GB2510070A - Downhole compliant dart-style reverse-flow check valve assembly - Google Patents

Abstract

An assembly comprising a tubular housing (30), an inlet housing (28) operatively coupled to the tubular housing, a venturi housing (38) that comprises an inlet housing end, a check valve end, a venturi passageway (36) disposed along a longitudinal axis between the inlet housing and the check valve end and a valve seat at the check valve end wherein the venturi housing is at least partially received by the tubular housing and at least partially received by the inlet housing, a first spring that axially biases the venturi housing with respect to the inlet housing and the tubular housing, a dart (68), a second spring that biases the dart in a direction toward the valve seat of the venturi housing, and a check valve housing that houses the dart and the second spring and is operatively coupled to the tubular housing.

Description

COMFU ANT [ART-STYLE RRVERSb-FWW CHECK VAI$VE.

CROSS RFFFRflCF TO NFl A I El) &PPLICA lION fks applicutiN' relates to.ne c[arn pnority -om S Piovs.onal Aphcaion Sena No 614 SIt hu flIed June 7 2009 wtucr is hill 1ncorporatcd homin by itflrence.

*MbLD* OOO2J ulie prewnt Qi'douix generilly xeLite\ to. ieck wuec ased fit on wction with;etioteuin to(Lrction iets n' and associaLd Jesices I\Iu' e \Lmcuua tbc ii scour -elatn to a dart-tyk nerst-flow cLe4J. alvc tch s çnis idod in gcs hr aTse &aJzed in an oil ci dew ihok an irc,t'ie"t B AfjQfj} j&i93j For uurposes of oornnTdnicating welL id swmace of a ti1the wSJ ray ncce e production tuhrn Mate specifcaL, th production tthrng yp1.afl) extends dnwtiholo into a: wrlthoit at the well.fl>r puq es.nainmnmlcnijnnwefl fluid from one or 1)l&m suhicersocan ir Miorts.Ihrcntgh a.oenuvai pa5ctgeway of n.eprdthwliofl tubing to the snrthce: Due to its welgh the cojuron. ohxellfloI4 that is preacot lithe. picduetion tuhkg may auppross tiwnttt*ar which the. well fluid is produced frru.n the ônnat.i.on. .Nkre specifically, the coLumn ol well Uu,d:asid "Ic prnuu.. on iub g xUt hydtotatw irnss. x that ncre.ise' with weff &pth ihus,..neur apariicuiar oroducing formation, the hydmabdic preasunr maybe siguificaur cnoug3i.to tutmtantiaily slow dciwu the.ni& w4dch the well Ibid itt produced From the. :tbthiatiOtL 100041 1ei piurose of icducir U. hd1o\taUc pictsswt and tThu ctha-cu thc rate at which fluid is p ti ed.:a irtiflchttllfttechnique may be employed. One sStechnique: involves icting.gas into the production tuhul5:to dispiacesowe of the well fluid inthetubing wIth fightergas. The. dispiwemem of theweli fluid with theiihter gas:reduces thehydrosratic.

pressure. ide th.e:prcdnetion tubIng and owttreservoieIbuids to enter the w&ibore at A::higher flow i-ate The gas to he in:ec*ed into th production tutnng iypiealh is nse*4 dowrthole va the. annul.u (the. annular space surrounding the [reduction. tdbirg)and enters the production tubing through one-or more gas lift valves.

an eAarn1e, Fi1 depicts a prior artgas lift system 10 that iucktdes a prxiuc ot nAioe I tha. exends nw' a weflhore kn paipose' of ps aueeur the cterr meludes a ga coitp essot 12 that is 1xaed at the arfacc & tao rAl c pe'unze as that is noroniatth 1 an. apn1s: I cvf the wejj. To control the.eomtnunjcati.on, di it5 b&tweWI. the ainulus I 5.atd a en.tiai.pasnway 17 of the production mhing 1.4, the stem may inci:ude: cecn sitJ pat ke a' ht inaithd 1t oi t rn indral.oi i6ti cr4 Jv dep ed xainpies). ach of.th hA dlaitdSs 16 Ideludes au asiociated gas lift vcdve 18 (as lift ahe-s 1Sa.8b and Sc c.picted as examples) to' puqioses 01 CS anh'h»=ng one vas fluid as cpimrwnic.aflon from. theannuwt 1$ to the udatrat paaageiflyt7. As i well known. thegas h'ft valves iSa. l8frand.ISoUre eornrnnn]y installed and r &icvod fixat mandre.tide.pock&s; such r'y t,on' a iehne anc K ko''1 tool irnorted sv thm the 7roducttc'n u1'ini 14 The gzaliftvalvc: 18 tpiealiy nonethia a shedk sdlv turaflgn1ettthaving s.c k vaNe ekmcnt that opo.usto aitowfluid flow.thuthea muhie. 11. into the mL ng 14 and o'o'es t. tic t"e fluid wouhi c therwe I ow' n ie oppc'srt Uu-eeuon when the piassute at the production tnbmg 14 exceeds th aunulus ptsure the valse elenient is ekiceci c idea t-rm a ea1 to pre'eir anyTnrse flow trout the ttôing [4 to the rmfltn l' I he pncii a t check ca w.rangen cots ate dLrned evenua1ly by a aigk pa of seahni ut-ttec, One cd the \Ca'mg wif±axs edoags ta a se'it wFrh is gcieaahy tted i a hot sas oi the like Pc thei se hoc ur1 cc bckn\ to salve deoenz that l cal1y spring oui'ed nO moved. dFth hi and outof engagement with the to cieseand open the clieclcvafre asuoeme'u ctependmg on a tLd p'csswe d«=tterential The yoke demen couM be a halt c,rt or poppet a IL.pnc., a dphragrn, etc In CCF4JI ugh tempraut.e wctmg co diuon sucYi as man nI well en.zo)lrnem 4 s cormen to usedaNtyp. thcck sake auangements where substantially only metal4o-rnetal sealing elements are used.. Metol-tometal sealing is mainly dependent on conidrndty between se$ jug, s&irfiecs sin:0tciefithth, and coiflact Contact sttesres sit netions of applied preoureand contrLansi. The preseal invcnior have Idanrithat a dialienge. cgit:athie ssdi&i a par iJachi;.-k.yplve Tangarnimt Is required to pFtCnI sthadfl at tow back pressures arid ovcfl wide range of bade pre$wres. lithe contact arcais too maP once ibevalve. is sijbjctto hi p.ressuro ii is plastically or non-reversibly defmiet if n c)ntaot ant S toe Jar the vaive auangeren can e-iDenene low contact tree at tras a thus wifl not S. \UMMItRY [00071 it: xescnt in; entors ha'c tecogni ccl diat the pt ur ai & does rot ade1uates provide th dewtd 5C4, ng oeLvrnc hi check \31 aET?flNtcni deinedt' a single pan et raimg swtcs curt as tvpw2ll iseo ai tkvznnok well eirsimn ients nd cithra In wide1 saruig CSt1LO C'XLCUCS ilk npeiutioa &idnial. the ?Wseat dtck art' relcte to solunons geeerall addiesag suc', ba' tug & Uo with an effect.e seahng acflun sstflu a Wide rnng' ol applied bac& pievres. tycic&1 1(1040 POt' notmth -r square in:h tph on chek vai?e a ngethenta which pmecntieverse:flow of floid such s.h'cm the.:tuNngt.o:the auba*t&, a well:aprclttidn. Tltcheck valve:citaugettient contettphiied bsith6hwethors pit*idd liluhIpic. deutcuted seJing s ulatch designed v meseit un-tceno'ite aetormanon and eaicagt regaxtiess af th.e*appli*e4Mack preoees nvr WIde bpe linQ rarigets [OtlO$J tn cneexample. aaappararus. uaabit vith:a weRitwiudes a gasiiftvàtve o avug a check ah e artar arnicn locared between an annu4us and passagewa; a a tub ag Thech$.k valveis actaptedto.sølcdyely allow a field flew Uongh the beck.vnive artangrrciit rom an inlet ide of the check a v arangei ant to at outlet ctc ot he check armngemcm;and i hissed to prevent a teakac flow from the check vah'e titan: the ntalei side ict the inter side, The enecievalve an'angementis denned by avid-ce denienc ttnyshie nto and opt ol eneagefleat v< eli a vahe seat trere ii one of the t&ve dejcnt, and the vaLe sect is a irc' sealing sin tetuft engazcable tth a r c nd seanag t.r u tuc on the thr ut ths. a] e demon and the vdhe seat, AUeaal onec.f thefirsa and second scaling athm-es include at hsastnne pair of sealing meathers (0O09 The check valve arrangtmem is adrwted to establish cue-way flow of ga inni the smnlns to the Jnssogewa, of the Oth ig rind rn'pond in a ritssutr Uflcr-nual tin re lwt ier a The va yr stat i' comments t'hrrne-1 h-s inernd stmrnirs of tFa a' ah-e ane idu4s ahigh j aure.seat jthitonahJ a io>v pnisuni acid othorL Thcilaid ontodimr-afls, dat vahe elemnt has i high ptcus dan poreon eiigagehle with lie kal pre-otne sea pertain antI a]ower pncssurc dartportibn engageabiewith the lower ptesswe. seictpordon. The high.

prsun acid p4ion rid the.low pius.swe acatportiun may he stationary or may bc.movahlv mouirted eiafive In one another. The. low pressure dart portion d tixe hi1j ptswt..dartpowon o ny be meraI or maj e mo able ni atv d to one anotFer ERIEF DESCRWIUON.CJF THE.flR4WflJS.

(0010J Fin a Jeria c thawazr at a pisor art ca' lift ystern u'Qed u a v 100111; fl. 2 iii aftagr.ient:anr view of a.:m.andrel htthng.a gas lift valve provided.

with.a.chec.:k val:ve.areantje.nieot acctlinp n th.weseni di seimn;ret [00121 Fig. 3 is an enlarged. fragmentany seetional.vaew of a gas lift valves1aowi.

irFig 2 vith óhéexarnple of the check valve arrangentent, FIg. 3a i.s a partiJ. detail view of the dheck valve arrangement of Fig. 3 in an pen condrtmn..

UNII4I. Fig. This tail vieW of the. check vAlve antgerneut of Fig. 3 in j low p evi.irt. edhPgteditiom am Si Frg:s.i a partial talivicw.of the cheek vaLve amnigement of Fig. 3 in a iirgh prekcuoz eahngcenthnn 10(UI6I Fig;. 4 is a enlarged.thrigrnantnry sectional. uew Of the gas. lift vaLve shown in Fig, 2 with. another example at a cheek nlvearrangethent; I g. 4a a nartial detad viei ot the cc...k wthe arangenito: of Hg 4 in th otta cOtditith, [001g Fit. 4b r a attrU c.etil vie ot the cheek valve arrange nr t <a Fig 4 a low pressure ceafing.:conditicrn; [0019] Fig 4c s tzu na cehil viesc or the heck A e arang.er o Hg 4 a hih.presaurc sealing con.di.tion [0020] Erg 5 an nLirgal t:agrnciary seutioial new ot the ga' LI valve of' H. 2 wi another enrnpie.oF check vrilve.arrarigemeni 100211 F t Sa r i pattal icun ue of the Jieck v ve airangenie'i <a I an open condi:tion:.; [0022] flf Th r, a part al ce&ail sn' o Lao ehcvk vaht am evnent of flg vi a low pressure: sealing condition; 10023] Fit. Sc is a perUnl detail V1CW or the check vadveranargernent of rig. ft aidgh prsiure seaThg c:otidiuou; 4..; [)241 I z G s an cmazgc fragmet ta'y iev "l ie ga lift,«=ils e o 2 witt another example of the cheek valve arrangement; (tW2SJ h a a aita en ii. v ew t the chack va ye rrarge iwrr & Ng 611 Cii O1)en condatinc 110261 fig 6h t' a p»=ma dca! vww of the chek valve ananpemk of fIg on a low.prawre sniint:.cnh1dftidn Fig nc ls a partial Jct& iew of the chcck rhe anaqgcme ci Hg 6 a high pmrsinv:s'ntt. condition: 100281 Fi.1 i aoebhtrgs. fraunentar sedonal ie ala difthtent ghs lift vlTv.. tith. iothetexainpte ofeheck vaiSe.aitaigemeut [0391 flg. Th iii partial detail view.oithc clnik vat lealtmontneflt of Ig.. 7 ti.

an open condition:: [003M Fig. 7b in partial detail view of the. cheek vndveatmngenteetof Pig. 7 ii a ow.:prete'sealThgcondutoii: Hg. k isa primal detati view or.the Lncckvalveairangeme.nL ot. Fig. I a hhth pressure sShia. con dition [0032] is: an enlarged fragmentary sectional woW eta gaslift vaIveWith another eaampleof chock vah'e anraegeineru; (0033] Fig. Sn is a artiat detail s4ew of the check valve. arrnuge.menrofHg. Sin an open condihom [0034] Pig. Sb is a partial detail view. of.the check. valve aitangeilient of Fig. S hi.

a Jew pressure seaifng:conthtion.; and [0035] Sc is a patital detail alew cf the dheck valve alTangr.menr of.Fjg, Sin a high pressure sealilip:cndution

DETAUJDPSCRIPTLON

[0036] TIn the. Fiui.oMng escriptio.a ettrtinaternishave been used. for brevity:, cktnrancc and.uidersthndin No.witiodesaiy imi.latioiwareto he implied therefrom. beyond the i%uirerneat il puoi at because such term' re a'co terdescirtve ruqosc ard ar ictenoec o be. Ln nadt. coush ned [he dtffctcul cuahigwaLc1u 4N uw.ii'd des.nLed 1eieia 1i14 lie u'eJ alone or c.onihinatkr with otter cot1tigui'atioDs s.tus.ud We&hvda. U. is lo I.expttyj aL WflOi s ccrntqthents atemnatr e and modUicgbeis a e posrnbte wnhrn the eop' of ie pproded dirns.

Reterthg now to the dnwings. Fi. Zilhatrain amandiel 20 having a cc pocket 22 pro iickct ith as ift aib' 2 usoct to r pula'e flu d irw ot na between rn a nus am cearrat passaaewy c4 a produc ba tting in 1 e. \ lowr porom cv m' gas hi w' e 14 rdndes ehen. ih' amrwprneiir 16 tfq nprn o low fluid flow from rho annulus inF> the production tubmg and do;e when ti: flu d woof! iXflerwLse flc'' ii the opposite daccuon As is stil kiewn ram the nnuiv n iornmurncatee t rough hgneti inietsht ther:nthti 2O:aiA gas liThv&vc 2$ as.depkted by arrow A.. Thefluid. as:reaffatedby the ched. ahe arranaerrm 2f thsto cut1et tht deas'er fl lu d wi the manirel 2 into the pnyductm:n tultig as.thPrtQfl{ 1 b catow 3.

[fl03S] In the cuur'1ei o iLl ow otherice coLd L tht v dcc ttflEtngeflient ithi2.meTh.ffleta5aIhig deinent as genttafly dit.tated3y'.hi:gh teniperature wodclng ci. nonmeits, soc acclovnhoe m n o s& 39] I and. 3a3c show one. example of oFeksàratrenient26 havn; an at tt cumpi' ant thrt checK rr oun td m a lower paruon of no as itt ah e 24 1 he gas hftvaive 2:4 has an in!ht secton2 attadhed tos tubular honsihg30 which, in lithi, iii in °s F"uoir e'd Ui a dewnwaid1 npenr ebtek se 1ou'g 32 TiThe iEn St clic ii a erie of nIdLI ine portc 4 whiu lecelyg fluid a'o that flows born th a"nauc iii) augh a ethrn a'sagea 3 tonsied in a no. n hru9nz 8 thai s scaled o tile ilet section 2'i sith a by lrrg 40 mu sapoorted at bie top ci bathing k) The 1rntun passza..wa { minimizes turbulencem the fJ;yf gax from the well annahisto theptudaction tubing; andis in comnnmn;cation:witla alubular lower passageway 42. thalexiendsinto the cfr4..y$t hOusipg.

32 (ins that flows nato the check c, ctrt'e hoos,.nk 32 cc.a thnu ongaudrnd1y esaendL a outlets 14 that in in eOn1U1U?Cat nfl With mcne.rcl o iIct o that git mTv >e der?erert inn if pmodtco.on tubing. The. gaslift vaive:24 heb des a seal. 46 that cwe.umcnbes thetubndioucthg i0 fOr.Th pu coffoththrig a sealed. regiS that ceunains thcmthaLinleiporis 34 and aligned irik.t.porb of the mandrel.211 [00401 The eik.vsdve aunngeinent 26 indiddes aii:antiular valve 4g by lowermost end cii the gas vave hnucin 30:whh the scat being ripened.aod closed.tbr 6*-cGtiX).ing.the. one-way flOw tereugh flit vatve24 xa a spring biased chede valve assernW 5G. As more.cieady seen. in Fit.. 3a, the valve. seat4fldehnedbva.hiah pressure seat 52 antU ow pn sire 54, In nie cxenp an cirthod ne"t of rig, i the c}vd> vai'a-as,cernhI U ias circular stepped dart ixxdy 56 which 1& slithbty niotmted in..a tubular receiver5S p.rcivided.ia the.

Lheck valve hnusrp C [ he ki t beds 56 tas a ewer nd oC wthch ts shdahly pothoned withy rt prni r 6 trriied a the l'nttn r ear of the rhck vdr heusirg 32 T e da*t body S6 futiher has a radially enlarged tIØp& odd 64 haidng aethitral recess 66 width extends downwardl. therejit.

[00411 A high presstre daft portiod 6 k: cOntruOted iTh.a tem 10 thatis teceivedithd fixed iii theetess 66 and4iaa a cInthed.pothth 72 sdlertively Sigageable. with thO.

bib p!.sst"sctt5l Awsecn. infig. low precdinte dzbtpoititai 4 hii a se4thni snthue 76.

that uidree' th d mtd porn on Ti a al so k.s n nog eenon 73 w.th r rck section 7o tha inposerttrtvee'n the domed porbon P n'id the pprend (i4.od dart hnJ 36 Thse'u ?.

surtace I'*ot nw piesure dart cort n /4 is e ecve engageabic AL.h low presnie scat 54 Ai e asic derneni s h a prmg SJ surrounds the btr ii 0 td is poinzaed aetween the neck sectror 8 of clan portirn "4 and an upperportior ot Ow body o to pi oeide a pietoad pnna toice en low p'tssure ian poitor "4 I he toss iCs5UiC cart pat. ni ias urnited;noscrnent Ira eon the dr'mrd pcrtion 2 of truth pxrssn Jar poition §b auo the upoei erd 64 of dait aodv 56 A cuU spring 84 Unc triOs the it body 36 twdha oppoc c' end engaged agWlc rr&ov shoulders oathc reath.ser5S the radially edkn4 jpn end 64.

,0G42 Spueg 84 normally iicntes to cc.it an upward toice on cheel< aIse ernbls 50 to dose cit tiaid c mrmuaon thro>agh the valve seat 48 as shown r' F 3c %en the theck ait asinbh 0 is installed in the ges Ith sake 24, no,a h eu'q Jel"vered and the pioductren nit seg press arc in the enc& i val e hoaag 32 ar nag on the ba ksacte ot Inc dirJ a\e a'sernb's fl n a' than liii &wuu5 o uJSfl' r''e in the ea lift hoisaig ( Floweser,. whe-rras benI.rrs to be punped the w.w.uhts or casing pistatuir is incruased mIinive to thO produdtioh tubing Pxssure.tO cxcii a fotio. on the cheek valve assembly.50; bias Qfsflg84. As it:luit.U1e d4fl body 56alorig with high pc dart poitiori 68 and low pessut pi ition 7 thrup-'y pops o.'eu (ha 3i0 aU renats fiuta seat 48 as,p or' 7..

cooipnsses.to permit gas tlow.from. the.aitmthis thiwgh the.as lift vahe.4 and check valve housing $2. luau the thandiri 20 and the pmducrion. tubing.

[0043] When the vs ii)V into the s hft ak e 24 is mduced and ewntuiaO v cat t off, the symg 84 returp the dieal.. salve essen*> cft (c)4flfs e>a *X A 4-i 4'1t aflnus res'je decreases i p' c'ure dihctnn& i' crciited si tt a low back pressure imflal.

to on die aEt as'rmhb Sfl and causuw ctrran' 7( of Jew p dart peruni i SCt& a ainstJOwSstseat 54.S thdwn in. Fig. .3k The USITOW corilact areahetween the low pressuai e&ing surface 76 and the low.ressu sett.54 ensures a ievetdfcdntadt stress.

sufficleutto seal off anyleak.. As ha&pressuteincreases thorn aiow.ievei to khighievei, the In I irdy c6 richtt e hh pecnv c art prLon 68 pub enoagernent againc. the hiub pitisute seat52 andcompteses.the spring. elentent 82 aainst thelow prossu If Portin 74 thid.The hiwp.tessutt sea; 54 a d$.ictetd.hii:Tig. Tht. dhedc vtthc a,trnb1 SO k notu.Mh;. closed againal soat48 so thatno trse flow is pornaitudfrnia& tubing to..tt.anuuhrt. Even at fflih haS pressu'e Lie ov pessure tthVseat pan 76 and 4. oidy he saLect to a s rth higbcr lévol of Contact. shesses thanlteipaiences.at low presaute; Ilik levetci cotanet stress.is.

dedgiled to spare die low p% dart/seiitpair76 and 54 topddlbitn4toi 0O44 Fua. 4 end a4 sluw another eurnpk ot a chack alve atTao2rnct 26 hv ng iii hair iathrr ftai out co"rp nirt Gail varse niountcd ir the ewii portrn & aa ft vu,e I n e&w pie, the check n1n. assembly SO empios a &ow it c'nv dart pcrfl -r 86 thrt i sek ctrseo cngagaa'ne with a luw rc'*a it' seat 88 & high pressure dart portion U as tixeti P) a u.ddntn 2 to oppei tnt 44 or thur huc.5 au'd is selects ci) ergageable with high pessu e eat 01 A s AC bun; g 6 is interpo'ed ma eces' 98 beoseen the dart bed) 6 and the low pressure dart portion 86,. and provides a.preiloaded sprhrg ibrcean low press tire dad portinn 8o vbich is,mouSd thkciimited rnovemente1ailveto high pressu e. dartponion 90.

tkwianrsi k t,rmkrue that cftie exampie cit 1s 3a-3e Afte cipemep cit tfr'chccLvilve atsenbty 30 at seen it Fit 4a, the' low "urti piec'euo' catsea non eaita of' lea oarssuic daEr rur 85 wawY >ow pic-eane e 18* aidru hr wave spnng °6 E" it) S nsrqueiulv, a'gh backpressurecauses high pressure dart porrion 9Q to seaLagains; high pressurese.at 94 (Fig. Ic).

[0Q4$]. Figs.Swid Sa*Sc show a furtherexwnple of acthcdk valve araaurncut 26 having an outer coutpliant seat dhedk. .Heiv a fLed. 1i1T pmsrurc soat.LOO is: dcfirtcd by a iowe.rrnotdp fg.. s:fift vive honing 30. A groove 102 machined in the boitn.. end 1 vaise botsng 30 s pmudei. an arnuhrxse nther or cc mg 04 which no'ria1li exerts a.downward biasingforoe on a rnm.ahk annuar low ptssure seat106/engageahie with a rebinci hut.1.0W The. low pressure seat.106 is tocated outside the flow path defined by passageway42. An upperlend of dart body 56 has a.!owpr asunadan pordon 110 integrally firme 1 nh a pr'soo' dart oWon 112 A1te opernng ci the cktk alit' a'uothly SO is scx a in 5a the °w piessue aetum in da t bucy 56 cauSe' an wal sethag ot the pesure dart podIon. 112 against the betthn cccl oilo.w pitssatre:seat 105 Fig; 5b); ATha pressum rises beyond: a predetermined threshold, theiow:preaure seat] 06 is pushed upwardh, Igarnst tie waw u hher t04, aid the ht i nrecsurc' dirt poatuin 10 se<us aum' the high ptenre: it. 100 fEi*: ). Again, th?JowprSortedatt/ssl paiz Ii 2 and 106 wiui main ala low frvei. Vertathii h rsnit thes pMetthigthe datifseal paitfium yieldIng (0046] flp. 6 Si 6a& show an addiflond] example of a check valve hrtangement26 baain-an.i.ntiercottipliant seat check. In this exiflpie.:a movaMeiow.pressure.

sett il4pravides t.hirtcdiameterat:te:hot mofpassngewly 42.ifl sasiifna1ve hansiQ 30 which bevatiedin size to enable greater flow of gas to a chamber ItS atidihe outlets 44 iii the cheek calve housing 32. Aschntrasted with the low pfesure seat 106 of Fig. 5, the low pressuie >cat 14 lies thredly a. the how pat tot the lift sc"c. 30 Tie ka piess c 11 * suriounde] h a C) ring I 6 for pres enung in leaks d,verv toe kw pieesne eat ti Ow gas Oft hetcsuig 0 & ssas e spring I It exerts a dewewant buistng:orcc en lost otnaua' seat 114 and a fLoJ h gi' presure sctt 20 is screwcd inc housing 30 cnn pies k'e a an p lox the ke' pe'uw heat Hi Folow g n7emng ct nc checs salse.bsnth1v 50 show in na bw prescuw causcs an flt'Ual ee' rig ot air w p e''u1edut porno 122 gamst th oorcm cid chow ptezcre I U sFtg oh, A the pces ule nse the Ion' paure sect 11 * is puahec N cdlly aani wc' e ahe1 11$ afd a hgn atss. e Oat ponon 124 eal aga ii 4 the igh prtcnrt,t'tt [2.0 [0047] Fi., 7 asid.7.a 7c show sci, another eacinpic o a check valve arrangement 2.( in whidb the yalveseal structure has a bed.high pressure &iatj2( deUried by an toner surface at ji) OOWU cOtubutar housing:30. ned a mox ihflew pres re:.seatl..2.thdefineri by a kt rtitQst r4,3. CY rat In gakd port on l1r 0 s at in Nh suw i5 torring pI'SageWaV 4' 0-rrg' 32. 1 4 a-e pro0Ldedto eat gaps brtwern the vtntuls hua'mg 3" and the tub.ikn houin A Spflr2 136 is mteio'ed ietv.een peche ste d\ a inlet h ustrnz 28 and vewn h'ustng 15 t' nontall., c-sen a dwiward uasoa ioct. uc the e)tirl lhusrng 8 Pc'Coiog oper'ng cr check eahe houtng 53 as shoan us Ft 1 1⁄4sw prey-un' 1n'Jws a dsrrct)ff'II&n I 32 o dan body I 6 mto eagaarment ith 1ov -wo'sutv scat 2R tint the hia of snng 36 (Pg Th %tt mirg pe",ure the!os ns e nt S is pished apwLdl) a a Si flu 136 and don ed portion 138 seals againsihigh pe-sutseat.12(5 (Fi*s, 7c). if.dosin.d. dart:hod 56 ard donni portion I 3 may be teplaccd n a Hnto flap niovahle v to and out of engagement wv seats 26 and illS [00481 Figs.Rnd Sa$-ho still ttother x:ampie. of a.eheck annilgornent 2.6 sin.nlar to*thnt* denerihed in Figs: 7 and 7a4c ovcoil for the UNICfl Of n high pwssw:e seat*mtnr f40 wbitrsavbq I dorienuvahiyattadhed onthe. bottom endof housing X.L S at dement 140 may he:&.ffie H1iied eta rtaldmctidlic: mutt dci ue a lexihiematerhs! a O-.dng 142 Is disposedhetween the tithdIr hou4sa 30 cpA the Otk valve ho't'g 32 PoLowm operin of check vasse assemhy o a' slbowi as Fig Sc low pre'aie ptshcs doned pordoni of dan body 56.into engagernctt with low pressure seat 18 against the bias of cprng 133 flg SI') High plestre pu'hes the low olvssnse se0t I 2 epwarcfs. and domed pc loft I 3d s'a1', tin thtx agcnns higil prcssasc set ekti cm 14-0 fig Sc [OOI flit piesentdc'lnsare lass ?mslde\ a g'i' 101 -cahe hert ig t ihe k árrthathnS that liwolvds Ihe> ne.h.niul{ijSie den and seal iea1in \iithices.to aiiain adesiS eahrg benas ar o'-ci a side ange ol nipI ed eatk pr swcs witboat hAagt or dconnaten 0 e o the da snob" s,at setg,atta v is p ekxided b) a swing ci other sastable eiare clement below apreddtermined low procaine, a sprug loaded pair of sealing swtces wifi be in nall rn contact Bes cad that pr000tctm t d Ic r passure, a second paro1 sealing surface-, s*iiI corPthintd a lgc: cdbtat. Th tirtpait at scaling wrfaccc will reniai:n at nfl doses utder]ojivtti co.W4it. c&sis and wi not dform pl asdeafly. AltJioughcniln ecamples shvtn hctiEs isavc.two. pairs of $1 ng ufe te, low ptawtand high preidute darts did asid he atderstcud that thc d!suosua cnotcaiplatcs tht u of more t-nm 1wo pans of rung surtacc ss diriatec' b) spvc.flc aopicnon and element -*10 -.

Claims (1)

1. I

   CLNMS

   An astembt como S:flg a 1ubtla! hnusnct -an atet hove that:S operativk y coup ad to the 1 bj:ar Jng a vent ri housrnq hat corrpna an inet housn and> a chock yoke and a longi udtta ax that extends between the 4nlet housing end and the c. at k vs v end.entun paa.-ageway d sposed between the inlet hou'4nj end and the chec vaA'e end ar a vave seat at the check vatve end wheren the van nil housrng s a ea& paffiaU-e-eved by detubt.lar housnq and at eastparU ly races ied by the snet hou&ng; a srs spnng that a y biases the.entun hou'ng with tezpect to the net ncussng and the tubuto husing a dat a s&ind aping hat bkmea The dart n a threc on a ard the *afve seat of the venLr: hen ng a Theck vake houssng that notres U r. dart anJ the eu>nd sprng and that sa operat V6LY coupted to the t1rMiar 1uU)9 The assemby of clafrn whe ci the F Set hone ng conpneoc a check valve enc r4 a vake seats the cierk.avem d 3. 1 ha assembly of c a rn 2 whren the valve seat of the vent ii hong a.d the -ake sed of the t jias h. nang rompdce a low oresaur va e rest and a hsgh pressure valve seat.

   4. The a serty of-lawn 2 wheresn the valve seat o the tubu at housirg s a seal efr-ment that ta coupac, Ic the I hular hen ng S -s aesembj of claim 4 where>n the seal element is formed at a rgw1 met. H material T a asseniay of c aim 4 whes i's the seal element is formed a non me flc I a ible ma anal.7 1 he assrby of c ah'n compnswig at east one 0 ang dposed be wean the entun housng and the tubular hotis ng.8 The assenby of clam I where n the fflek houny cornprses a shoukie the seats the h at spnng 9 the assamby T cleirn I Whe en t e ventu hous ng co prsea a snou!de that seats the first spnng 1 1 10. The assenib& of darn 1 hersi the net housrn1 comprise a houlth tha seat he spnng and a,he'e, the venlur hosing compns a siou-er that seats th fiatsprhg.I The aesemb y o am I cornpnsing a s at eernent that c reumsenoes th tubing -ious rg I he assemby of chin 11 wti rein he sea &ement f rrnc a sea{'ed eg n wth reaped to a be a of a mand.e where the seated egion mckdes an inet prt of the inlet tousing and an intet oort of the mandreL 1 The aesemb yet rla p 1 wherein the lart eomp(s a domed orüon 14 The asaernhlj o Jairn 1 whe en the dart no usea a ow pressi. re sea portion and a n g pess ret sS portion.