Glossary of pump terms A-Z A Absor bedPower :Theact ualamo mountofpowerbei ngconsumedbyt hepump mpata speci ficfl owandhead. Adapt er( orSuppor tHead) :Co nn ec t sa nda l i g nst h ep owe r( b ea r i n g)e ndo fa n ANSIpump mpt ot hewetend. A. N. S. I . B73. 1 St andar d:Ame r i c a n Na t i o na l St a nd ar d s I n s t i t u t e . A s e t of s pec i fi c at i ons( env el opedi mens i ons )f orc ent r i f ugal pumps . Absol ut e pr essur e( nor mal l yi n kPaA):At mo s ph er i cp r e s s u r ea dd ed t og au ge p r e s s u r e . Affini t yl aws:Th eyar eu s edt od et e r mi n ec h an ge si nc a pa c i t y ,h ea da ndp owe rd ue t ochangesi nshaf tspeed. The same mel awscanbe used t oest i mat echangesi n c apac i t y , headandpowerduet oc hangesi ni mpel l erdi amet er . Ai ri ngest i on:Ai ri sc o mi mi n gi n t ot h es t u ffin ffin gb oxb ec a us eo fan eg at i v es u c t i o n p r e s s u r e . Al i gnme nt :Thec ent r el i neoft hepumpi sper f ec t l yal i gnedwi t ht hec ent r el i neoft he dr i v er( us ual l yanel ec t r i cmot or ) . Ambi entt emp mper at ur eorpr essur e:Theenv i r onment alt emper at ur eorpr es s ur ei n t hear eawher et heequi pmenti sl oc at ed. At mospher i cpr essur e:Ats eal ev e l ,at mos pher i cpr es s ur e101. 3k PaA. APISt andar ds:St andar dspr oduc edbyt heAmer i c anPet r ol eum I ns t i t ut ef orv ar i ous pi ec esofequi pmentappl i edi nt heoi landgasi ndus t r i es . Var i ousAPIc odesar e appl i cabl ef orpump mps dependenton t he t ype ofpump mp. Exampl es ar e API 610, API 6 85e t c . Axi a lThr ust :Ther es ul t antofal lax i alf or c es( i . e.i ndi r ec t i onoft hepumps haf t ) ac t i ngi nt hepumpr ot or . Ax i a lThr us tBa l a nc i ng:Me t hodsb ywhi c ht heax i alt hr us ti sbal anc edt omi ni mi z e bear i ngl oads . B
Backt oBackI mpel l er s:I nmul t i s t agepumps ,s omei mp el l er sar el o c at e do nt he s haf tf ac i ng oppos i t e di r ec t i ons . Thi si s one me t hod ofac hi e vi ng ax i alt hr us t bal anc i ng. Ba ckpl a t e :Us e di ns o mec en t r i f ug alp umpst opo s i t i ont h es t uffingb oxandpr o v i de ani mpel l erwears ur f ac e. BackVane:A r a di a lna r r o wv a nel oc at e do nt hebac ks hr ou do fani mp el l eran di s des i gnedt obal anc eax i al t hr us t . Backpul loutpump:Ades i gnt hatal l o wst hewetendoft hepumpt obel ef tont he p i p i n gy e ta l l o wst h ep owe re nda nda da pt e rt ob er e mo v e d. A. N. S. I .p ump sa r e des i gnedt hi swa y . Back t o back doubl e seal :Two mechani calseal sl ocat ed i n a pump wi t ht he r ot at i ngs eal f ac esi noppos i t edi r ec t i ons . Bal anceHol es:Ho l e si nt h eb ac ks hr ou dofani mp el l erd es i gne dt oba l a nc ea x i a l t hr us t . Ba l a nc eds ea l :Ades i gni nwhi c ht hes ealf ac ec l os i ngar eai sr educ edt ol owert he c l os i ngf or c e,andr educ et heheatgener at i onbe t weent hef ac es . Bal lbear i ng:Cons i s t sofani nnerr ac e,anout err ac e,andas er i esofbal l sbet ween t hem.Of t enc al l edapr ec i s i onorant i f r i c t i onbear i ng. Ba r :Met r i cuni tf orpr es s ur eandi sequal t o100k Pa. Bar r i erflui d:Thehi ghpr es s ur efl ui dt hati sc i r c ul at edbe t weent het wos eal si na d ou bl e me c ha ni c a ls e al . Th efl u i ds h ou l de nt e rt h eb ot t o ma nd l e av et h et o pt o pr ev entai rpoc k et s . Ba sepl a t e :Th ep umpan dmo t o ra r emo un t e do nt h i su ni t . Be ar i ng:Suppor t st her o t at i ngs haf tandal l o wsi tt ot ur nwi t hami ni mum amountof f r i c t i on.Coul dbeei t hers l eev eorant i f r i c t i ont y pe. Be l l ows :Ac o mp on en to fame c ha ni c a ls e al t h atc a nb ema nu f a c t u r e df r o m me t a lo r nonmet al l i cmat er i al st oel i mi nat efl ex i ng,r ol l i ngors l i di ng. Bel tDr i ve:Ac ombi nat i onofbel t sandpul l ey st hatt r ans f er st or quef r om t hedr i v ert o t hepump.
B. E. P( BestEffici ency Poi nt ) :The besteffici encypoi nton a pump cur v ef ora s pec i fi ci mpel l erdi amet er .I ti st hepoi ntwher et hepo werc omi ngoutoft hepump ( wa t e rpo wer )i st h ec l os es tt ot hep owerus edb yt hepu mp( a bs or be dpo wer )f r om t hedr i v er .Thi si sal s ot hepoi ntwher et her ei snor adi aldefl ec t i onoft hes haf tc aus e byunequal hy dr aul i cf or c esac t i ngont hei mpel l er . Bufferflui d:Thel o w pr es s ur efl ui dt h ati sc i r c ul at edbe t wee nt het womec han i c al s ea li nat a nd em s ea l . BunaN:So me t i me sc al l e dNi t r i t e .Ac ommo ne l as t o merus e di nt hes ea l i n gofo i lo r wat er . Bushi ng:A c l os efi t t i ng s uppor tdev i c e us edt or es t r i c tfl ow be t ween t wo l i qui ds , t her mal l yi s ol at eahotl i qui d,s uppor tt her ot at i ngs haf torbr eakdownpr es sur e. By pa ssl i ne :Us edt oei t herr ec i r c ul at efl ui df r om t hepumpdi s c har get ot hes t uffing bo x ,t hes t u ffingb oxt ot hep umps uc t i o n,o rt h epu mpd i s c har get oal o werp r es s ur e po i nti nt h es y s t e m.Th i sc a na l s obeus e da saman ua lmean soffl o wc on t r ol . C Cannedpump:A s eal / l es spumpwi t ht hes haf t ,bear i ngsandr ot orc ont ai nedi na c an t op r e v entpr odu ctl e ak a ge. Th es e ar eg ener al l yl i mi t e dt op umpi ng c l ea n l ubr i c at i ngl i qui ds . Capa ci t y :Vol umet r i cflowofl i qui dmeas ur edi n,l i t r es / s ec ,m3/ hret c . Car t r i dgeseal :A s el f c ont ai nedas s embl yc ont ai ni ngt hes eal ,gl and,s l eev e,and bot hst at i onar yandr ot at i ngsealf ac es .Us ual l yneedsnoi ns t al l at i onmeas ur ement . Mu s tb eu s edi nap umpwi t hi mp el l e rc l e ar a nc ead j u s t me nt sar ema de . Ca vi t at i on:Cav i t i esorbubbl esf or mi nt hefl ui dl owpr es s ur ear eaandc ol l aps ei na hi gher pr es s ur ear eaoft hepump,c aus i ngnoi s e,damageandal os sofc apac i t y . Cent r e l i nede si gn:Th ep umpi smo un t e dt ot h eb as ep l a t eb yf ee ta t t a c he dt ot h e s i desoft hev ol ut ei ns t eadoft hebo t t om. Thes e ar eus edi nhi ghert emper at ur e pumpi ngappl i c at i onse. g.APIappl i c at i onsandal l owst her male xpans i ont ooc c uri n wi t houtt henec es si t yofr eal i gnment . Cent i poi se:Oneuni tf ordy nami cvi s cos i t yofal i qui d.
Cent i st ok e:One uni tf ort he k i nemat i cv i s c os i t y ofa l i qui d. Dy nami cv i s c os i t y di v i de db yt he l i qui ds p ec i fi cg r a v i t y att he s ame t empe r a t ur e gi v e sk i n emat i c v i s c os i t y . Ce nt r i f uga lpump:Apumpt hati mpar t sener gyt oal i qui dwi t hc ent r i f ugal f or c e. Cent r i f ugals epa r a t or( orc y cl ones epar at or ) :Equi pmentt hatut i l i s esc ent r i f ugal f or c et os epar at es ol i dsoutoft hefl ui d.I npumpi ng,t heyar eus edi ns eal fl us hl i nes . Change ofst at e:Th i sd efi nesa c han ge i np has ef ora nymat e r i ale. g .l i q ui dt o v apour ,l i qui dt os ol i d,s ol i dt ov apour . Cl os ec oupl e d:A c l o s ec o up l e dp ump i sc h ar a c t e r i s e db yac o mmo no rr i g i d l y c o up l e dmo t o ra ndp umps h af t .Th es ep ump sd on oth av eafl e x i b l ec o up l i n g.Th er e ar enopumpbear i ngsandal l t hr us ti sc ar r i edbyt hemot orbear i ngs . Concent r i ci t y :Wh en t h ep ar t ss h ar et h es a me c e nt e r l i n et h eya r ec o nc e nt r i ct o eac hot her . Condensat e:Thi sdefi ne st hec ha ng eo np has eofav a po urt ol i q ui de. g .s t e am t o wat er . Cons t antLe ve lOi l e r :Thi si sus edt omai nt ai nt heoi ll ev eli nabear i nghous i ngt o t hec or r ec tl ev el asoi l i sus ed. Cool i ng j ack et :Co ol i n gj a c k et sc a nb el o c at e do nt h ep umpc a s i n gsa nd/ o rt h e s t uffingbo xoft hepumpt oc ont r olt het emper at ur eoft hefl ui d.Cool i ngj ac k et sc an bepar toft hec omponentc as t i ngors epar at ebol toni t ems . Cor r os i on:Thi si sac hemi c alorel ec t r oc hemi c alr eac t i ononmat er i als ur f ac est hat c hangest hepr ofi l eand/ orc ompos i t i onoft hes ur f ac e. Cor r os i onr es i st ant :Anar bi t r ar yt er mt hati ndi c at esac or r os i onr at eofl es st han 0. 05mm peryear . Coupl i ng:Th i si su s ed t oc on ne ctt he p ump t ot he d r i v e r .I tt r an smi t st or que be t wee nt h edr i v e ran dpump.I tc anb eafl e x i bl ec o up l i ngt hatal l o wss omea x i al a nd r a di a lmi s a l i g nme nto rr i g i d wh i c hd oe sn ota l l o w f o ra ny mi s a l i g nme nt . Al l owabl emi s al i gnmenti sdet er mi nedbymanuf ac t ur er soft hecoupl i ng. Cr i t i cals peed:An yo bj e c tma de o fa ne l a s t i c ma t e r i a lh as a n at u r a lp er i o do f v i br at i on. Whena pump r ot orors haf tr o t at esatan ys peedc or r es pondi ng t oi t s
nat ur alf r equenc y ,mi norunbal anc eswi l lbemagni fi ed.Thes es peedsar ec al l edt he c r i t i c al s peeds . Cr yogeni c Pumpi ng:Thi sgener al l yr ef er st o pumpi ng l i qui d gas esatv er yc ol d t emper at ur es . Cut wat e r :A p ar to ft h ep umpc a s i n gt h atd i r e c t st h ep ump edl i q ui dt ot h ep ump di s c har ge. D D. I . N.st andar d:Thi si saGer mans t andar dt hatdefi nesv ar i ousi ndus t r i al pr oduc t s . De fle ct i on:Mov ementordi s pl ac ementoft hes haf ti nar adi al di r ec t i on. Dens i t y :Meas ur edi nk g/ m3orl b/ i n2.Thi si st her at i ooft hemas sofal i qui di na ci ficGr a v i t y . gi v env ol umet ot hemagni t udeoft hatv ol ume.Ref ert oSpe Desi gnDut yPoi nt :Thi si sge ner a l l ydefi nedf orap umpasac ap ac i t yatahe ado r pr es s ur eoft hel i qui dbei ngpumped,i deal l yt hedes i gndut ypoi ntonac ent r i f ugal pumpasatBEP. Di l at antl i qui d:A l i qui d whos ev i s c os i t yi nc r eas eswi t hi nc r eas ed s hearr at e e. g. agi t at i on. Di ffer e nt i a lPr es sur e :Th ed i ff er e nc eb et we en t h eo ut l e tp r e s s ur ea nd t h ei n l e t pr e ss ur e. Di ff er e nt i alpr e ss ur ei ss ome t i mes c al l e dt h e Pu mp T ot alDi ff er e nt i a l Pr es s ur e. Di schar geHead:Theout l etpr es s ur eoft hepumpc onv er t edt oheadofl i qui d. Doubl e seal :An out dat ed t er m descr i bi ng t wo seal si n a pump. The l at est t er mi nol ogyi s“ duals eal s ” ,bac k t obac kdoubl es eal sort andem s eal .I nt hepas t t het er m wasus edt odes c r i beahi gher pr es s ur ebar r i erfl ui dbe t weendual s eal s . Doubl esuct i onpump:Apumpwi t hani mpel l erwher el i qui dent er st hei mpel l eron b ot hs i d es . Th er o t o ri sg en er a l l y( b utn ota l wa y s )s u s pe nd ed b et we en t wo bear i ngs .Thes epumpsa r egener al l yo fhi gherc apac i t i es . Doubl e vol ut e:A c ent r i f ug alp ump des i g nt hati n c or po r at es t wo c utwa t er st o d ec r e as er a di a ll o ad sa nd mi n i mi s es h af td efl e c t i o n wh en t h ep ump i so pe r a t i n g a wa yf r o mt h eB. E. P .L owe r st h ee ffic i e nc yo ft h ep umpa ndt h er e f o r es e l d om u s e d ons mal l ers i z ei mpel l er s .
Dr yr unni ng:Oper at i ngapumpwi t houtl i qui di nt hepumpandt her ef or ei nt hes eal a r e a . Dua lSe al :T wos eal sr unni ngi nv ar i ousconfi gur at i ons :bac kt obac k ,t andem,f ac e t of ac e,orc onc ent r i c . Duct i l i t y:Thepr oper t yofamet alt hatal l owsagr eatdealofmec hani c aldef or mat i on wi t houtc r ac ki ng. E Effici ency:I nc ent r i f ugalpumps ,t hi si st he us ef ulpo weri nt he l i qui dt ot he e x pe nd edpo we r .Th ati sp owe ro uto ft h ep umpdi v i d edbyp owe ri n t ot h ep ump . El a st ome r :A r ubb er l i k e mat e r i alt ha t ,wh en c omp r es s ed a nd t he nr el ea se d wi l l bas i c al l yr et ur nt oi t sor i gi nal s hapei nl es st hanfi ves ec onds . El ect r ol ysi s:A p r o c e s si n v o l v i n gc h emi c a lc h a ng ec a us e db yt h ep as s a g eo fa n el ec t r i ccur r entt hr oughal i qui d. E. P. D. M orE. P. R:Et h y l enepr op y l en er ub ber .Th i si sac ommo ne l a s t o meru s edi n t hes ea l i ngo fwat erba s edan dh i ghe rp H ma t e r i al s .Ca nno tb eu se di npe t r ol eu m pr oduc t s . Er os i on:Thi si swearc aus edbymec hani c al ac t i onoft hel i qui dont hes ur f ac eoft he mat er i al s .I ti sobv i ous l ymor epr ev al enti ft hel i qui dc ont ai nssol i ds . Ey eoft hei mpel l er :Thec ent eroft hei mpel l erwher et hefl ui dent er s . F Face combi nat i on:Th e ma t e r i a l sc h o s en f o rt h et wo l a pp ed s e alf a c e s . An e xampl ei scar bongr aphi t er unni ngons i l i c onc ar bi de. Fac et of a cese al s :T wos e a l sr u nn i n ga ga i n s tac o mmo ns e a lf a c e. Th eb ar r i e r fl ui dpr es s ur ei sal wa y sl o wert hans t uffingbo xpr es s ur e. Face l ubr i cat i on:Th efl u i do rv a p ort h ate x i s t sb et we en l a pp ed me c ha ni c a ls e al f ac es . Facepr essur e:Thes um ofal lt hel oadsont hes ealf ac ei nc l udi ngt hes pr i ngl oad, hy dr aul i cl oadands haf tax i alt hr us t ,di v i dedbyt hear eaoft hes ealf ac e.Thi sf ac e l oadi sr educ edbyf r i c t i onbet weent hes l i di ngel as t omerandt hes haf tors l eev e.
Fl ashi ng:Ar api dchangei nphas ef r om al i qui dt oagas . Fl oode ds uc t i on:Thi sr ef er st oas i t uat i onwher et hel i qui dl ev elont hes uc t i ons i de o fap umpi shi g he rt h ant h ep umpc e nt e r l i n ea ndt h el i q ui dfl o wst ot h ep umpb y gr av i t y . Fl uor oc ar bon:Th i si sa g en et i ct e r mf o ra ne l a s t o me ro fwh i c h Vi t o n( a Du po nt p r o du c t )i s a t y p i c a le x amp l e . Th e ma t e r i a l ha s g oo d c o mp at i b i l i t y wi t h h ydr oc ar bons ,hashi ght emper at ur ec apabi l i t ybutpoormec hani c al l i f e. Fl us h:Put t i nganout s i del i qui di nt ot hes t uffingboxoft hepumpatapr es s ur ehi gher t hans t uffingbo xpr es s ur e.Al l oft hi sl i qui dmi x eswi t handdi l ut est hepumpedfl ui d. FootVal v e:A t y peofc hec kv al v ewi t habui l t i ns t r ai ner .Us edatt hepoi ntoft he l i qui di nt ak et or et ai nl i qui di nt hes y st em,pr ev ent i ngt hel os sofpr i mewhent he l i qui dl ev el i sbel owt hepumpc ent r el i ne. Fr e el e ngt h:Th eun co mpr e ss eda xi a ll en gt hofas e al . Fr i c t i on He ad:Thi si st he head l os sdue t of r i c t i on asl i qui dfl owsi n pi pesand fi t t i ngs . G Ga sk e t :Th i si sus e db et wee nt wos t at i cs ur f a ce st op r o v i deas eal . Ma def r om a v ar i et yofdef or mabl emat er i al s . Gl and:The p ar tt hath ol dso ne hal foft he mec h an i c a ls e ala nd at t ac h est ot he st uffingbox. H Ha r df a ce :As ealf ac eei t herr ot at i ngors t at i onar y .Themos tc ommonmat er i al sar e s i l i c onec ar bi de,c er ami c ,t ungs t enc ar bi de,St el l i t e,Ni r es i s t .Thehar df ac emus tbe t hewi ders eal f ac e. Hast el l oy“C”( al soknownasAl l oyC) :Ani c kel r i c h,c or r os i onr es i s t antandv er y har dal l oy . Head:Theequi v al enthei ghtoft hel i qui dt hatwi l lpr oduc eapar t i c ul arpr es sur e.Can bec al c ul at edf r om H( met r es ) =pr es sur ei nk Pa/ ( 9. 8xs pec i fi cgr av i t y ) .
Hor i z ont a l l ySpl i tPump:Thi si sapumpwher et hec as i ngi ss pl i ti nt ot wos ec t i ons i nt heax i alpl ane.Thi smeanst her ei sat opandbo t t omhal fc as i ng.Connec t i ons ar enor mal l yont hebot t omhal fc as i ngt oal l ow r emo v aloft het opc as i ngf orpump i ns pec t i onwi t houtneedi ngt odi s c onnec tpi pewor k . Hy dr a ul i cba l a nc e:Ame t hodofr edu ci n gmec h an i c als ea lf ac el oa di n gb yr ed uc i n g t hes eal f ac ec l os i ngar ea. Hydr ocar bon:Ape t r o l e um p r od uc tc on s i s t i n go fh y dr oge na ndc ar bo n. I I . D. :I ns i dedi amet er . I . S. O. :I nt er nat i onalSt andar dsOr gani z at i on.Se t spumpands eals t andar dsf ort he me t r i cc o mmu ni t y . I mpel l er :Ther ot at i ngc omponentofac ent r i f ugalpumpt hati mpar t sener gyt ot he fl ui db ei n gp umpe d.Av a i l a bl ei no pen,s emi o penan dc l os edde s i gn. I mpel l ere ye:Thec ent r eoft hei mpel l erort hepoi ntwher efl ui dent er st hei mpel l er . I mpe l l e rs hr oud:Th ep l a t e sl oc a t e d ono neo rb ot hs i desoft hei mp el l erv a nes . Pr ev ent ss ol i dsf r om penet r at i ngbehi ndt hev anes . I mpe l l e rv ane :L oc at edbe t wee nt h ee y ea ndt hedi s c ha r g es i d e oft hei mpel l e r . Di r ec t st hefl owoft hel i qui dt ot heout s i dedi amet eroft hei mpel l er . I nduc er :A s mal lax i alfl ow v anet hatat t ac hest ot hei mpel l erofac ent r i f ugalpump t h atr e du c est h eN. P . S. H.r e qu i r e db yap ump . Th i si mp r o v e me nto c c ur sac r o s sa nar r owc apac i t yr angeandt hei mpac tc anbedet r i ment al out s i deoft hi sr ange. I nduc t i onmot or :Th emo s tc o mmo nt y p eu s edi ni n du s t r y .Ha sas l i p pa geof2t o5 p er c e ntc o mp ar e dt os y nc h r o no usmo t o r s . I nl i nepump:Mo un t e di nt h ep i p i n gg en er a l l ybe t we ent wofl a ng es .Nob as ep l a t e oral i gnmentr equi r ed. J J a c k e t :Us ual l yr ef er st ot heheat i ng/ c ool i ngj ac k ets ur r oundi ngt hes t uffingboxon s omep umps . K
Ka l r e z ®:An“ el as t omer l i k e”mat er i almanuf ac t ur edbyE. I .Dupontt hati sus edt o s ealmos ts ol v ent sandot heraggr es s i v efl ui ds .I ti sa v ai l abl ei ns ev er aldi ffer ent g r a d e s . Ki l owat t :Onet hous andwat t s .Thenor mal uni tf orpo weri nt heme t r i cs y s t em. Kpa( ki l opascal s) :Amet r i cuni tofpr es sur e.
L Labyrinth seal: A non-contacting seal utilising a tortured path for the escape of the uid. Utilises a series of pressure drops to reduce the leakage. Lantern Ring: A device used to supply lubricant to packing. Usually located in the middle of the packing ring set. Line bearings: These position the rotor or shaft radially and are normally of the sleeve type. Generally used in vertical pumps. Liquefed Natural Gas LNG: This is liqueed gas from natural sources Liquefed Petroleum Gas LPG: This is liqueed petroleum gas hich is a by-product of the rening of crude petroleum oil. M Magnetic drive: A type of seal less pump that utilises permanent magnet technology to provide the rotation of the impeller. Mating ring: Another name for the hard face in a mechanical seal. !t can be either rotating or stationary. Mechanical seal: A positive sealing device used to seal all uids "liquids and gases#. The primary seal is a set of lapped seal faces that are installed perpendicular to the shaft. Metal bellows: Used in mechanical seal designs to eliminate the need for a dynamic elastomer and springs. Metal atigue: A breakage of the metal caused by the bending and e$ing of a metal part beyond its endurance limit. Minimum ow: The minimum capacity of a pump to prevent thermal and%or mechanical damage.
Moment o inertia: This represents a magnitude of the inertia in respect of the rotation around the a$is of the pump and drive rotor. Multistage Pum: This denes a pump that has more than one impeller on the shaft. N Negative ressure: A pressure belo atmospheric pressure. Newtonian !luid: A &etonian liquid is one hose viscosity does not change ith increasing shear rate e.g. hen agitated. Non "verloading Power: This refers to the ma$imum poer absorbed by a pump ith a specic impeller diameter and liquid.
'otors are
generally si(ed at the ne$t si(e above this poer. N#P#$#%#&: The net positive suction head available to prevent cavitation of the pump. !t refers to the suction side of a pump installation and is dened as the head acting on top of the liquid ) static head -vapor pressure head * friction head loss in the suction piping. N#P#$#%#R#: &et positive suction head required to prevent cavitation of a pump and is dependent on impeller and pump design. manufacturer determines the &+, by testing.
The pump
!n all cases/ it is
imperative that &+,A 0&+, to prevent cavitation " "#'#: 1utside diameter. "erating length: This measurement is set by manufacturers to provide the correct closing pressure on the to mechanical seal faces.
The
measurement can be made in a number of ays dependent on manufacturer. 1ne measurement is from the face of the stationary face to the location scres for the rotating part of the seal. "rifce Plate: A plate ith a hole smaller than the pipe diameter in hich it is located "ver hung imeller: &ot supported ith bearings on either side of the impeller. P
Pac(ing: The soft rings that a mechanical seal replaces to stop leakage. +acking must have a small leak because it orks on the theory of a series of pressure drops to reduce the stu2ng bo$ pressure to the point here the leakage is acceptable. Generally/ a minimum of ve rings of packing is required to do this. Parallel oeration: This refers to to or more pumps that are discharging to a common header. !t is important that the impeller speed and outside diameters are the same or one of the pumps may cause other pumps to operate at shut o3. %: A measure of the acidity or the alkalinity of a uid. The scale ranges from 4 "acid# to 56 "alkali# ith 7 considered neutral. Pie strain: The strain on the pump volute caused by the piping. !t ill cause e$cessive mechanical seal movement and can cause contact beteen rotating and stationary pump and seal components. !t can also cause serious misalignment ith resultant damage to bearings and couplings. Pitting: ,urface voids caused by corrosion/ erosion or cavitation. !t is possible for the three to occur at the same time. Positive 'islacement Pums: This is a collective denition of all pumps that operate according to the positive displacement principle. That is/ the liquid being pumped is displaced by a body hich periodically increases and decreases the orking volume. Power end: The end of the pump that attaches to the poer source and is not etted by the liquid. The bearings are in this part. Precision bearing: 8all or roller bearing as opposed to a sleeve bearing. Pressure gradient: The pressure drop beteen the seal faces. Priming: This refers to the lling of a pump ith liquid prior to operation. ) )uench: The introduction of a uid outside the seal to cool the product/ dilute any leakage across the seal faces or isolate seal faces from atmosphere. R
Radial *earing: This bearing handles most of the radial loads put on the impeller. !n an end-suction centrifugal pump it is the bearing located closest to the stu2ng bo$. Radial +hrust: This is the thrust produced in the radial direction i.e. at 94 degrees to the centerline of the shaft/ by forces acting on the impeller hen operating at points other than 8:+. Radially $lit ,asing: A pump casing ith the casing ;oint at 94 degrees to the shaft a$is. Rated "eration: This is the basis of selection of both pump and driver.
and
peristaltic
type
pumps
only
"both
are
positive
displacement pumps#. $eries oeration: To or more pumps connected ith the discharge of the rst pump discharging to the suction of the other etc. arely used these days.
$hat ac(ing: The soft packing located in the stu2ng bo$ to provide a shaft seal for pumps. $hat Power: The mechanical poer absorbed at the pump shaft. $hut o/ head: This is the ma$imum head that the pump can generate ith a given impeller outside diameter. !t is normally at (ero capacity. $leeve bearing: A non-precision or anti-friction bearing. !t is usually manufactured from carbon/ teon/ brass/ hite metal/ other synthetic bearing materials. $lurry: A slurry is a liquid in hich solids are present in suspension. $olubility: This denes the ability of a liquid to dissolve ith another liquid. =or e$ample/ ethanol ill fully dissolve in ater hereas oil ill oat on ater. $ecifc Gravity 0$G1: This is the ratio of the mass of a liquid for a knon volume to the eight of ater for the same volume. The reference is ater at 6 degrees > ith an ,G of 5.4. !f the liquid you are questioning ill oat on ater the specic gravity is less than one. !f it sinks/ it is higher than one. Note that this is based on the liquid not being soluble in ater. $ecifc $eed: ,pecic speed of a pump is determined by the geometry of a pump impeller.
The higher the specic speed the less &.+.,..
required. $tainless steel: Alloy steels containing a high percentage of chromium and%or nickel. $tatic head: The height of a liquid above a reference point e.g. pump centerline. $tationary ace: The seal face that does not rotate ith the shaft. $tu2ng bo3: The portion of the pump that held the packing and no holds the mechanical seal. $tu2ng bo3 ressure: The pressure in the stu2ng bo$ and generally beteen suction and discharge pressure but closer to suction pressure. $ubmersible um: A pump%motor pumpset that operates only hen totally submersed in the uid hich is being pumped.
$uction lit: +umping application here the liquid level on the suction side of the pump is belo the pump centerline. $ystem resistance ,urve: A graphed representation of ho total dynamic head varies ith capacity. A pump ill operate here the system resistance curve intersects the pump performance curve. $ystem head: The head caused by friction in the piping valves and ttings.
+ +andem seals: The seals are facing in the same direction ith a lopressure barrier uid circulating beteen them. +hermal conductivity: A measure of the material?s ability to conduct heat. This is a very important factor in the selection of mechanical seal faces. +hi3otroic uid: The viscosity of the uid decreases ith agitation. &on-drip paint is an e$ample of such a uid. +hrottling: This means closing of a valve on the discharge side of a pump to increase friction loss. This steepens the system resistance curve ith a resultant decrease in orate. 1pening the valve results in an increase in orate. +hrust bearing: This locates the rotor or shaft a$ially and is designed to handle any e$cess a$ial thrust load.
!n an end-suction pump/ it is
normally located close to the coupling. +hrust: !n a centrifugal pump it refers to the a$ial movement of the shaft. The thrust can be toards the et or poer end of the pump and at start up it thrusts in both directions. +otal 'ischarge %ead: This is equal to the pressure at the pump discharge connection converted to head of liquid. +otal 'ynamic %ead: Total dynamic head is equal to total discharge head minus total suction head +otal $uction %ead: This is equal to the pressure at the pump suction connection converted to head of liquid.
+ungsten carbide: A common hard face seal material available in several grades depending upon hardness and corrosion resistance. >obalt and nickel are the to most common types. +urbulence: This refers to disturbance of uid as it enters the suction connection and %or the impeller. This can cause cavitation problems in a centrifugal pump. This is often caused by an insu2cient length of straight pipe before the pump suction inlet. 4 4nbalanced seal: A mechanical seal not designed to balance the closing force beteen seals. efer to *alanced $eal# 5 5ariable seed motor: This is used to control o in a system by varying the frequency of the motor. A better system than throttling as it reduces poer consumption signicantly. 5acuum: This is a pressure less than atmospheric. 5aor ressure: 8elo this pressure/ the liquid at this temperature ill vaporise. 5aorisation: The uid passes from a liquid to a gaseous state. !f this happens at the seal faces the seal faces ill be blon open. 5elocity: A measurement of the speed of the liquid in the system. This is measured in metres per second. 5elocity head: This is part of the total head calculation.
This is
calculated from the formula @ v%g. 5ent: This removes air or gas from the system. !t is important to vent the stu2ng bo$ in vertical pumps to prevent the seal faces from running dry. 5iscosity: This is dened as the property of a liquid that o3ers resistance due to the e$istence of internal friction beteen layers ithin the liquid. 5iton6: An :.!. Bupont Bo manufactured uorocarbon elastomer idely used in the sealing industry. efer to !luorocarbon#
5olute casing: This derives its name from a spiral-shaped casing surrounding the pump impeller. !t converts velocity energy to pressure energy. 5orte3 Pum: A type of pump used to handle liquids ith entrained solids/ particularly stringy solids. The impeller is recessed into the volute. A very lo e2ciency design/ but practical in many applications. 5orte3ing liquid: >reating a Chirlpool a3ectD that can dra air into the suction of the pump. Eortecies can form both from the surface of the liquid and in vertical pumps/ from the oor of a pit or channel in hich they are located. 7 7ater hammer: This occurs in a closed piping system as a result of the pressure being rapidly increased hen the liquid velocity is suddenly changed. This damaging e3ect is usually the result of sudden starting/ stopping/ change in pump speed/ or the sudden opening or closing of a valve.