Patent ID: 8783647

Claim:
A method for controlling flow, comprising: providing a valve assembly to control fluid or gaseous flow from a first conduit to a second conduit, the valve assembly comprising: an actuator housing; an actuator piston disposed within the actuator housing to define a counter-biasing chamber and at least a first control chamber on the same side of the actuator piston, wherein the actuator piston includes a first substrate area that defines a portion of the counter-biasing chamber and a second substrate area that defines a portion of the first control chamber; a valve connected to the actuator piston, the valve having a valve face; a bore passing through the actuator piston and the valve thereby placing the valve face in fluid communication with the counter-biasing chamber; and a first pressure control port in fluid communication with the first control chamber; wherein the surface area of the first substrate area is less than the surface area of the valve face; operating the valve by applying a first pressure control signal to the first pressure control port on the actuator assembly.