CA2011536A1 - Control valve - Google Patents

Abstract

ABSTRACT

A diaphragm operated control valve wherein the diaphragm acts at the same time as a plug and as an actuator, in particular consisting of a chamber, divided in two by a resilient diaphragm, an offtake apt to connect the inlet and the outlet of said chamber, a pipe apt to connect said offtake to the upper part of said chamber, a needle inserted along said offtake, a spring to press said diaphragm towards a lower chamber.

Description

ll ~he pre6~nt inv~n~ion pr~pn~ a dlaphra~m control v~a1ve we~reln ~aid di~phragm .~ct, ~ot~; a~ an ~ ator and as a plug.
It is a r~ul~ion valvc with proportional and inte~r~l ~haracteristico, wherein th~ Y~luttin~ deYi~ eonr~i~Jts of a concave diaphra~m, in resiller~t ~na~erlal, tho por,ilion of whirh determine6 the opening of the line on which it i3 in~;ert~d, an~ ~hi~h is eontrolled by a pilot valve ar~d by a ~eedle valve inr;~rt~ along a by-puss oircuit.
In this wny i ~ i~ posslble ~o use the valve for a large nur1ber o~
~ifferent appli~,~tion~ by s1mply rhanging th~ pilot. v.~lv~ ~ype, with con~lderabl~ ~dvanta~es ber,n~lt;~, being the mai~ vHlv~ body the same for ~ll the applicati~nr~" th~ num~or of the parts to ~eop 11- F.to~k i8 highly reduced.
The invent10n ,h~r~oterlstic fenture ls the particul~r otructure and arrangemçnt rJf th~ part~, wh1,h ~llows a very pract1r,nl r~v~ilsbility to ~ho U8~ o~ tho valv~ ir~ cor.lparl~on tn tho already knowr, rca1lz3tiono.
Accordln~ to ~h~ pre~ont tr~hniqu~, a number of vnlv~ typ9~ ar~ known 2mong which, 1n partieular, thc so-r;~llod diaphra~m valv~c.
~hey are v~lv~ in whlch t.h~ olltflow port can be sh1~t up by pu~hin~ a dlaphra~m eap~hl~ to be ~e~'ormcd a~ainst ~ seat.
In these valvo3 th~ di~t;ra~ iully separatoo th~ actuating dcvlceY, ~enerally of m~ch~nlea1 t.yp~, rro~l th~ mfdium.
In othcr valvc types, th~ ~hulLing devlce consist6 of ~ mctsl plu~
connected, for ~xample, by mcant3 of u stom or ~ rl~id spindle, to B
dlaphr~tgm which actuates th~ ~lu~ movemont~ to open or c10se the medlum p~88~g~1.

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In both ca~ t~nry are valv~t~ includlng two dlf~t~rent deviees, the clo~i~sg devicc sr plu~ s.3nd ~he act\lat:ing device of samc: or actuator.
These valva~, cspet ially in oa~e tht~y have to be ~uto~3tie~11y act~ated, h~vt~ the disncivanta~;e Or a ct~rs~i~ruction which is sometimes ~omplicated and, anyw~y, rt slllt~ ~ulky ir- mssny os;sses.
In ordt~r to csvoi d the3e tro~ ies, the present invent.ion proposes Q
diaphrtigm v;31ve type wherc~ tht csiaphragm acts both A13 plu~ and as actuatt~r .
~his 1~ a valve where, by G~ able ad~usting device~, th~ 4eme pre~sure of the medium t.o ~e intercap~s~d operate~ the dl~phra~m movements.
Golng irsto detat l:~, accordinJ.? to tht~ invention, the valv~ consir~t~ of a chamber, ins~rtt~ti along the l~ne., divided in two ps3rt~ ~y means of a d~aphragm rn;~tle with ~ erial o s~p~ble to bo deformed.
Al~ offtakc, ;~lon~, whlch ~ neodlç t~nd a pilot v~lve are ln4erted, conneots the ms~in pipellntL to the part ei the chamber where s~ ~pring, actin~ on the dlaphr~um, i ~ nl~o loç~totl .
Conoe4uent1y, ~he dls.3phra~m ts ~;ubjected, on one sldt~, lo ~he ~sctlon of the medl~lm to ~e in~t~rccptt ti, alld, on the othe~ ~ide, tt~ t;he RCtion the medi~m oomitlg from aid of~tl~ks, and to the sprln~ tlction ~y properly aetine o~l ~oth nt~t~dle and pilot valve~, it is pos~lble to adJust the valve ept r~tiorl.
Thc present irlvent10n wil; now bt~ ~e~cribed in d~tall, wlth partioulsdr referenc~: to thc ~nclooed dr;3wirle~l whcre:
hows ~nd e~plodo~ vi~w of tho valve accordin~ t~the invention;
- vlg. 2 ~ ~ Rotl2matic~ v sh2w a va1ve ~cotion accordlng to the inve~tion in r~enin~ and closing po~tion respectiv~ly.
Accordin~ ~.o the ir~ventlon, thc valve lncludo~ a main ht~dy, shown ln its f~ll assembly wi~h l, to be. iserted along a pipellne 2 and which i~
subdivided into two p3rt~ ~y Q r~.ilient di~phragm.
Tho lower part sho~.~s a ~ottom 4 6haped with a serie6 o~ ribs or partition walla 4 h~ving ~ ~rvilin~ur upper edgt~ so a~ to allow ~i~phr~gm 3, ~hen pushed downwards, to loan all along against the upper ed8e~ 5 of ~aid wc~lls 4.
On the upper ~.iLde th~ v~lv~ i~ cl~ed by ~eana Or a cuv~r ~ whi~h de~lnes the external wall o~' the uppcr part oi~ the valve body. ~
In this up~,~t~r ~h~b~r ther~ i~ n h~lical sprin~, or ~lmilar, 7 which, by ~ lower w~aher 8, acts Otl lhe diaphragm 6, pughing it ~uwnw~r.~ds.
hn offtake 9, or~ the ~ody 1, o~rmeots the lower t~hamber oppo~ite ends etich other.
A o~entral pi~ ()t:t~nn~t~t,~ t,hl~ t~fftako wlth the uppe,r chamber.
Alon~ the o~'take there ar~ a ~traint~r 11, a neodl~ vnlv~ nd a pilot valve 13 of ~n4wn typ~ an~ which i~ ohosen dependin~ or, the ~y~tem whlch 1~ intended to ~e adoptod to pLlo~ ~he valvs 1, While operatirlg, the pilot valve o~en~ or olo~es the ~fft,ake ~, causin~ a ch~nge in th~ ~r~Yur~ in~id~ the ~Jpper chamber. Thls char,ue conaequently ¦causes a di~ m~nt of tho dlaphra~M 3 r~om the cl,o~ln~ po~tion, ~ho~n ¦in Fig. 3, wher~ th~ dl~phra~m 1~ ln cont~t wlt.h the od~e 5 Ho ¦preventing t.he me~3tu~ pa~s~saU~ t~ ~n openine postion ~h~r~ th~ dlaphr~em ¦moves away m~re ~r 1~ fr~m .~al~ walls 4.
The oper:t on can be bett~r cxplained wlth the rollowill~ ex~mple.

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Suppoein~ thet t.h~ velvY i~ islitially in clo~in~ post;on, i~ shown ln Fi~. 3, with the mediulrl whlch fi 11B the uppeir chambtir ~iide.
In this eR~e ~ht~ diaphra~m is, on the upper side, s1ihJe~t to a force equal to th~ pitren~i mediui7i presi~iure multlplied by thc whole diaphra~0 surface, plu~i ~he rorce exerted ~y the spring; ~n the lewer side, lt 18 ~ub~ected t.o a ferce ~nly ~-lual to the upstream and down~itre~m medium pressure multiplie~ hy the r.urfsl-~es where said pre~sure~ act.
In this e~e, ~he force wh1ch pu.shes the dlophragm d~wnw~rds previ~13, 80 keeping it clo~ed.
Let ug imme~itle t.hat at t.h~s ~.t.~o the utilizatlorl becomes active, ~io causlng a pressure reductiori do~Jnatream the valve (on the right of the rigure ) .
In this case thc pl10t valve 13 or~n~ allowln~ the p~FiFin~e of the fluld ~lon~ ofrtE~ke ~.
Since the narr~wln~ in the nt!~dle valve 12 cau6es a prc~surc drop in the le~t ~r~nch ef trl~ orrtahe, the ~reater prel3t~ure of th~ uid preeent ln the chamber wil] mnk~ thie t~ rlow along llneti 10 arld g, thu~ causlni a deeree~e Or ~tle pre~ure ln the pLpe over the diaphra~m, thua allowlne the fluid pre8suro in th~ mnin line to pu~h the diaphr~ upwsrds, aa ~uch as necessary for the downstream required capacity.
Ag ~g maximum Op~nin~, th~ dlaphra~m reaches the po8itlon ~hown ln Fig.
3.
Wher, the utilizatlon downstrcam the valve la reduced, the pilot vslve 13 throttle~ or c10s-3 thc offtakc '3; lts upstream prcs3urc and ~herefore the pres~re in t,he upper ohn~b~r lncrease and tend to rçaeh a value ' ~J; ~L r equal to the medium pr~s~urc inside the valve body.
~n this situnt~-,n where ~he ~resour~3 on both sldes Or th~ diaphragm balance, the ~iaphragm iY pu~hed by the force ex~rted by the spring ~.
When the ciiaphr~m geto in con~ct with the ed~e 5 of the wall 4, there's a reduction of the ~orce ex~rtcd by the low~r chan,ber pressure at3 the diaphragm surr~ce, ~n which ~hie pressure t~cts, io reduced 'oy the edge 5 aret~ ~o the di~phra~ttl set~l~r. ln closing position.
3urlng the rc~ula~ine a,ti~n o~ the valve, the rl~?edle valve 12, the ohoking pos~ion ~f which h~ heen duly set, act~ a~ reeulator of the V~lve action ve]ocity, Thls enableo to o~tair~ th~ ~tahlli2t~tion ln an irltermcdiate regulating po~tion or- ~ rl~w and Corltrollt~?d clo8ing Of th~ valve, ~voidtng in ~uch a ¦way dangeroa.~ waterht~mmt?rln~.
¦The advantà~b orrerkd hy thi~ typk of valve are consl~crable: oincs the clo~in~ ta~.e~ pl~c~ ~Jetween t~ ro~llinet surface ~the diaphragm 1 manu~actur~d in ~ot`t ma~erinl ~uch a~ EP~M rubber or VITON) and a oetal rlgld oeat, th~ ~et~ sh~torr i~. a~sured without any rlsk of dama~e in ca~o of ~olid lnel~Jslons ln ~he mcc~ium.
A valve with rc~ulr flow and without turbulenoe~ 1~ otabined .~nd, in oase of llne pr(?~sure failur~. tt~e v31vc close~ automatie~lly due to th~
cprin~ .
'rhis prevent~ thc pi~elin~ from enlpl:yine and the oubs~4ue~lt inconvenlent~
du~ to laek of the pump ot:~rt.-up, From a practic~l potnt of vl~:w, the valve, which can he mourlted both in horizontal arld vertical pO4ciO~ orfrs somo remarkabl c advant~ges since 2 ~

it can be fit ft~l~ m.~ny ~iff~r~nt npplicatlon~ by crlly eharl~in~ the p~lot v~lve tupe. ~ vn~qLIt~n~e, it i~ nece~sary to keep in stock only a llmlted numb~r r~f v~31v~ in~:~ i t is snough to hr~v~ ~ame àifft~rent pilot valve types to mcct all the possibli r~quirements.
Finally, ~h~ v~lve accordin2 to the inventlon eCt'J at the same tlme a6 plu~ valve and actuator, beirls~ evlce of simple construction cone~3ting Or ~ few p~r~s and whiah aorlsequently offers the advanta~e of ~ cheaper co~t ~nd an e.~.ier maintenancc.
The ~peci~ phr~m jhapin~ enable~ it to odopt~ any postien between thorie Or m~x. op~r~ing and elo~in~, position determin~d by the action of the ~prln~ ~nd ~h~ ~ervofllJ1d ~hich i~ the same m~dllJm flowing in the plpellne ir~t~rt epte~ by thc v~lve, Tn thi~ cas~, the ~orvoflllid ;~tr~ in the upper ch~mber with the pressure v~lues properly dctermined by ~he pllot valve.
While the valvt~ i~ op~nine, th~ dtàphragm po~ltion i~ ~etormlned by the 114uLd pre~ure actln~ on the lower di~phraem curfa~.
Tho varlbal~ corl~t~nt ~prln~ 7 ab~orbs a force more th~n proportional to the dlsphr~m llft, and thçrç.'ors proportionzl to the dynamlc forooç
~uitable for a propor~io-lal r~alation and wlthout o~e~llatlons of the diaphragm, wh~rl th~ n,arv~flu1d prs~sure chan~es.
'rhe pllot valv~ 13, ln rc1attc)ll to ~h~ paramoterfi accordllJK ~o which thc ma~n vAlvo open1n~ er elo~in)~ tormir,ed, act~ on th~ ~ervofluid flow ~o as to chan~e the preu~ur~ on t,~o diaphragm to l~t ~t move as lt 1~
requlred to confor~ the openilllr, ~roo of the valve ~o th~ re~uired ~apaclty.

W~en the v~lv~ r~ he~ thc opening degreo fit to the re4-lY~ted capacity, the pilot valve ra~et~ 40 ~h,~t th~ c.ontrol rlow becom~ again the aa~e ac ~efore the re~ula~in~ ~OtiOll, Fig. 4 ~r~ h ;~ hematically show a numbsr of different ~ppllcations of ~he valve ac-corclin,~ to ~h~ invention, only to give ~omc cxample~.
Flg, ~ showr~ ~hc cxa~ple of a pre~ure reducing valv~ wlth solenoid for remote shutoI'f of ~he m~in v~1vc fi~. 5 shows an clectrohy~raulically operated valv~ with clo~in~ speed a~justable in order to ~void waterhamm~rlng; flQ. 6 arl electrohydraulically oper~cd valve w~th a normally closed 401enoid valvc; fi~. 7 a level control valve; fig. 8 an electrohydr.~l~lieally operated v~lve with manual t~t v.~lve; fig. lO a spllt range pilot reducin~ v~lve for wlde preaeure control range; flg; 12 a level control v~lve; flg; 13 an electropneumQtically operated control valve.

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Claims (3)

1. Diaphragm operated control valve characterized by the fact that the diaphragm acts at the same time as a plug and an actuator.

2. Valve according to the claim 1, characterized by the fact that the same medium controlled by the valve is brought on said diaphragm to operate the valve.

3. Diaphragm control valve consisting of:
- a chamber, including an inlet and an outlet for the medium, divided in two by a resilient diaphragm perimetrically constrained on correspondence with the upper side of said chamber so as to subdivide it into two parts, the medium to be controlled flowing in the lower side of said chamber;
- an offtake apt to connect the inlet and the outlet of said chamber to each other:
- a pipe apt to connect said offtake to the upper part of said chamber;
- a needle valve and a pilot valve inserted along said offtake; the first one upstream and the second one downstream the said pipe connecting the offtake to the upper chamber:
- a spring apt to press said diaphragm towards the lower portion of the chamber;
- there being provided in the lower portion of the chamber is contained by walls forming a partition walls which has an upper edge with cruvilinear shape, said partition terminating, at the ends, in contact with the said diaphragm perimeter