Vavu ya butterfly, yomwe imadziwikanso kuti flap valve, ndi valavu yowongolera yokhala ndi mawonekedwe osavuta, omwe amatha kugwiritsidwa ntchito posinthira sing'anga pamapaipi otsika. Vavu ya butterfly imatanthawuza valavu yomwe mbali yake yotsekera (valavu ya disc kapena mbale ya butterfly) ndi diski ndipo imazungulira kuzungulira shaft ya valve kuti itsegule ndi kutseka.