Bearing Life Extension andReliability Features ofModern ANSI Pumps

Presented atThe 2nd International Conference

on Improving Reliability inPetroleum Refineries and

Chemical and Natural Gas Plants

Dr, L"" Nel"GO!Jds Pumps, Inc.

240 Fall Stree1Seneca Fan., New York 131 48 USA

..'-- ""- ""-

TABLE OF CONTENTS

2.4 Eflect of • .....,p depth on oon18m,Mlion cct'IGenlration .. ,

2 .S Ellect cf mcr_ hoat If.....fe' surface. . . , .. , ...

1. Overview, .

2. Feature Anarys's. . . . • . . . . . • . . .

2 .1 Ellect of fr ""rface "'.... increase,

2.2 Baaring I~e ( designed) ,

2. 3 Eflect of deeper sump on 011 c.icIel;on rate .

2.6 Summary of etr_ ., .... , .... ,

se

.. . . . . . ........ ,., 6

.. 11

..... 14

tsis

. .. 16

"ao

........ 20

.. .. ... . .. ... .. 22

. . .... 23

aa5. Summary .

6. References .

3 . ECOrlOmic Bel1efits .. .•... . .. , , .

4 . Testing . , . , .

4.1 Effe<:l of 011 leY.. on col lempem1ure, .... ,

4.2 Oi "'burpingO_ .

,

1. OVERVIEWANSI PU"1Pfl, simila r to tI>e one at>own In Fig,I . are u>ed e.lensive~ In lhe che micalprocess indualfi<os. Tho p....,p ia a singleatage, """'hung , end suction 00sIg<1 bui~ 10ANSI sper;i1icatiorYI (ReI·lll) ,

In!fO<b:ecI ln 1961 . this pump wasf1Idesigned In 1!11l1 by enhoneing power endl&IIlu"," , The ' edesigned new vltrSion w ,,"

nam<><! the ·X·Seci",,·. In tI>e "wet" end, theea5"'l1 and impeliet d" not change be( newaeeJ onerrt>e, d""igns ware added. The new

""'"111 consIiM...i"",~as """"'"In Fog, 1 and 2 a nd Table 1,

Thes& CMnges were rn&da not <>nty 10improva!he da"'ll". 001 .no 10 m";n1aOnCOIT4'lete interct>ang.eabilily w~h tM olddesign IOI Iie4d ret'Olits,

Thls in'Ip"""" <leSlgn was targeted to addvalue 10 a product. by increasing Moan T"""_ SChedule<l Mainlen ance (MTBSMj ,and Mean 11"", 8elWeen Failu,"" {MTBF),

To quantlfy lh&se lmplOY<lmel1ls, a r_ ililytesting program to confirm a nalytlcalmethods used On lhis paper. w,," coMuc«>d

This tBChniCal P"P'" present. tM results ol a.t"'" e>:>n<i.Icled 10 comparapu""lcomponenla ' eIiat>liIy. in ltIm"oi ore"'endo<l bearing lite and 'ecllcedmaintenance costs, lor a typiCal ANSI pump,eqcipped _ a new """111 Ira"'" (Mn<)V8l'S<Jalhe old <iesign {Mn.

Rathar Itl"" analyza all 01the """"'esmentionad in Table 1, ~ was _10 studylhe eIIec1a 01 just one or tI>a 1ealures. natn<>1ylhe larg e r t>eann-g oil """,p . The effects or_1eatures are av.,;tabIe lor presentationin ...,erate studies. In <>roe. to keep eachaubjeCl locu.ed a oo WIThin re asonable lengt h

The foilowing d iscussions are. lhetetore,concent'ated on the e ff9CI ol ,he larg", oilau"" on be"'ong IIIe , lncIessed CyCle Ole andreduced maintenance <:<;1St. fora lypjcalInstallation Analytical lomlJlations.assu~s and conclusiona a'e presentedli,st, foIlaw<ld by the tast MIa. as OOIlined Inthe tarOe or C<JnIenls

Table 1X·Sa"'. laalu" ." '- -1,

aa,s

e

la<Qer oil sornp volume

S;ghl glass forea..... mon~Clfing ol act.... oil _ .

Rig" Iram e (mo re rigid, sol") i0oi lor bene , ,,,,,,stance to P'P'8 load etrects

Standard ca<I>on-filler:l T_ labyl'irJIh oil seal• . Ma!J""OC seala ...e <>phona l

Opbonal C·I""" _ pt... for 5impler tJU"'!'"lo- moIor a l'9"ment _ , In Ilrn, reducedvil>ration

Lar1)8 seal oavrty le< bell.. seal lile via ",",,""'ed seal heal mndlliOnS and larg..Iiq"'d """""'" forcooIirlQ.

•

Power End Comparison

...,. (old.. dellg n)

­~--\~:::,~~~ '::..1

lUX (..,hlnoad "'"~nl

I~olntenonco. Ports 1 1--'llnlo<Cha~• .t>1I7_11....._~O~~lplion "" ' 0 (;omnMI<>ll11M ;Ball _"II " Ql!l\lQard x

1'= iShaft with l.ocI<flIJI & x~.~

!'kJl~m'" Qef1eQt~ xtae ' Shaft Sleeve x~~~Ile~Hoo~ng x16M &II Bearing . Inboard x??1311 Be"""ll£........ .[$Y;~ x2. 1 Frame . ~ . ll!' 1 ._ ,2;51 ~Wtt~1 ~"" x OplKw1<ol,!"1_MIX

'''' Qi Seal ·~rd x ~ ·nthOfll

sa .. !~al - I._ x labl"i.nth Of Up

""" Gasl<t!-_",me .I.c.AdS{ller x"" Re1ajnirlg Ring • Eltoaring x

tto\lSi37Q J;.P _ BcnstN~. ")rrpeller Adjustmerol370F C~~oot 10 Frame x~15 J am Nut~ller Adjustment ,." ...~~rir-g x.~ ~. "'" c, • " x No! used Of> MT

•

-~ADAPTER-------

•

lARGE DOL SIGHT GlASS.-..-..__ ..oI __ ""_~". ., ...

......""---

• 'J,• ,•

.-:/

• '.•,

(',,

••

"TX

CDNDITION" DN/T0R1NG SITES..,.,_.... ...-."""""'""' .._.........-""­.. ......... """"""_ .-

ElCTRA LO.R<;£D1LS..­

L.a<9ool _...­-,,_0_""-'--

Enhanced Power EndDesigned lot Reliability,Ex1ended Pump Ule

CA_-...LUD TEFLDN"lAlIYAlNTH DR. SEALS_...-"''"''-<..._.......----..........I8 EAR..G ASSE..SLV

--"" ..........._""00">g­...._'"'--""-.....- - - - ';l-

-_ ..................--'- """"-"""'"S<I'- ......M.....__.........__...-­...........-

e-f'ACEolDAPTERx·_ _ ~- ­~------

RIOlO .........,,=- _..--,.,--,- ......:._.--- .-_...._.

,

.2. FEATURE ANALYSISThe ANSI X-Series pump has a modulardesign, and has three main power end sizes:STX, MTX and XLT·X. The ' X" des ignationIndicates the new power end design.

The MTX bearing frame size covers themajority of applications, and can bereasonably called a "typical" bearing frame.The analysis performed in this work usedMTX versus MT power ends, although basicconclusions and findings of this work applysimilar ly to other frame sizes.

A key to a trouble-tree operation of the pumppower end is life extens ion of its ballbearlnqs. Bearings and mechanical sealsare known to contribute to the majority ofpump failures.

The life duration of ball bearings depends onseveral factors. Th e most Important of thesefactors is lubrication and tho condition of theoil in the sump. The MTX frame (nowdesign) has an all sump with approximatelythree times the capacity, of the older designMT frame. An MTX frame contains 2.6 pints(42 oz) of oil as compared to 0.8 pint (13 oz)for the MT (Ref. [2]) .

There are several benefits to this: cooler all,a cleaner lubrication environment andreduced oil oxidation. Specifically , a widersump makes it less sensilive to oil levelfluctuations by turbulence, while running witha constant Iovel oiler {option to a sight glass ,which is standard}. A greater sump depthresults In particulate settling at the bottomand cleaner oil reaching the bearings, as wellas an Increase in net heat transfer area ofthe housing walls.

2.1 Effect of free surface area ncreaseThe X·Series is provided with a sight glass,which gives an accurate lndicatlon by visualobservation of the oil level in the bearing frame.A constant level oiler Is available as an option,with tho tap provided for quiel< installation, ifdesired. In this sectJon we will analyze

8

operation of the bearings and oil conditionwith the oller Installed, as the case may be.The phenomenon called "oiler burping" iswell known in the industry , and can bedescribed as follows. Consider an oilerattached to a bearing frame as shown in R g.3A, when the pump is not running, and theoiler has just been filled to a proper lavel, asspecified in the oiler setting instructions.dimension "A" (19f.!.2in. for MT/MTX frame).{Note: It may be helpfu l to obtain a copy ofTechnology Nota #2 (a VCR tape) for bettervisualization of the oiler operation and properoil filling method, Ref. [8).)

Initially, the level of oil In the frame ltll~ isequal to the level in the oiler l..ci1. rV\l. whichactual ly controls the level In \he frame bycutting off the supply of air Into the oiler glasschamber as oil rises to L..",I"(A) during oil filling(Ref [8)). AI this point the oil level inside theoller chamber Is at l..cn""'bor(A) level.

fIJ I ""ell ..OIl'" <I\ilmllU

Figure 3ft: Oilleue! as inWally",t afta filL Primpnot m'l1Iing (LlI(A) =I.."iltr tA)).

Consider now what happens when the pumpstarts. The disk friction action of rotatingbearings picks up some oil from the housingand forms a rotating liquid disk. The level ofoil in the oiler wil l drop to level L.:.i ftB) tocompensate for the "disappeared" oil in thesump lti{B), (Fig. 3B).

"-~--

--

- -_ ...~---f.,."J& Oil _ ""'f'pwI .. . .....,,'"~_,,;I

........... ""__ ."10M""., .."."'" ' ''''' ' po.Clearty, air """ ""'"~ Into l/le oil..ohambe< (as sh<>wll) wr.ere ~ will d>splacesomo more oil OOJI '" tho glass chaO'tlel Intolhe oiler and housl'lg. The oil level wi~ riseullli • willouch the low'" end, I.e" theOpening 10 tho glass d1arnbet, <:u1I!ng 011 ""flurtr-.>r lIi< ""p/'1 ('FOg. 3Cl·

"-~--

- -_...~---f;g... X ' Oil _,.""'-hot k ........ ((1~

",,,,..,...,.,, /D-",'o(i0J ,"'I• .....,.;"gfroo-·

The process. l>y 1IsElIf, is rU dolJ it,.. lIlI lO P<"'l>...... iIi<> , .....,., tho 0111...... will sti~ be at thedesired level (cenler of the lower Mil)

The problem is, hOweve<, Inlll tho _ . L..and '- e re n<ll perlecl, bul e.t1ib~ w...-inesadue 10 lUrbu!e,.." end onurning ot 01 in thebearing hoosl'lg

As a ",.u~ , tho fol lowing regime mav exis!,IFig. 3D)'

.._~--

--

--_... ~---f;g.<" ,n 0i11<WI ........... """"""'" "''''''k.....

Now. lhe oi can lind ways among theturtlulenl peaks and "alleys to IIow irJIo lIle"arne, Iow"ing Itle _ in tho et>am_lOt.-"".and the _ in the frame wil be"ilI_ trlDn required, covarinij the ....... balaI><Jva its renl er. TliII oiler "burpi ng" woAco<ltir>Je unti !he oil ri58 ' higIl enough toprevent oit from enteri ng the glDss e!1amba<evan M l/le 1ow...1"allay" 01th<llurtlulenlie'<a1 (Fog :lEI, .._~-

- ---...~---flp'" ,I:.. SId ,l;uJ .",.._tWo. T.""'I...' .... ""r.

<f/«tl<o 0"''''11' ''''''.i~ rho. u.ipnI,

This resullirlg nil/CoIr oil laval wi! cause""""a.s<ld healing due to the cCo,i,ning •.,,",,,,ollhe oII-beari'lg contacl ""d, in tum , willoogatr.t<lly affilCl beaiing lile j... will be_late<),

•

F..... oil ..... (Fill 5 ).

.. . 'Ol:"lo (l>aII "* ......",,111e1) COYefed), . 1 25"" (.........-~)

a " 2OO'lO (el"",,", "'" oIlt101 . hlIlI coverell)

.--,, .~_.

.~..­._-­.-.-

T_ _ II"" ... 4 hoIn -... t... -.ore,~ ....__&t.... w. _(Flg, 6) ,

At. -..pecIOod . "'" 00 , ..... ol oil~""' .. iF ...

... "",..- . ,.,..-.ng ""'..-......~ 1O...

..,_10.. <111.'........

--hpow" -.....'::==,..".......,.oiI....,._..__

(' a I ' . c..lb. oil_toM I.' ol ...

__~l

c " .-ol "'" _l'oO'Il» .<IIo&ign -.g,.~

LM'e 1 ;"el."",Mlui .. _twoIA_._~ high 01_ - ""9' -. .&I., __ in lAcl.4)

, h-~---- -a-=-B:=:_--fl.-':'

hpow. 0 f ' '__----...--.._ INI ........ _ ...... CIIlIoln II

_ r-- -V- gIDIl "'" -..;J d ...."'_11 "*,,,", "' It _....,..,."_Ihif of in "'" _ . _ 11' II

...-_ol "'" oil _ -.g 'ao high • "'"hoIMI;. 0lM0usly,Ihif.QIall optiOn_ """'"' _ PlotlIem, ....,. no bottlt,.,11 PI_ I.• ., no 'b<IrpO>g', _ n. oil_ can be property ad j,,",ed """"' l~PU"'l' It OlMed

~".... """" f tho oMr (JplIonli_b tho loITX Ir_ .""'1u_ ol oil in "'"__be__lO lo...., ed ....

..... (&&_as~doIpll'll. n.__.d.....io.._""~

In_lO--'"'Ytho~olil... ,_....... "".........- ..-.;_~ M ..,. ....._'" '-.... r. __oI_~,b__.._'olr._F...... ·4l.---..-(Fi;. 4)__. ,.,..____oI_b<mIi _

1hif_In""_~.'ibeo_ _n.""""' ... _ ..~...... ,.,..---~ lObeil.. ~ ...,--lily 'I,"",

""'~""becIIm&: _ 1O~,0Ilal.__ 10 bII"""(l Nle?

To _this, _ "'" sec ol lOSl" w ,,",

<:or>cIi.><:Iedb_frame, Iod-.nino thoo!I&cl of baI ...... ,...Il"' .... an 01 ."..~,__.t,", end.~ty. an.......•

"':o ---. - - - , . --,. --=-.of u--11011 eo.erogo {""'" I

ril-"~ 0;1 />""';0"of .il l",d ~'

"'" 1"""..1•• 11,

~--

2.2 Bearing llIe (8a designed)In ltIe loIlowlng anaIysOs W1t wii use <latafrom the SKF bear'ongs m.....,al (Ref, l:!l),

Bot~ MTfMlX frames use 6309 'adialbewlng, and 5309 A-C, l!1rusl bearing . Thet~nJ'" bearing opeta1es undet ~Ighet loed ,and 1he<__,mines bearing life

minimum ""lUj'e_

The ma><imlln design loads iml'O""d on thisbe-mg "'" tho radial load. F...'COO Ibs. andl he a><ial load. f . _goo Ibs. These are~by Pu"'" hVd" "di<: lOads (wo<sl case),lransmitl<>d to II>e beanngs due to l!1eintern.. Pu"",, pres.&nI distribut ion.

T_b1• •~_ ii;;;- _,;...;..-- __':" 1'- --,,",.._.. _ ............ -• 0 • ,c _ •- , , - •• • • •• ,. •• "- .= I~"" •.= .= ". -'-1'" '"' " ,,- " - ••

.."~,_.. ---- 1=.,-:"'- -""w,,"w.. ~.

• ., • ., • • , '. ,_. ,_.- - - --• • • • • •- - -• • •• •• .\ .1 U • • " " o. , on o. ' " O.

1 "" .=.., .- ,- ' ."20 .~ O~

Table 2 p.10 contains basic parameters forthe 5309 A bearing. The calculations for thebearing life usually done for basic rated life,for 90% reliability, L 0 and adjusted rating lifeL..... (Ref. [3], pAO):

C 3 HfLlO :: (p ) 60xRPM (hrs), where

C is basic dynamic lead,P is an eq valent dynamic rating .(C:: 16,400 Ibs .• foe 5309 A bearing) :

l.o. :: a t ~ 8<3 or L,. :: a 1 /i;!3 L o,

wherea t :: 1 for 90% reliability calculations (Ref [3).p.3 ). andaZ) ls a mater ial and lubrication factor,obtained from charts.

The eq ivalent dynamic load can becalculated as follows (Ref. [3). p. 42):

p :: XF, + YF•.and for 5309 A bearing (Table 2) it is equa l to:

P =0.63 x 400 + 1.24 x 900:: 1368 lbs.

The requi red 011 viscosity for adequatelubrication (Fig. 7) can be determined fromDiagram 1 of (Ref (3). p. 32) , and is equal tou, = 82 cSt. The oil used for MTIMTXframes is ISO VG68 high quality turb ine oiland recommended temperatures range from120"F to 1BOoF. (Fig. 8) shows Diagram 2from the same reference (3). showingviscosity versus temperature. Usi ng 120· F,we will get u :: 45 cSt actual viscosity, whichwou ld give us a K (kappa) factor of

"K :: - :: 45/ 8 2 =5.5V I

1,000

500 ·

200

100

50

20

10

5

310 20 50 100 200 500 1,000 2,000

--- dm=(d+D)/2 mm

Figure 7;M in;m,m, ml"i"'r/ oil t"~,,'ity [tlTl . ghY'1I ",""rillS d,... (Rrf. /3/, , .,.32)

12

II

u ,-.--='.•-,-

The coefficM a., can oow be ,_ from I""mort In Table 4 (Rei_ 131.1>-:J<l , [)lag'''''' 3):

81 0> •.• , • • ' .---+K . D/u

(;SVn '" M~tmoI .,.. 1_""""'_"""'rinol , ....."i",,"'Y1""""'· ("4 /31.~J

F'" OUr K . 5.5, ..., . 2.5

We c.-. <10'0 calculate !he bearing lilll,

, (16,400 , .. 1f1,, - , '368) 6Ox35ao ,"1lO21hcs..~.... . 2.5 .8021 . 20.052 hr' , _2,3y""'_

TNsWikJe~Ihe-"""~

be<mg IiIe of 17,500 hrn,per ANSI~(ReI(2JI. "'~!oconstructa~_tMoillemper8lu"'ond

beaI1ng lIle, !of 8nf beamg. Fig. 10 _ oucI1a ' .......... ~.....-.g FIQS. Band 9.

-­,t.'"..­',,"00,­lO,_..­,­,,­,,­,.,....L~~;."_,;'~.M7.r-

"

dL ~ 'I,,' corresponds !<I""p«>.jmate~ 59%"""" (or IiP'lIio <:Nell ,,",9n leveQ for 1M l>aIIsize <J! S309 bearing oo;ngapproximately0.00' oj_or, (Fig. , 2). This c""",,por>dsl<> "",...,._toty 400 11<I<M. "",-"""" .,_ ingIi!e fH!I' (Fig 11)

Agliln, ....ng 17.SOO h<>urs ftS .. <Iesigonbearing liltt, this d<>erease correspo;<ls lC

,~ . lOO'lEo . 23% .

We can ...,.. say ""'!he , ~_oo~ ·_ due to oiler .......... 2.$% ile _ as"""1>'UJld to MTX In <dual ilslalaIions, even

lligf>or """"" _e tt>p:>r\9d, "" lhaI23'lr. is~ <:onservativ9Iy .,..,

2.3 Efl&CI of deeper Bump On alloxidation rate

The new design (MTX) ""...., is "",,_ablyI&rge< ,., VQIume (nea<ty tripled): lI1edimensionale~ of Oil in MTx and MTfta...- "'" shown in T~bI. 3:

The fraquerqo 01 oil cMnge WCklId.corresponclin(J1y bo %z ~ 1.9 """'""'"' or !helaIyef 6.• \imas a VfJ8J,""'"". 21lmes a year!or !he iaI;lesl M1X"-

Typically• ..., oil change Ial<es 15 ml""tes,whlch. m a mla or SOOIHR, is $15. plus 1hItcost or oil, say, 01 $5. to a 101a1 of $20 pe,ctlange. The ""' ......"'IIS w<;J<lkJ then boo

$2ll • (6 .4 • 2) • S88 pe< p<Jmp pa< y<>ar,

G_ ~...,.,,"'" (more oil) """ <lei"",",,"eIIeots on CJ<idalIon oIoi1. S""", _1aI<". piolaI rr<>oI!y !Ill II» layer otoil ""'" thefree ...l""" ..., prcpagat9S inIo !he Oil ......!me, _ ... "'" I'f'3'ier1l in loweram<U1IS Ina IaIije< """"" """". The ox_01 01 c:httmI<:aIy Ira """,11$ b most .......­~inIo_, ..._ ...,_

~ (ReI , (4]. p,S14) The a<:oop!lld nJlealttunb IoINil an _ ..0iI~",011O'C (11J' F)~ I!le o>o:idaliorlrate. AP''''' '' '' f "1_ an:! Operallon MMuar(A8I (5D.~ "" 01o:I'lar-y> III _""""y 6 monIhs. A>J was .rown .. _ 2-2,I!le MlX design......... n~ 4O"f<XlOIer .... (Fog. 11), l'Ildesignoi level. To

_the '"""" """ 01 _ b I!le MTIramo> as b MlX, !he oil would .......:Il<> bo

dIange<l """" fr<>qIJerfIv; ... 0l0d8lion ,"'"

-~1 . """.. . 3.2_ g_,

-..

. . ,.. ... ,.1

' -, ,

"

. . '. '. .­"

E'~.: - -+f ::J- j

-- - '-~ ~ -'-'-'-~"""'"- - J ;" ~ ':';; .-. - . - --- • •

, ' ~ i~, ,' ,"

­••­••......t:=;'"

rig. 11.. ""..r""""". ..ru- """__.oJlonm og Iif<. (No' " """ ,..-""-..-_

""-. 1""'S" ""J.......;po. to- M T."Mrr~

Obvlou~ , sOnce ttle MTX !r""'"~ withtI>e oIghl gla... no . ariaIion in AL 10\101 needbe aoooonled /of, sinc:e lIle oignt glass al40wsvisual <:or>Ir<> CHI>< 1I"Ie~I _,

I /••, -.....~~~ --- -- I

t. ,~ ·- \. -r

..

orr.. .." """" ......,..... oil "' . ..... .­, , in fie~=.-."""-*J.......__olcooCW•• _ .So....",. • 1arlJI'f ...... .~_10drrdr ....... _ _ 01 ...

-~ -t'JC ' p '0_5 1368 . 0 ,e (Ml)n.. 1ilIo <;<ltT_ f",*,,- -. ""'" be , _

from Rei [3]. pg. 36, _ • "'P'odueed inF~ 13

FOtciraonoil. __ 50. _ 101.,.,...,..ed _ _ 2. . ...... . ,.,01

~ _21n. ...,.........._-..g .

_."' ....."" ..T_.: E~ of oil eontamlrwllOtl .110 .,.,.,,," .,

V-"" ... b' '''''_'lCfard~~oI~(SKFe.teIDg}

_~dltion •Very Clean00iDtIa oIze 0I1he ..... 01_ k>bricanl ftIm 1Ndo _ t

'"'"eo_.lypicaIoI_..... lII_ ·tor... ..-.I ..- 0.'-eo_.1ypit;oIId t ,I ....~tor.__ 0'.............eo. .1ypit;oII of ' • .......... "'-lI"" _ ..... _ I----~I>gr.- ......~ 0,5 _ 0 .1-...,.-----• _ ........__.._ ... coo•••• ~ ......-"'--_.....",_.."",, -_'-"-__coo. ,_ "' .._ ..___.,-*'\1".____ 01-- .. -~

2.4 ftfKt or aump depth oncontamInation COI ..... ,b.11on

n...--~__ c:ontaminanIs 10_ .. \tle _ . -.no _it 'OS toaper• • in . c:Ioo"", oM _.-w:, As ....,~n In Table 3. the new",mp design Is2,3 ' ...... <;loooIpw, To~ 1/>11 -"lICl 01oortarrWIalicIn.-._ wII again ,_

ttl lN SKF camlog (Ral, [31):

-.... I1'1III .. lilT)( If_ oonraor. oil in-.coo......... -.;...._' 'l>l<_OJ'l._.. MT _ ...._ •• '.coo...... '_foI.-O-5l.

"

s+-- t--- /--- -+--yJ'-/t-I-'../-,L.l--cI--J!---A-- - j·-/--/

0 1

oos-l--~---ji---I--+--+--___!-__+---+------1D005 0.01 0 .02 0 .05 0 I (I;'

p~c

Figuu 13: " SIO correction[actors d,,~ 10 oil ..mtumination. (,cffJ}, 1'. J6)

2.5 Effect of Increased heat transfersurface

Friction fro m Ihe bearing motion results inheat generation. This heat is rejected to theoil, and must be carried out to the outside airvia conduction throug h the frame walls, andconvection to the outside air. Some of theheat also being transported to the pumpcas ing via shaft and bearing spacer piece,For the cases of pumpage temperatures intho range of 120 - l SO"F, this axialconduclion is relatively small, due to thesmall temperature grad ient between thebearing frame (heated by oil) and the casing(heated by pumpago).

In this study, we will assume that all heal Istransported to the outside air via bearingframe outside surfaces.

First, let's calculate the amount of heatgenerated by the bearing, using (Ref. [3), p. 46).

NR =1 .05 xl0~1 x M x RPM (heat),

whereM : 0.5 MFd,andM:O.00 15, for deep groove ba ll bearings.

_ H_oo.!. .-Tout (out.id.. ClIII)

1!m~ .....! ,~t ence datum

Tin

Hom- - - ..r~_-1C-

toO..4 1"

The MTX frame has ~::; _ 1.21 (21%)

grealer total heat transtsr area of the bearingframe au or surface. This results in coolersurface and cooler oil, as can be seen fromthe following calculations.

The mechanism of this heal transfer 15shown in (Fig. 15):

Fj~'lI"c 15: llcnt t,...,ns/er ntL'duwjsrn.

....Iable 5: Data for bearlna frame surfaceMT MTX

0 1. in. t 1.0 11.0O~ 7.5 8.5OJ 7.0 10.0I I .5 .5

_ 12 7.0 6.0_!-3 .5 1.5A l in~ 17.3 17.3A~ - t 64.9 160.2

f-A3 11.0 47.1

~E l 95.0 95.0AF ? 50.9 38.3A E3 5.7 27.8AF4 38.5 78.5AroTAL in2 383.3 464.2

c· ..."p)

Table 5 lists measured approximatedimensions for the surfaces in (Fig. 13) forMT and MTX frames'

...

to "...

The surfaces (cylindrical and ends) (Fig. 13)can be calculated as follows:

A, = It,O,Lt ~ - ~ (0 2, - 0 2

2)- 4lt l .--2 2

Ao ="4 (u 3 . 0 2)

A _ :II 0 '"1:4 = - 3

4

Figu'" 14: Bm,ins {ram geometry nl'prori,,,,,tions[o« I"., t rejection <Imdysis

F = 6OBON (1368 lbs.), bearing load,d=45 mm,so thatNR = 1.05 x 10 · x (0.5 x 0.0015 x 6080 x 45)

x 3580 = 120 W = 432 BTUHR

The radial bearing also generates heal.Usually it is approximately 25% of the thrustbearing, i.e.

BTU432 x 0.25 = 108 HR' and total heat is

BTU432 + 108 =540 HR

The heat transfer surfaces of the bearinghousing can be approximated as a series ofcylinders, with areas as shown on (Fig. 14).

Assume that for practical purposesTin =Toil, and write the conduc ion equationthrough the housing wall :

17

T"", _ To.Q .k An --,~-. _e k _34.9

BTU lot !ton (,ef 16J , p.~1HR x FT x oF

h _ 2.7 _ 8 TJ4, IRef [7], p, 3651HRfi' F

ler s """"me for simf>IiciIY

............. A = .... (lrom Tat>Ie.) , ,..,..O<ll.ide ail t""'P"l'Blu<e

T.... 100"F (",-""mer).

C8k:ulalions k>f t""'ll"'atuftl distritlulion "'enow S1r'"9M orward

MT"..... :

o '"T"".T... . /lA .H))+ 3l:l3.3 . 17S.1'F

2-7 x 144

cr 540 x (" !tlJT,..T""' /04 . 115.1 . :Bl3 .17:i3"F

349 x144lU X I, om s :

Toor· 1000 ~&l.2 . 162,()"F2 .7 x 1.4

~X{'Y,2)TI>I . 162.00--~. . • 162.2"'F34 9 x 4~,~. '«

11ill clear Irom It-.. above cabJlations that !heoil temperatu,e is lowe< k>f the larger sumpde&ign (MTX) by175.3 . 162.2 • 13.I'F,jvst due to the eftect of the i.-.creased cots"",_1,ansfe< 5<.II1""e 01 !he housing

"

In (Fig. 101, t.... lranslmes to _ oximalaly2200 Irsd~ In bearing liIe, or, using17,500 Ix. as r-o:>minel doesogn life.

1~ x 100% . 12.6% impr~

2.6 Summary of abo~ effect!JIn the ..oo.e ~ions 12.1 1h' oug/l 2.511toe_ng was detrl<lnSlr8ted:

a) F,ee "'-J"'l' surf..,. extension (~ion2,1.2 .2): Incr""..... bearing life by 2,3'li.

b) Deeper "'-Jmp <IIlcr8ase8 oil oxid"hon<;<>ro:;enlralion aod ,,..'-'Is In .,.,.;ngs 01approximate!'>' $86 per pump per ~.

(oe<:tion 23)

oj Dee\><K sump ..so ,ro<tJces oilconlaminalion at !he bearings _Impr0'Ye8life 2,1 limes (G8CIk:012.41

dl The inc,,,,,,,,,,, hea1lransteo- surface keep.the OilcooIar and e.<la-nd. bearings lite by12.11%

The ne.<l lWCliCln quanlifies lhe at><>.e data .,terms <:J economic benefrt!l

j l 1~ l · 8 I l .! I• Z~ l i~~, IU t I l, Ii !fl •11"1 ~2: lll!. r h~ h It. III· ~H ~ il!.~ I~H 'i'p! iii IIIi~ ~I'i~ lIiI! h IrMii Mj!it'I ~~f;i Hf~ lith il!H!PW II!·1 1 ~ ; tf i ' ~L!~ Ilf' il!'j!:t:i~ till,., hit..; ~HH IIi mhw~~iwi

:: !hi Iii iIhii H!j !Whli'". ... . -ri 111,1 Hi .!, I' PI nun L If {l'!ltl l

~t IJ th jjPif~lh IPll l

Ihh IH nil I hUi ~Hmh

e

4 . TESTINGA - "9 program",as conducted at tI>eTec/roology C&nI.'" 10 verily !he__calculations and to ""I'PO'l "'~h data lheas'''Jfl1'l'''''' made In this """'"

Tw<> ANSI 3196 p.umps were tes1ed, t\a.";l\9Iw<> d_enl POW"" 00<1" but with identicalhyd,eulics. The ~rst was en older design.MT !fame, er<l!he second w... en M"TXframe (X·Seriesl. (Fig 16) is a siOe-by-siGe

COfll"I'ison '" these two designs,

The following tests ",ere COOdJcledI . Etled 01 00 _ on beamgs and 001

t""""",,alUte ,

2, OHer "bu:ping. e!Ied, increasing 0'_in the '..--np.

•

4.1 Effec:t 01 o ll leVtlI on oiltemperature

AJJ. "so ,.sed in lhe p,evIous sed"",", the_ 01 011 In Ihol beating hoo.Jsjng. caverlng the......., I>BII to different SlJ_~"""', _ ....increased chu"""9 el!ed. am r...... In""",_dol_ bearing~U"'.

leading 10 tho boo'ing IWe reduction (Fig 11).

The 001 level ",,,,, <Xlfllrolied byvisualobservation via sigh! glass -...th caliblelionma1<o,g 101 O'll. .= ,5O'Ji, (desig n lBveI) , 75"",100lb , 125% and2OO'lEo, (Fig . 17 and 18)

fop.. ,~. 0:-_",_/MTlCI <fo"r:""''''''"'''''/''0__

.,

"

n.. old <lesigl doe. not have ...oIghl g.....prnv~on, A opeciall-shape oil level gaugew ,," ......,d 10 indItecttv mea....... tho oil level101_ ca..., (Fig 19).

~ .,'7 J ,.

t·..... , " OillL<wlli""1I' • ...t 'v__'to<IW MT,..._,

In trns le.bng. oonolanl _ oi_ we... notinsta/led. ThO. e'm....lO'd ll>e elle<:t of oiler"bUlping", and allowed ooncenl'a~ng on ' heoil ......1eIIect on temper alu"",,

P....-.pS we,e run tor4 hours at each oil """'I.etling , unl~ .lead\' .1"'" equ ilibrium1"""P"fl"Ule . wer<I ,8ElOIIed, Tl>e,m""""l''''''were . ,_inllMtoilWid 8llhe beatingout.... , ...,.,. The Slead\' . tme tempera t\Jfe 01co an<! bolaring w", e found te be . ory <:IO:ie

Ioeach othe< (Fig. 111·

4.2 Oller "burping" effectAll MT frame was equipped wIIh srloiIeI and aspecial oil ....... 9""1}8, inSlnJmented (Fog 20.)

r 1J>c MT(N_",.~ .....~ ......~.tkwl

vi'" _'_"'!/'.'" .~" ....,;....The p..-np was Slatled and 'sri unto oiier"burping' .topped , which tool< "PP,""imat.....10 minutes. The """" was then stoppedand 'eslarted again, causing additional"b..p;ng." M ... 3 ouch cyde•. no merebLtrping w.... observed , and th<l !inlll oil ielielin the~ increased by "JIpro. irnalely1/1&n., as discu. sed in section 2,2 and (Fig121. Thi. data i. bel_ to be conser'o'at.......,..nee lIMt add~ionaI plplng wllich wasreqUired 10 insla ~ _ gauge IW1lh e_,niWles , ale,) cau.... ... ,,",_a d"",,*,inge1Iect on !he oillu<tluler<:e, Of 'waviness",(Fog. 3J. The _ 1n. lNmentabon methodwas _ """I .i<JlIly becaus.e the !.IT momaprovides no other method to di,""ly conl,oIoil _. Thia" """,-he, a.ample oI_ !.lTX{wil11 slgllt glass as standard) <lesOgn

a"'anlage

The,el,"" , a 2.3% lift> dec,ease d.... to thoede< burp;ng ia bel_ Ie be conservaliliaand may probably~ 6 • 7'Jb lor _ a<:lL.ll'llparticular Insta llation in _field.

s. SUMMARYThIs pap<>< p<esented some o! lI"<l "'SU~S ofwori< done '" the Te<:11n1c81 Genter rl ft 1"''''1'manu!ac1u....,on the oubje<:t of improvingpu"",, "'liability, MId its Impect on MTBSMand MTBF. O t.lft<l\Jfiable data we'e obt.oined.OO/lllaring two clesigns - 1M old desigll anda ne w X·S8riol ' pOWer end

St'ldles conti""" on OIlIereI_ ofpumping oyOle""" to simllBrly qulll'l\ify u...,;,elIe<:t 011 both compor><Nlls I""Impr<>Y<lfTlents and lI"<l """,.. ,lie _s,lISSQCilMd with ...,.;:h irrc>,~ • •

REFERENCES_ ._"" _ _ Eto:I SuO\IOn~ "'"-"" ChomO;:oI""",-" ,~ N__ , ASt.E 813. ' '''- ''''' (_ <IINISlIiO.SME8n. ' ''_1'-'''''1

2, '_"-'~O'<i -...c._·,_ )'OO,__ "". ,m,), "SI<f'_~·~.1'"

• "CAC_"'~·,""'.I.CfIC_. R._, ,_o "_ ..... Openo;on ......... .. ... ' . " ,,,,,,,,,,,",,,"- ",,, '''''''

G, _J,P"_T_.eEO.~,,,,-HIl,'llIlll

1 St'ogIey, T E,. ·_ ~ Deoogn'. '" Edt"'" McOr.......~ '911

• ..... """"""' _ .... """ '"T_,,*,_~, ('VHs ..".. "",,".)~,~

_ _T_ .... ... pot_"'p""... "~T8ChOOI<>g ' R__~ ..... """'"''- (Su<:I1 " RIO!. ' 1

(@]GOULDS PUMP5.INC,