Abstract: A gate valve controls fluid communication from an inlet to an outlet relative to a reference pressure. A body defines a passage disposed in communication with the inlet, and an outlet port disposed in the passage communicates the passage with the outlet. A piston disposed in the passage is movable therein between first and second positions relative to the outlet port. The piston is movable in a first direction from the first position to the second position in response to an inlet pressure at the inlet. A gate disposed on the piston is biased transversely toward the outlet port. The gate moved by the piston adjusts flow from the passage to the outlet port. A pressure compensator disposed opposite the piston biases the piston in a second opposite direction from the second position to the first position. The pressure compensator has a chamber in communication with the reference pressure.

Abstract: A pilot-actuated spool valve comprises a generally cylindrical valve cage having a central axial cavity open at both ends and a plurality of generally radial openings connecting the central axial cavity to the external cylindrical surface of the cage; a valve sleeve sized to slide within the central axial cavity of the cage and having a first sealing surface at a first end and a second sealing surface at an opposing second end; a piston responsive to fluid pressure at a pilot inlet of the valve; a piston rod connected at a first end to the piston and having a threaded second end opposite the first end; and a cap nut in threaded engagement with the second end of the piston rod securing the valve sleeve to the piston rod. The cap nut is sized and configured to provide a clearance gap between the cap nut and the valve sleeve when the cap nut is fully tightened onto the threaded second end of the piston rod.

Abstract: A gate valve controls fluid communication from an inlet to an outlet relative to a reference pressure. A body defines a passage disposed in communication with the inlet, and an outlet port disposed in the passage communicates the passage with the outlet. A piston disposed in the passage is movable therein between first and second positions relative to the outlet port. The piston is movable in a first direction from the first position to the second position in response to an inlet pressure at the inlet. A gate disposed on the piston is biased transversely toward the outlet port. The gate moved by the piston adjusts flow from the passage to the outlet port. A pressure compensator disposed opposite the piston biases the piston in a second opposite direction from the second position to the first position. The pressure compensator has a chamber in communication with the reference pressure.

Abstract: A pilot-actuated spool valve comprises a generally cylindrical valve cage having a central axial cavity open at both ends and a plurality of generally radial openings connecting the central axial cavity to the external cylindrical surface of the cage; a valve sleeve sized to slide within the central axial cavity of the cage and having a first sealing surface at a first end and a second sealing surface at an opposing second end; a piston responsive to fluid pressure at a pilot inlet of the valve; a piston rod connected at a first end to the piston and having a threaded second end opposite the first end; and a cap nut in threaded engagement with the second end of the piston rod securing the valve sleeve to the piston rod. The cap nut is sized and configured to provide a clearance gap between the cap nut and the valve sleeve when the cap nut is fully tightened onto the threaded second end of the piston rod.