ʻO ka valve Butterfly, ʻike ʻia hoʻi ʻo flap valve, he valve hoʻoponopono me ka hana maʻalahi, hiki ke hoʻohana ʻia no ka hoʻololi ʻana i ka mana o ka medium i ka pipeline haʻahaʻa haʻahaʻa. ʻO ka valve Butterfly e pili ana i ka valve nona ka māhele pani (valve disc a butterfly plate) he diski a hoʻololi a puni ka pahu valve e wehe a pani.