Seat insert in a ball valve for cryogenic applications

Systems and methods are disclosed that include providing a valve suitable for maintaining a seal and preventing fluid flow through the valve at cryogenic temperatures. The valve includes a valve body having a longitudinal axis along a flow path through the valve, a ball selectively rotatable within the valve body to selectively allow fluid flow through the valve, a seat formed within the valve body and comprising a cavity having an angled wall, and a seat insert at least partially disposed within the cavity and having a first sealing surface that forms a first sealing interface with the ball to prevent leakage through a first leakage path and a second sealing surface that forms a second sealing interface with the angled wall to prevent leakage through a second leakage path when the ball valve is selectively rotated to prevent fluid flow through the valve.

BACKGROUND OF THE INVENTION

Valves are used to control the flow of fluids in a wide range of applications. Ball valves are typically used in applications where interruption of the flow of fluid through the ball valve is required. The interruption and establishment of fluid flow through the ball valve is accomplished via selective actuation of a ball within the ball valve. Generally, a seat insert within the ball valve provides a seal against the ball and a portion of the body of the ball valve. However, when a ball valve is subjected to extreme environmental conditions such as cryogenic temperatures, the seat insert and/or other portions of the ball valve may shrink, deform, or otherwise change, thereby allowing leakage of the fluid through the ball valve. Accordingly, the industry continues to demand improvements in ball valve technology for such applications.

SUMMARY

Embodiments of the present invention relate in general to a ball valve having a seat insert configured to provide a fluid tight seal when operated at or subjected to cryogenic temperatures, and more particularly to a ball valve having a seat formed within the valve body that includes a cavity having an angled wall and a seat insert at least partially disposed within the cavity and having a first sealing surface that forms a first sealing interface with the ball to prevent leakage through a first leakage path and a second sealing surface that forms a second sealing interface with the angled wall to prevent leakage through a second leakage path when operated at or subjected to cryogenic temperatures. A spring acting against a fixing plate may bias the seat insert against the angled wall, and the angled wall may drive or force the seat insert upwards, thereby increasing a sealing force between the seat insert and the angled wall of the seat to prevent leakage through secondary leakage path when cryogenic temperatures may cause the seat, the seat insert, or combinations thereof to shrink in size.

DETAILED DESCRIPTION

FIG. 1shows a partial cross-sectional view of a valve100according to an embodiment of the disclosure. Valve100may generally comprise a ball valve and comprise a valve body102having a longitudinal axis104along a flow path105through the valve100and a ball106selectively rotatable within the valve body102to selectively allow fluid flow along the flow path105and through the valve100. Valve100may also comprise a seat108comprising a cavity110formed within the valve body102and a seat insert112at least partially disposed within the cavity110. In some embodiments, the seat insert112may comprise a complementary profile and/or shape to the cavity110of the seat108. Accordingly, it will be appreciated that the seat108and the seat insert112may be designed to prevent leakage of a fluid through each of a first leakage path (shown as “1” inFIG. 1) and a second leakage path (shown as “2” inFIG. 1) when the ball106is selectively rotated to prevent fluid flow along the flow path105and through the valve100. Additionally, the valve100may also comprise a fixing plate128and one or more springs132.

In some embodiments, the cavity110may comprise a first major surface114(top), a second major surface116(bottom) opposite of the first major surface114, and an angled wall118disposed between the first major surface114and the second major surface116. In some embodiments, the first major surface114and/or the second major surface116may be substantially planar. Additionally, in some embodiments, the first major surface114and the second major surface116may be substantially parallel. However, in other embodiments, the first major surface114and/or the second major surface116may be non-planar.

In some embodiments, the angled wall118may me substantially planar. In other embodiments, the angled wall118may be non-planar (e.g., curved). In yet other embodiments, the angled wall118may comprise any combination of substantially planar and non-planar features. In some embodiments, the angled wall118may form an angle with the longitudinal axis104of at least 5 degrees, at least 10 degrees, at least 15 degrees, at least 20 degrees, at least 25 degrees, at least 30 degrees, at least 35 degrees, at least 40 degrees, at least 45 degrees, at least 50 degrees, at least 55 degrees, at least 60 degrees, at least 65 degrees, at least 70 degrees, or at least 75 degrees. In some embodiments, the angled wall118may form an angle with the longitudinal axis104that is not greater than 90 degrees, not greater than 85 degrees, not greater than 80 degrees, not greater than 75 degrees, not greater than 70 degrees, not greater than 65 degrees, not greater than 60 degrees, not greater than 55 degrees, not greater than 50 degrees, not greater than 45 degrees, not greater than 40 degrees, not greater than 35 degrees, or not greater than 30 degrees. Further, it will be appreciated that the angled wall118may form an angle with the longitudinal axis104that is between any of these minimum and maximum values, such as at least 5 degrees and not greater than 90 degrees.

In some embodiments, the seat insert112may comprise a first major surface120(top) adjacent to the first major surface114of the cavity110, a second major surface122(bottom) opposite of the first major surface120and adjacent to the second major surface116of the cavity110, a first sealing surface124disposed between the first major surface120and the second major surface122and adjacent to the ball106, and a second sealing surface126disposed between the first major surface120and the second major surface122, opposite of the first sealing surface124, and adjacent to the angled wall118. In some embodiments, the seat insert112may also comprise an extension134extending from the first major surface120. In some embodiments, the first major surface120and/or the second major surface122may be substantially planar. Additionally, in some embodiments, the first major surface120and the second major surface122may be substantially parallel. However, in other embodiments, the first major surface120and/or the second major surface122may be non-planar. In some embodiments, the first sealing surface124and/or the second sealing surface126may be substantially planar. However, in other embodiments, the first sealing surface124and/or the second sealing surface126may be non-planar (e.g., curved). In yet other embodiments, the first sealing surface124and/or the second sealing surface126may comprise any combination of substantially planar and non-planar features.

It will be appreciated that the first sealing surface124may be designed to form a first sealing interface with the ball106to prevent leakage through the first leakage path (shown as “1” inFIG. 1), and the second sealing surface126may be designed to form a second sealing interface with the angled wall118to prevent leakage through a second leakage path (shown as “2” inFIG. 1) when the ball106is selectively rotated to prevent fluid flow along the flow path105and through the valve100. As such, in some embodiments, the second sealing surface126may comprise a complementary profile to the angled wall118, such that in embodiments where the angled wall118is curved, the second sealing surface126may be curved, and in embodiments where the angled wall118is planar, the second sealing surface126may be curved, planar, or combinations thereof.

The first sealing surface124and the second sealing surface126may form a sealing angle. In some embodiments, the sealing angle may be defined as the angle between the first sealing surface124and the second sealing surface126. For embodiments having one or more planar sealing surfaces, the sealing angle may be determined using a planar vector of the one or more sealing surfaces. For embodiments having one or more curved sealing surfaces, the sealing angle may be determined using a tangent vector extending from a midpoint of the one or more curved sealing surfaces. In some embodiments, the sealing angle may be at least 45 degrees, at least 50 degrees, at least 55 degrees, at least 60 degrees, at least 65 degrees, at least 70 degrees, or at least 75 degrees, at least 80 degrees, at least 85 degrees, or at least 90 degrees. In some embodiments, the sealing angle may be not greater than 135 degrees, not greater than 130, not greater than 125 degrees, not greater than 120 degrees, not greater than 115 degrees, not greater than 110 degrees, or not greater than 95 degrees. Further, it will be appreciated that the sealing angle may be between any of these minimum and maximum values, such as at least 45 degrees and not greater than 135 degrees.

In some embodiments, the first sealing surface124may form a first sealing angle with the longitudinal axis104, and the second sealing surface126may form a second sealing angle with the longitudinal axis104. In some embodiments, the first sealing angle may be greater than the second sealing angle. In other embodiments, the second sealing angle may be greater than the first sealing angle. In yet other embodiments, the first sealing angle and the second sealing angle may be substantially equal.

In some embodiments, the seat insert112may be formed from a polymeric material. Accordingly, in some embodiments, the seat insert112may be formed from PTFE, a fluoropolymer, a perfluoropolymer, PTFE, PVF, PVDF, PCTFE, PFA, FEP, ETFE, ECTFE, PCTFE, a polyarylketone such as PEEK, PEK, or PEKK, a polysulfone such as PPS, PPSU, PSU, PPE, or PPO, aromatic polyamides such as PPA, thermoplastic polyimides such as PEI or TPI, or any combination thereof. Still further, in some embodiments, the seat insert112may be formed from one or more of the materials listed above that are modified with at least one filler (e.g., fibers).

In some embodiments, the fixing plate128may be coupled to and/or integrated with the body102of the valve100. In some embodiments, the fixing plate128may form a secondary cavity130within the cavity110of the seat108. One or more springs132(formed from titanium, stainless steel, carbon steel, other alloys, or combinations thereof) may generally be disposed within the secondary cavity130. In the embodiment shown, the spring132may comprise a standalone compression spring and be disposed within the secondary cavity130between the extension134of the seat insert112and the fixing plate128. As such, the spring132may bias the extension134of the seat insert112against the fixing plate128, thereby forcing the seat insert112towards the angled wall118and forcing the second sealing interface126into contact with the angled wall118. In turn, the angled wall118forces the seat insert112upwards, thereby forcing the first major surface120of the seat insert112into contact with the first major surface114of the cavity110of the seat108. The resulting contact thereby operates to substantially reduce and/or prevent leakage through the secondary leakage path.

In some embodiments, as compared to a traditional valve without an angled sealing interface, the angled wall118may increase a sealing force between the seat insert112and the seat108when cryogenic temperature conditions cause the seat insert112to shrink in size, deform, or otherwise change in profile or shape. In some embodiments, the angled wall118may increase the sealing force between the seat insert112and the seat108by at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 90%, at least 95%, at least 100%, at least 125%, or at least 150%. In some embodiments, the angled wall118may increase the sealing force between the seat insert112and the seat108by not greater than 500%, not greater than 400%, not greater than 300%, not greater than 200%, or not greater than 100%. Further, it will be appreciated that the angled wall118may increase the sealing force between any of these minimum and maximum values, such as at least 1% and not greater than 500%.

FIG. 2shows a partial cross-sectional view of a valve200according to an embodiment of the disclosure. Valve200, and components thereof, may be substantially similar to valve100. Valve200may comprise a ball valve and comprise a valve body202having a longitudinal axis204along a flow path205through the valve200, a ball206selectively rotatable within the valve body202to selectively allow fluid flow along the flow path205and through the valve200, a seat208comprising a cavity210(having a first major surface214, a second major surface216, and an angled wall218) formed within the valve body202, a seat insert212(having a first major surface220, a second major surface222, a first sealing surface224, a second sealing surface226, and an extension234) at least partially disposed within the cavity210, a fixing plate228that forms a secondary cavity230, and one or more springs232. However, in the embodiment shown, the spring232is integrated into the extension234of the seat insert212.

The extension234may generally comprise a cavity236. In some embodiments, the cavity236may comprise a U-shaped cavity formed between a pair of legs238,240. However, in other embodiments, the cavity236may comprise a rectangular-shaped cavity, a V-shaped cavity, or other-shaped cavity formed between the pair of legs238,240. One or more springs232(formed from titanium, stainless steel, carbon steel, or combinations thereof) may generally be disposed within the U-shaped cavity236. In the embodiment shown, the spring232may comprise a U-shaped compression spring and be disposed within the U-shaped cavity236between the pair of legs238,240. However, in other embodiments, the spring232may comprise any other profile and/or shape that is complementary to the cavity236. It will be appreciated that the extension234(with legs238,240) and/or the spring232may comprise an interference fit in the secondary cavity230. As such, the spring232may bias the first leg238against the fixing plate228and bias the second leg240against an inner wall of the secondary cavity230, thereby forcing the seat insert212towards the angled wall218and forcing the second sealing interface226into contact with the angled wall218. In turn, the angled wall218forces the seat insert212upwards, thereby forcing the first major surface220of the seat insert212into contact with the first major surface214of the cavity210of the seat208. The resulting contact thereby operates to substantially reduce and/or prevent leakage through the secondary leakage path, while preventing leakage through the primary leakage path.

Similarly to the angled wall118of valve100, the angled wall218of valve200may increase a sealing force between the seat insert212and the seat208when cryogenic temperature conditions cause the seat insert212to shrink in size, deform, or otherwise change in profile or shape. In some embodiments, the angled wall218may increase the sealing force between the seat insert112and the seat108by at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 90%, at least 95%, at least 100%, at least 125%, or at least 150%. In some embodiments, the angled wall218may increase the sealing force between the seat insert212and the seat208by not greater than 500%, not greater than 400%, not greater than 300%, not greater than 200%, or not greater than 100%. Further, it will be appreciated that the angled wall218may increase the sealing force between any of these minimum and maximum values, such as at least 1% and not greater than 500%.

FIG. 3shows a flowchart of a method300of preventing leakage in a valve100,200according to an embodiment of the disclosure. The method300may begin at block302by providing a valve100,200comprising a valve body102,202, a ball106,206selectively rotatable within the valve100,200, a seat112,212formed within the valve body102,202and comprising a cavity having an angled wall118,218, and a seat insert112,212at least partially disposed within the cavity110,210and having a first sealing surface124,224and a second sealing surface126,226. Method300may continue at block304by operating the valve100,200in cryogenic temperature conditions. Method300may continue at block306by selectively rotating the ball106,206to prevent fluid flow along a flow path105,205through the valve100,200. Method300may continue at block308by forming and/or maintaining a first sealing interface between the first sealing surface124,224of the seat insert112,212and the ball106,206to prevent leakage through a first leakage path (shown as “1” inFIGS. 1 and 2) and simultaneously forming and/or maintaining a second sealing interface between the second sealing surface126,226and the angled wall118,218to prevent leakage through a second leakage path (shown as “2” inFIGS. 1 and 2) while the ball106,206is selectively rotated to prevent fluid flow along the flow path105,205through the valve100,200.

In still other embodiments, the valve100,200may include one or more of the following embodiments:

Embodiment 1. A valve, comprising: a valve body; a ball selectively rotatable within the valve body; a seat formed within the valve body and comprising a cavity having an angled wall; and a seat insert at least partially disposed within the cavity and having a first sealing surface that forms a first sealing interface with the ball to prevent leakage through a first leakage path and a second sealing surface that forms a second sealing interface with the angled wall to prevent leakage through a second leakage path.

Embodiment 2. The valve of embodiment 1, wherein first sealing surface is curved, planar, or combinations thereof.

Embodiment 3. The valve of any of embodiments 1 to 2, wherein the second sealing surface comprises a complementary profile to the angled wall.

Embodiment 4. The valve of embodiment 3, wherein the angled wall is curved, and wherein the second sealing surface is curved.

Embodiment 5. The valve of embodiment 3, wherein the angled wall is planar, and wherein the second sealing surface is curved, planar, or combinations thereof.

Embodiment 6. The valve of any of embodiments 1 to 5, wherein the angled wall forms an angle with a longitudinal axis that is at least 5 degrees and not greater than 90 degrees.

Embodiment 7. The valve of embodiment 6, wherein the angled wall forms an angle with the longitudinal axis that is at least 5 degrees, at least 10 degrees, at least 15 degrees, at least 20 degrees, at least 25 degrees, at least 30 degrees, at least 35 degrees, at least 40 degrees, at least 45 degrees, at least 50 degrees, at least 55 degrees, at least 60 degrees, at least 65 degrees, at least 70 degrees, or at least 75 degrees.

Embodiment 8. The valve of any of embodiments 6 to 7, wherein the angled wall forms an angle with the longitudinal axis that is not greater than 90 degrees, not greater than 85 degrees, not greater than 80 degrees, not greater than 75 degrees, not greater than 70 degrees, not greater than 65 degrees, not greater than 60 degrees, not greater than 55 degrees, not greater than 50 degrees, not greater than 45 degrees, not greater than 40 degrees, not greater than 35 degrees, or not greater than 30 degrees.

Embodiment 9. The valve of any of embodiments 1 to 8, wherein the seat insert comprises a first major surface and a second major surface, wherein the first sealing surface is disposed between the first major surface and the second major surface, and wherein the second sealing surface is disposed between the first major surface and the second major surface.

Embodiment 10. The valve of embodiment 9, wherein the first sealing surface is opposite the second sealing surface.

Embodiment 11. The valve of any of embodiments 1 to 10, wherein the first sealing surface and the second sealing surface form a sealing angle.

Embodiment 12. The valve of embodiment 11, wherein the sealing angle is at least 45 degrees and not greater than 135 degrees.

Embodiment 13. The valve of embodiment 12, wherein the sealing angle is at least 45 degrees, at least 50 degrees, at least 55 degrees, at least 60 degrees, at least 65 degrees, at least 70 degrees, or at least 75 degrees, at least 80 degrees, at least 85 degrees, or at least 90 degrees.

Embodiment 14. The valve of any of embodiments 12 to 13, wherein the sealing angle is not greater than 135 degrees, not greater than 130, not greater than 125 degrees, not greater than 120 degrees, not greater than 115 degrees, not greater than 110 degrees, or not greater than 95 degrees.

Embodiment 15. The valve of any of embodiments 1 to 14, wherein the valve body comprises a fixing plate.

Embodiment 16. The valve of embodiment 15, wherein the fixing plate forms a secondary cavity within the cavity of the seat.

Embodiment 17. The valve of embodiment 16, further comprising: a spring disposed within the secondary cavity.

Embodiment 18. The valve of embodiment 17, wherein the spring biases the seat insert against the angled wall.

Embodiment 19. The valve of embodiment 18, wherein the angled wall forces the seat insert upwards to prevent leakage through secondary leakage path.

Embodiment 20. The valve of embodiment 19, wherein the angled wall increases a sealing force between the seat insert and the seat when cryogenic temperature conditions cause the seat, the seat insert, or combinations thereof to shrink in size.

Embodiment 21. The valve of any of embodiments 17 to 20, wherein the spring comprises a standalone spring.

Embodiment 22. The valve of embodiment 21, wherein the spring is disposed between an extension of the seat insert and the fixing plate.

Embodiment 23. The valve of embodiment 22, wherein the spring biases the extension of the seat insert against the fixing plate to force the seat insert against the angled wall.

Embodiment 24. The valve of any of embodiments 17 to 20, wherein the spring is integrated into the seat insert.

Embodiment 25. The valve of embodiment 24, wherein the spring is disposed in the secondary cavity within a U-shaped cavity of an extension of the seat insert.

Embodiment 26. The valve of embodiment 25, wherein the spring is disposed between a pair of legs of the U-shaped cavity.

Embodiment 27. The valve of embodiment 26, wherein the spring biases an inner leg of the U-shaped cavity against the fixing plate to force the seat insert against the angled wall.

Embodiment 28. The valve of embodiment 27, wherein the extension comprises an interference fit in the secondary cavity.

Embodiment 29. The valve of any of embodiments 17 to 28, wherein the spring is formed from titanium, stainless steel, carbon steel, or combinations thereof.

Embodiment 30. The valve of any of embodiments 1 to 29, wherein the seat insert is formed from PTFE, a fluoropolymer, a perfluoropolymer, PTFE, PVF, PVDF, PCTFE, PFA, FEP, ETFE, ECTFE, PCTFE, a polyarylketone such as PEEK, PEK, or PEKK, a polysulfone such as PPS, PPSU, PSU, PPE, or PPO, aromatic polyamides such as PPA, thermoplastic polyimides such as PEI or TPI, or any combination thereof.

Embodiment 31. The valve of embodiment 30, wherein the seat insert is formed from a material modified with at least one filler.

Embodiment 32. A valve, comprising: a valve body having a longitudinal axis along a flow path through the valve; a ball selectively rotatable within the valve body to selectively allow fluid flow through the valve; a seat formed within the valve body and comprising a cavity having an angled wall; and a seat insert at least partially disposed within the cavity and having a first sealing surface that forms a first sealing interface with the ball to prevent leakage through a first leakage path and a second sealing surface that forms a second sealing interface with the angled wall to prevent leakage through a second leakage path while the ball is selectively rotated to prevent fluid flow through the valve.

Embodiment 33. The valve of embodiment 32, wherein the angled wall increases a sealing force between the seat insert and the seat when cryogenic temperature conditions cause the seat, the seat insert, or combinations thereof to shrink in size.

Embodiment 34. The valve of any of embodiments 20 and 33, wherein the angled wall increases the sealing force between the seat insert and the seat by at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 90%, at least 95%, at least 100%, at least 125%, or at least 150%.

Embodiment 35. The valve of embodiment 34, wherein the angled wall increases the sealing force between the seat insert and the seat by not greater than 500%, not greater than 400%, not greater than 300%, not greater than 200%, or not greater than 100%.

Embodiment 36. A method of preventing leakage in a valve, comprising: providing a valve comprising a valve body, a ball selectively rotatable within the valve, a seat formed within the valve body and comprising a cavity having an angled wall, and a seat insert at least partially disposed within the cavity and having a first sealing surface and a second sealing surface; operating the valve in cryogenic temperature conditions; selectively rotating the ball to prevent fluid flow along a flow path through the valve; and forming or maintaining a first sealing interface between the first sealing surface of the seat insert and the ball to prevent leakage through a first leakage path and simultaneously forming or maintaining a second sealing interface between the second sealing surface and the angled wall to prevent leakage through a second leakage path while the ball is selectively rotated to prevent fluid flow along the flow path through the valve.

This written description uses examples to disclose the embodiments, including the best mode, and also to enable those of ordinary skill in the art to make and use the invention. The patentable scope is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.