Electronically controlled pressure relief valve

Patent metadata

Field	Value
Publication number	US-9915373-B2
Application number	US-201414452193-A
Country	US
Kind code	B2
Filing date	Aug 5, 2014
Priority date	Jul 8, 2011
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

A pressure relief comprises a valve body which includes an inlet bore that is connectable to a flow line, an outlet bore that is connectable to a vent line and a valve bore that extends to between the inlet and outlet bores. A valve member is slidably supported in the valve bore and is moveable between a closed position in which the fluid in the flow line is prevented from flowing from the inlet bore to the outlet bore and an open position in which the fluid in the flow line is permitted to flow from the inlet bore to the outlet bore. A solenoid operated pilot valve is connected to the valve body over the valve bore, and a fluid chamber is located in the pilot valve above the valve member. The fluid chamber is filled with a hydraulic fluid, and the hydraulic fluid in the fluid chamber is operatively engaged with the valve member. In a closed position of the pilot valve the hydraulic fluid is trapped in the fluid chamber to thereby prevent the valve member from moving from its closed position to its open position, and in an open position of the pilot valve the hydraulic fluid is released from the fluid chamber to thereby allow the valve member to move from its closed position to its open position.

First claim

What is claimed is:

1. A pressure relief valve which operates to control the flow of fluid from a flow line to a vent line when the pressure of the fluid in the flow line reaches a predefined maximum pressure, the pressure relief valve comprising:
a valve body which includes an inlet bore that is connectable to the flow line, an outlet bore that is connectable to the vent line and a valve bore that extends to between the inlet and outlet bores;
a valve member which is slidably supported in the valve bore and is moveable between a closed position in which the fluid in the flow line is prevented from flowing from the inlet bore to the outlet bore and an open position in which the fluid in the flow line is permitted to flow from the inlet bore to the outlet bore;
a solenoid operated pilot valve which is connected to the valve body over an end of the valve bore;
the pilot valve comprising a fluid chamber which is filled with a hydraulic fluid, the fluid chamber being sealed when the pilot valve is in a closed position, and the hydraulic fluid in the fluid chamber being operatively engaged with the valve member;
wherein in the closed position of the pilot valve the hydraulic fluid is trapped in the fluid chamber to thereby prevent the valve member from moving from its closed position to its open position, and in an open position of the pilot valve the hydraulic fluid is released from the fluid chamber to thereby allow the valve member to move from its closed position to its open position; and
wherein during operation of the pressure relief valve, the pilot valve is initially closed to contain the hydraulic fluid in the fluid chamber and thereby maintain the valve member in its closed position against pressure in the flow line, and then, when the pressure in the flow line reaches the predefined maximum pressure, the pilot valve is opened to release the hydraulic fluid from the fluid chamber and thereby allow the valve member to move from its closed position to its open position.

2. The pressure relief valve of claim 1 , wherein the pilot valve comprises a central bore within which the fluid chamber is formed and a first piston which is slidably positioned in the central bore between the fluid chamber and the valve member.

3. The pressure relief valve of claim 2 , wherein the central bore is aligned with the valve bore and the valve member is configured to engage the first piston.

4. The pressure relief valve of claim 3 , wherein the first piston is configured such that, as the pilot valve moves from its closed position to its open position, the first piston will displace the hydraulic fluid from the fluid chamber.

5. The pressure relief valve of claim 4 , wherein the pilot valve further comprises:
a relief port which is connected to the central bore and into which the hydraulic fluid is displaced; and
a second piston which is slidably supported in the central bore above the fluid chamber, the second piston being movable from a closed position in which the hydraulic fluid is prevented from flowing between the fluid chamber and the relief port and an open position in which the hydraulic fluid is permitted to flow between the fluid chamber and the relief port;
wherein the closed position of the second piston corresponds to the closed position of the pilot valve and the open position of the second piston corresponds to the open position of the pilot valve.

6. The pressure relief valve of claim 5 , wherein the pilot valve further comprises:
a seat member which is secured and sealed in the central bore between the fluid chamber and the second piston, the seat member comprising a through hole which connects the fluid chamber to the relief port;
wherein in the closed position of the second piston the second piston prevents the hydraulic fluid in the fluid chamber from flowing through the through hole to the relief port, and in the open position of the second piston the second piston permits the hydraulic fluid in the fluid chamber to flow through the through hole to the relief port.

7. The valve member of claim 6 , wherein the seat member comprises a valve seat which is connected to the through hole and the second piston comprises a closure member which is configured to sealingly engage the valve seat when the second piston is in the closed position.

8. The valve member of claim 5 , wherein the pilot valve further comprises:
a relief bore which is connected to the relief port; and
a third piston which is slidably supported in the relief bore to thereby define a relief chamber that is connected to the relief port;
wherein when the pilot valve is open and the valve member moves from its closed position to its open position, the hydraulic fluid is displaced through the relief port and into the relief chamber.

9. The valve member of claim 8 , wherein the pilot valve further comprises means for controlling the pressure which the third piston exerts on the hydraulic fluid.

10. The valve member of claim 9 , wherein the pressure controlling means comprises a compression spring which is operatively engaged between the third piston and a member which is fixed in position relative to the relief bore.

11. The valve member of claim 10 , wherein the member which is fixed in position relative to the relief bore comprises a body cap which is connected to the pilot valve over the spring member and the third piston.

12. The valve member of claim 10 , wherein the spring member is selected such that the third piston will exert a pressure on the hydraulic fluid of between about 200 psi and 250 psi.

13. The valve member of claim 10 , wherein the spring member is selected such that, when the pilot valve is open and the pressure of the fluid in the flow line drops to less than about 200 psi, the third piston will displace the hydraulic fluid from the relief chamber back through the relief port and into the fluid chamber.

14. The valve member of claim 8 , further comprising means for providing a visual indication that the valve member is in its open position.

15. The valve member of claim 14 , wherein the visual indication means comprises a stem which is connected to the third piston, wherein when the third piston is displaced by the hydraulic fluid entering the relief chamber, the stem will extend from an initial position which is indicative that the valve member is in its closed position to an extended position which is indicative that the valve member is in its open position.

16. The pressure relief valve of claim 1 , wherein the valve member comprises a lower end portion which, when the valve member is in its closed position, extends through and seals against a seal that is positioned between the inlet and outlet bores to thereby prevent fluid in the flow line from flowing between the inlet and outlet bores.

17. The pressure relief valve of claim 1 , wherein the valve member comprises a lower end portion and a seal which is mounted on the lower end portion, wherein when the valve member is in its closed position, the seal seals against a portion of the valve bore located between the inlet and outlet bores to thereby prevent fluid in the flow line from flowing between the inlet and outlet bores.

18. The pressure relief valve of claim 1 , further comprising:
a pressure transducer which generates signals indicative of the pressure in the flow line; and
a controller which actuates the pilot valve in response to the signals generated by the pressure transducer;
wherein when the pressure in the flow line reaches the predefined maximum pressure, the controller opens the pilot valve to rele

Assignees

• Fmc Tech Inc

Inventors

• Crawford Paul A

Classifications

• Y10T137/7761

  Electrically actuated valve · CPC title

• F16K17/02

  opening on surplus pressure on one side; closing on insufficient pressure on one side (check valves F16K15/00) · CPC title

• F16K31/124 Primary

  servo actuated · CPC title

• G05D16/2093

  with combination of electric and non-electric auxiliary power · CPC title

• F16K37/005

  for measuring fluid parameters (F16K37/0033 takes precedence) · CPC title