Njengoba izidingo zabantu zokuvikelwa kwemvelo ziya ngokuya ziba namandla, izidingo zamavalvu nazo ziyakhula, futhi izidingo zezinga elivumelekile lokuvuza lemithombo yezindaba ezinobuthi, ezivuthayo neziqhumayo ezitshalweni ze-petrochemical ziya ngokuya ziba nzima.Ama-valve ayimishini edingekayo ezitshalweni ze-petrochemical., Ukuhlukahluka nobuningi bayo kukhulu, futhi kungenye yemithombo eyinhloko yokuvuza kudivayisi.Kwabezindaba ezinobuthi, ezivuthayo neziqhumayo, imiphumela yokuvuza kwangaphandle kwe-valve iyingozi kakhulu kunokuvuza kwangaphakathi, ngakho-ke izidingo zokuvuza zangaphandle ze-valve zibaluleke kakhulu.Ukuvuza okuphansi kwe-valve kusho ukuthi ukuvuza kwangempela kuncane kakhulu, okungenakunqunywa ukucindezelwa kwamanzi okujwayelekile kanye nokuhlolwa kokuvala umfutho womoya.Kudinga izindlela zesayensi ezengeziwe kanye nezinsimbi eziyinkimbinkimbi ukuze kutholwe ukuvuza okuncane kwangaphandle.

Izindinganiso ezivame ukusetshenziswa zokuthola ukuvuza okuphansi yi-ISO 15848, API624, EPA indlela 21, TA luft kanye ne-Shell Oil Company SHELL MESC SPE 77/312.

Phakathi kwazo, isigaba A se-ISO sinezidingo eziphakeme kakhulu, silandelwa yisigaba A se-SHELL. Kulokhu,I-NSEN ithole izitifiketi ezilandelayo ezijwayelekile;

ISO 15848-1 isigaba A

I-API 641

I-TA-Luft 2002

Ukuze kuhlangatshezwane nezidingo zokuvuza okuphansi, ama-valve castings adinga ukuhlangabezana nezidingo zokuhlolwa kwegesi ye-helium.Ngenxa yokuthi isisindo samangqamuzana e-helium sincane futhi kulula ukungena kuso, ikhwalithi yokubunjwa iyinhloko.Okwesibili, uphawu phakathi komzimba we-valve kanye nesembozo sokugcina kuvame ukuba uphawu lwe-gasket, okuwuphawu olumile, okulula ukuhlangabezana nezidingo zokuvuza.Ngaphezu kwalokho, uphawu esiqwini se-valve luwuphawu oluguquguqukayo.Izinhlayiya ze-graphite zikhishwa kalula ekupakisheni ngesikhathi sokunyakaza kwe-valve stem.Ngakho-ke, ukupakisha okukhethekile okuvuza okuphansi kufanele kukhethwe futhi imvume phakathi kokupakisha kanye nesiqu se-valve kufanele ilawulwe.Ukuvuleka phakathi komkhono wokucindezela kanye nesiqu se-valve kanye nebhokisi lokugxusha, futhi ulawule ukushuba kokucubungula kwesiqu se-valve nebhokisi lokugxusha.