Valve having pressure balancing piston and method involving same

摘要

A valve assembly (10) is disclosed that provides for complete or partial fluid pressure balancing across the valve, and can be used for reducing valve actuation forces in order to employ electric actuation. The valve assembly (10) includes a valve housing (20) having a valve chamber, a flow passageway (28), and a piston chamber. A valve member (34) is disposed in the valve housing (20) and is movable along a valve axis (36). The valve member (34) is subjected to a first pressure, which urges the valve in a first direction. To counteract this force, a piston integral with the valve member is slidably arranged in the piston chamber. One side of the piston is subjected to this first pressure to provide a counterbalancing force. A pressure passage fluid communication (48) of the first pressure between the flow passageway (28) and said one side of the piston.