Abstract: The closing and sealing device for use in air admittance valves includes a valve housing (10) designed to be connected to the waste water pipe system, an upper cap (14) and a valve closing and sealing device which includes a fixed valve seat (22) and a movable closing member (24). The housing (10) includes at least one passageway (16) in communication with the surrounding atmospheric air, and at least one passageway (18) in connection with the inner space (19) of the sewage system, each of the passageways being in contact with the movable closing member (24).

Abstract: The valve is designed to be connected to a sanitary waste pipe system for admitting atomospheric air into the waste pipe towards the valve function elements in response to a pressure reduction in the system in order to protect the water traps in the system and to prevent discharge of contaminated air from the system to the atmosphere. It includes an oblong bowl-shaped valve housing (10), a vertical tubular member (12) extending downwards from the housing (10) and adapted to be connected to the waste pipe system, an inner space (18) within the valve housing (10) and containing the valve function elements (34), at least one passage (26) from the valve function elements (22) towards the surrounding atmosphere and a cover member (14) overlying the inner space and having a top wall spaced above the valve function elements (20, 22, 34).

Abstract: The closing and sealing device for use in air admittance valves includes a valve housing (10) designed to be connected to the waste water pipe system, an upper cap (14) and a valve closing and sealing device which includes a fixed valve seat (22) and a movable closing member (24). The housing (10) includes at least one passageway (16) in communication with the surrounding atmospheric air, and at least one passageway (18) in connection with the inner space (19) of the sewage system, each of the passageways being in contact with the movable closing member (24).