Patent ID: 7735513

Claim:
A flush valve for a waste water system, comprising: a valve body comprising a fluid inlet and a fluid outlet and a main valve element extending between the fluid inlet and the fluid outlet, the main valve element adapted for movement to allow fluid flow between the fluid inlet and the fluid outlet based on a pressure differential across a portion of the main valve element; a vent system comprising a control chamber in flow communication with the fluid inlet of the valve body and a vent outlet in flow communication with the fluid outlet of the valve body; a solenoid having a piston operable in a core tube in flow communication with the control chamber and configured to open to establish flow communication between the control chamber and the vent outlet thereby venting fluid from the control chamber to the fluid outlet and establishing a pressure differential across a portion of the main valve element and permitting the main valve element to open for fluid flow between the fluid inlet and fluid outlet of the valve body, and to close to prevent fluid communication between the control chamber and the vent outlet to close the main valve element; and a pressure sensor adapted to sense the fluid pressure of fluid within the core tube, wherein the solenoid is controlled to vent the control chamber for a period of time short enough to reduce the fluid pressure within the control chamber without opening the main valve element when the pressure within the core tube exceeds a predetermined pressure threshold.