Abstract: Methods for controlling flow are described herein that include a valve assembly provided and operated to control the flow from a first conduit to a second conduit. The valve assembly includes an actuator housing enclosing an actuator piston and defining a counter-biasing chamber and a first control chamber on the same side of the actuator piston, and a first pressure control port in fluid communication with the first control chamber. A valve is connected to the actuator piston and a bore passes through both the actuator piston and the valve thereby placing a face of the valve in fluid communication with the counter-biasing chamber. 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 where the surface area of the first substrate area is less than the surface area of the valve face.

Abstract: Methods for controlling flow are described herein that include a valve assembly provided and operated to control the flow from a first conduit to a second conduit. The valve assembly includes an actuator housing enclosing an actuator piston and defining a counter-biasing chamber and a first control chamber on the same side of the actuator piston, and a first pressure control port in fluid communication with the first control chamber. A valve is connected to the actuator piston and a bore passes through both the actuator piston and the valve thereby placing a face of the valve in fluid communication with the counter-biasing chamber. 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 where the surface area of the first substrate area is less than the surface area of the valve face.

Abstract: A valve actuator assembly, counter-biased by a working fluid (or gas) pressure, is disclosed. The valve actuator assembly comprises a valve and a pneumatic or hydraulic actuator. A port is defined axially through the valve and actuator that communicates a working fluid (or gas) pressure acting on the valve face to a counter-biasing chamber inside an actuator housing. This design eliminates, reduces, or overcomes a force acting on a face of the valve by communicating a common working pressure of the fluid (or gas) to a substrate on the actuator with a resultant force vector opposite the valve face.