Ivalvu iyingxenye yokulawula kusistimu yokulethwa koketshezi nemisebenzi efana nokunqanyulwa-, ukulawula, ukuphambukisa, ukuvimbela ukugeleza emuva, isilawuli, i-shunt noma ukukhululeka kokuchichima.
Amavalvu amasistimu okulawula uketshezi, kusukela kumavalufu alula-okuvala kuya ezinhlobonhlobo zamavalvu asetshenziswa kumasistimu okulawula ayinkimbinkimbi kakhulu, anenhlobonhlobo yokucaciswa nokucaciswa. Amavaluvu angasetshenziswa ukulawula ukugeleza kwezinhlobo ezahlukene zoketshezi ezifana nomoya, amanzi, isitimu, imidiya egqwalayo, udaka, uwoyela, insimbi ewuketshezi kanye nemidiya ekhipha imisebe. Amavalvu aphinde ahlukaniswe abe amavalvu ensimbi, amavalvu ensimbi, amavalvu ensimbi engagqwali (201,304,316, njll.), chrome molybdenum steel valves, chrome molybdenum vanadium steel valves, dual phase steel valves, plastic valves, non{7}}ezijwayelekile ngokwezifiso amavalvu Th,Njengempahla yamavalvu.
