Abstract: The air admittance vent (“AAV”) includes a cup shaped vent body and a vertically reciprocating valve element that seats against a valve seat that has two separate contact areas defined by an annular ridge and a conical face formed in the bottom of the vent body. When the valve element moves into its closed position, the pliable diaphragm of the valve element initially contacts the annular ridge, which forms a first part of the valve seat before moving fully into sealing contact with the conical face, which forms the second part of the valve seat. The contact with the annular ridge provides a first initial seal before the diaphragm nests into contact with the conical face to form a second seal with the valve seat.

Abstract: The air admittance vent (“AAV”) includes a cup shaped vent body and a vertically reciprocating valve element that seats against a valve seat that has two separate contact areas defined by an annular ridge and a conical face formed in the bottom of the vent body. When the valve element moves into its closed position, the pliable diaphragm of the valve element initially contacts the annular ridge, which forms a first part of the valve seat before moving fully into sealing contact with the conical face, which forms the second part of the valve seat. The contact with the annular ridge provides a first initial seal before the diaphragm nests into contact with the conical face to form a second seal with the valve seat.

Abstract: A head fitting for a bathtub waste water drainage system is disclosed. The head fitting simplifies leak testing in bathtub waste water drainage system and eliminates the need for a separate test cap and fastening hardware for leak testing. The head fitting includes an internal partition wall and a breakout test plug molded as an integral part of the head fitting. The internal partition wall and breakout test plug initially hermetically seal the flow passage of the head fitting for leak testing the drainage system. The test plug can be broken out from the internal partition wall to open the flow passage after leak testing and without damaging the head fitting. The test plug forms part of the partition wall defined by an annular groove in the partition wall. The groove forms an annular band of relatively thin material (fracture band) that integrally connects the test plug to the partition wall, but allows the test plug to be forcefully separated from the partition wall.

Abstract: A head fitting for a bathtub waste water drainage system is disclosed. The head fitting simplifies leak testing in bathtub waste water drainage system and eliminates the need for a separate test cap and fastening hardware for leak testing. The head fitting includes an internal partition wall and a breakout test plug molded as an integral part of the head fitting. The internal partition wall and breakout test plug initially hermetically seal the flow passage of the head fitting for leak testing the drainage system. The test plug can be broken out from the internal partition wall to open the flow passage after leak testing and without damaging the head fitting. The test plug forms part of the partition wall defined by an annular groove in the partition wall. The groove forms an annular band of relatively thin material (fracture band) that integrally connects the test plug to the partition wall, but allows the test plug to be forcefully separated from the partition wall.