US Patent 8136789 Drain valve actuators and methods of controlling drain valves

A valve actuator operates a valve, such as a drain valve of an industrial washing machine. The valve actuator has a permanent magnet DC motor which drives a gear train which rotatably drives an output shaft. The output shaft is engaged with the drain valve and moves the drain valve to open and closed positions as desired. The valve actuator also has a controller which controls operation of the valve actuator. The controller provides power to the motor only when needed to open and close the drain valve. The controller does not provide power to the motor when the drain valve is in the open and closed positions.