Patent attributes
A valve includes a modulating chamber for sending and receiving fluid through a first chamber port, a supply chamber, and a damping chamber for sending and receiving a second fluid through a damping chamber port. The valve also includes a passageway between the damping chamber and the supply chamber, and a piston assembly movable within the valve, wherein the piston assembly is configured to open and close a flow control device. The piston assembly includes a rod, a modulating piston attached to the rod movable within the modulating chamber, a supply piston attached to the rod movable within the supply chamber, and a damping piston attached to the rod movable within the passageway and the supply chamber. The piston assembly also includes a damping piston bypass that provides a restricted flow passage between the supply chamber and the damping chamber when the damping piston is located in the passageway.