handle external piping forces and moments. Although NEMA. SM 23 () or API Standard () have been conventionally referred to for allowable loads. NEMA SM (R) [ Withdrawn ] From (in USD). Secure PDF. ℹ Printed Edition + PDF; Immediate download; $; Add to Cart. NEMA SM23, SM • IEC • ATEX. • IEC Third Party Classifications. • Lloyds. • DNV GL. • ABS. • BV. • RINA. We have supplied steam solutions for a.
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SM (R, R). Steam Turbines for Mechanical Drive Service. Published by: National Electrical Manufacturers Association. North 17th Street. NEMA SMpdf - Download as PDF File .pdf), Text File .txt) or read online. NEMA SMpdf - Download as PDF File .pdf), Text File .txt) or read online. NEMA SM
NEMA does not certify, test, or inspect products, designs, or installations for safety or health purposes. The hire by means of spacers felt. The hire by means of spacers felt. Means should be provided far venting grease lutNi- cated bearings to pment the buildup of pnssure within the housing. Flag for inappropriate content.
NEMA standerd B. CasingsshallbeaxiallysplitJadiauysplifa a combination thereof. It sha also contain the low pressnn stage s of a multistage turbine. NEMA Standard IOW at rotatiogbladesandoneormorereversingchambas. Apressuredropoccursinboththesiatioaary and rotating elements. For condensing turbines, seals are arranged to jxemt pressmcand low mperalme. In verticat tmbrnes, these bearings tnri;sllv positiOn the mtar assembly.
They m of the antifrictm, laad, ar scgmeniai tutuigpadtypt. Authorized Engheeiing Inkrmillion The rating life is tbe number of houisatcunstant speed tbat9perctntofagroupofidcnticalbearhgswiiiopcratc befcxe the fitaevie-nce of fatigue devebps. Apotective device is one which, alone oras p? SM Page 5 2. Ref- mm Section 3. NEMAStandard ' For noocondensing mines the minimm maximnm exhaust steam pftssuR, Whichever is greater. Insulation for the high tempemm section of tht Wine to limit exposed siirfaoe temperatme to 16pF 74OC or other tempemture specified by the P-.
Coupling between the turine and driven machine normaiiy fumhhed by the m8nufacturea of the dnven equipment. GlandleakageevacUatingappIiratus whendiegland casngdesignrequiresitsuse.
Th- chometers shall be suitale for the specifmed eavi- Ionment. Supemhry instniments to monitor such as vibra- tion, axial shaft movement, tempemtms, etc. Shaftgroundingdevicetocarrytogromdanysatic romandwhichmayotherwisebuildtoLevelswhich ddamageturbhcbearings. Rotor turning gear togeUier with driving maus, engagement and isengagement feaiures, and lube oil pressure interlocks to permit slow turning of the mtorsystemonstatt-upandsbutdown.
AlbusSm quick and positive shutof of admjssion stcam f a emegencY tnppuig. Vacuumbreakertoadmitairiatotheexhau9tam nections d a condensing turbiue in cmk to reduce coastdowntime. Additbd items may be availsble. Anon- return valve br the extraction apallng s , which is also actpated by the ovaspetd tip system. SM page 7 speed 2. NEMA standprd NEMA stadard It is measured at the exhaust connection of the turbine and is expressed as a gauge pressure far n- ' airbineSandasanab- solute pressrrre for condensing tuhines.
Inlet steam tempeniture is the total teIn- of the steam supplied to the turbine. It is r n d at the cxhailst CoMectiOn of the tuxbine and is expresd m degrees Fahrenheit or in degrees Celsius. NEMAStanderd It is measuredat the exixmirn connection of the tintiineandis eJtpressedin egrees Fahrenheit or m degrees Celsius. PRESSURE The turbine shali be capable of operating without dam- ageat less than the guaranteedsteam flow tothe Mbine with average Wet pressure of percent of maximum idet steam pressure.
The inlet steam pxsure shall average not more than maximum pressiire over any 12 month opedug period, maximumpressurein maintainingtheseaverages,e;xcept Theinlttsteamprwsureshailnotexceed perccmd during a b d COilClitioI1S.
During abmnmal cosiditim, the steam paessare at the tiirbineinletconnection - shallbepermitredtoexdmax- h u m pressure briefly by as much as 2pesent, buthe aggre e drnation of such swings beyond 1M percent of maximum pssure shallnot exceed 12hwrsper 12mondi operatingpenod. NEMA- m. In maintaining this average, the tempemm shall not exceedmaximum tempemureby nme than 1fl 8oc exceptduringabnnmalcoaditions. It is d y e- in pounds ofsteamperhorstpower-hour orinkilogremsasteem pa kilowatt-hour.
N E M A W Singie vaive single stage hariuwall Ysplitcasingan- bines shall have steam cannections m the bwexhaifdthe trnbiae. NEMAStandard 8! Beating housings should be large enough to peanit solidsor water m d e to the bottarn and should haw a dtain connection at the lowest point, oil fiil fittings, and an oil level indicam. Sim- 2. Grease fittings should ex- tendtotheoutsideoftheniachiaetopermitregreas- ingduringopemion.
Means should be provided far venting grease lutNi- cated bearings to pment the buildup of pnssure within the housing. Facitiesforcoolingshouldbeprovidedwbennec- essary to assure the proper lubricant tempemme.
The cooling water shouid be suppiied at a tempera- ture not exceeding M coolets should be piped in paraci with acontintmus flow transfer valve to pert. Each cooler should be sized for the The oii coola should be capable of maimhhg the SM Page 11 total cooling loadandshouidbearrangedandventedf? Afiltafs shoptd be capable of nmving panicles iarger than 25 micmns. When the film is clean, the pmsurc drop sbould not exceed 5 Pgi 35 kPa atdesign t a n m a a d flow.
Each nUa should be sized fm the total oil flow end sbaild bc U- ranged aad vented for lminmining uthu filtawirh tbe tiirbineinoperation. Thermowells should b e p v i d d in the piping f a t h e m ofthCr- m e t e r repiacemait while oniine. Tbenmweias shouki begaSfilledOrcrnrosion-resistantbimetalliCtypc. Authorioed Engineering In- Authomed EngVieering I n h i i o n , 2. Authobd Engineefing Infonnetkn Enposed workiqg parts which affect aperation d the unit such as govexnor, govexnor inkage, fuiuum pomts, Valve stems.
The points to sidarelements. Pneumatic "blow down- may benectssary m someiostances. Aheater for the ail mservoir. Ifaa electric heater is specineditmustbeofawifncicntlylowwaadeasity topmt coking of lkoil An auxiliary pump may be reqiiired to eosure oil CircUlatBon for unitonn heating. An enclosure or bood witb venting to cover the govemlg system may be provided, and heating shouklbe supplied toprevent icing. The amount and type of enclosure and heating wiii be governed by localconditions.
AuthobdEngineeMgInfomiehon If this is not pnictical, the atmospheric candirioas should be called to the aaention of the manu- factufft. Suitable materials or protective coatings may be requiredtoansetthecomisiveeffectsofthefumes. When necessary, purge air connections on bearing housings, glaad cases, and govemm should be provided. Auth ired EnQnWring Infonnaoion s. Genedpressnre and tempexatme ranges ut sown in Figure Authorlled Engineering Information The absolute values for vibrath levels above 3ooo rpm can be derived from the following formule 1-M Shaft mechanid and electrid runout sbaii be deter- mined by slow rolling the rotor in its bearings while measming the Nwut witb a proximity probe.
NEMAStendard Manufacainr'snameandbcatioa 2 SaialnumW 3. Ratedborsepower 5. Ratedspeed 6. Maximuminletste9mpressure 7. Maximmillletsteamtunpenitiite 8. Maximumexhauststeampressure 9. Tripspeed Maximum continuous speed ifdifmnt fim rated rg6ed. This flow d highpressmfluidcausesthepistonmthepowcrcyinda to move in rcspaise to the signai h m thegovanar conQo1mechasiism. Extanal calm1 devices shall be me of thne Eypcs -mchangatypeis- dirtcts,iaDothe governing system which in hun positions the gomar coatrolled vaivt s.
The govenoat shall be! Aaxcd to providethe9pecinedadjustaiespecrange. Tbc gwawr shall be 8ekctcd to provide the specincd adjustable ranges f ai watroing patameta9 3.
NEMA standatd Rotational inertia of the equipment is relatively iargeforthepowerrating. Steam mditions produce a relatively low theoreti- calsteamrate.
Agowrnor system in seMce which meets ali the foliow- ingwnd. Thegovernorsystemisoperatinginamodeinwhich it m s to demand for electrical power. NEMAStanclard It is a measure of the speed gweming system insensitivity and is expressed in percent of xated speed 9. Far controlid extraction or conmiled induction type in sustained extraction or induction pressure when, with identical settings of all parrs of thespeed governing systtm and of the presswe reguiating system s , the exmxtmn a iaductian flow is gradually changed from rated flow Io zero flow.
NEMA- ! SM Page 21 3.
Sy- - Any panunetex could be secondary which is i g n d as lcQg asitisbelow the preset value. The following are accessories which may be selected,. Any signai that is out of range shwld cause immediate action by the electmiic govexnor to enSure safe operation of the tmbine, and should cause an alami indication.
A13 overspeedsensingDevlce action to close the trip valve at apmkammd -speed 41A mspeed ansing device is set The ovaspeed smsing device mc1Udes those elements which are direcily responsive to speed and which initiate NEMA standard NEMA standard Authohcl Engineering Infomiation Qiecknerieraloperatioa 6.
Actnai swnd pre9sure levels may not equa maximum t a b w valm for all fequewy bands. Section 7. AU m d soumi levels are assumed to be in k!
Corrections must be made f? Previous page is blank. SM page 28 All 3Ound--readings shallbercaorded as sound pressme pls in decibels at refereace pressure of two times 10' Newton per square meter. Miaophoae locations shall be approximately, but not less than, aae meter from any sound sotme being mea- d a n d a t a heigbt 1. Care shall be talrcn to avoid a poBitiai at the nodal point of standing wave.
ThcpaBitionofthemicm phane fmmeesirring kkgmund ambient sound and total swndshanbeidentical. Itmaybepossibletoaccomplishchis by inanlnting all Piping, using acoustic barners as appw pllate, and cowring some sound sources with lead blau- kets. Aumorired E n g M n g Infamalion However, noise measurements cannot be addedm subsracted directly.
Rather,measuremauscau be canbined wirb a coirection number. However, the graphic results are East and sufficiently ac- curareformosteagineaiagapplications. Thus, totai sound level is 87 deciLels. Authorired Engineering Information After instailation and operaton has commenced, an ovexall piant sound levei can be established and corrective measures Ealren to isolate the major sound producing por- tions of the process.
Authorized Engineering information All ojmlngs shall be jllugged oc cov- aad. Authonred Engineering Infarmath Any damageorshortagcsshouidbereportedimmediatelytothe tninsportatioacompanyandacopyofthereport- tothemanufactuta. AH material should be checked against the manu- immediately to themanufcturer. The equipment should at a times be storedin a clean, noncorrosive atmosphere and protected against loss, weather,damage, and fareig0 materials such as dust, sand, a d so forth indoor starage where constant ternpawe ismauitained at a levei which wiil p v m t condcz1sBtiQ1 is preferred.
The purchaser should seek the manu- facturers advice if storage conditions are other than thc above. Steam mditionsproduce a relatively low theoreticalsteamrate.
N E W S U d d SyAny panunetex could be secondary which i s i g n d as lcQgasitisbelow the preset value. Any p a r a m m may be primary which the governing. Shan notcxcetdoa psi 1. Any signai that is out o f range shwld cause immediate action by the electmiic govexnor to enSure safe operation of the tmbine. C D 1 1 0 1 1 0 1 1 0 theoverspbedscnsingdcvice.
NEMA Standd Authohcl Engineering Infomiation A13 overspeedsensingDevlce The ovaspeed smsing device mc1Udes those elements which are direcily responsive to speed and which initiate action to close the trip valve at apmkammd -speed NEMA standard The tnp speedseauigsshowninTable shall be above the speedreacbeddue t o the maximum speedrisecharacEeristic of the govetning system to avoid tripping the turbine on sudden loss of load.
Qiecknerieraloperatioa 6. AU m d soumi levels are assumed t o be in k! Corrections must be made f? Section 7. ThcpaBitionofthemicm phane fmmeesirringkkgmundambient sound and total swndshanbeidentical.
Care shall be talrcn to avoid a poBitiai at the nodal point of standing wave. Itmaybepossibletoaccomplishchis by inanlnting all Piping. Miaophoae locations shall be approximately. American Naticmal Standard S1. After instailation and operaton has commenced.
Authorized Engineering information Authorired Engineering Information A t ttit timeof shipment. B e h --up.
Aulhonzed EngineerKig Infomiation Authonred Engineering Infarmath Any aad. S f i k n t space andnecessary openings in the foundationsandkiuding! The hire by means of spacers felt.. Sucb piocb dares are arranged and planned to obtain the most Lwiskmy iImauion and commissionmg of the eqwp ment. The following procedm should be used for sizing the temporary Mow down line: Since the forcemaparticle is proportional tothe mass veiociry head of the fluid.
It is alwaysadvisable to blow to atmos3. AnewEargetshoutdbeitsedfareachttSandcheEsrget follows compand toanew one untiitheyqpeartobethesame..
Itisforthis pipe exit to atmosphere during blowdown is sonic. Qcl as usage. Tomake this assumpion. These readings will help substantiate the calculated boiler pressure and pipe Szes selected for the blowdown operation. N o t e that for a discharge pressure different than 30 psi. Pressurereadings during blowdown should be taken at the inltt u the stop valves andas close as possible t o the MowclownPipedischarge.
A f d i size Mock valve. The size effect is poportional to the ratio of diameters t o the fourth p o w. When the boiler pressure has dropped to approximately pSi [lo35 kpa gauge ]. Adequate pham communication between the b o i l e r mom and the operaror at the blow down valve m u s t be established This might also be backed up by a system of visuai communication.
The lauer connectionshould be made ata convenientlocation. When the lines are adequately warmed up. In no case. Then calculate. An anangrnent should also be made t o record the pressure readings a t the various siations simultaneously through proper communications. When performingthe blav.
Authonted Erigheerhrg Infomiation lllg If an expansion pint is impmpedy used. The t i e rods eliminate any axial flexibility. It is the purpose here to briefiy discuss piping arrangements and recammendfiangeloedinglimitationsimposed on steam turbines by piping.
Authorized bgimririg Infwmation In general. An uriffsalctedexpmSion pint will cause an axial uuust equal to tbe effective ana ofthe bellows times the intend pfesslm The magnitudeofthese forces may be geater than the l i m i t sforme exhaust flange.
FOI short runs which cannotbebiown down. Steam turbines have been very Carefdy designed t o provide for thermal expaeon and. The expansion joint is in shear which is the preferred use An umestrictedexpansionPrntplaced at the exhaust fiange of the turbine may exert an upward o r lifting force on dit turbine flange which in many cases is excessive. A rigid sup- portisnotsatisfactoPywherethennalexpansionmaycause the pipe t o move away from the support On the two types of rigid mpports shown in figue When the thrustdue toan expansionjointis less than the exhaust flange limits and no resminhg tie rods are used..
Auihorired EngineeringInformation Therearebasicallytwo -rigid and m g. Since this condition rarely exists. Resuitant fme pounds a t the CMnection.. Aspring support should not be used to appose the titrust ofanexpansianjointWhcnthepnssureisnmovedh the line. For sizes greater than this. It is not included as part of the piping load frwn F i g r i r e These resultant should not exceed: Therew device shalt give full relief atm mae thsn 10 pacent abovethe"start-to-open" pcwsure..
Authorired a nee ring Lnf maEkn Combined resuIcBnt ofinlet. The size o f the r n.
The relief valve is connected into tht piping system between the aubiueexhaustconnectieo and the nrst shutd valve. The full-flow relief device should be provided by the user aspart of the piping mstallationwhich iswrtanal to the tulbme. Authorized Engineering Infomiatkn For values beyond this.
Aftertbegront i s dry. Authorized Engimefing Infomatiori Aperiodic checkof theoil filtas or temporary screens should m e as a guide to detenninewtienmeoil isclean. Authorized Engineemg Inforniath Soieplate 3. Anchor Nut 6. Shims 7. Support Foot 2. Hold-down Bolt 4. Anchor Bolt 5. Nocozrectiori x ntedtdbwvalues 9 m. ZNE Limit 2.
Resultsfrompipts 1. Check t o see if thest forces and moments are within NEMAguidelines. Pamgmph 8. Paragraph 3 Cxhaustarea Remove sentinel warning valve and check for proper operation. Monthly 1. V i y inspect turbine for extemai damage and leaks. This is m it in predicting and scheduling inspection outages. Open exhaust shut off valve. Check operation of auxiliary oil pump.
High exhaust pressme and temperanne can cause last stage blade flutter. Check thrust bearing end piay.. Check shaft seals f aw e a r. Avoid slugs of w a t e r and unduly wet steam. Avoid great or sudden fluctuationsin pressure and temperamre of steam supply.. The steam supplied t o the turbine should be free of debris. Check for unusual vibration and noise levels.
Check operation of ail shut down devices. Check that shafts are fite of oil or grease. Casing distortion and damage and misalignment w i t h driven machines. Check overspeed governor.
Check trip valves o r trip and throttle valve for Operation. Seepiping f o a calcuiationS given in Section 8. Adjust governor speed. Frequency of inspection and degree of thoroughnessmay vary a n d a have tobe determhed by the mainteamce personnel: The foilowing is a typical maintenance program: Provide lubricating oil of proper quality and characwtics.. Maintain a log of aperating conditions.
Remove and clean steam strainer. Check auxiliary oil pumps.. Authorized Engineering Information T o ensure maximum protection. Item No. Driven Equip. Electrid supply: Direitos autorais: Pesquisar no documento. Maintlmance Intluduction Vivekanandan Mahendran. Lionel Torrado. Sridhar Mahalingam. Arya Aryan. Priyanathan Thayalan. Desmond Chang. Gregory Simmon. Ton Phichit. Ch Fai. Petar Jankovic. Mais de marsulex. Vikas Badhan. Populares em Physical Quantities.
Wei Quan. Romildo Gomes.