CN-121986229-A - Secondary seal on safety valve

Abstract

The closure member is configured to avoid or reduce the rate of leakage across the safety valve. These configurations may include a primary seal and a secondary seal, the combination of which may significantly reduce the flow exiting the device. The secondary seal may be embodied as a resilient member, such as a bent or crimped metal spring. The resilient member may compress and extend in response to the presence or absence of a load. This feature may maintain contact between the resilient member and the seat of the valve.

Inventors

• R. Krishvasan

Assignees

• 德莱赛有限责任公司

Dates

Publication Date

20260505

Application Date

20241017

Priority Date

20231018

Claims (20)

1. 1. A valve, the valve comprising: a preload unit configured to generate a load; A closure member under the influence of said load; a seat proximate the closure member, wherein the closure member and the seat are configured to contact one another to form a primary seal in a closed position, and A sealing member that seals around to form a secondary seal.
2. 2. The valve of claim 1, wherein the sealing member is configured to compress under load.
3. 3. The valve of claim 1, wherein the sealing member is configured to extend in the absence of a load.
4. 4. The valve of claim 1, wherein the sealing member completely surrounds the primary seal.
5. 5. The valve of claim 1, wherein the sealing member remains in contact with the seat when the closure member is separated from the seat.
6. 6. The valve of claim 1, wherein the sealing member comprises a pleated member.
7. 7. The valve of claim 1, wherein the sealing member is attached to the closure member.
8. 8. The valve of claim 1, wherein the sealing member is configured to change from a first configuration to a second configuration.
9. 9. The valve of claim 1, wherein the closure member has a recess to receive the sealing member.
10. 10. The valve of claim 1, wherein the closure member has a recess having a channel for receiving an end of the sealing member.
11. 11. A valve, the valve comprising: A movable plug; a fixed seat adjacent to the movable plug, and A distal seal disposed between the closure member and the seat, Wherein the distal seal surrounds a proximal seal formed between the closure member and the seat.
12. 12. The valve of claim 11, wherein the distal seal is attached to the movable plug.
13. 13. The valve of claim 11, wherein the distal seal extends from the movable plug toward the seat.
14. 14. The valve of claim 11, wherein the distal seal contacts both the movable plug and the seat when the distal seal is broken.
15. 15. The valve of claim 11, wherein the distal seal moves with the movable plug.
16. 16. The valve of claim 11, wherein the distal seal comprises a resilient member that stretches in response to movement of the movable plug.
17. 17. A valve, the valve comprising: A plug; Seat portion, and An annular ring coupled to the plug, the annular ring surrounding a portion of the plug that contacts the seat in a closed position to prevent material from flowing between the plug and the seat.
18. 18. The valve of claim 17, wherein the annular ring comprises a resilient member having an end attached to the plug.
19. 19. The valve of claim 17, wherein the annular ring comprises a resilient member having a first end attached to the plug and a second end in contact with the seat in the closed position.
20. 20. The valve of claim 17, wherein the annular ring comprises a resilient member having a first end attached to the plug and a second end in contact with the seat in the closed position and a partially open position in which the plug is spaced apart from the seat.

Description

Secondary seal on safety valve Cross Reference to Related Applications The present application claims the benefit of U.S. sequence 63/591,143 entitled "SECONDARY SEAL ON A SAFETY VALVE (secondary seal on safety valve)" filed on 10/18 of 2023. The entire contents of the present application are incorporated herein by reference in its entirety. Background Flow controls play an important role in many industrial facilities. For example, power plants and industrial process facilities use different types of flow controls to manage the flow of material (typically fluid) throughout a vast network of pipes, tanks, generators, and other equipment. Safety relief valves are "fail-safe" devices that prevent rapid increases in pressure on lines in these networks. These devices (also known as "safety" valves or "pressure relief" valves) are necessary to avoid "over-pressure" conditions that may damage equipment or parts of the facility. The safety valve may use a different mechanism to generate a closing or "biasing" force to maintain its closure member in contact with its seat. The resulting seal in this "seating area" prevents material flow unless a system pressure spike occurs that overcomes the "set point" to open the valve. A Pilot Operated Safety Relief Valve (POSRV) typically uses system fluid under control of the fluid control module to trigger operation between its closed and open positions. In other arrangements, coil springs and the like may generate the biasing load. However, it has been found that even in response to system pressures actually lower than the set point for the device, material may still leak through the seal at the seating area. Also, the density or other characteristics of the material may cause or exacerbate leakage. Compressible fluids may leak more than incompressible fluids, for example, because compressible fluids have a lower density than incompressible fluids. Disclosure of Invention The subject matter of the present disclosure relates to improvements to flow controls. Of particular interest are embodiments in which leakage of material from the seating area of the device may be prevented or captured. These embodiments may incorporate additional seals that reside outside of or around the "primary" seal formed by the closure member and the seat. This additional seal will prevent material flow that might pass through the main seal when the system pressure is at or near the set point. Drawings The present description makes reference to the accompanying drawings: FIG. 1 depicts an exemplary embodiment of a closure member for use in a safety valve; FIG. 2 depicts an example of a structure for the closure member of FIG. 1; FIG. 3 depicts an example of a structure for the closure member of FIG. 1; FIG. 4 depicts an example of a structure for the closure member of FIG. 3; FIG. 5 depicts an example of a structure for the closure member of FIG. 3, and Fig. 6 depicts a perspective view of an exemplary structure for the safety valve of fig. 1. The drawings and any description herein represent examples in which the present invention may be disclosed or explained. These examples include the best mode and also enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The drawings are not to scale unless the discussion otherwise indicates otherwise. Elements in an example may appear in one or more of several views or in a combination of several views. The same reference numbers may be used in the drawings to refer to the same or corresponding elements. The methods are merely exemplary and may be modified by, for example, reordering, adding, deleting, and/or altering individual steps or stages. The singular forms "a," "an," and "the" are intended to include the plural forms of any such names and any such items, components, elements or functions, unless the specification explicitly states or otherwise states such exclusions. Likewise, any reference to "one embodiment" or "an implementation" does not exclude the presence of other embodiments or implementations that also incorporate the features described. Detailed Description Features of the examples shown in the above figures will now be discussed. These features address material leaks in the safety valve that may occur in response to changes in the biasing force on the device. These changes may occur with an increase in system pressure that is known to reduce or decrease the effective biasing force. This response may cause material leakage as the system pressure approaches the set point of the device. Compressible and low density fluids (e.g., air) can exacerbate these problems, especially at high temperatures, which can further reduce the density of these fluids. Thermal deformations due to these high temperatures may also exacerbate leakage because critical parts may deform or distort. Other embodiments are within the scope of the present disclosure. Fig. 1