CA2234749A1 - Valve - Google Patents

Abstract

A valve assembly (100) comprises a valve body (110) having a fluid flow passageway (112-114) in communication with the valve body cavity (116) in which is disposed a flow control member (118) for selectively closing or opening the fluid flow passageway. A valve operator (150) actuates a stem (120) connected to the flow control member by a connecting means which allows axial movement of the stem (120) but substantially no rotary movement between the stem (120) and the flow control member (118). The flow control member (118) comprises stop means (130) to arrest axial movement of the stem (120) towards the flow control member (118) in order to transmit the stem force to the flow control member (118) so as to provide a better sealing function in the selected valve position. A stem moving means (152) associated with the valve operator and the steam causes the stem (120) to rotate and reciprocate. The valve operator (150) selectively moves the flow control member (118) to a flow closed position or to a flow open position.

Description

~-RPR-1g9~ i5;5~ FRCM TO ~ 5511~ F.~8~2 : ~0 97/~A8~ PCT~US95/135 o VA~
. .
F~ela o~ -the Invention The present invention relates to a ~alYe ~scPm~ly in which the flou COntrol mem~eX i~ act~ated by a rotary and ~eciprCCating st~m ~hi~h is co~nRcted to-the ~luw control memker by a e~L~.e~Lins means that permits the ~tem to recipro~ate zelati~e to th~ flo~ contr~l ~embor Brie~ Description o~ P~ior Alt In a rotary valve the clos~re me~ber is rotated ~etween op~n and clos~d po~ition~ o~ the valv~ and the rotation o~ the closure ~,.~.L~ is do~e by m~ns o~ a stem ~L~l~ L~ to the closure member. I~ a ball valYe, the ste~ only rota~es and does not reciprocate In a rotary tapered plug valve, e.~. a slee~e-lined pluy val~e,th~ stem also rotates and does not reciprocate. I~ znother kind o~ rot~y tapered plug valve, the plug li~tS
of~ the valve bod~ ~ieats ~nd then rot~te~i wit~l the help o~ a ~e~ ~hat iS
i}ltegra 1 l~ Le~3 to the plug whi~h there;l~ore also reci~rocaT:es with the s~e~ Hence some cavity s~ace needs to ~e provided inside the valve bo~y to a~ A~te rhe lir~ing Or the plug. ~hen ~his plu~ is resea~ed ont~ t~e ~alve ~ody sea~s, susD~nded particles in ~he rluid medium get trappe~ between the plU~ and ~he valve kody sea~s ~ereby compromising sealin~ integrity. So a l~ting Iype oS Pl~ can be used o~ly ~or clean ~luid~ without suspen~ea part~ cles and no~ ~or slurries, etc In ma~y o~ ~he valves in use today, the seali~g i~tegrity i~
~omprom~ se~ when t~e seali~g-sUrfaCeS ~ear out With valve usa~e and the valve starts to le, k~ The dead cavity 5pace in ~ v~l~e ~ody contrihutss tO the accu~nulation of debris in the b~dy c~vity This i~ disadvantay-eous par.ticularly for 5anitary appllcation~ o~ the ~alv~
~ ae a~ovQ ~re some cf the dr~acks of the prior art valves that are in u~ toda~ Ihere~or~ thore exi~ a n~Qd for a valve ~ h negl~g~ble dead cavi~y space in the v21~e body, for a v2lve t~at 2utoma-tically sel~-adjus~s ~or wear of ~he sealing ~ur~ac~, and ~or a valv~
that can ~e ~s~d ~or cl~an ~luids as w411 as fo~ ~1uid~ ~ith ~u~psnde~
particles Some prior art valve~ like ball v2l~esr depend on ~luid pressure to cause a seal and since ~he closure IL.~.~r is rotatea under full lo~d o~ fluid pre~surs ~cting o~ it, a laxge b~e~-away ~orque ~s ,, ~
_, . . _ .. ~. . , CA 02234749 l998-04-l4 -nr~ lgg8 15-5Z FRO~ -TO 0014165951163 P.09/27 W O 97~4899 PCTruS~ 3~ 9 ' rr~uired in order to rotate the closure member to the selected valve position. Therefore, there also e~is~s ~ need for a ~l~e i~ ~hi~h a ~eal is cau~ed i~nden~ of rlUid pLeS-~Ul~ and for a valve with lower break-awa~ ~orque.
In pr~or art, only no~-rota~y valves ~ith reciproca~ing stems are provided with stem back-seats t~a~ can be loaded wi~h ext~rn~ 1 1 y v2~ia~le stem aeati~g ~or~ in ~rde~ to sea~ the stem passageway ~rom the valve ~ody cavity ~or prr~entin~ ~U~itive emi~sions- So far it has been ~ouna dif~icult ~nd el~siv~ to pro~idQ back-seats on ro~ary valve stems to ~v~-L ~ugitive emissionS. Ihe current method o~ cont~in;n~ ~u~iti~e ~m;~5i~C in rot2ry ~lves is t~ put th~ stem PA~kin~ ~nder "live loading"
uith sprlngs which provides a constant ~ sive force on the stem pac~ing. ~hi5 ~,.~s~ivc fcrce on the 5tem p~cking i5 not a~tomatically sel~-ad_.usting and ~erely "contains" fDgitive emiss~ons in contras~ ~i~h "~e~ g~ 1~' ~r~r G~ there exist~ a ne~d ~or a ro~ary valve which could ~e ]?rovided uith stem back-seat wher~y the back-sea~ing ~orce automatically self-adjustS for wear of the se~lin~ s~rfaces in order to ~REv~NT ~ucitive emissions and not j~s~ to "contain" thQm as is the case ~ith li~e loadlng .

CA 02234749 l998-04-l4 R~ o 1~;5~ FF~Or, To ~ = 0~f~lc,a~ollc,o r.
. WO 97114899 PC'r~rUsg~ 35l!J
- Brief Descri~7 on o~ t71~le Present Invention I~.e ~.~.~ invention i~ concerned with 4bt~inin~ a better sea in a val~e ~77-71y thnt is actu~ed by a rotary and reci~rocating stem~
~ valve comprises a valve body having a body cav~ty and a fluid flou p~ ~way there~hrou~h in~ I.; ng the body cavity A ~lo~ control member co~sisting ~ a rotarY me~ker or ~ recipro~ating mem~r is di~pored in the ~ody cavity ~or selectivoly closing or opening the ~luid ~low ~,~. ~g/~ A ~alve op~ or is ~ to the ~107i~ control member ~or selec*ively mo~ng t~e ~low control member to a ~lo~ clo~ po~ition or to ~ ~lo~ open positio~ T~e v2lve operator ccl~,~rises a stem ~ ecLed to the flow cont_ol lL~e~Lel ~y a connec~ln~ mean~ th~t ~llows ~ial mo~ement o~
the ste~ ~41~ti~e to the ~lo~ control ~Ember but substantia~ly nc rotary n.Jv~~~L ~t~een the stem a~d Ihe ~low co~trol m ~ r. In other ~ords, the connectinl~ m~an~ is such t~a~ 1~ the rlow cGntr~l ~ e~ is hel~ statio-nary, the ~t~m c~nnot ~e rota~ed ~ut can be moved only ax~lly in relation to the ~10w cont~ol ~e~ FY~ of such connecting means are splines or a tongue and grove joi~t as in a ~all valve. Th~ flow control ~em~er ha~ stop means ~or arres~ing a~i~l l~.uv~nr c~ the stem tow~rds the ~low control ~e~er t~r~by transm~ttin~ the stem ror oe ~o the ~low control membe~ sc ~ to pro~ide a ~tter seal i~ the selected valve position.
A stem mo~ing means such as a Lirt-an~-Iurn ~h~ism is associa-ted with ~he val~ oper~tor and the ~tem whereby l~e said stem ~oving m~ns cau~os t~e ~em to mova in a 5equence o~ s~ePs that ~rovide~ only axial ~otion a~ay from ~e f ow cont~ol memker and t~ rotary mo~ion in response to movement of the valve op~rator in one Cirec~ion, and rotary motian and th~n only axial motion towaràs the ~lo~ co~trol member in r~ponse to ..,~v~ o~ the valv~ operator in a~other direction T~us, movement o~ the valve opcr2tor in said one direction ca~ses the flow control m~ber to bC s~bstanti~lly unloaded o~ axlal forc~ ~rom the stem and the ~t~m the~ ~ot2tcd in ord~r to selectively mo~e the ~low cOntrol m~mber, and movem~nt o~ t~e valve op~rator in ~aid ~nother direction causes the stem to be rot~ted in ord~r to selecti~ely move the flow control l~em~er 2.nd t~e ~low control me~ber then loade~ ~ith axial force by the s-oem so as tc p;rovide ~ tter se~ ~; n~ o~ the ~l~id ~10w r~ ISJD--ay in the selected v2Llve pc~sition thar~ ~hen the ax~al *o~ce ~ the ssem has not b~en applied to the ~lo~ con~rol mem~r.

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--s9a 1~:~ FRO~ Tu 0~ 1~ r W O97/l~99 PCTnJSss~l3s~s In on~ embo~i~cnt o~ the pre~nt in~n~ion t ~he valve ~ody h~s a ~tém seating suI~ce surrou~ding the stem r~cag~way which i~ in ~lui~
communication with the valve body cavity- The stem which paSSes t~rough the stcm F~Ss~Vay~ has a ~ack-seat that s~alingly engagOEs the ~tem seating sur~ace SO as to ~eal th~ stem pi~e5age~ay from ths valY~ bo~y ci3vlty lor ~v_.~Ling ~ugitive emlssions ~round the stem.
In another ~m~oA;m~nt of the ~L~5~11t inven~ion. the ~lOw cont me~be~ ha5 a hollou conduit th~rethrough alignabl~ with ~he ~luid ~lo~
passageway in ~he ~alve oDen po5ition- A stem movins m~i~n5 in t~e ~orm of a L~ft-Turn-and-~eseat ~h~n; ~ cau5e5 the ste~ to mo~e in a se~uence of steps that pro~ides onlY ~ al motion ~ay fro~ ~he ~low control member, then rotary mo~ion, i3nd t~en only axial ~ution towar~s the ~lo~
cont~ol me~ex i~ respoDse ~o mOVement Of the valve cperat~r in one direct~o~- The sai~ stem moui~ means ca~ses t~e stem ~o move in a ~ ~u~.~e o~ steps that provides only axial mot~on auay ~rom t~e rlow control u~L~ , then rotary motion, an~ t~en only zx~al motion touaras th~ ~lo~ co~trol mcmb~r i~ response to ~..J~ht o~ t~e valve ~perato~ in ~nother dir~ctio~ Thu~, by -sing a L~t-TUrn-and-Reseat Me~h~ni~ ~o~
the ~tom moving m~an~, th~ ~luid f~ oW passage~ay can be sealed f~om the valye k~dy cavity in the valve closed pQSition as well as in t~e valve open po~ition, w~en ~o de~ired In the pre~ent in~entlon the ~te~ reciprocates relati~e to ~e ~10~T control member, b~t the f1O~T cont~ol ~ember ~eed not reciprocate with the ste~ ~hen the stem moVeS away from the flow control memker.
The~o~or2, ~h~ bonnct can be placed ~TDry clo~ to the top of the ~1O~T
control ~ember in the ~alY~ ~ ~O a~ to minimi~ the dRad cavity ~pace in t;he valve body This is particularly impor~ant fo~ ~anitary applicatlons o~ the valve ~s~mhly The present in~ention there~ore a n~w ~alvc i~ which the ~lo~ control ~ember doec not ha~e to l~ft cle~ o~ the valve bvdy s~ats, th~r~by pe~mittin~ the u~e o~ the v2lve ~or h~ljng clean ~lui~s as w~ll a~ fluids h~ving particles in suspension, e.g. slurr~ .
e ~l~w co~t~ol m~mber i~ provided ~ith a rotatable ~run~ion at ~he bottorn ~or a rotary ~alve to render sealing i~dep~n~t o~ fluid pressure ~ithout the trunnion, s~alins ~unction is aide~ by ~luid ea~ul~ acting on Ihe Slow control member, but the bre~k-away toraue in~rehsC~. On the other hand, when th~ flo~ cont~ol ' ~ ~ith a runnion i~ unloaded o~ axial ~orce ~r~m t~e stcm, the sealins load on the downstream sea~ ls ~ubstantially ~ ~ed an~ the break-awiy ~orque is also reduced f~r rotating ~he ~low control member.

CA 02234749 l998-04-l4 ~o--f~PI~--1998 15:~ FR01;1 TD OE31~.~1659511c,a P. 12~27 W097/~899 pCTAUS95/13~29 In ~ ball valve thc ~11 i~ rcteLtcd und~r rull loa~ ~ct~ng on the doun~reaM scc~t. Therefore, thc ~low ccnt~ol membcr With a trunnion o~ the preser~t ill~t.2ntion has a lowe~ ~reak-away tor~ue than in a ball ~ralve.
e stop me~ns on the ~low control ~ember ~ the ~ i~vention ~rrcsts ~ci~1 lLI~V~L~ of thc ste~ tL7V2rds the ~low cc~ntrol .,~ t~ere~y t~nsm~tt_ng the stem ~orce to t~ flow co~t~l member 50 as to pro~i~e a better seal in 'che selected valve position ~ The val ve ope~ator xecip~C~a-les the stem and when ~he sealing surfaces wear out, th~ s~e~ needs to ~r2~rel a I iu~cle further ~;owards the rlO~ con~rol rne~er in o~der to main~in e~ecti~e se~lin~. The valvé ~perator not o~LY prov~des th additiona:L 5tem tr vel, but al so auton~tically sel~-adjusts t~e stem Eorce needed ~o maintain . CP;~ 1 in~ inte~rity .
Tl~e p~ese~t inventiorl iLs a ~Jer~ simple concept ~or a ~al~e that is ac~ua~ed by a ~ecipxocat~ng a~d rotating s~e~ It is a "~Ew USE"
concep~ ~or a stem mOV~ng mean~ suc~ as a Li~t-a~-Turn ~n~ni'm ~nd a novel conCept at tha~. This ~h~i teaches th~t ~ usiny a stop means to arrest axial motion of the stem towards the flo~ ~ontrol me~ber, th4 flo~ control ~ can ke loade~ ~ith additional ~or~e ~hen such is needed fo~ a ~etter 5eal ard the v~lve operator autom~tically provides the ~ere~x~ry externally ~2rlable stem ~orce to be loaded onto the ~low control msmb~. The connecting mean~ b~twe9n the ~tem and the ~low control ~ember t~u~ con~titutes a or~-way clutch ~y~tem ~y which t~e ~tem force l~ ;-r~-n~mitted to the flow control mem~er in one direction of ~tem ~u~ t~ and in the opposite direction of stem mo~ement, the ~oW
control m~amber is llnl ~ of the stem force there~y red~i~g the brea~-auay torque req~Lired to ~ove the flo~ control me~ber to the selected ~-lve po~ition.
It should be clearly understood here that the ~low control membe~
o~ the pr~3ent inv~ntion c~n be rotary type or rcciproc~ting tyF~ ~nat is, the flo~ ~~ontr~l m~mbe~ is dispo~ed in ~e val~c 'oody c~vity either to rotate or to re~ipro~ate between ope~ and clo6~d position~ of the valve.
In a rotary valve, the rota~y motiQn of the Ste~ is directl~ translated lnto rotary m~tion o~ the ~low conkrol m~mjcr- In ~ rcciproc2ting valve o~
the pre3~nt in~cntion, the connecting means ~ t'he ~tem an~ the ~low control m~mber ccn~orises means by w~ic~ the rotary mOtiOn O~ ~hc stem i5 ~ranslated into ~eciprocating motion ~f thc ~lc~ control-~.,~.. c. t~L~vel~e to the ste~ ~Xi5~ such as a ~ac~-a~d-pinlon arrangement,or a s~ot~n Yo~e-and-pin arran~ement -00 n~ 1998 15:53 FRO~ TO 001416595116O P.13/27 ~ W097/14899 PCTrUS~ 5~
. Por ex2~mple~ in a Iraditional wedge gate ~lve, th~ gate recipro-cate~ alon~ the stem ~Xi5 the~eby liftin~ the gate s~l jn~ sur~ace clear off the v21ve ~ody seating sur~ace. But in a reciprocating wedge ga~e val~e as constru~ted ln accordance with features o~ the ~L~s~l,L invention, the uedge ~ate reciprocates in a aireclion transverse to the ~tem ax~ s.
Con~eq~ently, the ~dge gate ~ in~ ~urface does not li~t clear o~f the valve bo~y seating.surface, ~ut slides alon~ the plane o~ t~e valve body seatin~ ace ~hen th~ gate reciprOC~ates tr~n ~erse to the stem axis Thus there is asort o~ scrap~ng action betwen the gate and the val~e body seats therc~ pe~nitting the ~ige gat~ ~lve of ~he present i~l~io~ to be used ~or ~nfllin5 fluids with pa~ticles in suspension, e.g Slurry. In a traditional uedge gate valve in ~hich the uedge gate reciprocates along the stem a~is, particles in s~Sp~n~i qn in the fluid get tr~pped in-~etween ~he ~ surfac~s ~hen th~ gat~ reseats ~n~o the v~lv~ body eats ~
thereby e~ v~lising ~P~l in5 integrity- Hence a ~raditional wedge ~ate valve ci~nn~t be u~ed :Eor slurri~. On the other hand, a w~dgla g:ste ~
as constru~ted in accordance with features of the ~- ~a~lL invention can ke use~ for slurries.
An obj ~ct of the present i~ventio~ is to provide ~or a val~e i~
whiCh the stem reciprocates rela~ive ~o Ihe flow con~rol III~IL~ and the st~m ~orce i~ tran~i~t~d ~o the ~lou co~t~ol ~em~er so as to provide a better ~e2' in the selected ~alve pos~tion.
~ notl~er obje~t o~ t~e present in~ention is to provide ~or a ~alve which auto~atically self-adj~sts for wear of ~e sealing sur~ace~ in order to ~aintain sealing in~egrity.
A ~urther object of the present invention is to provida for a ~al~ve ~hi~ comprises negligi~le dead ca~ity ~pace in the ~ ~e body Another objec~ of the ~r~e5~ invention is to provide for a valve wit}~ lo~er breaX--a~ay torq~le.
A .Further ohject of the present invention ~s to provide for a ~lv~ that can be used ~or hand~ clean f~uids as well as i~ ids ~ith pa~ticles in suspension.
Ot'her objects and ad~anta~es o~ the present inventio~ will become apparent as the following detailed description is reàd in conjunction with the h~~ iny dr8wings and tke appended claims.

9~ 15;50 FR0~ 10 ~1~105951100 ~.14~2r '. WO 9~/l4899 PCTrUS95/135~g Brief D~cription o~ ~he Dra~inqs Fig. 1 i~ a side elevational, partially cross-sectioned view 0~ a rotary plug val~e constructed in accoL~ wi~h th~ present in~cntion Fig 2 ii ~ partially dQtailed ~ross-sec~ion~l ~i~ o~ a r~cipro~t -ing wedge g2te v21ve co~structed ~ n a~-~L~ wlth th~ pre8ent in~ention.
Fig-2-A is a pa~tially de~alled cross-sectional ~i~ o~ the Yalve i~
Fig . 2, generally ta~en along 2A-2~ sho~ing t~ valve in the clos~d poeition, ~=
Detailed Pe~cription with re~Eerence to Fi~ 1, a ~alve ~ ~ly lO0 comprisîn~ a rotary -plug ls s~n a~ constructed in acGo~dan&~ with ~e-tures of the ~l~sent invention.
A ~alve body 110 incl~des ~luid floW pass2geWays 112 and llq on oppo~it_ sidc~ o~ tho ~alve body ~avit~ 116 which ope~5 to one side of the valve bo~r 11~ to c~mml~nicate ~~puardly ~ith the bonnet 142.
~ A flo~ ~onlrol ~emter a~ ~ly 118 comprising a tapered plug closure member ll9 is disposed in the ~c~y ca~rity 116 to open or cl~~e the ~luid ~low r~S o~e~y~; 112~ Irhe plug ll9 has a Sluid flow conduit 113 thcr~th~ol~h al igna~le ~.-it.h the :~luld flow pasad~ a~s 112--114 . Thc ~ral~e ~ody llO i~: lined ui'ch ~n el2s~0merie sleeve 13~ ~ith op~nin~ for fluid flow surro--n~;n~ the ~l~id ~low passageways 112, 114 to 5~Rl ~n~ly ~ngage the plug ll9 The ~lou Co~rol mem~er 118 is rota~:d by a ~al~E~ operatc:r 150 Uhich cornprises a stem 120 Ihat passe!s th~ough th~ stem p~!es:age~:ay 121 in t:he bonnet 142 Fne st:E!rn r~c~eway 121 co;~nunicates ~th the bc~dy cav~ty 116 and has a s~em ~eatiI~g ring 132 dispc~ed arounc~ the ~t~n p~a~ay. 1~21 l~e uppe~ end 123 of the stem 120 i~ ~or~nected to the ~lv~ operator 150 ~y a ste~ mo~ring means 1~i2 ~ which the stem 120 i9 rotated and :~eciprocated along the st~n aXis. The lo~er end o* the st~n 120 has an en~arged end 125 in ~he rorTn of a $ocl~et ~rit;~ splines 122 on inside di = ter Ihe plug ll9 nas a solt d sha~t at ~he ~ r ~nd ~i~h ~splines 124 on outsid~ diameter- The ~eTnale spl~nes 122 o~
the stem ~ne:~:he~s ~ith male spline~ 124 o~ th2 pl~, the~e~y permittinçr the s~em 1~0 to move a~ially relative to th~ ~l~v O~nt~ol ~ember 118. The slem 125 ha~
a stem ~ ac~ 128, ~lso ~alled the s~e;n back--5~at, th~t 5 n~ ly - engag~2s th~ ~;t~m s:eatlng surfa~e 13Z i~L oraer ~o pr~en~ :eugi~ re emi~wion~
It ~hould ~e :nade clear ~ hat the ~ e~female spline~ 1~9/122 in Fig. 1 can be in~erc~anged .

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-CA 02234749 l998-04-l4 ~8-~P~-1998 15'5~ FR-O~
TO ~1~165951163 P.15~27 : W 097/~489~ rCTAUS95/13529 gitive emiss~ons arlse ~hen ~ ids in t~e va1ve body c~vity 116 c~scape rrom around the st~sn. A pa~king gl~d 138 exerts ~,~"..~, t:5..ive ~oroe on the s cem packin~ lqO -~rol~nding the stem 123 lo mainta~ ~ive sealing enga~nen~: a~ound the st~m th~reby ~P~ 1 i ng Ihe s~em passa~cway 121 ~'rom ~he val~e b~dy cavity 116.
Ihc ~tem ma~ring meas~s 152 i~ a f~or~ of a "I,ift--'rUrTl--and R~se~
~rh~nl ~m arlc ca~ies ~h~ stem 120 to mo~e in a secIuence D~ steps th~t pr~v~es ODl~- axial motior~ a~ay ~rotn the ~lo~ co~trol m~er 118, then ro~cary mD~ion, ar~a th~n only axi~1 motion to~ara5 r.he :Elow cDnt;~ol roember llE~ in resporlse to move~ent o~ the val~e op4r~tor 150 in one dire~tio~
In , ~x~ to ll,o~ ~.L of the ~al~re opesatc~r 15rD in t~e o~posite direc--tion, the stem mov:~ns;a menns 152 ~a~ses the ~tem 120 to m~ve in a se~uence o:E ~teps ~lat pra~ides on~y axial motion a~ay frosn the i~low control ~ern~er 118,. t~ :rotary motion, ~nd then only a~~al mOtiOn towards Ihe ~10~ cosltr~l rne~be:r 1 1 ~1 . Il~e top sur~ac~: 130 o~ t~e plug 1 19 acts as s~op ~nea~ ~o arr.est ~w~cher axi~:~ motion of the 5tOEn 120 to~rd~ the plug 119, thereby ~ ransmit~ the stem force to the plug 119 when the bot~tom sur~'aee 12~ of the stem lZ5 engages the top s~rfa~ 130 o~ the plug 119 When the ~-tq~n 120 mo~res axially aw~y ~rom the plug 119, the pl~g 119 ls ~nlo~ of the stem ~o~Ce an~ thus less torque is needed ~ the valve op~rator 15Cl to r~tate the plup 119.
Wh.en ~he valve ~perator lSO i~ ~oved i~ one di~ection to open the ~alve, th~ ~tem 1~0 moves only aXially a~y ~rom the plug 119 which i~ then unloaded ~l~ t~e st~m *orce, t~e ~em 120 then rotates togsther ~ith the ~lo~ control member 118 throug~ a pre - det~r~d interYal o~ rotation, i~
this case 90 degree~. to open the rluid rlDw p~ssagew~y~ 114 by a~ign-i~g the cvnduit'll~ o~ the plug 119 ~ith t~e ~luio ~low p~ssaseways ~ 111. With ~urther movem~n~ o~ the v~l~e operat~r 150 in the samedirection to open t~ val~, the stem 120 moves onl~ axiall~ in the oppo-sit~ direl=tion to~ard~ th~ plug 119 U~til the bottom surface 126 of th¢
st~m 125 ~ngages t~ plug stop 130 there~y transmittiny the stem ~orce to th~ pl~g 119 to provide adaitio~al loa~ ~o the plug 119 ~or achieving a ~gher seali~g i~tegri~y tha~ ~hen the stem does not transmit ~orce to the plug~ Thus the ~lUid flow passageways llZ-114 a~e sealed ~rcm the v21ve ~o~y ca~it~- 116 in the valve open position o~ t~e rlO~ conlrol memker 11~_ ~n the valve operator 150 ~s ~v~ed i~ the o~po51te direction t~
c105~ ~he ~lvc, the said ~eguenc~ of ctem ~ovement described hereinabove is repeated. That i5, the stem 120 moves only axially away ~rom ~he ~-H~ o la~ F~O~ ~ ~ = ~~
Tu ~ ~ssa11~ P. ~r pl~g 1 l9 ~o Url~O~ plUg vE ~x;al Forc~ Frorr~ th~ en~ ,t~n ''~n ~-~kLal;~t~ t1~rrtl~ph ~0 de~r~es c~ hQr vith the pl t~ ~l9, an~ e s;t~m 1~
tl~n Tl~ovQS c~nly :-xially ~owacds the plug 119 unl~ le s~em surrace 125 ~ny;t~ e stcp 130 on the plu~ 119 ~he~eby tr~lns:mLt~irlS~ the~ 3tetn force ~o l~-e pl~lg 1L9 to sea1~ngly clctse t~-e ~1Uid fla~ p~S:s;tç~e~ays llz-lla in e va~e c.~os~d position l~te plug 119 carrir_s tr~lnnion 136 at th4 ~ottom ~y ~ llich tl-e 3enlin~3 ~unr tion is ~ende~ed In~ep:ndc~nt o~ id press:ure.
Nev~rth~leS~, rluid pressure air3s in ~:he s:ealin~ Et-nctictn by pushin~ the p~,~g or~to ~t~ downstre~trrl 5ea~ surro-~ndin~l the ~luid ~10w passageway.
171e E1~id Flow passagcW~y l lZ~ 1 is se~1Qd Erom ~h~ valve ~ody c~ity 116 in tl~e v~1v~ open position as we11 ~:3 itl ~l~e va1~e clos~d positiort o~ t;l~e Elow control m~m~er 118, ~nd this ~e~1ing i-- obtained by ~Ising a "Li~t-and-~h~rn" me~nanism t~o~ tS~e 5tem mo~ring rneans 152. ~he sternmovinc~ me~rts 152 t~at causes th~ stC~m to mo~re in a sequen~e ~ steps ttlat p~ovid~s only a~cial motion a~ay fro~n the pL~g llg. then rotary mation, and th~n only ~xial m~iCn ~owards ~he p~g 119, ls generally call~d a ~r lFt_ rurn-a~d-~5eat~' ~eans. Ihe Stem movln~ meanS 152 that causes the S~em tO
move i~ a se~uenc~ of ~tQ~s ~h~ prcvades ~nl~ axial mo~ion a~y f~om the plu~ and tn~n r~ta~y motion, is gene~allY C~Lled a ~'LiCt-and-Turn" ~4ans.
~-. th~ ~lee~e 1~4 ~ea~s out, the st~m lZO nee~s to t~avel a little ~rther to~rds ~ . pl~ 119 in order to maintain eEE~c~i~ sealing, and the valve op~ra~or ~.SO au~omatically p~vide~ e~ternally varia~le stem f~rc~ nee~ed ~o m3in~aln ~e3l~ng inte~rity. An example of a ~tem moving ~ans i~ the ~on~ o~ a "Lift-Turn-and-Reseat" mea~s and a "~i~t-and-Turn~ mean~ is eYpLai~ed i~ great detail~ VS~ P~t~nt ~o. 5,~07,176 ~ril l~, 1995 by Ne~relcar. Ot~er exsmple~ o~ t-Turn-and-Reseat~ m~an~ a~e:

~SA 2,39Z,8~0 Jan- 15, 1946 by Reed:
us~ 2,qq3.995 June Z2, 1948 by Snyderi U51~ 2,501,150 ~la~cll 21, l9S0 by r~nder~ion US~ Z,795,96~ June 18, 1957 by Heinen et al Us~ 2,a58,097 octo~:r 2E3, 19S8 by 21Oms~n et al:
Otl~er e,~ mpL~s C~ "Lift-and-l~rn" m~ns: are~
WSI~ 2,07f~,8~ prll 13, 19:~ by ~le~sem;
lJS~ Z,3~3,549 A~3glls~ 2~, 1945 by Tlilker:
USA 4,23~,157 Noverrber lB, l9E30 ~y Tlodycman et al;
US2~ 5,3~2,0Z8 J~ugl~st 30, 1994 by Ne~r~kar. _ AMENDED SHEET
IPE~A~EP

CA 02234749 1998-04-l4 ~-~r~ a;a~ r~u~
~ u ~l4l0a~a~ r . î
W~ 7~ 899 PC'rJ~SS~5/13~i29 'rhe ~alve ~ody 110 in Fig 1 is shown lined ~i~ elastameric slee~e 134. Howeve~, v~lve ~çdy 5eat rings o~ ~i~ply sealin~ ri~gs on thc plu~ 119 can al~o be u6ed Tne Stem 12~ connect~d to ~ne ~lu~ 119 by co~neetin~ means that allo~s a~ial m~vement o~ ~h~ stem 125 relati~e tne plug 1~ t substanti~lly no rotary mCve~ent between ~he s~em 125 and ~he plug 119. Said anothe~ w~y, ~he o~.cc~i~g ~ean5 ~etween ~he ~tem 125 ~n~ the pl~ 119 is such that ~f the plug 119 is held stationary, the ~tem 125 can~ot rotate ~ut can move omy axially ~elative to the plu~ 119.
Tn~ flow ~o~t~ol ~..~.~g~ 118 shown in Fig. 1 is a taperea plug ~owever, it should be clearly undeL 5 LoO~ here that the ~low control mem~er ~an be a~y o1:~er kind ~ clcsuSe member that can b~nc~it from adaitior~a ~orce ~om ~ne s~em to ~chie~ a higher 5P~ltn~ i~teg~ity t~an whsn t~e stem ~orce i~ no~C U5e~ .g. a 6ey..~.ted tapered plu$a~ a tapered ball, a ~ylindri~al plU~ with w~dging ~ S 0~ any other closuro mem}:er ~hat uses a wedgin~ pr~ nciple to o~tain E:ea~ling ~y ~ ni cal ~r~ans . Al~=o, the ~lo~ contr~l member Can c~ i=e a reciprocati~g wedsr~ ~t~ constru~t~d in acc3rd~r~ce ~ feature5 c,~ the ~ ent, imrex7tl0n. In such a constructlon, 'ch~ connecting mea~s be'c~ the s~L and the wedge s~te shall compri~;4 means by ~-hi.ch ~he ro~a~y mo~ion of the stem iS r,ransl;~ted into a reciprc~
ca~ing mot.i~n o~ t~e wedye gat~ in a dire~tion perpen~ to the atOE~
~is~ The p~esent ~entiOn th~s can ~e u~ed for ~ reciprocating gate v~lve in ~hich the *low control ~ember is a uedge gale that i~ dispocod in the V~lve body cavit~ tO recip~oc~t~ in a dir~C~iOn rransverse to the st~m ~ e ~plines 122/124 i~ ~ig. 1 ~r~ ~ho~n po~itionea i~side the ~onnet 1~. Howe~e~, th~e spllnes could be rep~sitioned outside the bonnet lq2 just abo~e the stem packing gland 138. thereby r4aUcing ~he stem tra~el ~it~in the st~m packing 1~0 and thus extending the l~e o~ the ~te~ ~ac~in~.
In prior ~rt o~ a ~raditional wedege gat~ ~al ve or ~ tapered plu5 V21~e ~sins 9 hi~t-and-q~rn mechanis~, the ste~ reciproca~ along the 5tem axis and the ~low control ~em~er ~s loade~ ~nd unlo~ded o~ thQ stem ~or~e.
~ut the ~l~v ~ontro mem~er also reciproc~t~3 C~n~L~ ~r~Lly w~t~ t~e s~em, ~here~y ~lciny th~ valve unsuita~le ~Dr u~e ~ith ~l~ids ~ith particles in .
suspension. The pres~nt in~ention of Fig. 1 re~ains the good ~eatures sf the Drio~ ar~ and in ~harp ccntrasr to ~ri~x art~the ~lo~ cont~o~ member 118 Or t~e pres~nt in~ention does ~c~ reciprocatc ~it~ the ~em 120 ~ut is oe~lnly lo~ded and unloaded o~ tne stem ~r~e ~ the re~iprocating stem This is an important di~ti~etion o~ the present invention o~er p~ior ar~

RPR--1~9~ 15: 55 FR~
TCI 130141b~g511b~ F lti~2 WO 97tl~899 ~C'r/US9~;/1352,Y
Regardin~ Fi~s. 2,2-A, only i~4~tant d~tail~ ~e ~hc~n for the sa~e of brcvity only to ill~strate how r~ary mo~ion o~ the ste~ is translated into xeeiprocatiny ~ollon ~ the ~lo~ contro~ member in a direction transverse to the stem a~is.
A recipr~catiny wedge g~te valve ~e~-m~ly 2~0 ~om~ri5es a ~alve bo~y 210 and ~ ~on~et 242 th~oug~ which ~he lower end 225 of ~e stem extends into ~ h~ bo~y_ cavity 216. A ~lOW control ~esber a~P~kly 2~E
compr~ses two se~m~nts ~19 and ~20 that wedge against each other and are held to~ether i~ a ~loating ~onn~ction by springs (not shoun) The ~lo~
~ontrol member 21~ i~ disposed in the bc~y cavity 216 and reciprocates in di~e~tion pe~pendicular to the stem ax~s ~o :selecti~ y c10~4 or ~pen the ~luid ~lcw p~s~geway ~12-214~ The stem 225 has sp~ines 222 ~n the o~ter diamet~rr The splines ~22 mesh with li~e ~plin~ o~ th~ i~ner dia_ meter of the p~nion 226 and pe~mit the stem 225 to move along the stem axis relativ~ to the ~ W control m~iber 218 un~il the.bott~l sur~a~e 228 of the ctem 225 ~y_~ th~ top s~r~ace 230 o~ ~he s~y~ "~ 219 thereb~
transmitting t~e stem ~orce to the ~lo~ Control mem~er 21~ During the rotary motion ~ ~he ~tcm 225 th~ pinio~ 226 ~ota~es ~ith stem and at the 5am~ time en!~ages the rack 224 on the ~low ContrOl member ~ 220 thereby causin~ the rlGW ~o~tsol ~ember 21a to reciprocate in a direction perp4n~ r to the stem aXi5 as shoun in F~g. 2-A. It should ~e made clear that only one sesment 21g ~ill ~u~~i~e to constitute the ~low conlrol mem~,e~ 218 instead of t~o SEy~ S 21~,220 and in that case the ra~k ~24 should be placed on th~ segme~t 219 ~a~iations in the ra~k-and-pinion arrangement are also possible. ~or example, t~e rack 224 c~ ke linear or cuu~ed ana ~he ~low control mem~4r ~haped accordingly, along ~ith th~ body cavity and the v2lve ~ody ~eats.
The taper angle of the plug 119 in ~ig l and the wedge anyle in ~ig.2 is extr~ely impo~tant in bringing about the relea~e o~ ~he wedying forces .~om the valve ~ody seats af~e~ the ~low co~trol mem~er 118, 218 r~specti~ely ic ~ ~d of axial ~orce from the stem u~en the s~em move~
away fro~ the flow control mem~er. This ~gle mus~ ~Q greater than the an~le o~ repose for the materials used.'Peciding on th~s optimum angle - ~cr the ~lc~ control mem~er req~ires extraordinary technical ~kill in thesu~ject mat,ter an~ i~ generall~ beyond the .~..~ehe~sion of one Of , ordinary s~ill in the art.

r PR--1958 1~;55 FROI-i --0 ~ 1~165gSll~ f'. l~Z
. w 097~899 FCTr~s95/~35~9 ~ Thus, the ~ ~... t in~ention ~ applica~le to a v~lve in w~ich the ~lo~ ~ontrol memb~r consi5t~ o~ a rota~y mem~e~ or a re~iproc~ti~g membez and is loade~ w~th additio~l fosc~ ~rom the stem co ac~ieve n better ~1 than ~hen ~h~ stem force is not applied to the ~lou c~ntrol memb~r and the s~em mc~ny means ~ransm~ts the ~tem ~or~e to the ~l~w con~rol .
pre~i~ely ~hen the-additional force is n~eded.

From the a~Gve description it i~ clear _hat ~he ~s~t inven~ion is uell adap~ed ~o carry ~ut the ohj ectG and to attain the en~s and aevant -ages mentio~ed ~e~in as well a~ those inherc~t in the i~ent~o~ While pre~ently pr~erred embo~ents have L~n a~scribed ~or ~oses o~ this a;~ , it ~ill ~e ~lde~aLOOd ~hat ~ UUS changes m~y ~e made whic~
will reaaily s~ ~ct the~selves ~Q those skilled in the art lnd ~hi~h a~e r' ~ ~nthln the spirit ar the invention di~l~s~ and a~ de~ined in the appended ~~

Claims (10)

What is claimed:

1. A valve (100) comprising:

a valve body (110) having a body cavity (116) with a fluid flow passageway (112-114) therethrough defining a fluid flow path intersecting the body cavity (116);

a flow control means (118) disposed in the body cavity (116) for selectively closing and opening the fluid flow passageway;

a valve operator means connected to the flow control means (118) and comprising:

a valve operator (150):

a stem (120) having a stem axis and connected to said flow control means (118) by a connecting means that allows axial movement of the stem (120) relative to the flow control means (118) but allows substantially no rotary movement of the stem (120) when the flow control means (118) is held stationary: the improvement comprising:

a stem moving means (152) operatively connected with the valve operator (150) and the stem (120) for selectively moving the stem (120). said stem moving means (152) causing the stem (120) to move in a sequence of steps that provides only axial motion and then rotary motion in response to movement of the valve operator (150) in one direction, and rotary motion and then only axial motion in response to movement of the valve operator (150) in another direction: and a stop means (130) disposed on the flow control means (118) for arresting axial movement or the stem (120) towards the flow control means (118) and thereby transmitting a stem force to the flow control means (118), whereby movement of the valve operator (150) in said one direction causes the flow control means (118) to be substantially unloaded of axial force from the stem (120) and then the stem (120) rotated, and movement of the valve operator (150) in said another direction causes the stem (120) to be rotated and then the flow control means (118) loaded with an axial force by the stem (120) so as to provide a better sealing function in a selected valve position than when an axial force by the stem (120) has not been applied to the flow control means (118).

2. The valve (100) as defined in claim 1, wherein said stem moving means (152) causes the stem (120) to move in a sequence of steps that provides only axial motion away from the flow control means, then rotary motion and then only axial motion towards the flow control means in response to movement of the valve operator (150) in said one direction.

3. The valve (100) as defined in claim 1, wherein said stem moving means (152) causes the stem (120) to move in a sequence of steps that provides only exial motion away from the flow control means (118), then rotary motion and then only axial motion towards the flow control means (118) in response to movement of the valve operator (150) in said another direction.

4. The valve (100) as defined in claim 1, wherein the flow control means (118) further comprises a hollow conduit (113) therethrough alignable with the fluid flow passageway (112-114) in the valve body (110).

5. The valve (100) as defined in claim 1, wherein the stem moving means (152) further comprises a lift-and-turn means for causing only an axial movement of the stem (120) during a limited interval of movement of the valve operator (150 and for causing the stem (120) to rotate during a lime of movement or the valve operator (150) other than the limited interval.

6. The valve (100) as defined in claim 1, wherein the flow control means (118) further comprises a plug (119) rotatably disposed in the valve body cavity (116).

7. The valve (100) as defined in claim 6, wherein the flow control means (118) further comprises a trunnion (136) on the valve body (110) rotatable about the stom axis and disposed on a side of the flow control means (118) opposite the stem (120).

8. The valve (100) as defined in claim 1, wherein the valve body (162) further comprises:

a stem passageway (121) in fluid communication with the body cavity (116) and a stem seating surface (132) surrounding the stem passageway (121), and the stem (120) passing through the stem passageway (121); and the stem, (120) further having a stem sealing surface (128) disposed around said stem (120) to sealingly engage the stem seating surface (132) surrounding the stem passageway (121) in response to selective movement of the stem (120) away from the flow control means (118) wherein the valve operator means auto-matically provides a self adjusting and externally variable stem force for sealing the stem passageway (121) from the valve body cavity (116).

9. The valve (200) as defined in claim 1, wherein the connecting means between the stem (225) and the flow control means (218) further comprises means for causing the flow control means (218) to reciprocate in a direction transverse to the stem axis in response to rotary movement of the stem (225).

10. The valve (200) as defined in claim 1, wherein the connecting means between the stem (225) and the flow control means (218) further comprises a rack (224)-and-pinion (226) arrangement between the flow control means (218) and the stem (225).