Patent ID: 7744060

Claim:
A method of operating a fluid control valve, said method comprising: providing a valve including a valve control chamber, a valve seat, a fluid flow path through said valve seat, a valve diaphragm, and a valve actuator, and providing a pilot valve; holding said valve diaphragm closed with the force of said valve actuator in an inactive state; pneumatically reducing the force of said valve actuator against said valve diaphragm while changing the pressure in said valve chamber to hold said valve diaphragm closed to create an active shut valve state; and releasing the pressure in said valve control chamber to open said flow path through said valve seat to create an active open valve state, wherein said releasing comprises venting said valve control chamber through said pilot valve wherein said pilot valve is a three-way normally open valve, said providing further comprises providing a source of pressurized fluid, said changing the pressure in said valve chamber comprises connecting said valve chamber to said pressure source, and said releasing further comprises actuating said pilot valve to disconnect said valve chamber from said pressure source.