annular valve disk or body 148 u2032 having a plurality of apertures 151 u2032 the frame 132 u2032 has a hinge 134 u2032 with a first end 136 u2032 and a second end 138 u2032 sized for receipt within the indentations 46 u2032 on the side wall 33 b u2032 on the lower portion 20 b u2032 of the housing 20 u2032 each of the first and second ends 136 u2032 138 u2032 terminates at a nub 139 u2032 for pivotally mounting the frame 132 u2032 in the indentations 46 u2032 of the housing 20 u2032 the hinge 134 u2032 defines a pivot axis x u2032 and is joined to a valve body support 142 u2032 by a connector 140 u2032 the valve body support 142 u2032 comprises a circular body 144 u2032 and a plurality of protruding hooked fingers 146 sized to be received within the apertures 151 u2032 on the valve body 148 u2032 for retaining the valve body 148 u2032 on the valve body support 142 u2032 the connector 140 u2032 includes a groove 141 u2032 defined between a first cam surface 143 u2032 and a second cam surface 145 u2032 spaced from the first cam surface 143 u2032 the first cam surface 143 u2032 comprises a first horizontal section 143 a u2032 and a laterally offset second horizontal section 143 b.