Valavu ndi gawo lolamulira mu kayendedwe ka madzimadzi, ndi ntchito zochepetsera, kulamulira, kusokoneza, kulepheretsa kuponderezana, kukhazikika kwa mphamvu, kupatukana kapena kuchepetsa kupanikizika.
Valva yomwe imagwiritsidwa ntchito mumayendedwe owongolera madzimadzi, kuchokera pa valavu yosavuta kwambiri kupita ku makina owongolera okha, mitundu yake ndi mafotokozedwe ake ndi osiyanasiyana.Mavavu amatha kugwiritsidwa ntchito kuwongolera kutuluka kwamitundu yosiyanasiyana yamadzimadzi monga mpweya, madzi, nthunzi, zotengera zosiyanasiyana zowononga, matope, mafuta, zitsulo zamadzimadzi ndi ma radio radio.Malinga ndi nkhaniyi, valavuyo imagawidwanso kukhala mavavu achitsulo, mavavu achitsulo, ma valve zitsulo zosapanga dzimbiri (201,304,316, etc.), mavavu achitsulo a chromium molybdenum, chromium molybdenum vanadium zitsulo mavavu, mavavu achitsulo awiri, ma valve apulasitiki, opanda ma valve. -mavavu okhazikika okhazikika, etc.