Patent ID: 8465000

Claim:
An electric motor actuated stop and self-closing check valve for controlling a forward-flow and a back-flow of a liquid in a liquid conveying line, comprising: A. a valve body having an inlet port and an outlet port relative to said forward-flow of said liquid; B. a valve seat disposed within said valve body intermediate said ports; C. a valve disc disposed within said valve body having an elongated disc stem which extends through said valve body, said valve disc and said disc stem being free to move along a longitudinal axis of said valve stem to either: (i) a closed position whereat said valve disc sealingly engages said valve seat to prevent said back-flow of said liquid; or (ii) an open position whereat said valve disc is spaced from said valve seat; D. a disc disposed outside said valve body that co-acts with said elongated disc stem; E. an electric motor operationally attached to said valve body; F. an actuator rod moveable by action of said electric motor to be disposed at either: (i) an extended position whereat said actuator rod contacts said valve stem and restrains said valve disc at said closed position preventing said forward-flow and said back-flow of said liquid; or (ii) a retracted position whereat said actuator rod is retracted and said valve disc is free to move along said longitudinal axis without action by said electric motor, such that: (a) the valve disc moves to said open position solely through action of said forward-flow of said liquid on said valve disc and said forward-flow of said liquid occurs through a portion of said valve body; and (b) the valve disc moves to said closed position through action of a momentary back-flow of said liquid on said valve disc and said back-flow of said liquid is prevented; and G. a spring configured for providing a bias to said valve disc and said disc stem toward said closed position, whereby the spring only partially closes the valve to reduce the distance the valve disc must move to fully close as a result of back-flow of said liquid.