US Patent 7503341 Self cleaning flow shutoff valve and associated methods

The present flow shutoff valve comprises a flow metering sleeve positioned within a flow passage. The sleeve and a housing of the valve define an annular space. The sleeve includes a flow metering aperture downstream of the annular space. A valve member is slidably mounted within the sleeve. The valve member is movable between a no flow position, a normal flow position and a shutoff position. The valve is self cleaning, so that it reduces the buildup of sediment within the valve.