Phakathi kwabasebenzisi abasebenzisa iivalvu zeglowubhu ezinobubanzi obukhulu imihla ngemihla, badla ngokuxela ingxaki yokuba iivalvu zeglowubhu ezinobubanzi obukhulu zidla ngokuba nzima ukuvala xa zisetyenziswa kumajelo eendaba ezinomahluko omkhulu woxinzelelo, njengomphunga, amanzi anoxinzelelo oluphezulu, njl. Isizathu sale ngxaki sibangelwa kuyilo lwesakhiwo se-valve kunye ne-torque enganeleyo yokuphuma kwinqanaba lomntu.

Uhlalutyo lobunzima ekuTshintsheni iiValufa ezinkulu zeDayimitha

I-avareji yamandla omlinganiselo othe tye womntu omdala yi-60-90kg, ngokuxhomekeke kumzimba ohlukeneyo.

Ngokubanzi, indlela yokuhamba kwevalve yeglowubhu yenzelwe ukuba ibephantsi kwaye ibephezulu ngaphandle. Xa umntu evala ivalve, umzimba womntu utyhala ivili lesandla ukuba lijikelezise ngokuthe tye, ukuze i-flap yevalve iye ezantsi ukuqonda ukuvala. Ngeli xesha, kuyimfuneko ukoyisa indibaniselwano yemikhosi emithathu, ezizezi:

(1) I-axial thrust force Fa;

(2) I-friction force Fb phakathi kokupakisha kunye ne-valve stem;

(3) Amandla okungqubana kwe-Fc phakathi kwesikhondo sevalve kunye nondoqo wediski yevalve

Isixa semizuzu ngu-∑M=(Fa+Fb+Fc)R

Ingabonwa ukuba ubukhulu bedayamitha, kokukhona i-axial thrust force inkulu. Xa isondele kwimeko evaliweyo, i-axial thrust force iphantse isondele kuxinzelelo lwangempela lombhobho wombhobho (ngenxa ye-P1-P2≈P1, P2=0)

Umzekelo, i-valve yeglowubhu ye-DN200 yecaliber isetyenziswa kumbhobho womphunga we-10bar, i-axial thrust yokuqala yokuvala i-Fa=10×πr2=3140kg, kunye ne-horizontal force circular efunekayo ukuvala isondele kumandla omjikelezo othe tye onokukhutshwa yimizimba yabantu eqhelekileyo. umda wokunyanzeliswa, ngoko kunzima kakhulu kumntu omnye ukuvala ngokupheleleyo i-valve phantsi kwalo mqathango.

Ngokuqinisekileyo, ezinye iifektri zincoma ukuba zifake iivalve ezinjalo ngasemva, ezisombulula ingxaki yokuba nzima ukuvala, kodwa kukho ingxaki enzima ukuyivula emva kokuvala.

Uhlalutyo lweeMbangela zokuvuza kwaNgaphakathi kweeValuvu zeGlobe zeDiameter enkulu

Iivalvu zeglowubhu ezinobubanzi obukhulu zisetyenziswa ngokubanzi kwiibhoyila, iisilinda ezingundoqo, ii-steam mains kunye nezinye iindawo. Ezi ndawo zinezi ngxaki zilandelayo:
(1) Ngokuqhelekileyo, umahluko woxinzelelo kwibhoyila mkhulu kakhulu, ngoko ke izinga lokuhamba komphunga nalo likhulu, kwaye umonakalo wokhukuliseko kumphezulu wokutywina nawo mkhulu. Ukongezelela, ukusebenza kakuhle kokutsha kwebhoyili akukwazi ukuba yi-100%, okuya kubangela ukuba i-steam kwi-outlet yebhoyili ibe nomthamo omkhulu wamanzi, oya kubangela lula i-cavitation kunye ne-cavitation umonakalo kwi-valve yokutywinwa kwendawo.

(2) Kuba ivalve yokumisa kufuphi nendawo yokuphuma kwibhoyila kunye ne-sub-cylinder, ngenxa yokuba umphunga osandul 'uphuma kwibhoyila une-intermittent superheating phenomenon, kwinkqubo yokufudumeza kwayo, ukuba unyango oluthambileyo lwebhoyila alulungile kakhulu, inxalenye yamanzi idla ngokugqithiswa. Izinto ze-Acid kunye ne-alkali ziya kubangela umhlwa kunye nokhukuliseko kwindawo yokutywina; ezinye izinto ezicwebezelayo zinokuncamathela kumphezulu wokutywina wevalve kwaye zibe yikristale, okukhokelela ekubeni ivalve ingakwazi ukutywina ngokuqinileyo.

(3) Kwi-valve yokungena kunye ne-outlet ye-sub-cylinders, ukusetyenziswa komphunga emva kwevalve kukhulu kwaye ngamanye amaxesha kuncinci ngenxa yeemfuno zemveliso kunye nezinye izizathu. Ibangela ukhukuliseko, i-cavitation kunye nomnye umonakalo kwindawo yokutywinwa kwevalve.

(4) Ngokuqhelekileyo, xa kuvulwa umbhobho onobubanzi obukhulu, lo mbhobho kufuneka ufudunyezwe kwangaphambili, yaye inkqubo yokufudumeza kwangaphambili ngokuqhelekileyo ifuna ukuba kudlule umphunga omncinane umphunga, ukuze umbhobho ube nokucotha nangokulinganayo shushu ukusa kumkhamo othile ngaphambi kokuba isivalo sokumisa sivulwe ngokupheleleyo ukunqanda ukwenza umonakalo wombhobho. Ukufudumala okukhawulezayo kubangela ukwanda okugqithisileyo, okonakalisa ezinye iindawo zokudibanisa. Nangona kunjalo, kule nkqubo, ukuvulwa kwevalve kuhlala kuncinci kakhulu, okubangela ukuba izinga lokukhukuliseka libe likhulu kakhulu kunesiphumo esiqhelekileyo sokusetyenziswa, kwaye kunciphisa kakhulu ubomi benkonzo yendawo yokutywinwa kwevalve.

Izisombululo zoBunzima ekuTshintsheni iiValufa zeGlobhu yeDiameter Enkulu

(1) Okokuqala, kucetyiswa ukuba ukhethe ivalve yeglowubhu evaliweyo, ethintela impembelelo yokumelana ne-frictional yevalve ye-plunger kunye nevalve yokupakisha, kwaye yenza utshintsho lube lula.

(2) Undoqo wevalve kunye nesitulo sevalve kufuneka senziwe ngezinto ezinokuxhathisa ukhukuliseko olulungileyo kunye nokusebenza kakuhle, okunje ngeStellite carbide;

(3) Kunconywa ukuba kuthathwe i-disc ye-valve ye-disc, engayi kubangela ukukhukhula okugqithisileyo ngenxa yokuvula okuncinci, okuya kuchaphazela ubomi benkonzo kunye nesiphumo sokutywinwa.