Wannan jerin bawul ɗin makafi mai siffar fanko ana kuma kiransa da goggle valve, flap valve, fan valve, kuma na'urar ce da za ta iya yanke matsakaicin iskar gas da GB6222-86 "Dokokin Kare Gas Na Masana'antu" ke buƙata. Ana amfani da shi a matsakaicin tsarin bututun iskar gas na masana'antu da masana'antar hakar ma'adinai, gudanarwar birni, kariyar muhalli da sauran masana'antu, musamman dacewa da cikakken yanke mai guba, mai cutarwa da iskar gas. Hakanan ya dace a yi amfani da shi azaman farantin makafi a ƙarshen bututun don rage lokacin kulawa ko haɗa sabon tsarin bututun. Idan aka kwatanta da sauran na'urorin bawul waɗanda ke yin cikakkiyar yankewa a cikin bututun, wannan jerin bawul ɗin farantin makafi mai siffar fan yana da halaye na tsarin labari, nauyi mai sauƙi, ƙaramin girman, aiki mai dacewa, saurin aiki, da ingantaccen yanke yankewa. gas yi.