Electric motor actuated stop and self-closing check valve

摘要

An electric motor actuated stop/check valve for industrial use such as liquid pumping systems which has a controlled opening and closing rate when liquid flow is in a forward direction but closes quickly upon reverse flow of liquid with no action from the electric motor actuator. A valve disc having an elongated disc stem contacts a valve seat when in a closed position to stop liquid flow. Actuation of the valve is by an electric motor which provides movement to an actuator rod which contacts the disc stem. The disc stem and the actuator rod are not connected which allows the valve disc and disc stem free movement, by action of the momentarily back-flowing liquid, to a back-flow preventing closed position when liquid forward flow is reversed. No action by the electric motor is required. A spring biasing the valve disc toward the closed position and a hydraulically operated valve closing-speed regulator reduces or eliminates slamming of the valve disc against the valve seat. In a preferred method of operation liquid surge pressure transients are reduced or eliminated and slamming of valve components is prevented.