Ngokomphezulu wokutywina,iivalve zesangoinokwahlulwa ibe ziindidi ezimbini: itywina eliqinileyo kunye netywina elithambileyo.Uthini umahluko phakathi kwevalve yokutywina ethambileyo kunye nevalve eqinileyo yokutywina:
Ivalve yesango lokutywina: Izinto zokutywina kuzo zombini iindawo zokutywina zizinto zentsimbi, ezibizwa ngokuba “lutywino oluqinileyo”.Ukumelana nobushushu obuphezulu, ukuxhathisa ukunxiba, iipropathi ezilungileyo zoomatshini ezifana ne: intsimbi + yentsimbi;intsimbi + ubhedu;intsimbi
+ Igraphite;intsimbi + intsimbi yengxubevange.Izinto zokutywina ezisetyenziswa ngokuqhelekileyo zezi: I-13Cr insimbi engenasici, i-hard-face i-alloy materials, i-sprayed tungsten carbide, njl. Umphezulu wokutywina awuvalwanga kakuhle.
Ivalve yesango lokutywina: iperi yokutywina yenziwe ngezinto zentsimbi kwelinye icala kunye nelastiki engeyiyo intsimbi kwelinye icala, ebizwa ngokuba “yitywina elithambileyo”.Ukutywinwa kolu hlobo lwesitywina kulungile, kodwa akuxhathisi kubushushu obuphezulu, kulula ukunxiba, kwaye kuneempawu ezimbi zoomatshini.Njenge: intsimbi + irabha;intsimbi + PTFE, njl.njl. Kuthetha ukuba icala elinye leperi yetywina lenziwe ngezinto ezinobunzima obuphantsi.Ngokuqhelekileyo, isihlalo sokutywinwa esithambileyo senziwe ngezinto ezingezona zetsimbi ezinamandla athile, ukuqina kunye nokumelana nobushushu.Inokusebenza kakuhle kokutywinwa kwaye inokufikelela ku-zero ukuvuza, kodwa inobomi obude.Xa kuthelekiswa nokungaguquguquki kakuhle kwiqondo lobushushu, isitywina esiqinileyo senziwe ngentsimbi, kwaye ukusebenza kokutywina kumbi kakhulu, nangona abanye abavelisi bebanga ukuba banokufikelela kwi-zero ukuvuza.Injongo yokuveliswa kwevalve yesango lokutywina elithambileyo: ukusombulula ingxaki yesitulo sevalve kunye nomgangatho wokutywina wepleyiti yevalve idliwe okanye ikhubazeke, ipleyiti yevalve inokubuyisela ngokuzenzekelayo isigqubuthelo esiqinileyo kunye noxinzelelo oluzenzekelayo ivalve yesango lokutywina elithambileyo, kunye nokusombulula ingxaki yezinto ezithambileyo zokutywina zonakaliswe kukukhuhlana Ingxaki yendawo yokutywina, kuba umkhono wokutywina wevalve yesango unokutshintshwa, ukwandisa kakhulu ukusetyenziswa kwevalve.
Uluhlu olusebenzayo lwevalve yesango lokutywina elithambileyo: ububanzi (p50-p400mm, uxinzelelo 2.5-4.0MPa, ulwelo olwahlukeneyo lobushushu obuqhelekileyo obungaphantsi kwe-200℃).
Isitywina esithambileyo asikwazi ukuhlangabezana neemfuno zenkqubo yezinye izinto ezonakalisayo, kwaye isitywina esiqinileyo sinokuyisombulula!
Ezi ntlobo zimbini zamatywina zinokuncedisana.Ngokuphathelele ukuqina, itywina elithambileyo lilungile, kodwa ngoku ukuqina kwetywina eliqinileyo nako kunokuhlangabezana neemfuno ezihambelanayo!I-advanteji yetywina elithambileyo kukusebenza kakuhle kokutywinwa, kodwa into engalunganga kukuba kulula ukuguga, ukunxiba, kwaye inobomi obufutshane benkonzo.Isitywina esiqinileyo sinobomi obude benkonzo, kodwa ukuqina kubi kakhulu kunoko kwetywina elithambileyo.