Ultralow-temperature hard sealing three-eccentric center butterfly valve

Abstract

The utility model relates to the field of three-eccentric center butterfly valves, in particular to an ultralow-temperature hard sealing three-eccentric center butterfly valve, a main flow channel is formed in a valve body, a butterfly plate is arranged in the main flow channel in a sealing mode, the butterfly plate is connected with a valve rod, an executing mechanism drives the valve rod to rotate, the valve rod drives the butterfly plate to rotate in the valve body, and blocking or circulation of media is achieved. The butterfly plate and the main flow channel are sealed through a butterfly plate sealing assembly, and the butterfly plate sealing assembly is detachably arranged between the butterfly plate and the valve body. A valve cover is arranged on the valve body in a sealing mode and comprises an upper valve cover body and an extension valve cover body, a top operation hole and a top installation hole are formed in the top of the valve body, the upper valve cover body is assembled on the top operation hole in a sealing mode, the valve rod is assembled in the top installation hole, and the extension valve cover body is arranged outside the valve rod in a sleeving mode. The bottom of the extension valve cover is hermetically matched with the upper surface of the top mounting hole. The detachable butterfly plate sealing assembly is adopted to be matched with the top operation hole of the valve body, so that the valve can be maintained and replaced on line.

Description

Technical Field

[0001] This utility model relates to the field of triple eccentric butterfly valves, specifically to an ultra-low temperature hard-seal triple eccentric butterfly valve. Background Technology

[0002] A butterfly valve is a simple regulating valve that can also be used for on / off control of low-pressure pipeline media. Traditional butterfly valves are typically used in applications with normal temperature, low pressure, and low sealing requirements. With the continuous development of modern process technology and materials industry, to meet various operating conditions, butterfly valves have evolved from concentric to single eccentric, double eccentric, and triple eccentric valves. Triple eccentric butterfly valves, due to their excellent performance, are widely used in process control and various important pipelines in major industrial fields such as power, petrochemical, metallurgical steelmaking, water treatment, natural gas extraction, and offshore platforms. Existing triple eccentric butterfly valves mostly adopt an integrated butterfly plate sealing structure, which has poor sealing performance and cannot adapt to low-temperature conditions, resulting in serious shortcomings in use. Utility Model Content

[0003] In view of the defects of the prior art, the purpose of this utility model is to provide a hard-seal triple eccentric butterfly valve that can be applied to low-temperature structures, thereby improving the sealing performance of the valve.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an ultra-low temperature hard-seal triple eccentric butterfly valve, comprising a valve body, a valve stem, a butterfly plate, and an actuator. A main flow channel is formed within the valve body, and a butterfly plate is sealed within the main flow channel. The butterfly plate is connected to the valve stem. The actuator drives the valve stem to rotate, thereby causing the butterfly plate to rotate within the valve body, achieving the blocking or flow of the medium. The butterfly plate and the main flow channel are sealed by a butterfly plate sealing assembly, which is detachably disposed between the butterfly plate and the valve body. A valve cover is sealed on the valve body, comprising an upper valve cover and an extended valve cover. A top operating hole and a top mounting hole are formed on the top of the valve body. The upper valve cover is sealed on the top operating hole, and the valve stem is assembled in the top mounting hole. The extended valve cover is fitted over the valve stem, and the bottom of the extended valve cover is sealed to the upper surface of the top mounting hole.

[0005] Furthermore, the butterfly plate sealing assembly includes a butterfly plate sealing ring and a pressure ring. The butterfly plate sealing ring is provided on the butterfly plate sealing surface on the outer periphery of the butterfly plate, and the butterfly plate sealing ring is assembled and fixed by the pressure ring. A valve seat assembly is provided in the valve body. The valve seat assembly includes a valve seat that is detachably installed in the valve body. A valve seat sealing ring is provided between the valve seat side surface and the valve body. A hard metal sealing layer is formed on the valve seat sealing surface on the inner diameter surface of the valve seat. The valve seat sealing surface is in sealing fit with the outer peripheral surface of the butterfly plate sealing ring.

[0006] Furthermore, the valve seat sealing surface is a conical surface.

[0007] Furthermore, the outer circumferential surface of the butterfly plate is provided with an assembly groove for assembling the butterfly plate sealing ring, and the outer circumferential surface of the butterfly plate is provided with a stepped structure. The pressure ring is assembled on the stepped structure, and the stepped structure is connected to the assembly groove. The end face of the pressure ring abuts against the end face of the butterfly plate sealing ring to press the butterfly plate sealing ring.

[0008] Furthermore, the valve seat assembly also includes a valve seat pressure plate, a set ring, set bolts, a four-ring, and a positioning pin. A positioning pin is provided between the valve seat and the valve body. A valve seat pressure plate is provided on the side of the valve seat away from the valve seat sealing ring. A four-ring is embedded in the valve body. The set ring is positioned and assembled with the four-ring. A plurality of set bolts are threaded onto the set ring. The plurality of set bolts abut against the surface of the valve seat pressure plate, so that the valve seat pressure plate is pressed tightly against the side surface of the valve seat.

[0009] Furthermore, the valve stem is keyed to the butterfly plate and fixed with bolts. The valve stem is fitted with an upper support sleeve and a lower support sleeve for positioning and supporting the butterfly plate. The upper support sleeve and the lower support sleeve are respectively supported between the upper and lower ends of the butterfly plate and the valve body.

[0010] Furthermore, the valve cover also includes a lower valve cover, and the bottom of the valve body is provided with a bottom mounting hole for assembling the valve stem. The bottom mounting hole and the top mounting hole are aligned vertically. The lower valve cover and the valve body are connected by studs and nuts.

[0011] Furthermore, the upper end face of the lower valve cover is steppedly engaged with the lower surface of the bottom mounting hole and sealed by a spiral wound gasket and a spring accumulator, with the spiral wound gasket and the spring accumulator being offset on the two stepped surfaces.

[0012] Furthermore, a sliding bearing that rotates with the valve stem is provided on the inner wall of the bottom mounting hole.

[0013] Furthermore, a stop block is provided at the bottom end of the valve stem, and the stop block and the valve body are engaged in a vertical stop-stop engagement. A stop groove corresponding to the stop block is provided inside the lower valve cover, and a disc spring and a support pad are provided in the stop groove from bottom to top. The disc spring supports the support pad and engages with the stop block for a stop-stop engagement.

[0014] Furthermore, the extended valve cover is connected to the valve body by studs and nuts. The lower end face of the extended valve cover is steppedly engaged with the upper surface of the top mounting hole and sealed by a spiral wound gasket and a spring accumulator. The spiral wound gasket and the spring accumulator are offset on the two stepped surfaces.

[0015] Furthermore, the inner wall of the top mounting hole is provided with a sliding bearing that rotatably engages with the valve stem.

[0016] Furthermore, a drip tray is provided on the outer surface of the extended valve cover.

[0017] Furthermore, the upper valve cover is connected to the valve body by studs and nuts, and an upper valve cover gasket is provided between the upper valve cover and the valve body.

[0018] Furthermore, the cryogenic hard-seal triple eccentric butterfly valve also includes a bracket, the actuating structure is mounted on the bracket, and the top of the extended valve cover is fixedly connected to the bracket by studs and nuts.

[0019] Furthermore, the inner wall of the extended valve cover is formed from top to bottom with a sealing fit section, a contact fit section, and a clearance fit section. The sealing fit section of the extended valve cover is sealed with the valve stem through a sealing packing assembly. The contact fit section of the extended valve cover is in contact with the valve stem to position the valve stem axis. The clearance fit section of the extended valve cover is in clearance fit with the valve stem.

[0020] Furthermore, the sealing packing assembly is provided between the upper part of the extended valve cover and the valve stem. The sealing packing assembly includes a packing pressure plate, a packing sleeve, packing, a packing pad, and a packing spring accumulator. The sealing mating section at the upper part of the extended valve cover forms a sealing groove. The packing spring accumulator, the packing pad, and the packing are arranged sequentially from bottom to top in the sealing groove. The packing is sealed to the valve stem. A packing sleeve and a packing pressure plate are arranged sequentially above the packing. The mating surface between the packing sleeve and the packing pressure plate is a conical surface. The packing pressure plate is connected to the extended valve cover by a clamping bolt. The head of the clamping bolt is pre-tightened with a spring to the packing pressure plate.

[0021] Furthermore, a spring groove is provided radially on the outer circumferential surface of the valve stem, and an antistatic spring is installed in the spring groove. One end of the antistatic spring abuts against the bottom of the spring groove, and the other end of the antistatic spring abuts against an antistatic steel ball. The antistatic steel ball contacts the inner wall of the valve body and is used for guiding support when the valve stem rotates.

[0022] Furthermore, the valve body is an integral cast structure, with both ends of the valve body welded to the pipeline, and the valve stem is an integral structure; the butterfly plate is keyed to the valve stem and fastened with screws, and the butterfly plate rotates synchronously by rotating the valve stem.

[0023] The beneficial effects of this utility model are as follows: The ultra-low temperature hard seal triple eccentric butterfly valve of this utility model adopts a detachable butterfly plate sealing assembly, which, together with the top operating hole of the valve body, allows the valve body to be repaired and replaced online without disassembling the butterfly plate sealing assembly in case of damage. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a cryogenic hard-seal triple eccentric butterfly valve;

[0025] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0026] Figure 3 for Figure 1 Enlarged view at point B in the middle;

[0027] Figure 4 for Figure 3 Enlarged view at point I;

[0028] Figure 5 for Figure 1 Enlarged view at point C;

[0029] Figure 6 for Figure 1 Enlarged view at point D;

[0030] In the diagram: 1. Bracket, 2. Packing sleeve, 3. Packing, 4. Packing gasket, 5. Packing packing spring accumulator, 6. Extended valve cover, 601. Sealing section, 602. Contact section, 603. Clearance section, 7. Drip tray, 8. Spiral wound gasket, 9. Spring accumulator, 10. Sliding bearing, 11. Upper support sleeve, 12. Butterfly plate, 13. Key, 14. Valve stem, 15. Lower support sleeve, 16. Valve body, 17. Support pad, 18. Disc spring, 19. Lower valve cover, 20. Actuator, 21. Upper valve cover, 22. Upper valve cover gasket, 23. Four-ring, 24. Set ring, 25. Valve seat, 26. Butterfly plate sealing ring, 27. Pressure ring, 28. Locating pin, 29. Set bolt. 30. Anti-loosening steel wire; 31. Valve seat sealing ring; 32. Valve seat sealing surface; 33. Valve seat pressure plate; 34. Stop block; 35. Antistatic spring; 36. Antistatic steel ball; 37. Packing pressure plate; 38. Tightening bolt. Detailed Implementation

[0031] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0032] See appendix Figure 1The cryogenic hard-seal triple eccentric butterfly valve includes a valve body 16, a valve stem 14, a butterfly plate 12, and an actuator 20. The valve body 16 is an integrally cast structure, with both ends welded to pipelines. A main flow channel is formed within the valve body 16, and the butterfly plate 12 is sealed within the main flow channel. The butterfly plate 12 is connected to the valve stem 14. The actuator 20 drives the valve stem 14 to rotate, which in turn drives the butterfly plate 12 to rotate within the valve body 16, thus achieving the blocking or flow of the medium. The butterfly plate 12 and the main flow channel are sealed by a butterfly plate sealing assembly. The valve body 16 is sealed with a butterfly plate sealing assembly that is detachably disposed between the butterfly plate 12 and the valve body 16. A valve cover is sealed on the valve body 16, the valve cover including an upper valve cover 21 and an extended valve cover 6. A top operating hole and a top mounting hole are formed on the top of the valve body 16. The upper valve cover 21 is sealed and assembled on the top operating hole, and the valve stem 14 is assembled in the top mounting hole. The extended valve cover 6 is fitted over the valve stem 14, and the bottom of the extended valve cover 6 is sealed and fitted with the upper surface of the top mounting hole. The top operating hole is located on the valve body inlet side.

[0033] Based on the above technical solution, the valve body adopts an integral casting structure, which is aesthetically pleasing, saves space and materials, and is welded to the pipeline at both ends to reduce the risk of leakage. The top operating hole and the upper valve cover 21 mainly serve to facilitate the maintenance of the internal seal of the valve body. Maintenance of the internal seal can be performed by opening the upper valve cover 21 without disassembling the valve body. The valve's upper flange adopts an ISO5211 standard flange design, which can meet the installation requirements of various actuators such as electric actuators, pneumatic actuators, and manual actuators.

[0034] Furthermore, the butterfly plate sealing assembly includes a butterfly plate sealing ring 26 and a pressure ring 27. The butterfly plate sealing ring 26 is provided on the butterfly plate sealing surface on the outer periphery of the butterfly plate, and the butterfly plate sealing ring 26 is assembled and fixed by the pressure ring 27. A valve seat assembly is provided inside the valve body 16. The valve seat assembly includes a valve seat 25 that is detachably installed in the valve body 16. A valve seat sealing ring 31 is provided between the side surface of the valve seat 25 and the valve body 16. A hard metal sealing layer is formed on the valve seat sealing surface 32 on the inner diameter surface of the valve seat 25. The valve seat sealing surface 32 is sealed and fitted with the outer peripheral surface of the butterfly plate sealing ring 26.

[0035] Based on the above technical solution, the butterfly plate sealing surface adopts an independent butterfly plate sealing ring 26 structure. The independent butterfly plate sealing ring has self-centering performance when the valve is closed, and the sealing effect is significantly improved compared with the integrated butterfly plate sealing ring. At the same time, it has online maintainability and can be replaced online.

[0036] Furthermore, the valve seat sealing surface 32 is a conical surface, and its inner diameter gradually increases along the medium flow direction. The conical surface ensures an interference fit with the butterfly plate sealing ring 26, guaranteeing the sealing effect between the butterfly plate sealing ring 26 and the valve seat sealing surface 32. The valve seat 25 is a movable valve seat. When the valve is closed, under the pressure of the fluid medium, the valve seat moves towards the butterfly plate, compressing the butterfly plate sealing ring 26. Through the sealing fit between the butterfly plate sealing ring 26 and the valve seat sealing surface 32, the higher the pressure, the greater the compression of the butterfly plate sealing ring 26, and the more reliable the butterfly valve's seal.

[0037] Furthermore, the outer peripheral surface of the butterfly plate 12 is provided with an assembly groove for assembling the butterfly plate sealing ring 26, and the outer peripheral surface of the butterfly plate 12 is provided with a stepped structure. The pressure ring 27 is assembled on the stepped structure, and the stepped structure is connected to the assembly groove. The end face of the pressure ring 27 abuts against the end face of the butterfly plate sealing ring 26 to press the butterfly plate sealing ring 26.

[0038] Furthermore, the valve seat assembly also includes a valve seat pressure plate 33, a retaining ring 24, retaining bolts 29, a four-ring 23, and a locating pin 28. A locating pin 28 is provided between the valve seat 25 and the valve body 26. A valve seat pressure plate 33 is provided on the side of the valve seat 25 away from the valve seat sealing ring 31. A four-ring 23 is embedded in the valve body 26. The retaining ring 24 is positioned and assembled with the four-ring 23. Several retaining bolts 29 are threaded onto the retaining ring 24, and these bolts abut against the surface of the valve seat pressure plate 33, pressing the valve seat pressure plate 33 tightly against the side surface of the valve seat 25. The valve seat adopts an independent replaceable structure, ensuring that the valve seat can be replaced online without disassembling the valve body in case of damage to the valve seat sealing surface.

[0039] Based on the above technical solution, the top operating hole is located on the inlet side of the valve body 16, and the valve seat assembly is located on the inlet side of the main flow channel of the valve body. Both the valve seat assembly and the butterfly plate sealing assembly are detachable, and the valve seat assembly and the butterfly plate sealing assembly inside the valve body can be maintained and replaced online through the top operating hole.

[0040] Furthermore, the valve stem 14 is keyed to the butterfly plate 12 and fixed with bolts. The valve stem 14 is fitted with an upper support sleeve 11 and a lower support sleeve 15 for positioning and supporting the butterfly plate. The upper support sleeve 11 and the lower support sleeve 15 are respectively supported between the upper and lower ends of the butterfly plate 12 and the valve body 16.

[0041] Furthermore, the valve cover also includes a lower valve cover 19, and the bottom of the valve body 16 is provided with a bottom mounting hole for assembling the valve stem. The bottom mounting hole and the top mounting hole are aligned vertically. The lower valve cover 19 and the valve body 16 are connected by studs and nuts.

[0042] Furthermore, the upper end face of the lower valve cover 19 is steppedly engaged with the lower surface of the bottom mounting hole and sealed by the spiral wound gasket 8 and the spring energy storage ring 9, with the spiral wound gasket 8 and the spring energy storage ring 9 being staggered on the two stepped surfaces.

[0043] Furthermore, a sliding bearing 10 is provided on the inner wall of the bottom mounting hole to rotate with the valve stem 14.

[0044] Furthermore, a stop block 34 is provided at the bottom end of the valve stem 14. The stop block 34 and the valve body 16 are engaged in a vertical upper limit stop. A stop groove corresponding to the stop block 34 is provided in the lower valve cover 19. A disc spring 18 and a support pad 17 are provided in the stop groove from bottom to top. The disc spring 18 supports the support pad 17 and engages with the stop block 34 to limit the stop.

[0045] Furthermore, the extended valve cover 6 is connected to the valve body 16 by studs and nuts. The lower end face of the extended valve cover 6 is steppedly fitted with the upper surface of the top mounting hole and sealed by a spiral wound gasket 8 and a spring accumulator ring 9. The spiral wound gasket 8 and the spring accumulator ring 9 are staggered on the two stepped surfaces. The extended valve cover and the valve body adopt a double sealing structure of spring accumulator ring and spiral wound gasket. The spring accumulator ring and the spiral wound gasket are assembled on two stepped surfaces and staggered in the horizontal and vertical directions to form a labyrinth seal, ensuring the sealing effect.

[0046] Furthermore, a sliding bearing 10 is provided on the inner wall of the top mounting hole to rotate with the valve stem 14.

[0047] Furthermore, a drip tray 7 is provided on the outer surface of the extended valve cover 6. The butterfly valve in this embodiment is a cryogenic butterfly valve, in which a cryogenic medium flows through the valve body, and the drip tray 7 is used to collect condensate on the valve.

[0048] Furthermore, the upper valve cover 21 is connected to the valve body 16 by studs and nuts, and an upper valve cover gasket 22 is provided between the upper valve cover 21 and the valve body 16. The upper valve cover gasket 22 is used for sealing between the upper valve cover 21 and the upper end face of the top operating hole.

[0049] Furthermore, the cryogenic hard-seal triple eccentric butterfly valve also includes a bracket 1, on which the actuating structure 20 is mounted. The top of the extended valve cover 6 is fixedly connected to the bracket 1 by studs and nuts. The actuating structure 20 is keyed to the valve stem, driving the valve stem to rotate.

[0050] Furthermore, the inner wall of the extended valve cover 6 is formed from top to bottom with a sealing fit section 601, a contact fit section 602, and a clearance fit section 603. The sealing fit section of the extended valve cover 6 is sealed with the valve stem 14 through a sealing packing assembly. The contact fit section of the extended valve cover 6 is in contact with the valve stem 14 to position the axis of the valve stem 14. The clearance fit section of the extended valve cover 6 is in clearance fit with the valve stem 14 to reduce friction during the rotation of the valve stem.

[0051] Furthermore, the sealing packing assembly is provided between the upper part of the extended valve cover 6 and the valve stem 14. The sealing packing assembly includes a packing pressure plate 37, a packing sleeve 2, packing 3, a packing pad 4, and a packing spring energy storage ring 5. The sealing mating section at the upper part of the extended valve cover 6 forms a sealing groove. The packing spring energy storage ring 5, the packing pad 4, and the packing 3 are arranged sequentially from bottom to top in the sealing groove. The packing 3 is sealed to the valve stem 14. The packing sleeve 2 and the packing pressure plate 37 are arranged sequentially above the packing 3. The mating surface between the packing sleeve 2 and the packing pressure plate 37 is a conical surface, which can form a self-centering effect and produce a tightening effect as pressure increases. The packing pressure plate 37 is connected to the extended valve cover 6 by a clamping bolt 38. The head of the clamping bolt and the packing pressure plate 37 are pre-tightened by a spring.

[0052] Based on the above technical solutions, the long valve stem and extended valve cover structure is suitable for cryogenic valves, ensuring that the sealing packing assembly at the top of the valve is not affected by the cryogenic medium.

[0053] Furthermore, a spring groove is provided radially on the outer circumferential surface of the valve stem 14, and an antistatic spring 35 is installed in the spring groove. One end of the antistatic spring 35 abuts against the bottom of the spring groove, and the other end of the antistatic spring 35 abuts against the antistatic steel ball 36. The antistatic steel ball 36 contacts the inner wall of the valve body 16 and is used for guiding support when the valve stem 14 rotates.

[0054] Furthermore, the valve stem 14 is an integral structure; the butterfly plate 12 is keyed to the valve stem 14 and fastened with screws, and the valve stem 14 rotates to drive the butterfly plate 12 to rotate synchronously.

[0055] This cryogenic hard-seal triple-eccentric butterfly valve is suitable for liquefied natural gas and other media with temperatures above -196℃. The working principle is as follows: the actuator rotates the valve stem 90° counterclockwise, causing the butterfly plate to rotate and opening the valve, allowing the medium to pass through from the inlet side; the actuator then rotates the valve stem 90° clockwise, causing the butterfly plate to rotate and closing the valve, cutting off the medium in the pipeline. The extended valve cover meets relevant standard requirements and is designed using finite element software temperature field analysis to ensure no freezing point at the packing. The upper valve cover adopts an ergonomic design concept to ensure easy online maintenance. The valve stem uses an integral structure with high machining precision and strong torque bearing capacity, and is equipped with an anti-static device, making it suitable for flammable and explosive media conditions. The three eccentric values ​​of this triple-eccentric butterfly valve are designed using three-dimensional software dynamic simulation analysis, meeting the requirements for full differential pressure sealing in both directions. It is a torque-type sealing butterfly valve with reliable sealing and can withstand high pressure, high temperature, and low temperature operating requirements.

[0056] It should be noted that the parts of this utility model not described in detail are existing technologies.

[0057] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0058] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0059] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0060] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0061] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0062] The above examples are merely preferred embodiments of this utility model. Obviously, this utility model is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of this utility model should be considered within the protection scope of this utility model.

Claims

1. A cryogenic hard-seal triple eccentric butterfly valve, characterized in that: The valve body includes a valve body, a valve stem, a butterfly plate, and an actuator. A main flow channel is formed within the valve body, and a butterfly plate is sealed within the main flow channel. The butterfly plate is connected to the valve stem. The actuator drives the valve stem to rotate, which in turn causes the butterfly plate to rotate within the valve body, thus blocking or allowing the flow of the medium. The butterfly plate and the main flow channel are sealed by a butterfly plate sealing assembly, which is detachably disposed between the butterfly plate and the valve body. A valve cover is sealed on the valve body, comprising an upper valve cover and an extended valve cover. A top operating hole and a top mounting hole are formed on the top of the valve body. The upper valve cover is sealed and fitted onto the top operating hole, and the valve stem is fitted into the top mounting hole. The extended valve cover is fitted over the valve stem, and its bottom is sealed to the upper surface of the top mounting hole. The valve stem is keyed to the butterfly plate and fixed with bolts. The valve stem is fitted with an upper support sleeve and a lower support sleeve for positioning and supporting the butterfly plate. The upper support sleeve and the lower support sleeve are respectively supported between the upper and lower ends of the butterfly plate and the valve body. The valve cover also includes a lower valve cover. The bottom of the valve body is provided with a bottom mounting hole for assembling the valve stem. The bottom mounting hole and the top mounting hole are aligned vertically. The lower valve cover and the valve body are connected by studs and nuts. The upper end face of the lower valve cover and the lower surface of the bottom mounting hole are steppedly engaged and sealed by a spiral wound gasket and a spring accumulator. The spiral wound gasket and the spring accumulator are offset on the two stepped surfaces. A sliding bearing that rotates with the valve stem is provided on the inner wall of the bottom mounting hole. A stop block is provided at the bottom end of the valve stem. The stop block and the valve body are engaged in a vertical stop engagement. The lower valve cover is provided with a stop groove corresponding to the stop block. A disc spring and a support pad are provided in the stop groove from bottom to top. The disc spring supports the support pad and engages with the stop block for a limit stop.

2. The cryogenic hard-seal triple eccentric butterfly valve according to claim 1, characterized in that: The butterfly plate sealing assembly includes a butterfly plate sealing ring and a pressure ring. The butterfly plate sealing ring is provided on the butterfly plate sealing surface on the outer periphery of the butterfly plate, and the butterfly plate sealing ring is assembled and fixed by the pressure ring. A valve seat assembly is provided in the valve body. The valve seat assembly includes a valve seat that is detachably installed in the valve body. A valve seat sealing ring is provided between the valve seat side surface and the valve body. A hard metal sealing layer is formed on the valve seat sealing surface on the inner diameter surface of the valve seat. The valve seat sealing surface is a conical surface, and the valve seat sealing surface is in sealing fit with the outer peripheral surface of the butterfly plate sealing ring.

3. The cryogenic hard-seal triple eccentric butterfly valve according to claim 2, characterized in that: The outer circumferential surface of the butterfly plate is provided with an assembly groove for assembling the butterfly plate sealing ring. The outer circumferential surface of the butterfly plate is provided with a stepped structure. The pressure ring is assembled on the stepped structure. The stepped structure is connected to the assembly groove. The end face of the pressure ring abuts against the end face of the butterfly plate sealing ring and presses the butterfly plate sealing ring tightly.

4. The cryogenic hard-seal triple eccentric butterfly valve according to claim 2, characterized in that: The valve seat assembly further includes a valve seat pressure plate, a set ring, set bolts, a four-ring, and a positioning pin. A positioning pin is provided between the valve seat and the valve body. A valve seat pressure plate is provided on the side of the valve seat away from the valve seat sealing ring. A four-ring is embedded in the valve body. The set ring is positioned and assembled with the four-ring. Several set bolts are threaded onto the set ring. Several set bolts abut against the surface of the valve seat pressure plate, so that the valve seat pressure plate is pressed tightly against the side surface of the valve seat.

5. A cryogenic hard-seal triple eccentric butterfly valve according to any one of claims 1-4, characterized in that: The extended valve cover is connected to the valve body by studs and nuts. The lower end face of the extended valve cover is steppedly fitted to the upper surface of the top mounting hole and sealed by a spiral wound gasket and a spring accumulator. The spiral wound gasket and the spring accumulator are offset on the two stepped surfaces. The inner wall of the top mounting hole is provided with a sliding bearing that rotates with the valve stem. The upper valve cover is connected to the valve body by studs and nuts, and an upper valve cover gasket is provided between the upper valve cover and the valve body.

6. A cryogenic hard-seal triple eccentric butterfly valve according to any one of claims 1-4, characterized in that: The system also includes a support bracket, on which the actuator is mounted. The top of the extended valve cover is fixedly connected to the support bracket via studs and nuts. The inner wall of the extended valve cover forms a sealing fit section, a contact fit section, and a clearance fit section from top to bottom. The sealing fit section of the extended valve cover is sealed to the valve stem via a sealing packing assembly. The contact fit section of the extended valve cover is in contact with the valve stem to position the valve stem axis. The clearance fit section of the extended valve cover is in clearance fit with the valve stem. The sealing packing assembly is disposed between the upper part of the extended valve cover and the valve stem. The sealing packing assembly includes a packing pressure plate, a packing sleeve, packing, a packing pad, and a packing spring accumulator. The sealing fit section at the top of the extended valve cover forms a sealing groove. The packing spring accumulator, a packing pad, and packing are disposed sequentially from bottom to top within the sealing groove. The packing is sealed to the valve stem. A packing sleeve and a packing pressure plate are disposed sequentially above the packing. The mating surface between the packing sleeve and the packing pressure plate is a conical surface. The packing pressure plate is connected to the extended valve cover via clamping bolts.

7. A cryogenic hard-seal triple eccentric butterfly valve according to any one of claims 1-4, characterized in that: A spring groove is provided radially on the outer circumferential surface of the valve stem. An antistatic spring is installed in the spring groove. One end of the antistatic spring abuts against the bottom of the spring groove, and the other end of the antistatic spring abuts against an antistatic steel ball. The antistatic steel ball contacts the inner wall of the valve body and is used for guiding and supporting the valve stem during rotation.

8. A cryogenic hard-seal triple eccentric butterfly valve according to any one of claims 1-4, characterized in that: The valve body is an integral cast structure, and both ends of the valve body are welded to the pipeline. The valve stem is an integral structure.

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