Patent ID: 7654503

Claim:
A valve assembly comprising: a main valve including a valve body having an inlet, outlet, and means adapted to selectively open and close fluid flow between the inlet and the outlet; a pilot valve including a housing having a first port, a second port, and a third port, a valve seat formed on the housing circumscribing the first port, and a first piston having a first end and a second end disposed within the housing, the first piston including a valve disk formed on the second end thereof, the valve disk and the valve seat forming a substantially fluid tight seal when in contact with one another to selectively establish fluid communication between the first port of the pilot valve and one of the second port and the third port of the pilot valve; a first conduit providing fluid communication between the first port of the housing of the pilot valve and the means adapted to selectively open and close fluid flow between the inlet and the outlet of the main valve; a second conduit providing fluid communication between the second port of the housing and one of the inlet and the outlet of the main valve; and a third conduit providing fluid communication between the third port of the housing and one of the inlet and the outlet of the main valve, wherein fluid communication between the main valve and the pilot valve is employed to cause a movement of the first piston within the housing of the pilot valve and an associated opening and closing of fluid flow between the inlet and the outlet of the main valve.