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.
NOTICE AND DISCLAIMER
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statement.
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STQ-NEMA
SM 23-ENGL 1991
6470247 0524297 714
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TABLE OF CONTENTS
FOREwom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sectkn 1
sectm2
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CiassiñedbyExhaustcaiditiasis..............................
.
-N
Tiabmc ..................................
CoadensingTUrbinc ...................................
classified by Number of Stages and Coam1Valves ....................
SingleValveSingieSEagC'Iirrbint ............................
Single Vaive MuuistegeMine .............................
Multi*
sil@ stage m
i
n
e ............................
Muitivaive Muitisiage'ïixòine .............................
C i a s s i ñ d b y ~ N e e d s................................
controlled (Alumtic) Exeraction Turbine .......................
NoncwtrolletiExtractiosi nlrbhw ............................
Noacontrolled Induction 'linbine ............................
CmmUed InQiCtim(Mixdnesslire) M e .....................
InductimExtractionTirrbine ..............................
SteamIIiabinecctUl~ts..................................
Turbinecasmg .......................................
SteamInletEndseCtion .................................
ExhaustEI?dstction ...................................
Irlemedia&sactiw ...................................
Steam Chest (GOV~IIKN
vahe Body) ............................
SteamRing .........................................
Nozzles ...........................................
StatiomyReveEngBladcs ................................
StationaryRevczsingCham~ ..............................
Diciphragm .........................................
sw.nlrbirbe ........................................
ImpuIseStage ......................................
ReactianStage ......................................
shaftseals .........................................
casingshaftseals .....................................
Intemagestlaftseals ..................................
BearingHousing ......................................
Bearings ...........................................
RacüaiBcarings .....................................
ThnistBearings .....................................
AntitÌiCtianBearings ...................................
RotorAssembly .......................................
wheels@iscs) .........................................
Biades(Buckets) ........................................
Shroud .............................................
Handvalve@) .........................................
RotectiveDevice .......................................
COnmhgDevi~. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ExtemalcontrolDevice ....................................
WamingDeVice ........................................
SCOPE
REFERENCEDSTANDARDS AND DEPlNlïïONS
RefaencedSEancbrrds
Definithm
CONSTRUCTION
'I)pesofSteamT
PiSc
i
ii
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1
1
3
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plr
sectlocr2
...................................
Sentinel W h g Valve
soleplate(s) ..........................................
Basephte .........................................
FeatmsandAccessan?es
...................................
BasicFeaMesaQd...............................
OptiOnalFeaMesandAccessorics . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
c o n t r o n e d ~ ~ a n d c o n t r o l l ?Itrrbines
e d ~ .................
Ncmwntroiled Exüacîh Turbhes
.............................
Nonconp.olled InductiaiIlabines .............................
?IiirbineRating.........................................
power ............................................
speed ............................................
Ratedspeed .......................................
Maximum continwusspeed ..............................
N d Power end Speed and Steam Caiditions .....................
Stcamconditiaas: ......................................
MinimwnSteam(hKiibS ...............................
MaximumStcamconditions ..............................
MinimumEnergystcamccmditions ..........................
Inletsteampressure ...................................
ExhaiistSteampressUre .................................
Extraction Steam Rressiire
................................
Induction Steam Pressure ................................
Inlet Steam Tempemure ..................................
ExhaustSteamT~
perame
...............................
..............................
Extiaction SteamTemperatrae
LndpctimSteam Tempgatme
Maximum Mowable Working PressuresandTeanptmtms
DualSteamconditions
..............................
..............
.................................
.............................
..........................
Thermodynamic?Iienns ....................................
SteamRateS .........................................
TheOretidSteamRate .................................
ActualsteamRates ...................................
GuaranteedSteamRate .................................
VauiationsinSteamconditions
Flow Limits for an Automatic Exaaction ? M i h e . . . . . . . . . . . . . . . . . . .
HowrjmitpforanInductionTurbine
Units of Measurement for Absolute
and Gauge Pressure . . . . . . . . . . . .
I
?Iiirbineconnectiais......................................
outputshaftExte~..................................
.....................................
...................................
...........................................
Steamcohus
AuxiliaryconnectionS
LlbiClUb
..................
NonpFessure?lSpeLubncation(Single stage lbbines)
oil Lulnicztred sleeve Beanngs (HarizwEalTiirbines)
G?ease or oillubricatadAntinictionBearings .....................
pressure?lslpeoilLu~
InProduction
Oilnrmpr ........................................
oilReservoir
.................
...............................
.......................................
.......................................
oilcooler ........................................
OilFdt~zs.........................................
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S T D - N E M A SM 23-ENGL L99L
section2
Sedkn 3
b470247 0524299 5 9 7
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vi’bration ..........................................
Singlestageïùrbim ..................................
M d t i s t a g e ï ù r b ~ ...................................
clitwspeeds.L...................................
NameplateData .......................................
CONTROLS ..........................................
GoveaningSystem .......................................
SpeedGOmar .......................................
Multivariable Govexnor ...................................
CoatmlMeChanism .....................................
GOvmorconmlled WVe(S) ...............................
Servomom System .....................................
E x t e m a l C d D e v i w ..................................
Speedcbangetlype ...................................
RemoteSetPointQpe ..................................
Valve Actuating..................................
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 ..............................
PressureReguiatioaiC .
............................
stability ...........................................
pressure control perfamilmce ...............................
Compensated coatrol System .................................
Electronic Governing System .................................
Basic Features ........................................
Accessones .........................................
Control Primiries .....................................
Control of inâuctimor Extracoon ............................
Missing Signai Detection Featrae ............................
SensorRedundancy ...................................
piping and Instnunentation
nwisons for the Esrvin>nment
Eaclosufe
Exposwe to Nanrral Elements
Exposure to Abnonnal Ahnœphedic conditioas
GeneraiRequiremeats
PltsSureandTempemmRanges
......................................
...........................................
Automatic S t a t Controls ...................................
OverSpeeaTnp
Genexal
.
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A)
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STD.NEMA Sfl 23-ENGL 1991 m b470247 0524300 039
secth4
secSIon5
Sectbn6
sectm7
sectkn8
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Overspeed'LtipSystem ...................................
OverspeedScnsingD .................................
n i p speed ..........................................
nipvalve ..........................................
Combined 'Ltip and IhrottltValve .............................
overspeednipsystemsetting ...............................
FACIDRYTESTING .....................................
'Iiirbine .............................................
HydroTd ..........................................
NoLoadRUnmngTesc ...................................
SOUNDPñESSUREJEVELS ................................
Gtaeral .............................................
swnd€3essweLev& .....................................
soSmd~LevelMtasuremcntprocedme........................
Camction for BacLgrwnd Noise ...............................
souadResolution .......................................
Instnuneats...........................................
S d A ü e nd o n .......................................
PRapARATI0NFORS"TANDSTORAGE
....................
PRûïECTiON
BasicFeaûues
UanUalTrip
S h i j l p i D g R e ......................................
~
Shipneat ............................................
W i t and Storage of Equipmeat ..............................
INSTALLAIION
In-tion
...........................................
SupervisionOfIaseallation
.......................................
...................................
...........................................
Fouudation .........................................
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.............................
SteamPipingSystems .....................................
I n e t i o n .........................................
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......................................
Grwting ............................................
FlushingûiiSystem ......................................
OPERATONANDMAINTENANCE ............................
The Piping noblem as Applied to ?brbines
FbmsDue to Stearn Pressure
FbmsDue to Temperatwe
FarcesDue to Dead Weight
AuowaMe Fœces and Moments on Sttam Turbines
DrainPiping
IÆak-ofli
Fuil-FiowReii&Device
CoUptingAlignmcnt
seCtrOn9
In-tim
..........................................
operatioa ............................................
Noncondensin
' g 'hbine opetatianof aMultisragecondensia
. g'Ihrbine ..........
'I)pical SEertmg Seqaence fima Steam nirbine ........................
..........................................
Maintlmance
Intluduction
.........................................
p.pc
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S T D m N E U A SU 23-ENGL 1991
SeCtknS
Sacth10
6470247 0524303 T75
pige
UitemalWaterWashing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
steamhinty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INQUIRYGUIDE.. .....................................
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S T D * 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,considaationbas been given to the work of other organizations. such as the American
National Standards institute, the American Peuoleum institute, the AmericanBoiler 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 multistagemechanid 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~ofthedifferingmechantcaldesigns of turbines.
NEMA Standards P u b l i a SM 23-1991revises and SupeISedes the NEMA StandardsPubliCation Steam Turbinesfor Me~hanicalz)rive S e M e , SM 23-1985.
User needs have been considertd throughout the development of this standard. Proposed M
recommmdedrevisions 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
S T D - N E M A SU 23-ENGL L99L
ii
b 4 7 0 2 4 7 0524303 848