| 摘要 |
<p>A flow shut off valve (10, 51) for residential water line pressure includes a housing (12) having an inlet (14, 18), an outlet (16, 20) and a passage (21) therebetween with a valve seat (30) in the passage. A valve element (34) is slidably mounted within the passage and includes a cavity (44) open to the inlet and orifices (46) partially restricting flow from the cavity to the passage. A spring (50) biases the valve element toward the inlet. Reduced back pressure at the outlet drives the valve element into a closed position with a sealing surface (48) against the valve seat to terminate flow. In a first position the restrictive orifices are closed by the housing to block communication between the inlet and the outlet. In an intermediate position, the orifices are open and the sealing surface is not against the valve seat. A motion damper (52) may be employed to allow for start-up conditions.</p> |
