Self-compensation type wide-temperature-range fireproof low-torque PEEK ball valve and compensation method based on pressure difference

Abstract

The invention discloses a self-compensation type wide-temperature-range fireproof low-torque PEEK ball valve and a compensation method based on differential pressure, and belongs to the technical field of ball valves.The self-compensation type wide-temperature-range fireproof low-torque PEEK ball valve comprises a valve body, the opening ends of the two sides of the valve body are connected with end covers through bolts, a valve seat is arranged on the inner side of the valve body, a ball body is arranged on the valve seat, a spring is arranged in the valve seat, and the valve body is connected with the valve body through bolts; a supporting ring is arranged on the inner wall of the valve body and located on the side end face of the valve seat, a valve rod is arranged at the upper end of the valve body, a spherical surface is arranged on the valve rod, and the spherical surface arranged on the valve rod is connected with the valve body in a sealed mode through a valve rod sealing ring. The problems that an effective fireproof lip cannot be designed on an existing end cover, the sealing performance is greatly reduced, the applicable temperature range is limited, and leakage is caused due to the fact that a valve seat sealing face is scratched when a valve is opened and closed are solved. The valve has the advantages of valve seat abrasion self-compensation, wide temperature application range, fire prevention, low torque, abrasion resistance, corrosion resistance, medium adhesion prevention and the like.

Description

Technical Field

[0001] This invention relates to the field of ball valve technology, and particularly to a self-compensating wide-temperature-range fireproof low-torque PEEK ball valve and a compensation method based on pressure difference. Background Technology

[0002] A ball valve is a valve in which the opening and closing element (the ball) is driven by the valve stem and rotates around the valve's axis. It can also be used for fluid regulation and control. A PEEK ball valve is a type of ball valve that uses polyetheretherketone (PEEK) material for key components such as the valve seat and sealing ring. It utilizes the excellent properties of this high-performance engineering plastic to adapt to harsh working environments. PEEK ball valves have diverse structural designs and wide applications. Common structures include two-piece and three-piece designs, with the three-piece type connected by bolts for easy maintenance. Currently, conventional three-piece PEEK ball valves on the market have the following problems:

[0003] 1) Conventional three-piece PEEK ball valves have the function of allowing the valve body to be removed separately for online maintenance in order to achieve welding of the end cap to the pipeline. However, an effective fireproof lip cannot be designed on the end cap.

[0004] 2) PEEK material has high hardness and poor elasticity compared to other non-metallic materials, requiring a large pre-tightening sealing pressure. Therefore, when using PEEK as the valve seat of a soft-seal floating ball valve, the valve torque is often very large. Moreover, the compression of the PEEK valve seat during sealing is very small. During use, after a small amount of wear on the valve seat sealing surface, its sealing performance will be greatly reduced. In addition, as a non-metallic material, the hardness and elasticity of PEEK are significantly affected by temperature, resulting in a relatively limited applicable temperature range.

[0005] 3) In conventional ball valves, when the valve is in a medium that is prone to scaling or a medium that is prone to mixing with metal and solids, and the valve is in a closed state for a long time, the surface of the ball on the side with the medium is prone to scaling or solid particles adhering to it, while the medium adhering to the other side of the valve will dry and harden. This will cause the valve to scratch the valve seat sealing surface and cause leakage when the valve is opened and closed. Summary of the Invention

[0006] The purpose of this invention is to provide a self-compensating wide-temperature-range fireproof low-torque PEEK ball valve and a pressure differential compensation method, which features self-compensation for valve seat wear, wide temperature range, fireproof, low torque, wear resistance, corrosion resistance and media adhesion prevention, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A self-compensating, wide-temperature-range, fire-resistant, low-torque PEEK ball valve includes a valve body. Both open ends of the valve body are bolted to end caps. A valve seat is located inside the valve body, and a ball is mounted on the valve seat. The valve seat has a built-in spring, which enables self-compensation. A support ring is located on the inner wall of the valve body, situated on the side face of the valve seat. A valve stem is located at the upper end of the valve body, and a spherical surface is mounted on the valve stem. The spherical surface on the valve stem is sealed to the valve body via a valve stem sealing ring.

[0009] Preferably, the gap between the valve stem and the valve body is filled with packing material, which is compacted into the valve body by a pressure sleeve.

[0010] Preferably, a disc spring is provided on the valve stem, and the disc spring is mounted on the pressure sleeve by a nut, and an anti-loosening cap is provided on the nut.

[0011] Preferably, the inner wall of the valve body is provided with a metal spiral wound gasket, and the valve body is sealed to the end cap through the metal spiral wound gasket.

[0012] Preferably, the inwardly contracting recess at the lower end of the valve stem is connected to the outwardly extending protrusion of the valve body via an O-ring.

[0013] Preferably, the two sides of the sphere are machined into flat surfaces, and the flat surfaces on both sides are sandblasted and then coated with a Teflon anti-stick coating.

[0014] Preferably, the spring is an O-type spring or a V-type spring.

[0015] Preferably, the valve body is provided with a hanging lug, which is used to hang a nameplate or tag.

[0016] According to another aspect of the present invention, a compensation method for a self-compensating wide-temperature-range fire-resistant low-torque PEEK ball valve based on differential pressure is provided, implemented based on the self-compensating wide-temperature-range fire-resistant low-torque PEEK ball valve as described above, comprising:

[0017] When there is no pressure difference or the pressure difference is small, the spherical diameter of the valve seat sealing surface is smaller than the spherical diameter of the ball. After assembly, the center of the spherical sealing surface of the valve seat and the center of the ball form an eccentricity. At this time, the valve seat and the ball form a lip contact. Under the action of the spring, the lip of the valve seat and the ball are tightly fitted to form an effective seal. At this time, the torque is generated by the friction between the valve seats at both ends and the ball.

[0018] When the differential pressure increases, the ball is pushed towards the valve seat behind it. At this time, the outer lip of the valve seat is not enough to support the ball, causing the valve seat to flex and deform. The ball and the entire sealing surface of the valve seat are in contact. The inner part of the valve seat is solid, which can effectively seal with the ball and support the ball to prevent the valve seat from being crushed by the ball. At this time, in addition to the sealing force formed on the valve seat by the ball due to the pressure difference, the outer lip of the valve seat will also generate a large sealing force between the valve seat and the ball under the action of the pressure difference.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. In this invention, the spherical diameter of the valve seat sealing surface is smaller than the spherical diameter of the sphere. After assembly, the center of the spherical sealing surface of the valve seat and the center of the sphere form an eccentricity. At this time, the valve seat and the sphere form a lip-shaped contact. The two sides of the sphere are machined into flat surfaces, and the flat surfaces on both sides are sandblasted and then coated with a Teflon anti-stick coating. This can prevent the medium from scaling or adhering on the flat surface. Even if a small amount of medium adheres, it will not contact the valve seat sealing surface, thereby avoiding scratching the sealing surface. Because there is a Teflon anti-stick coating on the flat surfaces on both sides of the sphere, the medium can easily wash away the slightly adhered material during the valve opening process.

[0021] 2. The valve seat of this invention has a built-in O-type spring or V-type spring. After assembly, the O-type spring or V-type spring is in a compressed state. Even if the valve seat sealing surface is worn, or deformed or its performance changes due to temperature, the O-type spring or V-type spring can enable the valve seat to achieve self-compensation, still achieving good sealing, extending service life, and having a wide applicable temperature range. In addition, the valve stem is designed with a spherical surface. When the handle is subjected to an abnormally large downward force, such as stepping on the handle, it will cause the valve stem to tilt. The valve stem sealing ring contacts the spherical surface provided on the valve stem. Even if the valve stem tilts, the spherical surface contact can still be maintained, without affecting the sealing performance. Attached Figure Description

[0022] Figure 1 This is a perspective view of the self-compensating wide-temperature-range fireproof low-torque PEEK ball valve of the present invention.

[0023] Figure 2 This is a cross-sectional view of the self-compensating wide-temperature-range fireproof low-torque PEEK ball valve of the present invention.

[0024] Figure 3 This is a schematic diagram of the structure of the sphere of the present invention, in which both sides are machined into planes;

[0025] Figure 4 This is a schematic diagram of the structure of the sphere with Teflon anti-stick coating sprayed on both sides.

[0026] Figure 5 This is a schematic diagram of the structure in which the valve seat and the ball form a lip-shaped contact according to the present invention;

[0027] Figure 6 This is a schematic diagram of the valve seat built-in O-type spring of the present invention under no-load or low-pressure conditions.

[0028] Figure 7 This is a schematic diagram of the valve seat built-in O-type spring under high pressure according to the present invention;

[0029] Figure 8 This is a schematic diagram showing the state of the built-in O-type spring in the valve seat of the present invention when it is burned;

[0030] Figure 9 This is a schematic diagram of the low-pressure side of the valve seat when the built-in O-type spring of the present invention is compressed.

[0031] Figure 10 This is a schematic diagram of the valve seat built-in V-shaped spring of the present invention under no-load or low-pressure conditions.

[0032] Figure 11 This is a schematic diagram of the valve seat built-in V-shaped spring under high pressure according to the present invention;

[0033] Figure 12 This is a schematic diagram of the valve seat built-in V-shaped spring of the present invention during actual firing;

[0034] Figure 13 This is a schematic diagram of the low-pressure side of the valve seat when the built-in V-shaped spring of the present invention is compressed.

[0035] Figure 14 A schematic diagram of a conventional valve stem sealing structure using a flat gasket design;

[0036] Figure 15 A schematic diagram of a conventional valve stem sealing structure using a conical sealing gasket design;

[0037] Figure 16 This is a schematic diagram of the valve stem sealing structure of the present invention, which adopts a spherical design.

[0038] In the diagram: 1. Valve body; 2. End cap; 3. Ball; 4. Valve seat; 41. Spring; 5. Valve stem; 51. Spherical surface; 6. Support ring; 7. Valve stem sealing ring; 8. Pressure sleeve; 9. Disc spring; 10. Metal spiral wound gasket; 11. Packing; 12. O-ring; 13. Nut; 14. Locking cap; 15. Bolt; 16. Lug. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] To address the issues of existing end caps being unable to incorporate effective fire-resistant lips, significantly reduced sealing performance, limited applicable temperature range, and valve leakage caused by scratching the valve seat sealing surface during opening and closing, please refer to [link to relevant documentation]. Figures 1-16 This embodiment provides the following technical solution:

[0041] The self-compensating wide-temperature-range fireproof low-torque PEEK ball valve includes a valve body 1, on which a lug 16 is provided for hanging a nameplate or tag.

[0042] Both open ends of the valve body 1 are connected to the end cap 2 by bolts 15. When there is no pressure difference or the pressure difference is small, the spherical diameter of the sealing surface of the valve seat 4 is smaller than the spherical diameter of the ball 3. After assembly, the center of the spherical sealing surface of the valve seat 4 and the center of the ball 3 form an eccentricity. At this time, the valve seat 4 and the ball 3 form a lip contact. Under the action of the spring 41, the lip of the valve seat 4 and the ball 3 are tightly fitted together, thereby forming an effective seal.

[0043] In this embodiment, a metal spiral wound gasket 10 is provided on the inner wall of the valve body 1. The valve body 1 is sealed to the end cap 2 through the metal spiral wound gasket 10, which can make the connection between the valve body 1 and the end cap 2 tight.

[0044] A valve seat 4 is provided on the inner side of the valve body 1, and a ball 3 is provided on the valve seat 4.

[0045] It should be noted that the principle of forming a lip contact is as follows: the spherical diameter A of the sealing surface of the valve seat 4 is smaller than the spherical diameter B of the ball 3. After assembly, the center of the spherical sealing surface of the valve seat 4 and the center of the ball 3 form an eccentricity of l. At this time, the valve seat 4 and the ball 3 form a lip contact.

[0046] The valve seat 4 has a built-in spring 41, which enables the valve seat 4 to achieve self-compensation and ensures good sealing.

[0047] Specifically, when there is no pressure difference or the pressure difference is small, the spherical diameter of the sealing surface of valve seat 4 is smaller than the spherical diameter of ball 3. After assembly, the center of the spherical sealing surface of valve seat 4 and the center of ball 3 form an eccentricity. At this time, valve seat 4 and ball 3 form a lip contact. Under the action of spring 41, the lip of valve seat 4 and ball 3 are tightly fitted, thus forming an effective seal. At this time, the torque is mainly generated by the friction between the two valve seats 4 and ball 3. When the pressure difference increases, ball 3 is pushed towards the rear valve seat 4. The outer ring lip is insufficient to support the ball 3, causing the valve seat 4 to flex and deform. The entire sealing surface of the ball 3 and the valve seat 4 are in close contact. The inner ring of the valve seat 4 is solid, which can effectively seal with the ball 3 and support the ball 3, preventing the valve seat 4 from being crushed by the ball 3. At this time, in addition to the sealing force formed on the valve seat 4 by the pressure difference thrust of the ball 3, the outer ring lip of the valve seat 4 will also generate a large sealing force between the valve seat 4 and the ball 3 under the action of pressure difference. Under the action of the two sealing forces, its sealing performance is more reliable.

[0048] In this embodiment, the two sides of the sphere 3 are machined into flat surfaces, and the flat surfaces on both sides are sandblasted and then coated with a Teflon anti-stick coating.

[0049] It should be noted that the two sides of the ball 3 are machined into flat surfaces, and after sandblasting, a Teflon anti-stick coating is applied. This prevents the medium from scaling or adhering to the flat surface. Even if a small amount of medium adheres, it will not come into contact with the sealing surface of the valve seat 4, thus avoiding scratching the sealing surface. Because there is a Teflon anti-stick coating on the flat surfaces of the two sides of the ball 3, the medium can easily wash away the slightly adhered material during the valve opening process.

[0050] In this embodiment, spring 41 is an O-type spring or a V-type spring.

[0051] It should be noted that the valve seat 4 has a built-in O-type spring or V-type spring. After assembly, the O-type spring or V-type spring is in a compressed state. If the sealing surface of the valve seat 4 is worn, or deformed or its performance changes due to temperature, the O-type spring or V-type spring can enable the valve seat 4 to achieve self-compensation, still achieve good sealing, and extend its service life.

[0052] When unloaded or under low pressure, the ball 3 and the valve seat 4 make narrow-surface contact. Under the action of the spring 41, the lip of the valve seat 4 and the ball 3 fit tightly together, thus forming an effective seal.

[0053] Under high pressure, the pressure difference of the medium pushes the ball 3 to press against the valve seat 4. The ball 3 is pushed towards the valve seat 4 behind it. At this time, the outer lip of the valve seat 4 is not enough to support the ball 3, causing the valve seat 4 to bend and deform. The entire sealing surface of the ball 3 and the valve seat 4 are in contact. The inner part of the valve seat 4 is solid, which can effectively seal with the ball 3 and support the ball 3 to prevent the valve seat 4 from being crushed by the ball 3. At this time, in addition to the sealing force formed on the valve seat 4 by the pressure difference thrust of the ball 3, the outer lip of the valve seat 4 will also generate a large sealing force between the valve seat 4 and the ball 3 under the action of the pressure difference.

[0054] During the fire, the pressure difference of the medium pushes the ball 3, and the non-metallic valve seat 4 melts and fails after being burned. The ball 3 and the fireproof sealing lip of the support ring 6 come into contact to form an effective seal.

[0055] In the case of low pressure, the valve seat 4 is limited when under pressure, and the valve seat 4 and ball 3 are connected to the middle cavity before they are separated.

[0056] The inner wall of the valve body 1 is provided with a support ring 6, which is located on the side end face of the valve seat 4. When burning, the medium pressure difference pushes the ball 3, and the non-metallic valve seat 4 melts and fails after burning. The ball 3 and the fireproof sealing lip of the support ring 6 come into contact to form an effective seal.

[0057] A valve stem 5 is provided at the upper end of the valve body 1. A spherical surface 51 is provided on the valve stem 5. The spherical surface 51 on the valve stem 5 is sealed to the valve body 1 through a valve stem sealing ring 7.

[0058] It should be noted that conventional valve stem sealing structures are typically designed with flat or conical gaskets. When the handle is subjected to an abnormally large downward force, such as when a foot steps on the handle, the valve stem may tilt, creating a leakage path and causing the valve stem seal to fail.

[0059] In this embodiment, the valve stem sealing structure is designed with a spherical surface 51. When the handle is subjected to an abnormally large downward force, such as when a foot steps on the handle, the valve stem will tilt. The valve stem sealing ring 7 will then contact the spherical surface 51 on the valve stem 5. Even when the valve stem 5 is tilted, the spherical surface 51 will still maintain contact and will not affect the sealing performance.

[0060] In this embodiment, the gap between the valve stem 5 and the valve body 1 is filled with packing material 11. The packing material 11 is compacted into the valve body 1 by the pressure sleeve 8. By filling the gap between the valve stem 5 and the valve body 1 with packing material 11 and compacting the packing material 11 by the pressure sleeve 8, the connection between the valve stem 5 and the valve body 1 can be made tight.

[0061] In this embodiment, a disc spring 9 is provided on the valve stem 5. The disc spring 9 is mounted on the pressure sleeve 8 via a nut 13. An anti-loosening cap 14 is provided on the nut 13. The anti-loosening cap 14 can prevent the nut 13 from loosening, thereby ensuring that the pressure sleeve 8 is always pressed against the packing 11.

[0062] In this embodiment, the inwardly contracting recess at the lower end of the valve stem 5 is connected to the outwardly extending protrusion of the valve body 1 via an O-ring 12.

[0063] To better demonstrate the compensation process of a self-compensating wide-temperature-range fire-resistant low-torque PEEK ball valve based on differential pressure, this embodiment provides a compensation method for a self-compensating wide-temperature-range fire-resistant low-torque PEEK ball valve based on differential pressure. This method is implemented using the aforementioned self-compensating wide-temperature-range fire-resistant low-torque PEEK ball valve and includes:

[0064] When there is no pressure difference or the pressure difference is small, the spherical diameter of the sealing surface of the valve seat 4 is smaller than the spherical diameter of the ball 3. After assembly, the center of the spherical sealing surface of the valve seat 4 and the center of the ball 3 form an eccentricity. At this time, the valve seat 4 and the ball 3 form a lip contact. Under the action of the spring 41, the lip position of the valve seat 4 and the ball 3 are tightly fitted to form an effective seal. At this time, the torque is generated by the friction between the valve seats 4 and the ball 3 at both ends.

[0065] When the pressure difference increases, the ball 3 is pushed towards the valve seat 4 behind it. At this time, the outer lip of the valve seat 4 is not enough to support the ball 3, causing the valve seat 4 to flex and deform. The entire sealing surface of the ball 3 and the valve seat 4 are in contact. The inner part of the valve seat 4 is solid, which can effectively seal with the ball 3 and support the ball 3 to prevent the valve seat 4 from being crushed by the ball 3. At this time, in addition to the sealing force formed on the valve seat 4 by the pressure difference thrust of the ball 3, the outer lip of the valve seat 4 will also generate a large sealing force between the valve seat 4 and the ball 3 under the action of the pressure difference.

[0066] Specifically, the working principle of the differential pressure compensation method is as follows:

[0067] When there is no pressure difference or the pressure difference is small, the spherical diameter of the sealing surface of the valve seat 4 is smaller than the spherical diameter of the ball 3. After assembly, the center of the spherical sealing surface of the valve seat 4 and the center of the ball 3 form an eccentricity. At this time, the valve seat 4 and the ball 3 form a lip contact. Under the action of the spring 41, the lip position of the valve seat 4 and the ball 3 are tightly fitted, thus forming an effective seal. At this time, the torque is mainly generated by the friction between the valve seats 4 at both ends and the ball 3.

[0068] When the pressure difference increases, the ball 3 is pushed towards the valve seat 4. At this time, the outer lip of the valve seat 4 is insufficient to support the ball 3, causing the valve seat 4 to flex and deform. The entire sealing surface of the ball 3 and the valve seat 4 are in contact. The inner part of the valve seat 4 is solid, which can not only achieve effective sealing with the ball 3, but also support the ball 3, preventing the valve seat 4 from being crushed by the ball 3. At this time, in addition to the sealing force formed on the valve seat 4 by the pressure difference thrust of the ball 3, the outer lip of the valve seat 4 will also generate a large sealing force between the valve seat 4 and the ball 3 under the action of the pressure difference. Under the action of the two sealing forces, its sealing performance is more reliable.

[0069] At this time, the valve seat 4 upstream of the valve is not in contact with the ball 3 under the limiting effect of the metal support ring 6. That is, the torque of the valve is mainly generated by the friction between the ball 3 and the valve seat 4, which is pushed by the medium thrust. This effectively reduces the torque of the valve. At the same time, the valve cavity is connected to the upstream valve, and there will be no problem of the medium being trapped in the cavity. The trapped medium is easy to decompose or vaporize, which will cause abnormal increase in internal cavity pressure and cause valve body rupture.

[0070] In summary, the spherical diameter of the sealing surface of the valve seat 4 in this invention is smaller than that of the spherical diameter of the ball 3. After assembly, the center of the spherical sealing surface of the valve seat 4 and the center of the ball 3 form an eccentricity. At this time, the valve seat 4 and the ball 3 form a lip-shaped contact. The two sides of the ball 3 are machined into flat surfaces, and after sandblasting, a Teflon anti-stick coating is applied. This prevents the medium from scaling or adhering to the flat surface. Even if a small amount of medium adheres, it will not contact the sealing surface of the valve seat 4, thus avoiding scratches on the sealing surface. Because there is a Teflon anti-stick coating on the flat surfaces of the ball 3, the medium can remove the slightly adhered material during valve opening. The valve seat 4 has a built-in O-type or V-type spring. After assembly, the O-type or V-type spring is in a compressed state. If the sealing surface of the valve seat 4 is worn, or deformed or its performance changes due to temperature, the O-type or V-type spring can enable the valve seat 4 to achieve self-compensation, still achieving good sealing and extending service life. In addition, the valve stem 5 is designed with a spherical surface 51. When the handle is subjected to an abnormally large downward force, such as stepping on the handle, it will cause the valve stem to tilt. The valve stem sealing ring 7 contacts the spherical surface 51 on the valve stem 5. Even if the valve stem 5 tilts, the spherical surface 51 can still maintain contact, without affecting the sealing performance.

[0071] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A self-compensating wide-temperature-range fireproof low-torque PEEK ball valve, comprising a valve body (1), characterized in that, The valve body (1) has two open ends connected to end caps (2) by bolts (15). A valve seat (4) is provided on the inner side of the valve body (1). A ball (3) is provided on the valve seat (4). The valve seat (4) has a built-in spring (41). The valve seat (4) can achieve self-compensation through the built-in spring (41). A support ring (6) is provided on the inner wall of the valve body (1). The support ring (6) is located on the side end face of the valve seat (4). A valve stem (5) is provided at the upper end of the valve body (1). A ball (51) is provided on the valve stem (5). The ball (51) provided on the valve stem (5) is sealed to the valve body (1) through a valve stem sealing ring (7).

2. The self-compensating wide-temperature-range fireproof low-torque PEEK ball valve according to claim 1, characterized in that, The gap between the valve stem (5) and the valve body (1) is filled with packing material (11), and the packing material (11) is pressed into the valve body (1) by the pressure sleeve (8).

3. The self-compensating wide-temperature-range fireproof low-torque PEEK ball valve according to claim 2, characterized in that, A disc spring (9) is provided on the valve stem (5), and the disc spring (9) is provided on the pressure sleeve (8) by a nut (13). An anti-loosening cap (14) is provided on the nut (13).

4. The self-compensating wide-temperature-range fireproof low-torque PEEK ball valve according to claim 3, characterized in that, The inner wall of the valve body (1) is provided with a metal spiral wound gasket (10), and the valve body (1) is sealed to the end cap (2) through the metal spiral wound gasket (10).

5. The self-compensating wide-temperature-range fireproof low-torque PEEK ball valve according to claim 4, characterized in that, The inwardly contracting recess at the lower end of the valve stem (5) is connected to the outwardly extending protrusion of the valve body (1) via an O-ring (12).

6. The self-compensating wide-temperature-range fireproof low-torque PEEK ball valve according to claim 5, characterized in that, The two sides of the sphere (3) are processed into flat surfaces, and the flat surfaces on both sides are sandblasted and then coated with a Teflon anti-stick coating.

7. The self-compensating wide-temperature-range fireproof low-torque PEEK ball valve according to claim 6, characterized in that, The spring (41) is an O-type spring or a V-type spring.

8. The self-compensating wide-temperature-range fireproof low-torque PEEK ball valve according to claim 7, characterized in that, The valve body (1) is provided with a hanging ear (16), which is used to hang a nameplate or position plate.

9. A compensation method for a self-compensating wide-temperature-range fire-resistant low-torque PEEK ball valve based on differential pressure, implemented using the self-compensating wide-temperature-range fire-resistant low-torque PEEK ball valve as described in claim 8, characterized in that... include: When there is no pressure difference or the pressure difference is small, the spherical diameter of the sealing surface of the valve seat (4) is smaller than the spherical diameter of the ball (3). After assembly, the center of the spherical sealing surface of the valve seat (4) and the center of the ball (3) form an eccentricity. At this time, the valve seat (4) and the ball (3) form a lip contact. Under the action of the spring (41), the lip position of the valve seat (4) and the ball (3) are tightly fitted to form an effective seal. At this time, the torque is generated by the friction between the valve seats (4) and the ball (3) at both ends. When the pressure difference increases, the ball (3) is pushed towards the valve seat (4) behind it. At this time, the outer ring lip of the valve seat (4) is not enough to support the ball (3), causing the valve seat (4) to bend and deform. The entire sealing surface of the ball (3) and the valve seat (4) are in contact. The inner ring of the valve seat (4) is solid, which can effectively seal with the ball (3) and support the ball (3) to prevent the valve seat (4) from being crushed by the ball (3). At this time, in addition to the ball (3) being pushed by the pressure difference to form a sealing force on the valve seat (4), the outer ring lip of the valve seat (4) under the action of the pressure difference causes the valve seat (4) and the ball (3) to generate a large sealing force.

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