I-valve iyithuluzi lokulawula ukugeleza, ukucindezela, kanye nendlela uketshezi oluya ngakhona.Uketshezi olulawulwayo kungase kube uketshezi, igesi, ingxube ye-gas-liquid, noma ingxube ewuketshezi oluqinile.I-valve ngokuvamile ngomzimba we-valve, ikhava, isihlalo, izingcezu ezivulekile nezivaliwe, indlela yokushayela, izimpawu nezinsimbi, njalonjalo.Umsebenzi wokulawula we-valve uncike endleleni yokushayela noma uketshezi ukushayela ukuphakamisa, ukushelela, ukushwibeka noma ukuzungezisa ukunyakaza kwezingxenye zokuvula nokuvala ukuze ushintshe usayizi wendawo yomgijimi.

Amavalvu anezinhlobonhlobo zokusetshenziswa futhi ahlobene kakhulu nempilo yabantu yansuku zonke, njengompompi bamapayipi amanzi namavalvu okunciphisa umfutho wezitofu zegesi ye-petroleum ewuketshezi.Amavaluvu nawo ayizingxenye ezibalulekile ezinhlobonhlobo zemishini enjengenjini evuthayo yangaphakathi, izinjini zesitimu, ama-compressor, amaphampu, ama-pneumatic actuators, izimoto zesistimu yokushayela i-hydraulic, imikhumbi nezindiza.

Ngaphambi kuka-2,000 BC, amaShayina ayesebenzisa amapayipi oqalo namavalvu kakhokho emapayipini amanzi, amasango amanzi emiseleni yokunisela, kanye nama-valve okuhlola amapuleti ekuncibilikiseni okuncibilikisa ngokuthuthukiswa kobuchwepheshe bokuncibilikisa kanye nemishini yokudonsa amanzi, ama-valve epulaki ethusi kanye nomthofu avele eYurophu.Ngokwethulwa kwe-boiler, i-1681 yethula i-valve yokuphepha yohlobo lwesando se-lever.1769 kanye nama-valve okuhlola ayengamavalvu ayinhloko kuze kube yinjini ye-Watt steam.Ukusungulwa kwenjini ye-steam kwaletha i-valve emkhakheni wemboni yemishini.Ngaphezu kwepulaki, ama-valve okusiza kanye nokuhlola asetshenziswa ezinjini ze-Watt's steam, ama-butterfly valves asetshenziselwa ukulawula ukugeleza.Ngokunyuka kokugeleza kwe-steam nokucindezela, ukusetshenziswa kwe-valve yepulaki ukulawula ukungena kwe-steam kanye nokukhipha injini ye-steam akukwazi ukuhlangabezana nezidingo, ngakho-ke kukhona i-valve yesilayidi.

Ngaphambi nangemva kuka-1840, kwakunamavalvu embulunga aneziqu ezicushiwe kanye nama-Wedge Valves aneziqu ezinentambo ye-Trapezoidal, okwaba impumelelo enkulu ekuthuthukisweni kwamavalvu.Ukubonakala kwalezi zinhlobo ezimbili zama-valve akwanelisi nje kuphela isidingo esikhulayo sokucindezela nezinga lokushisa ezimbonini ezihlukahlukene ngaleso sikhathi, kodwa futhi kwanelisa isidingo sokulawulwa kokugeleza.Kusukela ngaleso sikhathi, ngokuthuthukiswa kwemboni yamandla kagesi, imboni ye-petroleum, imboni yamakhemikhali kanye nomkhakha wokwakha imikhumbi, zonke izinhlobo zama-valve okucindezela okuphezulu naphakathi ziye zathuthukiswa ngokushesha.

Ngemuva kweMpi Yezwe Yesibili, ngenxa yokuthuthukiswa kwezinto ze-polymer, izinto zokugcoba, insimbi engagqwali kanye ne-cobalt-based carbide, i-Old Plug Valve kanye ne-butterfly valve isetshenziswe ezinhlelweni ezintsha, i-valve yebhola kanye ne-diaphragm valve iye yathuthukiswa ngokushesha.Ama-valve e-globe, ama-valve esango namanye ama-valve ezinhlobonhlobo ezikhulayo kanye nekhwalithi.Imboni yokukhiqiza ama-valve kancane kancane ibe umkhakha obalulekile embonini yemishini.I-valve ngokuya ngokusetshenziswa komsebenzi ingahlukaniswa nge-valve yokuvimba, i-valve yokulawula, i-valve yokuhlola, i-diversion valve, i-valve yokuphepha, i-valve ye-multi-purpose valve 6 izigaba.