Stopcock especially for water hydrant giving rapid interruption of water flow

摘要

The stopcock consists of a seat (22) and a mobile valve (23) equipped with at least one sealing washer (30). The face of the valve adjacent to the edge of the seat has a groove (31) in it, into which the washer is compressed by a shearing force when the valve is pressed against the seat. In a variant of the design the groove can be in the face of the seat instead of the valve. The stopcock can incorporate an automatic shut-off system in the form of a spring which pressed the valve against the seat when the pressure of water against its exposed face is not greater than the pressure on its opposite face. The sealing washer is fitted freely into a recess (28) in the valve face and is made from a resilient material such as an elastomer, PTFE or polyethylene.