Patent ID: 7503341

Claim:
A self cleaning flow shutoff valve configured to be installed in a water line to stop flow in response to an excess water flow condition, the valve comprising: a housing defining a flow passage and a valve seat; a flow-metering element positioned within the flow passage, the flow-metering element including a flow metering aperture on a downstream portion thereof, the flow metering aperture providing fluid communication through a body wall of the element; a valve member slidably mounted within the flow-metering element, the valve member being movable between a no flow position, a normal flow position and a shutoff position, a downstream end of the valve member including a sealing portion configured to selectively engage the valve seat; and a biasing element disposed between the housing and the valve member so as to bias the valve member away from the valve seat; wherein (a) when the valve member is in the no flow position, an upstream end of the valve member engages the housing adjacent an inlet end of the housing, the sealing portion is spaced from the valve seat, and the valve member does not cover the flow metering aperture; (b) when the valve member is in the normal flow position, the upstream end of the valve member is spaced from the housing, the sealing portion is spaced from the valve seat, and the valve member does not cover the flow metering aperture; and (c) when the valve member is in the shutoff position, the upstream end of the valve member is spaced from the housing, the sealing portion engages the valve seat, and the valve member covers the flow metering aperture.