High-performance polymer self-positioning valve seat plug valve for severe working conditions

Abstract

The high-performance polymer self-positioning valve seat plug valve comprises a valve body, a valve seat, a plug body and a valve deck, the valve seat is arranged in the valve body, the plug body is located in the valve seat, the two sides of the valve seat are assembled with the valve body and the plug body in a sealed mode respectively, and the valve deck is arranged on the valve seat. The plug body can rotate relative to the valve body to open or close fluid media, the valve seat is made of polyimide or ultra-high molecular weight polyethylene or polyether-ether-ketone, and a positioning structure is arranged on the upper portion of the valve seat and used for being matched with the valve cover positioning structure to limit the valve seat. The high-performance polymer self-positioning valve seat plug valve for the harsh working condition is directly arranged in the valve body in a natural and normal-temperature state without heating the valve seat to soften the valve seat, the phenomena of taking out, tearing and the like of the valve seat can be effectively avoided, the maintenance frequency is reduced, and the replacement efficiency is greatly improved; meanwhile, it is possible to cut and grind the surface of the inner cavity of the valve body to improve the surface smoothness of the valve body, sealing can be achieved by applying small external force to the plug body, and the operation torque is small; the plug valve can meet the requirements of high-temperature, high-pressure and nuclear radiation working conditions, the use temperature and pressure range of an original plug valve is widened, and the plug valve can be used in working occasions with nuclear radiation.

Description

Technical Field

[0001] The present invention relates to the field of valve technology, and in particular to a high-performance polymer self-positioning valve seat plug valve for harsh working conditions. Background Art

[0002] With the advancement of industrialization, especially the rapid development of industries like oil, natural gas, and nuclear power, the demand for fluid control equipment has increased dramatically. A plug valve is a valve that opens or closes by rotating the plug 90° to connect or disconnect the valve body. It is widely used in industries like petrochemicals, chemical engineering, nuclear power, coal gas, natural gas, liquefied petroleum gas, HVAC, and shipping.

[0003] A common form of soft seal is formed by a metal plug body and a polymer valve seat. These are commonly used in media delivery systems operating under low-pressure, normal-temperature, and corrosion-resistant conditions. For example, Chinese patent application number 201410564586.4 discloses a low-torque soft-seal plug valve comprising a valve body and a plug body. These valves are characterized by: a valve stem connected to the plug body, the upper portion of which is threadedly connected to the valve body; a rolling bearing disposed between the valve stem and the valve body, near the plug body; a stopper disposed on the upper portion of the rolling bearing, the stopper width being greater than the bearing width; a stopper-compatible step disposed on the valve body; and a valve seat in close contact with the plug body. The plug body is also tightly secured to the valve seat, which is a soft seal made of polytetrafluoroethylene (PTFE). A sealing compensation mechanism is also provided between the valve seat and the valve body. However, this soft-seal plug valve requires a rib on the inner wall of the valve body to position the valve seat and prevent the polymer valve seat from rotating with the metal plug body. This prevents the interior of the valve body from being machined through cutting or grinding to obtain a high-quality sealing surface, making sealing between the valve stem and the valve seat difficult. To achieve a good sealing effect, a large external force is usually required on the plug body, resulting in a large sealing load and operating torque. Because the ribs protrude toward the center of the valve body and naturally block the valve seat from being pressed down, the valve seat needs to be heated to soften it before it can be pressed and embedded in the valve body, resulting in low assembly efficiency. In addition, the valve seat is usually made of polytetrafluoroethylene, which is not only weak in strength but also softens rapidly with increasing temperature, resulting in a significant cold flow effect. The friction caused by the rotation of the plug body causes it to slip, often causing the valve seat to be pulled out or torn, leading to seal failure and requiring frequent maintenance and replacement. Since the valve seat is embedded in the valve body, it must be destroyed to be removed, resulting in low maintenance efficiency.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The problem solved by the present invention is that the existing soft-sealed plug valve has the problems of great sealing difficulty, large operating torque, great difficulty in assembly and manufacturing / maintenance / low efficiency, and cannot be used in harsh working conditions such as high temperature / high pressure / nuclear radiation.

[0006] In order to solve the above problems, the present invention provides a high-performance polymer self-positioning valve seat plug valve for harsh working conditions, including a valve body, a valve seat, a plug body, and a valve cover. The valve seat is arranged in the valve body, and the plug body is located in the valve seat. The two sides of the valve seat are sealed with the valve body and the plug body respectively. The plug body can rotate relative to the valve body to disconnect or close the fluid medium. The valve seat is made of polyimide or ultra-high molecular weight polyethylene or polyetheretherketone and a positioning structure is arranged on the top. The lower part of the valve cover is provided with a matching structure for cooperating with the positioning structure to limit the valve seat.

[0007] The present application sets a positioning structure on the top of the valve seat and limits the material to a high-strength polymer material, which can be limited by cooperating with the valve cover. Since the inner cavity surface of the valve body is no longer provided with plate ribs, the valve seat can be directly installed into the valve body under natural and normal temperature conditions. There is no need to heat the valve seat to soften it. During maintenance, the valve seat can be directly removed and replaced on site without returning to the factory for operation, thereby improving maintenance efficiency. Since the structure of the valve seat is intact, the damaged surface can be processed and reused, which is economical.

[0008] At the same time, it is possible to process the inner cavity surface by cutting and grinding to obtain a high-quality sealing surface. Sealing can be achieved by applying a small external force on the plug body, and the operating torque is small. The use of high-strength polymer materials can avoid phenomena such as valve seat pulling out and tearing, greatly extending the maintenance cycle. Since the valve seat is made of high-performance material, the operating temperature limit of the plug valve is extended from 120°C to 300°C, and the operating pressure level is increased from 10MPa to 75MPa. At the same time, it meets the use requirements of radiation medium conditions and granular medium conditions in the nuclear power field, significantly expanding the scope of use of existing soft-seal plug valves.

[0009] Preferably, the valve seat is a conical hollow sleeve with a flow channel window provided on the side wall, and a plurality of positioning structures are provided on the top of the valve seat, and the positioning structures are arranged at equal intervals along the outer peripheral surface of the valve seat.

[0010] This setting utilizes an evenly spaced positioning structure to ensure that the valve seat is evenly stressed during installation or operation, avoiding deflection or misalignment and reducing the risk of leakage; it effectively shares external loads and vibrations, reduces deformation or wear of the valve seat under high-pressure differential conditions, and reduces local wear caused by fluid impact or turbulence.

[0011] Preferably, the positioning structure is a groove, which includes a first bottom surface and a first side wall and a second side wall. The first side wall and the second side wall are located on both sides of the first bottom surface. During assembly, the first bottom surface, the first side wall and the second side wall are respectively fitted with the matching structure.

[0012] This setting can increase the contact area with the mating structure, and at the same time can constrain the positioning structure in three-dimensional space to significantly reduce the risk of micro-displacement caused by vibration or load during operation; the rigid constraint of the groove combined with the elastic deformation ability can absorb vibration energy and reduce the risk of damage due to water hammer effect; the synchronous fit of the bottom surface and the double side walls makes the contact stress evenly distributed to avoid unilateral wear and extend the life of the sealing surface; at the same time, the valve seat can be installed or removed along a fixed trajectory, which greatly shortens the maintenance time and difficulty.

[0013] Preferably, the inner and outer walls of the valve seat form an inner sealing surface and an outer sealing surface, respectively, for sealing with the plug and valve body. This arrangement utilizes the inner sealing surface to form a primary seal with the plug, while the outer sealing surface and valve body form a secondary seal. An external axial load is used to push the valve seat against the valve body, enhancing the sealing pressure ratio of the outer sealing surface while maintaining effective sealing of the inner sealing surface, achieving leak-proofing under all operating conditions.

[0014] Preferably, the roughness of the inner cavity surface of the valve body and the outer surface of the plug body does not exceed Ra0.4. This setting can make the surfaces of the valve body and the plug body smooth, thereby ensuring that the two fit tightly with the valve seat to achieve sealing.

[0015] Preferably, a sealing gasket is disposed between the valve body and the valve cover, a rotating shaft is disposed on the upper portion of the plug body, a through-hole is disposed in the center of the valve cover, the rotating shaft passes through the through-hole, and a sealing assembly is disposed between the rotating shaft and the through-hole. This arrangement utilizes the sealing gasket to achieve a static seal between the valve body and the valve cover, preventing leakage of media along the flange surface, while the sealing assembly provides a dynamic seal for the gap between the rotating shaft and the through-hole, ensuring no leakage during rotational motion and simultaneously preventing external dust and moisture from intruding into the valve cavity of the valve body, thereby achieving two-way isolation and protection within the piping system.

[0016] Preferably, the valve body includes a main structure having an inner cavity surface, wherein the inner cavity surface partially cooperates with the valve seat to form a sealing surface. This arrangement enables an external axial load to push the valve seat against the inner cavity surface, thereby forming a sealing surface with a forced sealing function, and is almost leak-free under both high-pressure and low-pressure conditions.

[0017] Preferably, a first step surface and a second step surface are provided on the top of the main structure, a first matching portion and a second matching portion are provided on the valve cover, the second step surface is limitedly assembled with the first matching portion, the first step surface is matched with the second matching portion, the first matching portion and the second matching portion are located on the periphery of the through hole and are coaxially arranged.

[0018] This arrangement enables the first mating portion and the second stepped surface to form the primary sealing surface, while the second mating portion and the first stepped surface form the secondary sealing surface. This arrangement allows the medium pressure to push the valve cover against the main structure under high-pressure conditions, so that both sealing surfaces are stressed synchronously, the sealing pressure is evenly distributed, and localized leakage is effectively prevented.

[0019] Preferably, the positioning structure is provided on the second mating portion and is coaxial with the through hole. This arrangement enables the valve core / stem and other components to move along a single axis, with a radial offset of ≤0.05mm during assembly, ensuring precise alignment of the key moving component (valve core) and the sealing surface. It also creates a self-guiding effect during assembly, reducing manual adjustment errors and significantly improving assembly efficiency.

[0020] Compared with the prior art, the plug valve described in the embodiment of the present invention has the following beneficial effects: 1) The high-performance polymer self-positioning valve seat plug valve for harsh working conditions described in this application improves the material and structure of the valve seat on the basis of eliminating the plate ribs. It can be directly installed into the valve body under natural and room temperature conditions without heating the valve seat to soften it. It can also effectively avoid the phenomenon of valve seat being pulled out or torn, reducing the maintenance frequency and greatly improving the replacement efficiency; 2) This application sets a positioning structure on the top of the valve seat and limits the material to high-strength polymer material, which can be achieved by cooperating with the valve cover. It is limited, so the valve seat can be directly installed into the valve body in a natural, room temperature state, without the need to heat the valve seat to soften it. During maintenance, the valve seat can be directly removed and replaced on site without returning to the factory for operation, thereby improving maintenance efficiency; 3) Since the valve seat positioning structure is adapted to high-performance materials, the operating temperature upper limit of the plug valve is extended from 120°C to 300°C, and the operating pressure level is increased from 10MPa to 75MPa. At the same time, it meets the use requirements of radiation medium conditions and granular medium conditions in the nuclear power field, significantly expanding the scope of use of existing soft-seal plug valves. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural diagram of an existing soft-sealed plug valve;

[0022] Figure 2 It is a structural diagram of the valve body in the existing soft-sealed plug valve;

[0023] Figure 3 A schematic diagram of a positioning structure for a ferrule in a high-performance polymer self-locating seat plug valve for harsh working conditions according to an embodiment of the present invention;

[0024] Figure 4 This is a schematic structural diagram of the valve seat according to an embodiment of the present invention;

[0025] Figure 5 Schematic diagram of the structure of the valve cover according to an embodiment of the present invention.

[0026] Description of reference numerals:

[0027] 1-valve body; 11-main structure; 12-inner cavity surface; 13-inner cavity sealing surface; 14-rib plate; 15-second step surface; 16-first step surface; 2-valve seat; 21-outer sealing surface; 22-inner sealing surface; 23-flow channel window; 24-positioning structure; 3-plug body; 4-sealing gasket; 5-valve cover; 51-first matching part; 52-second matching part; 53-middle through hole; 54-positioning structure; 6-shaft sealing assembly. DETAILED DESCRIPTION

[0028] To make the above-mentioned objects, features and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is made in conjunction with the accompanying drawings. The technical features of the embodiments of the present invention can be combined with each other without conflict.

[0029] like Figure 1-2 As shown, the existing plug valve is a fast-opening straight-through valve, including a valve body 1, a valve seat 2 and a plug body 3. The plug body 3 is made of metal, and the valve seat 2 is usually made of polytetrafluoroethylene and is arranged between the plug body 3 and the valve body 1. A first sealing surface is formed between the outer surface of the valve seat 2 and the inner surface of the valve body 1, and a second sealing surface is formed between the inner surface of the valve seat 2 and the outer surface of the valve body 1. The first sealing surface and the second sealing surface are both conical surfaces with a certain angle. The inner cavity surface 12 of the valve body 1 is provided with a plate rib 14 for limiting the valve seat 2.

[0030] Since the valve seat 2 needs to be softened during assembly to better fit the irregular surface of the inner cavity surface 12 of the valve body 1, the material of the valve seat 2 is usually selected from polytetrafluoroethylene, which has low strength and is easily deformed. Due to its poor wear resistance and temperature resistance, this material cannot be used for media containing particles or in working conditions above 120°C, which greatly limits its application range. To this end, the applicant proposes the following technical solution:

[0031] like Figure 3-5 As shown, a high-performance polymer self-positioning valve seat plug valve for harsh working conditions includes a valve body 1, a valve seat 2, a plug body 3, and a valve cover 5. The inner surface of the valve body 1 is tightly fitted with the outer surface of the valve seat 2, and the outer surface of the plug body 3 is tightly fitted with the inner surface of the valve seat 2. A sealing gasket 4 is arranged between the valve body 1 and the valve cover 5, a rotating shaft is arranged on the upper part of the plug body 3, a through hole 53 is arranged in the center of the valve cover 5, the rotating shaft passes through the through hole 53, and a sealing assembly 6 is arranged between the rotating shaft and the through hole 53. The material of the valve seat 2 is polyimide or ultra-high molecular weight polyethylene or polyetheretherketone, and a positioning structure 24 is arranged on the top, and a matching structure 54 is arranged at the lower part of the valve cover 5 for matching with the positioning structure 24 to limit the valve seat 2.

[0032] The present application sets a positioning structure 24 on the top of the valve seat 2 and limits the material to a high-strength polymer material, which can be limited by cooperating with the valve cover 5. Since the inner cavity surface 12 of the valve body 1 is no longer provided with plate ribs 14, the valve seat 2 can be directly installed into the valve body 1 under natural and normal temperature conditions. There is no need to heat the valve seat 2 to soften it. During maintenance, the valve seat 2 can be directly removed and replaced on site without returning to the factory for operation, thereby improving maintenance efficiency. Since the structure of the valve seat 2 is intact, the damaged surface can be processed and reused, which is economical.

[0033] At the same time, it is possible to process the inner cavity surface 12 by cutting and grinding to obtain a high-quality sealing surface, and sealing can be achieved by applying a small external force on the plug body 3, and the operating torque is small; the use of high-strength polymer materials can avoid phenomena such as the valve seat 2 being dragged out and torn, and the maintenance cycle is greatly extended; since the valve seat 2 is made of high-performance material, the upper limit of the operating temperature of the plug valve is extended from 120°C to 300°C, and the operating pressure level is increased from 10MPa to 75MPa, while meeting the use requirements of radiation medium working conditions and granular medium working conditions in the nuclear power field, significantly expanding the scope of use of existing soft-seal plug valves.

[0034] The rotating shaft is connected to the external operating mechanism for opening and closing the stopcock. The external operating mechanism can be powered by human power, electric power, pneumatic power, hydraulic power, or any other power source, without limitation. The shaft seal assembly 6 can consist of an O-ring and a sealing packing, or can be provided with either a single O-ring or a single sealing packing.

[0035] As an example of the present invention, the valve seat 2 is a conical hollow sleeve with a flow channel window 23 provided on the side wall. A plurality of positioning structures 24 are provided on the top of the valve seat 2. The positioning structures 24 are arranged at equal intervals along the outer circumference of the valve seat 2. This arrangement utilizes the positioning structures 24 arranged at equal intervals to ensure that the valve seat 2 is evenly stressed during installation or operation, avoiding deflection or misalignment and reducing the risk of leakage; effectively sharing external loads and vibrations, reducing deformation or wear of the valve seat 2 under high pressure differential conditions, reducing local wear caused by fluid impact or turbulence, and reducing flow-induced noise and vibration. The positioning structures 24 can be one or more, and can be continuous or spaced protrusions or grooves.

[0036] As an example of the present invention, the inner wall surface and the outer wall surface of the valve seat 2 respectively form an inner sealing surface 22 and an outer sealing surface 21, which are respectively used for sealing assembly with the plug body 3 and the valve body 1.

[0037] This setting uses the inner sealing surface 22 and the plug body 3 to form a main seal, and the outer sealing surface 21 and the valve body 1 to form an auxiliary seal. The medium pressure is used to push the valve seat 2 to the valve body 1, thereby enhancing the sealing pressure ratio of the outer sealing surface 21 and forming a forced sealing effect; the same forced sealing effect also occurs on the inner sealing surface 22, achieving leakage prevention under all working conditions; furthermore, under high temperature conditions, the difference in expansion coefficients between the valve body 1 and the plug body 3 can be compensated by independent fine-tuning of the dual sealing surfaces. When the sealing surface is worn, the medium pressure pushes the valve seat 2 to move toward the valve body 1, so that the outer sealing surface 21 continues to fit and compensate for the wear gap, thereby effectively extending the service life. It is suitable for high temperature and high pressure conditions and conditions containing particulate media.

[0038] Preferably, the positioning structure 24 is a groove, which includes a first bottom surface and a first side wall and a second side wall. The first side wall and the second side wall are located on both sides of the first bottom surface. During assembly, the first bottom surface, the first side wall and the second side wall are respectively fitted with the matching structure 54.

[0039] This setting can increase the contact area with the matching structure 54, and at the same time can constrain the positioning structure 24 in three-dimensional space to greatly reduce the risk of micro-displacement caused by vibration or load during operation; the synchronous fitting of the bottom surface and the double side walls makes the contact stress evenly distributed to avoid unilateral wear and extend the life of the sealing surface; at the same time, it allows the valve seat 2 to be installed or removed along a fixed trajectory, greatly shortening the maintenance time and difficulty.

[0040] As an example of the present invention, the roughness of the inner surface 12 of the valve body 1 and the outer surface of the plug body 3 does not exceed Ra0.4. This configuration can make the surfaces of the valve body 1 and the plug body 3 smooth, thereby ensuring that they fit tightly with the valve seat 2 to achieve a seal.

[0041] As an example of the present invention, the valve body 1 includes a main body structure 11 , the main body structure 11 has an inner cavity surface 12 , and a portion of the inner cavity surface 12 cooperates with the valve seat 2 to form a sealing surface 13 .

[0042] A second step surface 15 is provided on the top of the main structure 11, and a first matching portion 51 and a second matching portion 52 are provided on the valve cover 5. The second step surface 15 is limitedly assembled with the first matching portion 51, and the first step surface 512 is matched with the second matching portion 52. The first matching portion 51 and the second matching portion 52 are located on the periphery of the through hole 53 and are coaxially arranged.

[0043] This arrangement enables the first mating portion 51 and the second stepped surface 15 to form the primary sealing surface, while the second mating portion 52 and the first stepped surface 512 form the secondary sealing surface. Under high-pressure conditions, the medium pressure pushes the valve cover 5 against the main structure 11, causing both sealing surfaces to be stressed synchronously and evenly distributed with respect to the sealing pressure, effectively preventing localized leakage. Furthermore, the first and second mating portions 51, 52 can be fine-tuned collaboratively under conditions of thermal deformation or vibration to compensate for sealing surface wear and maintain long-term sealing stability. Furthermore, the position-limiting assembly of the second stepped surface 15 and the first mating portion 51 constrains the axial displacement of the valve cover 5, while the engagement of the second mating portion 52 and the first stepped surface 512 further limits radial offset and effectively distributes external loads.

[0044] As an example of the present invention, the positioning structure 54 is provided on the second mating portion 52 and is coaxially arranged with the through hole 53. This arrangement enables the valve core / stem and other components to move along a single axis, with an assembly radial offset of ≤0.05 mm, ensuring precise alignment of key moving components (such as the butterfly plate or valve core) with the sealing surface. It also creates a self-guiding effect during assembly, reducing manual adjustment errors and significantly improving assembly efficiency.

[0045] Compared with traditional soft-sealed plug valves, the high-performance polymer self-positioning valve seat plug valve for harsh working conditions described in the present invention eliminates the plate rib 14. By improving the material and structure of the valve seat 2, it can be directly installed into the valve body 1 under natural and normal temperature conditions without heating the valve seat 2 to soften it. It can also effectively avoid the valve seat 2 being dragged out or torn, and the maintenance frequency is reduced and the replacement efficiency is greatly improved. At the same time, it makes it possible to cut and grind the inner cavity surface 12 of the valve body 1 to improve its surface smoothness. Sealing can be achieved by applying a small external force on the plug body 3, and the operating torque is small. The change in material also significantly expands the scope of use of existing soft-sealed plug valves.

[0046] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A high performance polymer self-locating seat plug valve for harsh working conditions, characterized by: The invention comprises a valve body (1), a valve seat (2), a plug body (3), and a valve cover (5), wherein the valve seat (2) is arranged in the valve body (1), the plug body (3) is located in the valve seat (2), the outside and the inside of the valve seat (2) are respectively sealed with the valve body (1) and the plug body (3), and the plug body (3) can rotate relative to the valve body (1) to disconnect or close the fluid medium. The material of the valve seat (2) is polyimide or ultra-high molecular weight polyethylene or polyetheretherketone, and a positioning structure (24) is arranged on the top. The lower part of the valve cover (5) is provided with a matching structure (54) for matching with the positioning structure (24) to limit the valve seat (2).

2. The high performance polymer self-positioning seat plug valve for harsh working conditions according to claim 1, characterized in that: The valve seat (2) is a conical hollow sleeve with a flow channel window (23) provided on the side wall. A plurality of positioning structures (24) are provided on the top of the valve seat (2), and the positioning structures (24) are arranged at equal intervals along the outer peripheral surface of the valve seat (2).

3. The high performance polymer self-positioning seated plug valve for harsh working conditions according to claim 2, characterized in that: The positioning structure (24) is a groove, and the groove includes a first bottom surface and a first side wall and a second side wall. The first side wall and the second side wall are located on both sides of the first bottom surface. During assembly, the first bottom surface, the first side wall and the second side wall are respectively fitted with the matching structure (54).

4. The high performance polymer self-positioning seated plug valve for harsh working conditions according to claim 1, characterized in that: The inner wall surface and the outer wall surface of the valve seat (2) respectively form an inner sealing surface (22) and an outer sealing surface (21), which are respectively used for sealing assembly with the plug body (3) and the valve body (1).

5. The high performance polymer self-positioning seated plug valve for harsh working conditions according to claim 4, characterized in that: The roughness of the inner cavity surface (12) of the valve body (1) and the outer surface of the plug body (3) does not exceed Ra 0.

4.

6. The high performance polymer self-locating seat plug valve for severe working conditions according to claim 5, characterized in that: A sealing gasket (4) is provided between the valve body (1) and the valve cover (5), a rotating shaft is provided on the upper part of the plug body (3), a through hole (53) is provided at the center of the valve cover (5), the rotating shaft passes through the through hole (53), and a sealing assembly (6) is provided between the rotating shaft and the through hole (53).

7. The high performance polymer self-locating seat plug valve for severe working conditions according to claim 6, characterized in that: The valve body (1) comprises a main body structure (11), the main body structure (11) having an inner cavity surface (12), and a portion of the inner cavity surface (12) cooperates with the valve seat (2) to form a sealing surface (13).

8. The high performance polymer self-locating seated plug valve for severe working conditions according to claim 7, characterized in that: A second step surface (15) and a first step surface (16) are provided on the top of the main structure (11); a first matching portion (51) and a second matching portion (52) are provided on the valve cover (5); the second step surface (15) and the first matching portion (51) are assembled in a limited manner; the first step surface (16) and the second matching portion (52) are assembled in a matching manner; the first matching portion (51) and the second matching portion (52) are located on the periphery of the through hole (53) and are coaxially arranged.

9. The high performance polymer self-locating seat plug valve for severe working conditions according to claim 8, characterized in that: The positioning structure (54) is arranged on the second matching portion (52) and is coaxially arranged with the through hole (53).

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