones,should receive anacoustic check an overaU calibration before and afterevery swnd pressure evel test.

Authorired Engineering Information 621-1979.6.7 SOUNDAmNUATIONIt isrecommended that acoustic81treatment or turbinesand similarmachinery be applied after instailationof theequipment and ensuing piant operation. F a c m which&ea sound levels are many and varied and may not beassociated as closely with the machinery itself as withsteam velocities in piping and othersound sources.After instailation and operaton has commenced, anovexall piant sound eveican be establishedand correctivemeasures Ealren to isolate the major sound producing por-tionsof theprocess.Authorized Engineering information 6-21-1979.

O 1 2 3 4 5 6 7 8 9 1 0DIFFERENCE BETWEENSOUNDS dB)

Flgure6 2SMINDR E S L U I "


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SM 23-1991Page 31Section 7PREPARATIONFOR SHIPMENTAND STORAGE

7.1 SHPPING PREPARATIONnit turbine and ail scparate parts shall be properlytaggodandidentifiedAt ttit timeof shipment,aiieqoscdnonmachinedsur-faces shall be protected widl OpLe coiitof shop paintaadcoatingorcovaiagorboth Aiiexpastdmachincdsur-k c s a n d oiiIiaparvoH.iateriorsshall be protected with a

nist pvenmtive. All ojmlngs shall be lluggedoc cov-aad. lleinteIiorofthertbineshallbesaitablytFeaudtoprcvcntnisttiooalprotectionand packaging.Ocean freight or extended storage shall require adi-Theppamionassumesthas~ewillbesoarrangdtbattheequipncntwillbeprotectedagainstloss,~onandwtathadamage.ki(h0rlled Engineering Infomiawn 11-14-1985.

7.2 SHIPMENTThepurchaser*since he has the most wmpete knowl-edge of ocal conditions,should specify he deliverypointrindprovide infamiadonon he methodof handtingtothepointddelivery.Thcmanufacairashouduseshippmgmethodsandshipp a r t s i n t h e s e q ~ r e q ~ f ~ y i n s t a l l a r m na w l

blies c r ~ p n mo shipment.protactthe equipment if die ins- isdehyed.

NEMASEandard11-14-1885.

i & d f y d l ~ s b ip m e r i t s b y m a r k i n g i n d iv i d u a ~ ~ ~ -Themanufacaurersshouldspcc i fy the~pfcpB-retiOnandproteCtivecoatingSthatsbouldbeprwidedto

The purchaser should advise the mandacturer of thcunladmg facilities available and whether skids will benewsaryformllinglargeassemblesintopoStion.Authonred Engineering Infarmath11-14-1985.7.3 RECEIPT AND STMIAGEOFEQUIPMENTUpon eceipt, hepurchasershouldcheck ail equipmentfor darnagt which may have o c c d in transit. Anydamageorshortagcsshouidbereportedimmediatelytothetninsportatioacompanyandacopyofthereport-tothemanufactuta.AH material should be checked against the manu-

immediately to themanufcturer.The equipment should at a imes be storedin a clean,noncorrosive atmosphere and protected against loss,weather,damage,and areig0materialssuchasdust,sand,a d o forth indoor starage where constant ternpaweismauitainedat a levei which w i i l p v m t condcz1sBtiQ1is preferred. Th e purchaser should seek the manu-facturers advice if storage conditions are other than thcabove.Specialattentionandcureshouldbegiven to thesmageB e h -up, the oil orpnxemtive usedin thebear-inghousingshouldbeflushedoutandrepiacedwirhc~lubricatmg oil of the recommended type. Grease lubri-

Prior to start up, forced lubrication systems should beAulhonzed EngineerKig Infomiation11-14-1885.

fsctraers packiug liss and my discrepancies repoml

. .

ofpartshavmgexposedmachinedsurfaces.

cated bearings m a y require lubrication prior to start-up.checkedforproperoperation.


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ST D-NEMA SM 2 3 - E N G L 1791 b 4 7 0 2 4 7 0524332 6 4 9

SM 23-7997Page33Sectlon 8INSTALLATION

ai INTRO DU^TbetmbineshauMbeiilptnllulmaccardencewithrwFommendationsandinsmictionsispuedbydrcmanufac-The m f o m i a t i o n c o n ~ i nection 8ispovided toasgist~prirchasaarhiscontractatintbepropahandlioggndinmiliahrn0fmtcbamcaldriveweamtiabmes.There&e m i y vatiabies mvohrcd mtheaquipnent funiishedmethodofshiplaent,andtypcsofiir9rallntinn.uierefore,itisnot eesi'ble todetailstep-by-stepproCadurW.AuihairodEnginwring Infomath11-13-1969.It is f c c o m m a hat the man-'S representa-tive faqwise theia9iallationofthetmbiac. hemstatltt-tion procedure should be in accordance withrecammndatiaisandiartnictim~bythemanufac-turcrutham drawingsarbyoibeameans. Sucb piocb

Lwiskmy iImauion and commissionmg of theeqwppauyqualifiedlabor,incl~qpalinedsupervisim,isrequiredfoapmpetirldhtm,scastupand~m.

nt

82 SUPERVISION OFINSTAUATION

dares are arranged and planned to obtain the mostment.

-Engineering- * 6-21-1079.

83 INsTALmnoNpropermazallatiaai s a e c t s p a r y f m ~ i r ; a y pera-tion.* nsershOuldprovideanadequate fauidation tomaintain alignmentandsbould installpiping tominimizet x t a n a l f ~ a n d m o m e n t s o n m e M b i a e .S f i k n t space andnecessary openingsin the founda-insWahn of theequ'ipmentSuitablcqmiqs should bepuvicd in the building to admit the quipmew mepurchaser should provide sufncient space raound thequipmalt forsavicmg, includingthe ripaceformwingthe rotor and setting down he upper half of the turine

Authorized Engineersiq Infomiation 11-14-1985.casing.

tionsandkiuding !aluCtun shaildbe pwided for the

8.3.1 FOUndatlOnFoundations should be sufficiently heavy and rigid tofarm a permauentiy nonwarpmgsmictinie.Themanufacturezshouldiunisbdimensionaldrawingsto enabe thepurchasez to design a suitable foundationof

"he fwndation souldbedesigned so hat it WUbsorbto a large extent the vibrath of die unit installed on it.hire by means of spacers(felt, coak,and so ortii) so thatoutsi& vibrationwi l lnotbetransmioed tothefoundation.

a m p l e ~ ~ a n d s t r e n g t h f o r t h e e q u i p ~ t s p e c i 6 e d .

nefouadabon shouldbeisolated~thebuildingstnic-

~Inlet 175 53 175 53Exhaust 250 76 450 137

Induction 175 53 175 53Extraction 250 76 250 76

-

8.3.3 Cleaning af Tutt~ne team ppingAsourceofcleansteam,free~foreignparticles,must

be provided to the nlet of the turbineconnecaons.TheStation piping and theboiler system should be cleaned in


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S T D - N E M A SM 23-ENGL L991 I 470247 0524333 585

SM 23-1991Page34~ w i t h t h e p o c e d u r e s s u b s e q u e n t l y w i g g e s t e d i n

steam Mowingisfequiredforall main steam, eal andadnussion piping before the steam turbii is put intoaperation. steam Mowing greatly reducespotealtial dam-steambbwingisbestachievedbyrepeatedbeatingandcoalingwhichwin~altwiateeiqiensaiandcoanactionintkpipingwhichwinhelpbasenpipe~ . tisforthis~ t h a t th e M o w d o w n s h o u i d b e a t f u ll p n s 9 u r e an d

terrpwratiae for severalminutes to allow thepipc 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 dbeallowedtoco0lbef~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 ~subsequentblowsshouldiiseapolishedstedwgetatdiecndoftheMowdowniinetoactasanindicatiaiofckantmess~shouldbepolishedonbodisi&stoobia indoubl ieusage.AnewEargetshoutdbeitsedfareachttSandcheEsrgetcompand toanew oneuntiitheyqpeartobethesame. Seeepurchasershouldprovidetemporarypiphgrequlledfortheblowdown. It isalwaysadvisabletoblow toatmos-phereoutsidethestationinanareawberesteamarperticleswouldnotinjurepersonnelaraffectequipnentnitpblowpiping must be arge enough to develop a mass velocityhead in the permanentpiping at ieast equal to thatdevd-oped during full load Operation. Blowdown lines shouldbe installedwith adequateanchors oprevent pipe w h i pping ocdamage. "he trip throttlevalve andstramer mustbe removedandallvalves in themain healer should bewideopen.The following procedm should be used for sizing thetemporaryMow down ine:Since the forcemaparticle is proportional tothe massveiociry head of the fluid, t appears reasonable that themass velocity head cieveiojxd during die Mowing cyclemust be at leastequai to that developed during full &adoperation. 'ibis should rake care of most hose pieces.However, timeEactoris involved;no ne canbe surehowlong it takes pipe scale to loosen up, ar such things as

d e r o assure theavaiiability of clean steam.. .age tothe turbim by weid beadsand pipe slag.

Figure8-1f~~~ggesedtargetinstal)atim.

pieces of welding rod to work their way ttuuugh thepipelhesandsupeitieaterlllbes.calculationscanbe made to show how much flow andwhat drum pressuream necessary foranassumedtempo-rary ppe size to a c b mass velocity head duringcleaning quaitothatattainedduring fuii loadoperatiai,basedMthe followinn:1.

2

3.

AS I nrst atten+, assume that tfie velocity at thepipe exit to atmosphere during blowdown is sonic,and that the pressure, Ppjllstinsidlediepipatthtexit isu) si. Tomake this assumpion,it is neccs-ssay thata l lofthe flow ateas in &he ystem be equalto, 01 arger than, thedischargeam.Estimate the steam conditions (piessiae, enthalpy)at the boiler outla expected during steam blow-down.Fnim b e c u r v e ~ i n F i g u r e 8 - 2 r e a d ~ m a ~flow function,F3o. Calculate themassfl

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~~-

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

O 1 2 3 4%'

Figure4PRESSURE DISTRIBUTK)NNEAR M EEND OF A PIPEDISCHARGINGSTEAMAT SONICVELoclfvin applyingFigure8-3, assume as a rst hial thatL isingthe equivalentlength of elbows, tees, etc. in the tem-porary system. calculate the5 nci aiter the curve inF m -3 and hu s calculateP,theptsamatthcdistanceLf r an theexist. Note hatif-& thewmpmry pipe ismore than5 , use a sharterL which w i makc? equa 5wtm+ isgnater tiun5, thepressuredrop sa straight-line frmction of L and can be caicuiaied by the conven-tional method. Then calculate, by conventionalthe piping from point Lfrom theexitto theboileroutlet,thusarriving at theboiler outlet prrssiire, Pc.4. Next, cacuiatethe cleaning farce ratio at theboiler

enthalpy. This mio compares the mass-velocityhead during cleaning with dut developed c&uingnomialfuii-loadoperation. nie leaningfacc ratioisexpressedby:

dietotalequivalentIcngthofthetempararypiping,niclud-

FLDandusecoxmpdmgP/Ppto CalculatePattheshortsL.

straight-line methods, the press~re rop due to riction in

outlet, using the calculated Pc and the expected

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

5.

SM 23-1991Page 35(Pv~ pressure-specifvolumeproductduring(P-) = pressure at maximum load flow at

boiler outlet,psia(Pc) = presslireduring cleaningat boileroutlet,psia( P V ~pssure-specific volume product atmaximm load flowat boiler outlet,Ifthisxatio,R,islessthanareandthesteam velocityinthesupeheatertubesislessthan wice heabw-able, divi& the pnssure assume inside pipe exit,Pp,by thisratioand epeattheaboveprocess. Thus,the equired low andgressuresforequivalent clean-ing forcescan be deteamined. hereby estabMingthe required sizes for the temporary blowpipes.Notethat fora discharge pressure differentthan 30psi, the low functionis

cleaning atboilerouuet,ft3/in2

ft3/in2

The~ofthetemporarypipeisamostimportantfactor.nieused a argerpipewiU result in lesserflows and lesserpressureh e i srequired or the same cleaning farce. Thesize effectis proportional to the ratioof diameters to thefourthpow.Inno case, however, should the temporarypipe have a greater flow area than the permanentpiping.Pressure eadingsduring blowdown should be taken atthe inla u) he stop valves andas ciose aspossibleto theMowdownPipedischarge.The lauerconnection should bemade ata convenient ocation,but notlessthan20 diame-ters fran the discharge end of the blowpipe in order toobtain a stablepressure Feading. Thesereadings will helpsubstantiate the calculatedboiler pre

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