Valves bụ ngwa ngwa eji emepe na mechie pipeline, na-achịkwa ka ọ na-eruba, gbanwee na jikwaa paramita (okpomọkụ, nrụgide, na mgbaba) nke usoro mbufe. Dị ka ọrụ ya si dị, enwere ike kewaa ya na valvụ mechiri emechi, valvụ nlele, valvụ na-achịkwa, na ihe ndị ọzọ.

Ihe valvụ ahụ bụ ihe na-achịkwa n'ime usoro nnyefe mmiri, nke nwere ọrụ nke ịkpụpụ, nhazi, ntụgharị, mgbochi nke nlọghachi azụ, nkwụsi ike, ntụgharị ma ọ bụ njupụta, na enyemaka nrụgide. Valves eji na sistemụ njikwa mmiri, sitere na valvụ ndị na-emechi emechi kachasị mfe ruo na valvụ dị mgbagwoju anya ejiri na sistemụ njikwa akpaka nwere ụdị dị iche iche na nkọwapụta.

Enwere ike iji valvụ chịkwaa ụdị mmiri dị iche iche dị ka ikuku, mmiri, uzuoku, mgbasa ozi dị iche iche na-emebi emebi, apịtị, mmanụ, igwe mmiri, na mgbasa ozi redioaktivu. A na-ekewakwa valvụ n'ime valvụ nkedo nkedo, valvụ nkedo ígwè, igwe anaghị agba nchara, chromium-molybdenum ígwè valves, chromium-molybdenum vanadium ígwè valves, duplex ígwè valves, plastic valves, valves na-abụghị ọkọlọtọ ahaziri, wdg dị ka ihe ha si dị.