Secondary seal on safety valve

Abstract

The closure member is configured to avoid or reduce a leak rate on the relief valve. These configurations may include a primary seal and a secondary seal, the combination of which may significantly reduce flow exiting the device. The secondary seal may be embodied as a resilient member, such as a curved or pleated metal spring. The resilient member may be compressed and extended in response to the presence or absence of a load. The feature may maintain contact between the resilient member and the seat of the valve.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Serial No. 63 / 591,143, filed October 18, 2023, entitled "SECONDARY SEAL ON A SAFETY VALVE". The entire contents of this application are incorporated herein by reference. Background Technology

[0003] Flow controls play a vital role in many industrial facilities. For example, power plants and industrial process facilities use different types of flow controls to manage the flow of materials (typically fluids) throughout a vast network of pipes, tanks, generators, and other equipment. Safety relief valves are "fail-safe" devices that prevent a rapid increase in pressure on pipelines within these networks. These devices (also known as "safety" valves or "pressure relief" valves) are necessary to avoid "overpressure" conditions that could damage equipment or parts of the facility.

[0004] Safety valves can use various mechanisms to generate a closing or “biasing” force to maintain contact between their closing member and their seat. The resulting seal in this “seat area” prevents material flow unless a system pressure spike occurs to overcome the “set point” to open the valve. Pilot-operated safety relief valves (POSRVs) typically use system fluid under the control of a fluid control module to trigger operation between their closed and open positions. In other devices, helical springs and similar devices can generate a bias load. However, it has been found that material can still leak through the seal in the seat area, even in response to system pressures that are actually below the set point for the device. Similarly, the density or other properties of the material can also cause or exacerbate leakage. Compressible fluids may leak more than incompressible fluids, for example, because compressible fluids have a lower density than incompressible fluids. Summary of the Invention

[0005] This disclosure relates to improvements in convection controls. Of particular interest are embodiments that can prevent or trap material leakage from the mounting area of ​​the device. These embodiments may incorporate an additional seal residing outside or surrounding the "main" seal formed by the closure member and the seat. This additional seal will prevent material flow through the main seal when the system pressure is at or near the set point. Attached Figure Description

[0006] This instruction manual refers to the following figures:

[0007] Figure 1 An exemplary embodiment of a closure member for use in a safety valve is described;

[0008] Figure 2 Describing for Figure 1 Examples of the structure of closed components;

[0009] Figure 3 Describing for Figure 1 Examples of the structure of closed components;

[0010] Figure 4 Describing for Figure 3 Examples of the structure of closed components;

[0011] Figure 5 Describing for Figure 3 Examples of the structure of closed members; and

[0012] Figure 6 Describing for Figure 1 A perspective view of an exemplary structure of a safety valve.

[0013] The accompanying drawings and any descriptions herein represent examples that disclose or explain the invention. These examples include the best mode and also enable any person skilled in the art to practice the invention, including making and using any device or system and performing any combined methods. Unless otherwise stated in the discussion, the drawings are not drawn to scale. Elements in the examples may appear in one or more views or in a combination of views. The same reference numerals may be used in the drawings to denote the same or corresponding elements. The methods are merely exemplary and may be modified by, for example, reordering, adding, deleting, and / or changing individual steps or stages. Such stages and any parts, components, elements, or functions may be identified in this specification by the singular form of the words “a” or “an”; however, this should not exclude any plural form of such names unless the specification expressly states or indicates such exclusion. Similarly, any reference to “an embodiment” or “a specific embodiment” does not exclude the existence of other embodiments or specific embodiments also incorporating the described features. Detailed Implementation

[0014] Features of the examples shown in the above figures will now be discussed. These features address material leakage in safety valves that may occur in response to changes in the bias force on the device. These changes may occur with an increase in system pressure, which is known to reduce or decrease the effective bias force. This response can trigger material leakage when the system pressure approaches the device's setpoint. Compressible and low-density fluids, such as air, can exacerbate these problems, particularly at high temperatures, which can further reduce the density of these fluids. Thermal deformation caused by these high temperatures can also worsen the leakage, as critical components may deform or twist. Other embodiments are within the scope of this disclosure.

[0015] Figure 1 A schematic diagram illustrating an example of a closure assembly 100 is shown. This example exists within a distribution network 102, which is typically designed to transport material 104 through a network of conduits 106. Network 102 may include a flow control 108 having a valve body 110 for connecting the device in series with conduits 106. Flow control 108 may also have a preloading unit 112 to generate a load L that regulates the flow rate through valve 114; for example, load L may maintain contact between the closure member 100 and the seat member 116. In one specific embodiment, the closure member 100 may include a plug member 118 and a sealing member 120.

[0016] In a broader sense, the closure member 100 can be configured to reduce leakage in the safety valve. These configurations can improve the seat "tightness" at the interface between the closure member 100 and other parts of the valve. This feature can reduce or even eliminate leakage at this interface, which may occur at or near the system pressure at the set point of the device.

[0017] Distribution system 102 can be configured to deliver or move resources. These configurations can manifest as large-scale infrastructure. Material 104 can also include gases, liquids, solid / liquid mixtures, or liquid-gas mixtures. Conduit 106 can include pipes or lines that can be connected to pumps, boilers, etc. The conduit can also be connected to tanks or storage containers. In many facilities, this equipment forms a complex network.

[0018] Flow control 108 can be configured to release pressure in these complex networks. These configurations may include safety valves and similar devices. Valve body 110 is typically made of cast or machined metal. This structure may form flanges at openings identified here as “I” and “O”. Adjacent conduits 106 may be connected to these flanges. Preloading unit 112 may include devices that can generate load L. These devices may store energy, for example, due to deformation or similar changes in length or size. For this purpose, helical springs or compression springs may be dominant, as they can compress or extend in response to changes in system pressure P. Other devices may incorporate pilot valves into designs that use an air supply to maintain load L as needed.

[0019] Valve 114 can be configured to regulate the flow rate of material 104 out of network 102. These configurations can form a “primary” seal between seat 116 and plug member 118, typically a metal-to-metal seal; however, this disclosure also contemplates elastomeric or elastomeric-to-elastomeric seals. Metal-to-metal seals are effective under harsh conditions, such as in networks of materials moving corrosive or hazardous materials or materials under high temperature or high pressure.

[0020] Sealing member 120 can be configured to prevent material 104 from leaking through the main seal. These configurations can include devices located at or near members 116, 118. These devices can surround all or part of the main seal, typically engaging both members 116 and 118 to form a “secondary” seal. This feature traps material 104 within the valve 114, reducing the amount of material 104 that would otherwise leak from outlet O. In use, each of these seals can both seal and bear load L in response to operating conditions in the valve 114. For example, in the absence of system pressure or at low system pressure, the main seal can perform most (if not all) of the sealing and bearing functions. However, an increase in system pressure may transfer one or more of these functions to the secondary seal. In one embodiment, the construction of the secondary seal can simplify valve repair and maintenance at a lower cost, as it can be easily removed and replaced by a technician.

[0021] Figure 2 Depicting Figure 1 A schematic diagram of an example valve 114. This example includes a recess 122, such as a groove or cutout, that penetrates the outer surface to reduce the diameter of the plug member 118 at one end. A ring-shaped or annular device 124 can be fitted into the recess 122. This "ring" can be configured to completely or partially surround a contact interface C formed at the location where the plug member 118 contacts the seat 116. The contact interface C can form a primary seal preventing material 104 from flowing through the seat 116. In one embodiment, the ring can remain in contact with both the seat 116 and the plug member 118, as mentioned herein, even if the plug member 118 moves away from or separates from the seat 116. This feature can form a secondary seal preventing material 104 leakage until the system pressure causes the valve to fully open to release pressure in the network 102.

[0022] Figure 3 Depicting Figure 2 A schematic diagram of an exemplary structure of the ring device 124. This structure may include an elastic unit 126 having a body comprising metal or a network 102 ( Figure 1 The material is conditionally compatible and dominates the process. The body can be made of a material that is responsive to preloaded unit 112 ( Figure 1The presence or absence of a biasing force alters the geometry of the configuration. For this purpose, a curved or pleated geometry may dominate, as it can compress into a first configuration in response to a biasing force that contacts the plug member 118 with the seat 116 and forms a contact interface C. In one embodiment, the resilient element 126 may have a first end 128 proximate to the seat 116. A second end 130 may be coupled to the plug member 118. Welding or high-strength adhesives may be used in this application; however, other types of fastening techniques may also be prevalent. Fasteners may engage with a channel 132 in the plug member 118, which may also receive the second end 130. The use of fasteners (or similar fastening techniques) allows technicians to easily remove and replace the resilient element 126 if needed. This feature can reduce the cost (labor and time) for technicians to repair or perform maintenance on the flow control 108.

[0023] Figure 4 A second configuration for the resilient member 126 is shown. In this configuration, the geometry of the body of the resilient member 126 changes with the position of the plug member 118 relative to the seat 116. This position can correspond to a system pressure near a set point for the flow control 108. In one example, the system pressure can cause the plug member 118 to separate from the seat 116, thereby disrupting the primary seal to form a gap G1 (which is typically microscopic in scale). The body of the resilient member 126 can extend or elongate (in the second configuration) to maintain contact between the first end 128 and the seat 116. This feature holds the secondary seal in place to accommodate or prevent the flow rate F1 of material 104 from leaving the valve 114. Typically, the gap G1 can be formed under system pressure that is not originally intended to actuate the valve 114 to its open position, which would allow material 104 to exit the device.

[0024] Figure 5 A third configuration for the elastic member 126 is shown. This configuration can respond to network 102 ( Figure 1 An overpressure condition occurs on the plug member 118. This condition can cause the plug member 118 to separate from the seat 116, thereby creating a gap greater than G1 ( Figure 4 The gap G2 can correspond to the open position of valve 114. In one embodiment, the body of the elastic member 126 can be separated from the seat 116 in the open position of valve 114. This feature allows the flow rate F1 of material 104 to be discharged through valve 114.

[0025] Figure 6A perspective view of an exemplary structure for flow control 108 is depicted. This structure can be embodied as a safety valve. The valve body 110 can form a robust fluid connection 134 having a pair of openings (e.g., a first opening 136 and a second opening 138). The fluid connection 134 can be configured to handle the pressure of various fluids, including, for example, steam common in nuclear facilities and similar power plants. These configurations can have a structure typically made of cast, forged, or machined metal to form a flow path for fluid to flow between pipes P1 and P2. Flanges 140 (or other fittings) at openings 136 and 138 can be fitted with the fluid connection 134 to connect to pipes P1 and P2. Fasteners such as bolts can be used to ensure a secure connection. The structure can also have a valve cover 142 having a structural member 144 attached to the fluid connection 134. The structural member 144 can have various configurations. A mechanical actuator 146 can reside on top of the valve cover 142. Mechanical actuator 146 can be connected to preload unit 112 to preload compression spring.

[0026] In light of the foregoing, the improvements described herein can reduce leakage rates in safety valves. These improvements prevent material leakage from the interface between the closing member and the seat until the system pressure reaches or exceeds the set point (or a predetermined actuation pressure) for the device. This feature addresses the problem that some valves begin to open in response to system pressure near (and typically below) this set point. Furthermore, seals consistent with this disclosure prevent unwanted material escape and are compatible with extreme operating conditions (e.g., high temperatures and high pressures) and corrosive materials that preclude the use of more conventional elastomers or “soft” metals.

[0027] The following examples include certain elements or clauses describing embodiments contemplated within the scope of this specification. These elements may be combined with other elements and clauses to further describe the embodiments. This specification may include and contemplate other examples that would occur to those skilled in the art. Such other examples fall within the scope of the claims if they have structural elements that are indistinguishable from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

Claims

1. A valve, the valve comprising: Preloading unit, the preloading unit being configured to generate load; The closed member under the influence of the load; A seat portion that is close to the closure member, wherein the closure member and the seat portion are configured to contact each other to form a primary seal in the closed position; and A sealing member that surrounds the seal to form a secondary seal.

2. The valve of claim 1, wherein the sealing member is configured to compress under load.

3. The valve of claim 1, wherein the sealing member is configured to extend in the absence of load.

4. The valve of claim 1, wherein the sealing member completely surrounds the main seal.

5. The valve according to claim 1, wherein the sealing member remains in contact with the seat when the closing member is separated from the seat.

6. The valve according to claim 1, wherein the sealing member comprises a corrugated member.

7. The valve of claim 1, wherein the sealing member is attached to the closing member.

8. The valve of claim 1, wherein the sealing member is configured to change from a first configuration to a second configuration.

9. The valve of claim 1, wherein the closing member has a recess to receive the sealing member.

10. The valve of claim 1, wherein the closing member has a recess having a channel for receiving an end of the sealing member.

11. A valve, the valve comprising: Removable plug; A fixed base portion, said fixed base portion being adjacent to the movable plug; and A distal seal is disposed between the closure member and the seat. The distal seal surrounds the proximal seal formed between the closure member and the seat.

12. The valve of claim 11, wherein the distal seal is attached to the movable plug.

13. The valve of claim 11, wherein the distal seal extends from the movable plug toward the seat.

14. The valve of claim 11, wherein when the distal seal is damaged, the distal seal contacts both the movable plug and the seat.

15. The valve of claim 11, wherein the distal seal moves together with the movable plug.

16. The valve of claim 11, wherein the distal seal comprises an elastic member that extends in response to movement of the movable plug.

17. A valve, the valve comprising: Plug; Seat; and An annular ring is attached to the plug and surrounds the portion of the plug that contacts the seat in the closed position to prevent material from flowing between the plug and the seat.

18. The valve of claim 17, wherein the annular ring includes an elastic member having an end attached to the plug.

19. The valve of claim 17, wherein the annular ring includes an elastic member having a first end attached to the plug and a second end in contact with the seat in the closed position.

20. The valve of claim 17, wherein the annular ring includes an elastic member having a first end attached to the plug and a second end in contact with the seat in the closed position and the partially open position, wherein the plug is spaced apart from the seat in the partially open position.

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