LIFT CHECK VALVE WITH DASHPOT

摘要

LIFT CHECK VALVE WITH DASHPOT An improved check valve has an operating chamber with a disc disposed therein which is capable of axial movement from a closed position against a valve seat to an opened position to prevent feedwater from flowing from the normal outlet to the normal inlet of the valve. A cylindrical member extends upwardly from the disc through a fixedly mounted baffle plate which generally separates an upper portion of the operating chamber from the lower portion. A piston is mounted on an extended end of the cylindrical member to generally define a dashpot chamber between the piston and the baffle plate. The dashpot chamber entraps a greater volume of feedwater when the valve is open than when closed to limit valve closure rate by limiting the rate at which feedwater leaves the dashpot chamber during closure.