Ivalve yokukhutshwa komoya edibeneyo enesantya esiphezulu idityaniswe kunye neenxalenye ezimbini zevalve yomoya we-diaphragm yoxinzelelo oluphezulu kunye ne-inlet yoxinzelelo oluphantsi kunye nevalve yokukhupha, Inemisebenzi yokukhupha kunye nokuthatha.