Five-eccentric ultralow-temperature two-way pressure butterfly valve

Abstract

The five-eccentric ultralow-temperature two-way pressure butterfly valve comprises a valve body, a valve shaft and a butterfly plate, a valve seat, a corrugated pipe and a limiting ring are arranged in the valve body, the two ends of the corrugated pipe are fixed to the valve seat and the limiting ring respectively, the valve seat is located in a movable groove formed by the limiting ring and the valve body, and the axial size of the valve seat is smaller than the size of the movable groove; the butterfly plate is sleeved with a sealing ring, the inner diameter of the sealing ring is smaller than the outer diameter of the position, used for installing the sealing ring, of the butterfly plate, and the outer edge of the sealing ring is arranged in a special-shaped ball arc face and abuts against the sealing face of the valve seat to seal the valve. According to the five-eccentric ultralow-temperature two-way pressure butterfly valve, the sealing ratio between the sealing ring and the valve seat is uniform by arranging the radial self-adaptive floating sealing ring structure, dynamic change is formed by combining two-way pressure, the valve seat moving relative to the valve body is arranged, the self-sealing force of the valve seat is enhanced by means of the pressure of a two-way medium, and the sealing effect is improved; and the bidirectional isobaric sealing performance of the five-eccentric all-metal hard sealing butterfly valve under ultralow-temperature working conditions such as LNG (liquefied natural gas) is met.

Description

Technical Field

[0001] The invention relates to the technical field of butterfly valves, and in particular to a five-eccentric ultra-low temperature bidirectional pressure butterfly valve. Background Art

[0002] A butterfly valve is a valve that uses a disc-type opening and closing member to reciprocate about 90 degrees to open, close or adjust the flow of the medium. The butterfly valve is not only simple in structure, small in size, light in weight, low in material consumption, small in installation size, small in driving torque, easy and quick to operate, but also has good flow regulation function and closing and sealing characteristics at the same time. It is one of the fastest growing valve varieties in the past decade. The use of butterfly valves is very extensive, and its variety and quantity are still expanding, and it is developing towards high temperature, high pressure, large diameter, high sealing, long life, excellent adjustment characteristics, and one valve with multiple functions. Its reliability and other performance indicators have reached a high level.

[0003] Butterfly valves can be divided into one-way pressure butterfly valves and two-way pressure butterfly valves. When the front of the one-way pressure butterfly valve is closed, the disc plate must face the flow direction of the medium. The medium only flows in one direction. There is an arrow on the valve body indicating the flow direction of the medium. The flow direction of the medium should be paid attention to during installation. The installation and use conditions of the one-way pressure butterfly valve are relatively limited. It does not have the ability to face the reverse medium pressure. Therefore, it is easy to leak or be damaged when the medium is reversed. The two-way pressure butterfly valve can face or back to the flow direction of the medium. It is not necessary to pay attention to the flow direction of the medium during installation. There is no arrow on the valve body indicating the flow direction of the medium. Therefore, the sealing of the two-way pressure butterfly valve is particularly important. However, there are certain differences in the sealing effects on both sides of the existing two-way pressure butterfly valves, and some two-way pressure butterfly valves use fixed sealing methods due to unreasonable design, which are very prone to leakage after a long period of use. Summary of the invention

[0004] In view of the prior art, the object of the present invention is to provide a bidirectional pressure butterfly valve for a butterfly valve, which can obtain a stronger sealing effect by setting a dynamic sealing structure and improve the sealing performance by means of medium pressure.

[0005] In order to achieve the above objectives, the technical solution adopted in the present invention is: a five-eccentric ultra-low temperature bidirectional pressure butterfly valve, comprising a valve body, a valve shaft and a butterfly plate, a sealing seat assembly is arranged in the valve body, the sealing seat assembly comprises a valve seat, a bellows and a limit ring, the two ends of the bellows are respectively fixed on the valve seat and the limit ring, the limit ring is fixed relative to the valve body, the valve seat is located in a movable groove formed by the limit ring and the valve body, and the axial dimension of the valve seat is smaller than the dimension setting of the movable groove, a sealing ring is sleeved on the butterfly plate, the inner diameter of the sealing ring is smaller than the outer diameter setting of the butterfly plate for the sealing ring installation, and the outer edge of the sealing ring is a special-shaped spherical arc surface setting, which is against the sealing surface of the valve seat to seal the valve.

[0006] As a further arrangement of the above scheme, a three-way clamping ring and a limiting bolt are also arranged in the valve body. The three-way clamping ring is clamped in the clamping ring groove on the inner wall of the valve body. The limiting bolt passes through the three-way clamping ring and presses against the end of the limiting ring, so that the other end of the limiting ring is tightly fixed to the step surface of the inner wall of the valve.

[0007] As a further configuration of the above scheme, both ends of the bellows are sealed and fixed to the limit ring and the valve seat end by welding, and the bellows is used to extend or contract when the valve seat moves relative to the limit ring.

[0008] As a further configuration of the above scheme, the butterfly plate is also provided with a pressure ring and screws for axially limiting and fixing the sealing ring relative to the butterfly plate. The valve body is also respectively provided with a sealing gasket, a valve seat gasket and an anti-loosening gasket. The sealing gasket is used for sealing contact between the sealing ring and the butterfly plate, the valve seat gasket is used for sealing between the limiting ring and the valve body, and the anti-loosening gasket is used for fixing the screws.

[0009] As a further arrangement of the above scheme, the valve shaft and the butterfly plate are connected by an axial flat key, and a shaft sleeve and a positioning sleeve are also sleeved on the valve shaft. The shaft sleeve is used to replace the direct wear of the valve body and the valve shaft. Two positioning sleeves are provided, which are respectively sleeved on the upper and lower ends of the valve shaft relative to the butterfly plate. The positioning sleeve is axially movable relative to the valve shaft, and the connection structure of the flat key and the arrangement of the positioning sleeve enable the butterfly plate.

[0010] The five-eccentric ultra-low temperature bidirectional pressure butterfly valve structure of the present invention has at least the following effects: 1. The butterfly plate is fixed by flat keys and positioning sleeves to form adaptive sealing floating. The cavity gap X formed by the setting that the inner diameter of the sealing ring is smaller than the outer diameter of the positioning part of the butterfly plate is further improved, so that it can better adaptively adjust the sealing lifting effect under complex working conditions of high and low temperature alternation; 2. A sealing seat assembly structure is provided, a floating valve seat is set, and its movable position is limited by a limit ring connected to the valve seat, and a bellows is set to seal its movable gap. The movable valve seat is in a sealed state, and the dynamic changes formed by the bidirectional pressure are used to obtain the self-sealing force of the valve seat by the pressure of the bidirectional medium, thereby further improving the sealing effect and meeting the bidirectional isobaric sealing performance of the five-eccentric all-metal hard-sealed butterfly valve under ultra-low temperature conditions such as LNG. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the five-eccentric ultra-low temperature bidirectional pressure butterfly valve of the present invention.

[0012] Figure 2 It is a schematic diagram of the internal structure of the five-eccentric ultra-low temperature bidirectional pressure butterfly valve of the present invention.

[0013] Figure 3 For the present invention Figure 2 Enlarged view of point B in the middle.

[0014] Figure 4 Schematic diagram of the sealing seat assembly of the present invention.

[0015] Figure 5 This is a schematic diagram of the pressure flow principle in the valve of the positive pressure sealing structure of the present invention.

[0016] Figure 6 This is a schematic diagram of the pressure flow principle in the valve of the reverse pressure sealing structure of the present invention.

[0017] Figure 7 Schematic diagram of the eccentric principle analysis of the five-eccentric ultra-low temperature bidirectional pressure butterfly valve of the present invention Figure numerals: 1. valve body; 2. valve seat; 3. bellows; 4. valve seat gasket; 5. limiting ring; 6. three-open clamp; 7. limiting bolt; 8. shaft sleeve; 9. valve shaft; 10. positioning sleeve; 11. sealing gasket; 12. sealing ring; 13. pressure ring; 14. anti-loosening washer; 15. screw; 16. butterfly plate; 17. step surface of valve inner wall. DETAILED DESCRIPTION

[0018] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0019] like Figure 1-7 A five-eccentric ultra-low temperature bidirectional pressure butterfly valve according to the present invention is shown. Figure 1-2 The valve body 1, the valve shaft 9 and the butterfly plate 16 are provided, wherein the reference Figure 2-3 A sealing seat assembly is arranged in the valve body 1, and the sealing seat assembly comprises a valve seat 2, a bellows 3 and a limit ring 5. The two ends of the bellows 3 are respectively fixed on the valve seat 2 and the limit ring 5. The limit ring 5 is fixed relative to the valve body 1. The valve seat 2 is located in a movable groove formed by the limit ring 5 and the valve body 1, and the axial dimension of the valve seat 2 is smaller than the dimension setting of the movable groove. A sealing ring 12 is sleeved on the butterfly plate 16. The inner diameter of the sealing ring 12 is smaller than the outer diameter setting of the butterfly plate 16 for the installation of the sealing ring 12. The outer edge of the sealing ring 12 is a special-shaped spherical arc surface, which is against the sealing surface of the valve seat 2 to seal the valve.

[0020] As a further arrangement of the above scheme, a three-way clamping ring 6 and a limiting bolt 7 are also arranged in the valve body 1. The three-way clamping ring 6 is clamped in the clamping ring groove 18 on the inner wall of the valve body 1. The limiting bolt 7 passes through the three-way clamping ring 6 and presses against the end of the limiting ring 5, so that the other end of the limiting ring 5 is tightly fixed to the step surface 17 of the valve inner wall.

[0021] As a further configuration of the above scheme, the two ends of the bellows 3 are sealed and fixed to the limit ring 5 and the end of the valve seat 2 by welding, and the bellows 3 is used to extend or contract when the valve seat 2 moves relative to the limit ring 5.

[0022] As a further configuration of the above scheme, the butterfly plate 16 is also provided with a pressure ring 13 and a screw 15, which are used to axially limit and fix the sealing ring 12 relative to the butterfly plate 16. The valve body 1 is also respectively provided with a sealing gasket 11, a valve seat gasket 4 and an anti-loosening gasket 14. The sealing gasket 11 is used for sealing contact between the sealing ring 12 and the butterfly plate 16, the valve seat gasket 4 is used for sealing between the limiting ring 5 and the valve body 1, and the anti-loosening gasket 14 is used for fixing the screw 15.

[0023] As a further arrangement of the above scheme, the valve shaft 9 is connected to the butterfly plate 16 by an axial flat key. A shaft sleeve 8 and a positioning sleeve 10 are also sleeved on the valve shaft 9. The shaft sleeve 8 is used to replace the direct wear of the valve body 1 and the valve shaft 9. Two positioning sleeves 10 are provided, which are respectively sleeved on the upper and lower ends of the valve shaft 9 relative to the butterfly plate 16. The positioning sleeve 10 is axially movable relative to the valve shaft 9. The flat key connection structure and the positioning sleeve 10 enable the butterfly plate 16 to move relative to the valve shaft 9 within a certain axial range, and the axial movement is not too large when restricted by the positioning sleeve 10. Therefore, when the sealing ring 12 is subjected to the reaction force of the valve seat 2, the axial movement is adaptively adjusted. Firstly, a uniform annular seal can be formed to improve the sealing effect. Secondly, the problem of the butterfly plate 16 being stuck relative to the valve seat 2 is avoided.

[0024] All-metal movable sealing structure: The sealing ring 12 of the present invention is fixed to the butterfly plate 16 by means of screws 15 and a pressure ring 13. However, the inner diameter of the sealing ring 12 is smaller than the outer diameter of the butterfly plate 16 where the sealing ring 12 is fixed, so that there is a cavity gap X between the two. Figure 3 As shown, the existence of the gap X allows the sealing ring 12 to be in a floating state on the step plane of the butterfly plate 16 and allows a small range of adaptive movement in the radial direction. This characteristic structure allows the sealing ring 12 of the present invention to adaptively abut against the sealing surface of the valve seat 2 under high and low temperature alternating working conditions. Compared with the sealing ring 12 of the prior art, the sealing ring 12 of the present embodiment is less likely to cause interference and bite, thereby reducing the excessive abutment pressure between the sealing ring 12 and the valve seat 2, ensuring that the butterfly plate 16 is in place when closing the valve, and avoiding excessive extrusion of the sealing ring 12 to cause rapid axial aging and damage.

[0025] Further Figure 3As shown, the valve seat 2 of this embodiment is welded to one end of the bellows 3, and the other end of the bellows 3 is welded to the limit ring 5, and the connection between the two forms a welding ring 30, as shown in FIG. Figure 3 This arrangement enables the valve seat 2, bellows 3 and stop ring 5 to form an integral sealing seat assembly. The sealing seat assembly is built into the inner cavity of the valve body 1 and fixed to the valve inner wall step surface 17 through the flanged surface of the stop ring 5, and holds a valve seat gasket 4 for preventing the medium from leaking from the valve inner wall step surface 17 and the stop ring 5. Figure 3 The limiting ring 5 is fixed to the valve body 1 by the limiting bolt 7 and the three-way clamping ring 6. The three-way clamping ring 6 is clamped in the clamping ring groove 18 to maintain axial fixation. The three-way clamping ring 6 is threadedly engaged with the limiting bolt 7 and extends out to abut against the end face of the limiting ring 5 to limit the axial movement of the limiting ring 5. Under positive and negative pressures, the axial pressure generated in the medium will not affect the axial movement of the limiting ring 5. Instead, the valve seat 2 is pushed to move circumferentially, thereby abutting against the valve body 1 or the limiting ring 5 more tightly by the medium pressure during the movement. The movable gap between the valve seat 2 and the limiting ring 5 is sealed by the retractable bellows 3. The limiting ring 5 will remain completely fixed to ensure the medium seal between the sealing seat assembly and the inner wall of the valve body 1.

[0026] The sealing structure setting of the sealing ring 12 and the valve seat 2: the sealing surface of the valve seat 2 is a perfect circular structure after the elliptical cone is beveled, the sealing surface of the sealing ring 12 is a special-shaped spherical arc surface, the sealing ring 12 and the valve seat 2 form a forced line sealing structure, and the metal elastic line sealing structure can ensure that the sealing pair has a higher specific pressure and can achieve high temperature and high pressure dual pressure line sealing performance.

[0027] The eccentric structure principle of the five-eccentric butterfly valve of the present invention (elliptical cone bevel cutting circle sealing system (reference Figure 7 The structure, Figure 7 For Figure 2 Schematic diagram of the section taken along the AA direction) Eccentricity 1: Axial eccentricity, the valve shaft is located behind the valve seat, so that the seal can completely and tightly contact the entire valve seat.

[0028] Eccentricity 2: Radial eccentricity, the center of the valve shaft deviates from the center line of the valve body, reducing the squeezing and scraping effect between the sealing ring and the valve seat when the valve is opened and closed.

[0029] Eccentricity 3: Angular eccentricity, the center axis of the elliptical cone of the valve seat deviates from the center line of the valve body flow channel, eliminating the friction interference of the sealing pair during opening and closing. The elliptical cone is cut at a specific angle to form a perfect circular sealing surface, and the angle of the elliptical cone surface is not a constant value, that is, α≠β.

[0030] Eccentricity 4: Eccentric position, turning the bevel of the elliptical cone into a perfect circle, making the valve seat sealing section a perfect circle geometry. The flow area is larger, the circumferential seal ratio pressure is more uniform, and leakage points are more likely to occur. The above is a four-eccentric structure.

[0031] Eccentricity 5: Forced line seal, the five-eccentric butterfly valve is derived from the four-eccentric butterfly valve. The valve seat sealing surface of the five-eccentric butterfly valve has the same structure as the four-eccentric structure, but the sealing surface of the sealing ring is changed from an eccentric right conical curved plane to a special-shaped spherical arc surface. The spherical arc sealing surface and the right circular sealing surface of the valve body seat form a line seal pair. The line seal is forced by the medium pressure and the torque applied by the valve shaft. Since the contact area of ​​the line seal pair is very small, the sealing pressure ratio obtained under the same torque force and pressure is larger, and the right circular sealing pressure ratio is uniform, ensuring the performance of zero leakage. The five-eccentric forced line seal pair, under high temperature, ultra-low temperature and temperature alternating conditions, the sealing pair deforms evenly under thermal expansion and contraction, maintaining stable sealing performance.

[0032] The working principle of the bidirectional isobaric sealing function of the present invention is as follows: The butterfly plate 16 of the embodiment of the present invention is connected to the valve shaft 9 by a flat key, so that the butterfly plate 16 is positioned in the valve body 1 by the positioning sleeve 10, and the sealing ring 12 is fixed to the butterfly plate 16 by the pressing ring 13 and the screw 15. The sealing ring 12, the butterfly plate 16 and the valve shaft 9 form a whole, and the valve shaft 9 is driven to rotate by an external power mechanism to realize the opening and closing actions.

[0033] 1. Positive pressure principle, such as Figure 5 As shown: The valve seat 2 , the bellows 3 and the limiting ring 5 are welded together to form a movable sealing seat assembly, and the sealing seat assembly is fixed to the step surface 17 of the valve inner wall by a three-way clamp ring 6 and a limiting bolt 7 .

[0034] When the valve encounters Figure 5 When the positive pressure is shown, the pressure area of ​​the medium acting on the seal seat assembly is as follows Figure 5 The annular surface of the cross section A shown in the figure will form a thrust F1 on the annular surface, which will push the valve seat 2 to Figure 5 As shown in the right direction, due to the fixing effect of the three-way clamp ring 6 and the limit bolt 7, the limit ring is fixed on the step surface 17 of the inner wall of the valve, and the limit ring 5 remains fixed, so that the bellows 3 is compressed, and finally the right side of the valve seat 2 reaches the limit ring 5 and no longer moves. The limit ring 5 and the valve body 1 are sealed by the valve seat gasket 4, and the medium cannot leak from the outer circle side of the valve seat 2, and can only flow from the medium flow channel in the middle of the valve body 1 in the positive direction, that is, from the left to the right.

[0035] As described above, the valve shaft 9 of the present invention receives the torque M, driving the butterfly plate 16 to rotate clockwise. When the butterfly plate 16 reaches the closed position, the sealing ring 12 contacts the valve seat 2. At this time, the torque M causes the sealing ring 12 and the valve seat 2 to produce a cam effect, which causes the sealing ring 12 and the valve seat 2 to form a torque sealing pressure ratio.

[0036] Secondly, when the positive pressure is Figure 5 , the medium pressure acts positively on the entire butterfly plate to form a pressure F2. Due to the gap between the axial hole of the valve body 1 and the valve shaft 9, the deformation of the valve shaft 9 and the accumulated tolerance gap, the positive pressure F2 pushes the butterfly plate 16 to move toward the valve seat 2. This activity forms a trend for the sealing ring 12 to approach the valve seat 2. Due to the radial eccentricity of the eccentric 2, the valve shaft 9 is not at the center of the butterfly plate 16. The center line of the valve shaft 9 is used as the boundary. At this time, the butterfly plate 16 forms two large and small force areas, and an eccentric unbalanced torque M0 is formed on the butterfly plate 16. The eccentric unbalanced torque M0 pushes the butterfly plate 16 and the sealing ring 12 to rotate clockwise to close, so that the sealing ring 12 forms a trend to be close to the valve seat 2.

[0037] As mentioned above, under the combined force and combined torque positive pressure of the positive pressure F2, torque M, and eccentric unbalanced moment M0, the effect of enhancing the zero leakage sealing performance is achieved, and the greater the positive pressure, the better the sealing performance is relatively.

[0038] 2. Reverse pressure principle Figure 6 As shown: First, when the butterfly plate 16 is in the closed position, the torque M of the valve shaft 9 passes through the butterfly plate 16 and the sealing ring 12, and forms a cam effect with the valve seat 2. The sealing ring 12 and the valve seat 2 form a torque seal pressure ratio. When the reverse pressure is applied, Figure 6 The medium pressure acts in the reverse direction on the entire butterfly plate 16. Due to the gap between the axial hole of the valve body 1 and the valve shaft 9, the deformation of the valve shaft 9 and the accumulated tolerance gap, the reverse pressure F2' pushes the butterfly plate 16 toward the valve shaft 9. This activity forms a tendency for the sealing ring 12 to separate from the valve seat 2.

[0039] Third, due to the radial eccentricity of the eccentric 2, the valve shaft 9 is not at the center of the butterfly plate 16. With the center line of the valve shaft 9 as the boundary, the butterfly plate 16 forms two force areas of large and small. When the butterfly plate 16 is pressed in the reverse direction, an eccentric unbalanced torque M0' is formed. The eccentric unbalanced torque M0' pushes the butterfly plate 16 and the sealing ring 12 to rotate counterclockwise, so that the sealing ring 12 tends to separate from the valve seat 2.

[0040] Referring to the above principle, the existing conventional five-eccentric butterfly valve has a tendency for the sealing ring 12 to separate from the valve seat 2 when reverse pressure is applied. The greater the pressure, the worse the sealing performance.

[0041] The embodiment of the present invention adopts a valve seat 2 with bellows telescopic function, which effectively compensates for the tendency of the sealing ring 12 to separate from the valve seat 2 under reverse pressure. The principle is as follows: the valve seat 2, the bellows 3 and the limit ring 5 are welded together to form a movable sealing seat assembly, and the sealing seat assembly is fixed on the step surface of the inner wall of the valve by a three-open clamp ring 6 and a limit bolt 7, so that when reverse pressure occurs, the pressure area of ​​the sealing seat assembly is affected by the pressure medium. Figure 6 The annular surface of section B is shown. The reverse pressure medium forms a thrust F1' on this annular surface. This thrust F1' pushes the valve seat 2 to move toward the sealing ring 12. At the same time, based on the axial direction of the valve seat 2 Figure 6 The left side of the valve seat 2 moves, and the bellows 3 stretches. The extension of the bellows 3 also avoids the gap between the valve seat 2 and the limit ring 5. The axial movement of the valve seat 2 makes up for the gap of the sealing ring 12 retreating toward the direction of the valve shaft 9, so that the valve seat 2 and the sealing ring 12 maintain a better sealing pressure ratio.

[0042] The bellows 3 and the movable and retractable valve seat 2 provided in the present invention can fully meet the bidirectional isobaric sealing performance of the five-eccentric all-metal hard-sealed butterfly valve in ultra-low temperature working conditions such as LNG.

[0043] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A five-eccentric ultra-low temperature bidirectional pressure butterfly valve, comprising a valve body (1), a valve shaft (9) and a butterfly plate (16), characterized in that: A sealing seat assembly is arranged in the valve body (1), and the sealing seat assembly comprises a valve seat (2), a bellows (3) and a limit ring (5), the two ends of the bellows (3) are respectively fixed on the valve seat (2) and the limit ring (5), the limit ring (5) is fixed relative to the valve body (1), the valve seat (2) is located in a movable groove formed by the limit ring (5) and the valve body (1), and the axial dimension of the valve seat (2) is smaller than the dimension setting of the movable groove, the butterfly plate (16) is sleeved with a sealing ring (12), the inner diameter of the sealing ring (12) is smaller than the outer diameter setting of the butterfly plate (16) for the sealing ring (12) installation position, and the outer edge of the sealing ring (12) is arranged in a special-shaped spherical arc surface to abut against the sealing surface of the valve seat (2) to seal the valve.

2. A five-eccentric ultra-low temperature bidirectional pressure butterfly valve according to claim 1, characterized in that: A three-way clamping ring (6) and a limiting bolt (7) are also provided in the valve body (1). The three-way clamping ring (6) is clamped in a clamping ring groove (18) on the inner wall of the valve body (1). The limiting bolt (7) passes through the three-way clamping ring (6) and presses against the end of the limiting ring (5), so that the other end of the limiting ring (5) is tightly fixed to the step surface (17) of the inner wall of the valve.

3. The five-eccentric ultra-low temperature bidirectional pressure butterfly valve according to claim 1 is characterized in that: The two ends of the bellows (3) are sealed and fixed to the limit ring (5) and the end of the valve seat (2) by welding, and the bellows (3) is used to extend or contract when the valve seat (2) moves relative to the limit ring (5).

4. The five-eccentric ultra-low temperature bidirectional pressure butterfly valve according to claim 1 is characterized in that: The butterfly plate (16) is also provided with a pressing ring (13) and a screw (15) for axially limiting and fixing the sealing ring (12) relative to the butterfly plate (16).

5. The five-eccentric ultra-low temperature bidirectional pressure butterfly valve according to claim 4 is characterized in that: The valve body (1) is also provided with a sealing gasket (11), a valve seat gasket (4) and an anti-loosening gasket (14), respectively. The sealing gasket (11) is used for sealing abutment between the sealing ring (12) and the butterfly plate (16), the valve seat gasket (4) is used for sealing between the limit ring (5) and the valve body (1), and the anti-loosening gasket (14) is used for fixing the screw (15).

6. The five-eccentric ultra-low temperature bidirectional pressure butterfly valve according to claim 1 is characterized in that: The valve shaft (9) and the butterfly plate (16) are connected by an axial flat key. A shaft sleeve (8) and a positioning sleeve (10) are also sleeved on the valve shaft (9). The shaft sleeve (8) is used to replace the direct wear of the valve body (1) and the valve shaft (9). Two positioning sleeves (10) x are provided, which are sleeved on the upper and lower ends of the valve shaft (9) relative to the butterfly plate (16) respectively. The positioning sleeve (10) is axially movable relative to the valve shaft (9).

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