BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The subject matter of the present disclosure relates to valves. More particularly, it relates to pressure-compensated valves for use in a subsea environment.

2. Description of the Related Art

U.S. Pat. No. 4,456,028 discloses a relief gate valve. However, the valve is not suitable for use in the subsea environment. It requires manual adjustment for setting the opening pressure and does not compensate for the hydrostatic pressure. Moreover, it has no means for preventing backflow through the valve if, for any reason, the outlet pressure exceeds the inlet pressure.

A gate valve suitable for subsea applications is disclosed in U.S. Pat. No. 7,520,291, which is incorporated herein by reference and is shown inFIG. 1. Briefly, the gate valve10has three body parts, including a main body part12, an outlet body part14, and a pressure compensator76. The three body parts12,14, and76are generally rectangular parallelepipeds secured together by threaded engagements.

An axial passage16in the main body part12forms an inlet20that may be adapted to make a connection with a pipe or other conduit leading to a fluid reservoir or line whose pressure may be limited by the valve10. The passage16in the main body12further includes transverse cylindrical bore64that receives a cylindrical seat ring46providing a valve seat. The seat ring46has a passage48extending axially therethrough. Meanwhile, a cylindrical bore22in the outlet part14of the valve10provides a lateral passage with an outlet18that, by way of example, may be adapted to make a fluid connection with a conduit leading to a subsea well.

The inner end of seat ring46protrudes into the axial bore16in the main body part12and its upper edge provides a mechanical stop for positioning a valve actuator68. The inner face of seat ring46may be planar and adapted to seal with a gate or seal disc58on the valve actuator68.

In particular, a blind hole or cavity is provided in one side of actuator68, and a helical pressure spring60disposed within cavity bears at one end against the closed end of cavity and at the other end against the gate or seal disc58. The pressure of the axially compressed spring60presses disc58against the face of the seat ring46to seal off the passage48as long as the disc58and the seat ring46are coaxial.

The outlet body14has a threaded nose section for engaging a corresponding socket in the side of main body12. A poppet valve26has a nose piece28with a seal30and has a spring29. The poppet valve26fits within the bore22of the outer body14, and the poppet valve26can be set in sealing engagement with a conical seat24to control communication from the seat passage48out the outlet body18. In this way, the poppet valve26acts as a check valve and ensures that fluid only flows through valve10in the intended direction.

A valve stem52extends coaxially from the actuator68, and an O-ring74in a circumferential groove seals the stem52to the body of bore16. Above the valve stem52, the pressure compensator76threads onto the main body12. The pressure compensator76comprises a central axial chamber94within which is disposed concentric helical compression load springs102and104. The upper ends of the load springs bear against a threaded cap84which is retained in the central bore of the pressure compensator76by engagement with a threaded portion.

The lower ends of the load springs102and104bear against a generally circular bearing plate96having inner and outer shoulders. The bearing plate96has a conical socket106on its distal face for contacting a hemispherical end54of the valve stem52.

A plug110has an orifice112in fluid communication with a chamber118of a central extension95such that one side of a free-floating piston88may be normally exposed to ambient pressure, which the other side is exposed to an incompressible fluid in the compensator's chamber94.

Load springs102and104act to push the valve stem52into the main body part12(downward inFIG. 1) until the shoulder72on the actuator68rests on the upper edge66of the inner end of the seat ring46that protrudes into the passage16. In this position, the seal disc58may be coaxial with the seat ring passage48and the valve10is closed. If the inlet pressure rises sufficiently to overcome the combined force of the springs102and104, the ambient pressure, and the gate-seat friction, the actuator68moves such that the stem52extends farther out of the main body part12. This action compresses the load springs102and104, expels fluid in the chamber118(displacing the piston88), and the gate seat disc58moves away from coaxial alignment with the seat ring passage48, thereby opening the valve10.

A reduction in inlet pressure will allow the load springs102,104and the ambient pressure due to the hydrostatic head acting on the stem52to return the valve10to the closed position wherein the passage48is blocked by the seal disc58.

Although this gate valve10may be effective for subsea applications, operators are continually striving to improve performance and reliability while meeting even more extreme and harsh conditions found in a subsea environment.

The subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.

SUMMARY OF THE DISCLOSURE

As disclosed herein, a gate valve is used for controlling fluid communication from an inlet to an outlet relative to a reference pressure. The inlet and outlet are defined in a receptacle of a component. The gate valve comprises a cartridge, an outlet port, a piston, a gate, and a pressure compensator.

The cartridge is configured to position in the receptacle of the component having the inlet and the outlet. The cartridge is disposed in sealed communication with the inlet and the outlet and defines a passage in communication with the inlet. The outlet port is disposed in the passage and communicates the passage with the outlet. The piston is disposed in the passage and 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 level at the inlet.

The gate is disposed on the piston and is biased transversely toward the outlet port. The gate moved by the piston adjusts flow from the passage to the outlet port. the pressure compensator is disposed opposite the piston and biases the piston in a second opposite direction from the second position to the first position. The pressure compensator comprises a housing defining a chamber in communication with the reference pressure. The housing is configured to affix in the receptacle and hold the cartridge therein.

The piston can comprise a proximal end disposed toward the inlet; and wherein the pressure compensator comprises a seat component being separate from the housing, the seat component defining an orifice for passage of a distal end of the piston therein.

The seat component can be sandwiched between the housing and the cartridge.

The pressure compensator can comprise: a bearing plate movable in the chamber and engaged with the distal end of the piston; and at least one spring disposed in the chamber and biasing the bearing plate toward the seat component.

The outlet port can comprise a flat seating surface disposed around the outlet port, wherein the gate comprises: a pin disposed in a transverse hole in the piston, and a spring in the transverse hole biasing the pin against the flat seating surface.

The cartridge can define a cross opening communicating the passage outside the cartridge. Also, the outlet port can comprise an insert sealed in the cross opening, the insert defining a first orifice therethrough communicating the passage outside the cartridge.

The gate valve can comprise a retention nut affixed externally in the cross opening and holding the insert in the cross opening, the retention nut having a second orifice in communication with the first orifice of the insert.

The pressure compensator can comprise a vent port communicating the chamber with the reference pressure.

The pressure compensator can further comprise a free-floating piston in the vent port separating internal fluid in the chamber from external fluid outside the pressure compensator.

A gate valve as disclosed herein is used for controlling fluid communication from an inlet to an outlet relative to a reference pressure. The valve comprises a first body, an outlet port, a second body, a piston, a gate, and a pressure compensator.

The first body defines a passage in communication with the inlet at a first end of the gate valve, and the outlet port is disposed in the passage of the first body. The second body is affixed to the first body. The second body defines a chamber in communication with the reference pressure. The first and second bodies defines an interface therebetween communicating the outlet port with the outlet at a second end of the gate valve.

The piston is disposed in the passage and 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 level at the inlet. The gate is disposed on the piston and is biased transversely toward the outlet port. The gate moved by the piston adjusts flow from the passage to the outlet port. The pressure compensator is disposed in the chamber of the second body opposite the piston and biases the piston in a second opposite direction from the second position to the first position.

The piston can comprise a proximal end disposed toward the inlet; and wherein the pressure compensator comprises a seat component being separate from the first and second bodies, the seat component defining an orifice for passage of a distal end of the piston therein.

The seat component can be sandwiched between the first and second bodies.

The pressure compensator can comprise: a bearing plate movable in the chamber and engaged with the distal end of the piston; and at least one spring disposed in the chamber and biasing the bearing plate toward the seat component.

The outlet port can comprise a flat seating surface disposed around the outlet port, wherein the gate comprises: a pin disposed in a transverse hole in the piston, and a spring in the transverse hole biasing the pin against the flat seating surface.

The gate valve can comprise: a first flow passage defined in the first body and communicating the outlet port with the interface between the first and second bodies; and a second flow passage defined in the second body and communicating the interface with the outlet at the second end of the gate valve.

The interface can comprise an annular chamber formed between the first and second bodies.

The first body can define a cross opening exposed to the passage and disposed in communication with the interface via the first flow passage.

The outlet port can comprise an insert disposed in the cross opening, the insert having a bore with a first opening exposed to the passage, a second opening of the bore exposed to the cross opening in communication with the interface via the first flow passage.

The insert can be sealed in the cross opening.

The gate valve can comprise a retention nut affixed externally in the cross opening and holding the insert in the cross opening.

The pressure compensator can comprise a vent port communicating the chamber with the reference pressure.

The pressure compensator can further comprise a free-floating piston in the vent port separating internal fluid in the chamber from external fluid outside the pressure compensator.

The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure.

