| 摘要 |
<p>The closing and sealing means 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 valve closing and sealing means consisting of 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 said passageways being in contact with the movable closing member (24). The closing means comprise a rigid movable closing member in the shape of a poppet valve (40) having an inverted bowl shaped central part (42) provided, at its periphery, with an inverse angled conical surface (44) extending upwards and designed to cooperate with the sealing means consisting of a fixed valve seat (22) having an upper edge provided with a soft annular seat (50) presenting a thin annular cantilever lip (52) extending towards the centre of the seat (22).</p> |
