Abstract: A regulator valve has a check valve manifold for use in subsea control circuits. For example, the regulator valve having the check valve manifold can be used in a circuit between a directional control valve and an actuator for a gate valve. The check valve manifold can have a flange that attaches to the regulator valve to communicate with the supply-side and outlet-side of the regulator valve. Internal communication inside the manifold includes a check valve. If the pressure in the circuit downstream of the regulator valve needs to be vented, the check valve can open to allow the pressure to bleed from the outlet-side back to the supply-side without needing to pass through the internal pressure control valve of the regulator.

Abstract: An undersea hydraulic coupling member having a ring-shaped seal with multiple sealing surfaces extending radially inwardly therefrom is disclosed. The multiple sealing surfaces help guide the probe of the male coupling member into the female member without the risk of drag or galling of the receiving chamber or metal seal retained therein. The seal has an interfit with reverse inclined shoulders in the female member to restrain the seal from moving radially inwardly due to vacuum or low pressure. The seal also includes an internal biasing element to restrain the seal from moving radially inwardly during de-mating of the coupling members.

Abstract: A female undersea hydraulic coupling member is equipped with a plurality of pressure-energized metal seals configured to seal between the body of the female member and the probe of a corresponding male hydraulic coupling member in response to ambient hydrostatic pressure and/or hydraulic fluid pressure. Pressure-energized metal seals may also be provided to seal between the body of the female coupling member and a removable seal retainer or seal cartridge. In one particular preferred embodiment, the pressure-energized seals are back-to-back metal C-seals separated by annular seal supports having a generally T-shaped cross section and retained on one or more shoulders in the body of the female member by a removable seal cartridge.

Abstract: A regulator valve has a check valve manifold for use in subsea control circuits. For example, the regulator valve having the check valve manifold can be used in a circuit between a directional control valve and an actuator for a gate valve. The check valve manifold can be a flange that attaches to the regulator valve to communicate with the supply and outlet of the regulator valve. Internal communication inside the manifold includes a check valve. If the pressure in the circuit downstream of the regulator valve needs to be vented, the check valve can open to allow the pressure to bleed from the outlet back to the supply without needing to pass through the internal pressure control valve of the regulator.

Abstract: A female undersea hydraulic coupling member is equipped with a plurality of pressure-energized metal seals configured to seal between the body of the female member and the probe of a corresponding male hydraulic coupling member in response to ambient hydrostatic pressure and/or hydraulic fluid pressure. Pressure-energized metal seals may also be provided to seal between the body of the female coupling member and a removable seal retainer or seal cartridge. In one particular preferred embodiment, the pressure-energized seals are back-to-back metal C-seals separated by annular seal supports having a generally T-shaped cross section and retained on one or more shoulders in the body of the female member by a removable seal cartridge.

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 probe seal for a female hydraulic coupling member has both internal and external pressure-energized seals. The outer wall or opposing ends of the seal have one or more pressure-energized seals for sealing between the body of the probe seal and the body of a coupling member in which the probe seal is installed. Annular, L-shaped, T-shaped or angled grooves in the inner wall of the seal form cavities and sealing projections that can be urged in an inward, radial direction by fluid pressure within an associated cavity to increase the sealing effectiveness between the body of the seal and the probe of a male hydraulic coupling member inserted in the receiving chamber of the female coupling member.

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 probe seal for a female hydraulic coupling member has both internal and external pressure-energized seals. The outer wall or opposing ends of the seal have one or more pressure-energized seals for sealing between the body of the probe seal and the body of a coupling member in which the probe seal is installed. Annular, L-shaped, T-shaped or angled grooves in the inner wall of the seal form cavities and sealing projections that can be urged in an inward, radial direction by fluid pressure within an associated cavity to increase the sealing effectiveness between the body of the seal and the probe of a male hydraulic coupling member inserted in the receiving chamber of the female coupling member.

Abstract: A probe seal for a female hydraulic coupling member has both internal and external pressure-energized seals. The outer wall or opposing ends of the seal have one or more pressure-energized seals for sealing between the body of the probe seal and the body of a coupling member in which the probe seal is installed. Annular, L-shaped, T-shaped or angled grooves in the inner wall of the seal form cavities and sealing projections that can be urged in an inward, radial direction by fluid pressure within an associated cavity to increase the sealing effectiveness between the body of the seal and the probe of a male hydraulic coupling member inserted in the receiving chamber of the female coupling member.

Abstract: A subsea hydraulic system comprises a dual (or dual action) check valve on a port for connection to a remotely operated vehicle (ROV). The check valve provides backpressure to flow in either direction. This keeps hydraulic fluid in the hydraulic system, and seawater out. If flow needs to return to the ROV, it may flow out the port, subject to a selected back pressure.

Abstract: A subsea hydraulic system comprises a dual (or dual action) check valve on a port for connection to a remotely operated vehicle (ROV). The check valve provides backpressure to flow in either direction. This keeps hydraulic fluid in the hydraulic system, and seawater out. If flow needs to return to the ROV, it may flow out the port, subject to a selected back pressure.

Abstract: A probe seal for a female hydraulic coupling member has both internal and external pressure-energized seals. The outer wall or opposing ends of the seal have one or more pressure-energized seals for sealing between the body of the probe seal and the body of a coupling member in which the probe seal is installed. Annular, L-shaped, T-shaped or angled grooves in the inner wall of the seal form cavities and sealing projections that can be urged in an inward, radial direction by fluid pressure within an associated cavity to increase the sealing effectiveness between the body of the seal and the probe of a male hydraulic coupling member inserted in the receiving chamber of the female coupling member.

Abstract: A control program for a positive displacement metering system measures the time required for the travel of a free piston in a cylinder of known volume to determine an average flow rate during a full stroke of the piston. The system may also measure and record the inlet and outlet pressures or the differential pressure between the fluid inlet and outlet. The control program positions a four-way valve which may function as an adjustable metering orifice in response to the measured average flow rate and/or changes in the inlet and outlet pressures to achieve the desired flow rate. At the end of each stroke, the four-way valve is repositioned to reverse fluid flow through the metering cylinder. The system may revise the valve position settings for both forward and reverse strokes based on the measured time required for a full stroke at a certain valve position. In this way, the system automatically and iteratively compensates for changes in fluid properties and fluid pressure.

Abstract: A poppet valve for a hydraulic coupling member has an internal, spring-loaded check valve (which may be a ball check valve) in fluid communication with a bleed passage. The check valve may be configured as a pressure-relief valve which bleeds off excess hydraulic fluid pressure within the coupling member to a preselected value. A poppet valve according to the invention may be used in female coupling members and/or male coupling members. Certain embodiments of the invention may be retrofitted to coupling members of the prior art.

Abstract: A control program for a positive displacement metering system measures the time required for the travel of a free piston in a cylinder of known volume to determine an average flow rate during a full stroke of the piston. The system may also measure and record the inlet and outlet pressures or the differential pressure between the fluid inlet and outlet. The control program positions a four-way valve which may function as an adjustable metering orifice in response to the measured average flow rate and/or changes in the inlet and outlet pressures to achieve the desired flow rate. At the end of each stroke, the four-way valve is repositioned to reverse fluid flow through the metering cylinder. The system may revise the valve position settings for both forward and reverse strokes based on the measured time required for a full stroke at a certain valve position. In this way, the system automatically and iteratively compensates for changes in fluid properties and fluid pressure.

Abstract: A probe seal for a female hydraulic coupling member has both internal and external pressure-energized seals. The outer wall or opposing ends of the seal have one or more pressure-energized seals for sealing between the body of the probe seal and the body of a coupling member in which the probe seal is installed. Annular, L-shaped, T-shaped or angled grooves in the inner wall of the seal form cavities and sealing projections that can be urged in an inward, radial direction by fluid pressure within an associated cavity to increase the sealing effectiveness between the body of the seal and the probe of a male hydraulic coupling member inserted in the receiving chamber of the female coupling member.

Abstract: A poppet valve for a hydraulic coupling member has an internal, spring-loaded check valve (which may be a ball check valve) in fluid communication with a bleed passage. The check valve may be configured as a pressure-relief valve which bleeds off excess hydraulic fluid pressure within the coupling member to a preselected value. A poppet valve according to the invention may be used in female coupling members and/or male coupling members. Certain embodiments of the invention may be retrofitted to coupling members of the prior art.

Abstract: A dummy undersea hydraulic coupling member protects an opposing undersea hydraulic coupling member when the hydraulic lines are not operating. The dummy undersea hydraulic coupling member has a water displacement expansion chamber with a piston in the chamber that allows trapped water and/or air to move from the receiving chamber into the water displacement expansion chamber during connection of the dummy coupling member to the opposing coupling member. The piston has both a primary seal and a secondary, hydrostatic seal for preventing seawater from entering the portion of the water displacement expansion chamber that is contacted by the primary seal.

Abstract: A poppet valve for a hydraulic coupling member has an internal, spring-loaded check valve (which may be a ball check valve) in fluid communication with a bleed passage. The check valve may be configured as a pressure-relief valve which bleeds off excess hydraulic fluid pressure within the coupling member to a preselected value. A poppet valve according to the invention may be used in female coupling members and/or male coupling members. Certain embodiments of the invention may be retrofitted to coupling members of the prior art.