Vavu ndi chipangizo chowongolera kutuluka, kuthamanga, ndi komwe madzi amadziwira.Madzi oyendetsedwa amatha kukhala madzi, gasi, osakaniza amadzimadzi, kapena osakaniza amadzimadzi olimba.Vavu nthawi zambiri ndi thupi la valve, chivundikiro, mpando, zidutswa zotseguka ndi zotseka, makina oyendetsa galimoto, zisindikizo ndi zomangira, ndi zina zotero.Ntchito yolamulira ya valve imadalira njira yoyendetsera galimoto kapena madzimadzi kuti ayendetse kukweza, kusuntha, kugwedezeka kapena kuyendayenda kwa magawo otsegulira ndi kutseka kuti asinthe kukula kwa malo othamanga.

Mavavu ali ndi ntchito zosiyanasiyana ndipo amagwirizana kwambiri ndi moyo wa tsiku ndi tsiku wa anthu, monga matepi a mapaipi amadzi ndi ma valve ochepetsera mphamvu a masitovu a gasi wamafuta amafuta.Mavavu ndiwofunikanso pazida zosiyanasiyana zamakina monga injini zoyatsira mkati, injini za nthunzi, ma compressor, mapampu, ma pneumatic actuators, ma hydraulic drive system, zombo ndi ndege.

Isanafike 2,000 BC, ndi Chinese ntchito mipope nsungwi ndi valavu Nkhata Bay mu mapaipi madzi, zipata madzi mu ngalande ulimi wothirira, ndi mavavu cheke mbale mu smelting mvuvu ndi chitukuko cha smelting teknoloji ndi makina hayidiroliki, mkuwa ndi kutsogolera pulagi mavavu aonekera ku Ulaya.Ndi kukhazikitsidwa kwa boiler, 1681 idayambitsa valavu yachitetezo chamtundu wa lever.1769 ndi ma valve cheke anali ma valve oyambirira mpaka injini ya nthunzi ya Watt.Kupangidwa kwa injini ya nthunzi kunabweretsa valavu m'munda wamakampani opanga makina.Kuphatikiza pa pulagi, mpumulo ndi ma valve owunika omwe amagwiritsidwa ntchito mu injini za nthunzi za Watt, ma valve a butterfly amagwiritsidwa ntchito kuwongolera kuyenda.Ndi kuwonjezeka kwa nthunzi ndi kuthamanga kwa nthunzi, kugwiritsa ntchito valavu ya pulagi kuti athetse kutentha kwa nthunzi ndi kutuluka kwa injini ya nthunzi sikungathe kukwaniritsa zofunikira, kotero pali slide valve.

Chaka cha 1840 chisanafike komanso pambuyo pake, panali mavavu a padziko lonse okhala ndi tsinde zomangika ndi ma Wedge Valves okhala ndi tsinde za Trapezoidal, zomwe zinali zopambana kwambiri pakukulitsa ma valve.Maonekedwe a mitundu iwiriyi ya ma valve sikungokwaniritsa kufunikira kowonjezereka kwa kuthamanga ndi kutentha m'mafakitale osiyanasiyana panthawiyo, komanso kukhutiritsa kufunikira kwa kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe kake.Kuyambira pamenepo, ndi chitukuko cha mafakitale mphamvu zamagetsi, makampani mafuta, makampani mankhwala ndi shipbuilding makampani, mitundu yonse ya mavavu mkulu ndi sing'anga kuthamanga kwapangidwa mofulumira.

Pambuyo pa Nkhondo Yachiwiri Yadziko Lonse, chifukwa cha chitukuko cha zipangizo za polima, zopangira mafuta, zitsulo zosapanga dzimbiri ndi cobalt-based carbide, Old Plug Valve ndi valavu ya butterfly zakhala zikugwiritsidwa ntchito muzogwiritsira ntchito zatsopano, valavu ya mpira ndi diaphragm valve yapangidwa mofulumira.Mavavu a Globe, ma valve a pachipata ndi ma valve ena amitundu yosiyanasiyana komanso abwino.Makampani opanga ma valve pang'onopang'ono asanduka gawo lofunikira pamakampani opanga makina.Vavu malinga ndi kugwiritsa ntchito ntchito imatha kugawidwa mu valavu yotchinga, valavu yowongolera, valavu yoyang'ana, valavu yosinthira, valavu yachitetezo, valavu yamitundu yambiri 6.