Eccentric sealing butterfly valve

Abstract

The invention relates to the technical field of valves, and discloses an eccentric sealing butterfly valve which comprises a valve body, a sealing assembly and a valve plate. The metal valve seat capable of sliding in the medium flowing direction in a reciprocating mode is arranged at the inlet end of the valve body, and the arc inclined face is arranged on the metal valve seat, so that after the valve plate is eccentrically installed, the arc face of the valve plate is gradually attached to the arc inclined face of the metal valve seat in the closing process, linear contact sealing is formed, the attaching tightness and consistency of a sealing pair are improved, and the service life of the valve plate is prolonged. The sealing performance is obviously enhanced; according to the structural design that the sealing assembly slides in the flowing direction, the arc face and the arc inclined face are attached all the time in the sealing state, the leakage situation caused by abrasion of the metal valve seat or the valve plate is avoided, the local stress concentration phenomenon is effectively reduced through cooperation of the arc face and the arc inclined face, and the service life of the valve is prolonged. Meanwhile, due to the eccentric structure, frequent scouring and hard collision of the sealing face are avoided, abrasion of the sealing contact face is relieved, and the service life of the valve is prolonged.

Description

Technical Field

[0001] This invention relates to the field of valve technology, specifically to an eccentric sealing butterfly valve. Background Technology

[0002] Butterfly valves, as valve devices with simple structure, rapid opening and closing, and low fluid resistance, are widely used in fluid transportation systems. Among them, double eccentric butterfly valves are widely used in industries such as petroleum, chemical, water treatment, and power generation due to their advantages such as low opening and closing torque, flexible operation, and good sealing performance. In existing technology, double eccentric butterfly valves typically employ a soft-seal structure, where the valve disc is made of metal, while the valve seat is made of non-metallic material. This type of soft-seal structure ensures a certain sealing performance while having lower manufacturing costs and a relatively simple processing technology.

[0003] However, soft-seal structures are susceptible to damage under conditions involving particulate or unclean media. When valves are frequently opened and closed, or when the media contains hard particles, non-metallic valve seats are easily scratched or pulled, damaging the sealing surface and causing media leakage, thus reducing the valve's sealing reliability and service life. Furthermore, to improve sealing performance, some existing technologies attempt to use built-in metal valve seat structures, but these often suffer from poor design leading to disruption of the waterline, affecting the valve's normal operation, or are difficult to widely adopt due to complex structures and high manufacturing costs. Summary of the Invention

[0004] This invention provides an eccentric sealing butterfly valve to solve the problem that existing butterfly valves cannot achieve both reliable sealing and stable water flow.

[0005] This invention provides an eccentric sealing butterfly valve, comprising: a valve body, a sealing assembly, and a valve plate; the valve body has a flow channel for media flow, and a valve shaft is provided within the valve body; the sealing assembly is disposed within the flow channel at the inlet end of the valve body, the sealing assembly includes a metal valve seat adapted to reciprocate along the media flow direction, and the metal valve seat has an arcuate inclined surface; the valve plate is disposed within the valve body, the end of the valve plate near the sealing assembly is provided with an arcuate surface, the valve plate is eccentrically mounted via the valve shaft, and the valve shaft drives the valve plate to rotate, so that the valve plate and the sealing assembly have a sealing state in which the arcuate surface and the arcuate inclined surface cooperate and a conducting state in which the arcuate surface and the arcuate inclined surface are disengaged.

[0006] Beneficial effects: This invention provides an eccentric sealing butterfly valve. By incorporating a metal valve seat that slides reciprocally along the flow direction of the medium at the valve body inlet, and by adding an arc-shaped bevel to the metal valve seat, the arc surface of the valve plate gradually conforms to the arc-shaped bevel of the metal valve seat during the closing process after eccentric installation, thus forming a line contact seal. This improves the tightness and consistency of the sealing pair, significantly enhancing sealing performance. The sliding design of the sealing assembly along the flow direction ensures that the arc surface and the arc-shaped bevel remain in contact during the sealing state, preventing leakage due to wear of the metal valve seat or valve plate. Furthermore, the cooperation between the arc surface and the arc-shaped bevel effectively reduces local stress concentration. Simultaneously, the eccentric structure avoids frequent scouring and hard impacts on the sealing surface, thereby slowing down wear on the sealing contact surface and extending the valve's service life. This invention, through optimized design of the metal valve seat structure and the eccentric arrangement of the valve plate, balances sealing reliability and waterline stability, overcoming the technical shortcomings of traditional butterfly valves that struggle to achieve both simultaneously, and possesses significant practical value and promotional significance.

[0007] In some embodiments of the present invention, the sealing assembly further includes a limiting member and an elastic member. The limiting member is disposed on the side near the valve plate. The valve body is provided with a first mounting groove. The limiting member is disposed in the first mounting groove and extends partially into the flow channel. The limiting member can abut against the first end face of the metal valve seat to limit the sliding displacement of the metal valve seat. One end of the elastic element is connected to the valve body, and the other end is connected to the second end of the metal valve seat. The elastic element is adapted to drive the metal valve seat to slide back and forth along the direction of medium flow.

[0008] In some embodiments of the present invention, the limiting member has a circular structure, and the portion of the limiting member extending into the flow channel is provided with a plurality of clearance holes.

[0009] In some embodiments of the present invention, the second end of the metal valve seat is provided with a receiving cavity, and the elastic element is disposed in the receiving cavity.

[0010] In some embodiments of the present invention, in the sealed state, the arc surface and the arc inclined surface are in close contact with each other, the limiting member and the first end face of the metal valve seat have a first gap, and the elastic member is in a compressed state. In the conducting state, the arc surface and the arc inclined surface are separated from each other, the limiting member abuts against the first end face of the metal valve seat, and the elastic member is in a compressed state or in its original length state.

[0011] In some embodiments of the present invention, the flow channel is provided with a stepped portion near the outlet end, and a guide groove is provided on the side of the stepped portion near the valve plate, and the first end of the metal valve seat is installed in the guide groove.

[0012] In some embodiments of the present invention, in the sealed state, there is a second gap between the second end face of the metal valve seat and the stepped portion; in the conductive state, there is a third gap between the second end face of the metal valve seat and the stepped portion, and the third gap is larger than the second gap.

[0013] In some embodiments of the present invention, the inner ring end face of the metal valve seat is flush with the stepped portion.

[0014] In some embodiments of the present invention, the sealing assembly further includes a sealing element, the metal valve seat is in the form of an annular structure, the valve body is provided with a second mounting groove at a position relative to the metal valve seat, the sealing element is disposed in the second mounting groove, and the outer annular end face of the metal valve seat is sealed to the valve body through the sealing element.

[0015] In some embodiments of the present invention, the sealing element includes a first sealing element and a second sealing element, the first sealing element and the second sealing element being spaced apart along the flow direction of the medium, the first sealing element being a flexible sealing element and the second sealing element being a rigid sealing element. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of an eccentric sealing butterfly valve provided in some embodiments of the present invention; Figure 2 for Figure 1 A magnified view of part A in the diagram.

[0018] Explanation of reference numerals in the attached figures: 1. Valve body; 11. Flow channel; 2. Valve plate; 21. Arc surface; 3. Sealing assembly; 31. Metal valve seat; 32. Limiting element; 33. Elastic element; 34. First sealing element; 35. Second sealing element; 311. Arc slope. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Reference Figure 1 and Figure 2 As shown, Figure 1 The arrows in the diagram indicate the direction of medium flow. This invention provides an eccentric sealing butterfly valve, comprising: a valve body 1, a sealing assembly 3, and a valve plate 2; the valve body 1 has a flow channel 11 for medium flow, and a valve shaft is provided inside the valve body 1; the sealing assembly 3 is disposed in the flow channel 11 at the inlet end of the valve body 1, and the sealing assembly 3 includes a metal valve seat 31, which is adapted to reciprocate along the medium flow direction, and the metal valve seat 31 has an arc-shaped inclined surface 311; the valve plate 2 is disposed inside the valve body 1, and the end of the valve plate 2 near the sealing assembly 3 is provided with an arc-shaped surface 21. The valve plate 2 is eccentrically mounted by the valve shaft, and the valve shaft drives the valve plate 2 to rotate, so that the valve plate 2 and the sealing assembly 3 have a sealing state in which the arc-shaped surface 21 and the arc-shaped inclined surface 311 cooperate and abut against each other, and a conducting state in which the arc-shaped surface 21 and the arc-shaped inclined surface 311 are disengaged from each other.

[0021] Specifically, the eccentric sealing butterfly valve provided by this invention features a metal valve seat 31 that can reciprocate along the flow direction of the medium at the inlet end of the valve body 1. An arc-shaped inclined surface 311 is provided on the metal valve seat 31. After the valve plate 2 is eccentrically installed, its arc-shaped surface 21 gradually contacts the arc-shaped inclined surface 311 of the metal valve seat 31 during the closing process, thus forming a line contact seal. This improves the tightness and consistency of the sealing pair, significantly enhancing the sealing performance. The sliding structure of the sealing assembly 3 along the flow direction ensures that the arc-shaped surface 21 and the arc-shaped inclined surface 311 remain in contact during the sealing state, preventing leakage due to wear of the metal valve seat 31 or the valve plate 2. Furthermore, the cooperation between the arc-shaped surface 21 and the arc-shaped inclined surface 311 effectively reduces local stress concentration. Simultaneously, the eccentric structure avoids frequent scouring and hard impacts on the sealing surface, thereby slowing down the wear of the sealing contact surface and extending the valve's service life. This invention optimizes the structure of the metal valve seat 31 and the eccentric arrangement of the valve plate 2, taking into account both sealing reliability and water line stability. It overcomes the technical defects of traditional butterfly valves, which cannot achieve both simultaneously, and has significant practical value and promotional significance.

[0022] It is understandable that both the valve plate 2 and the metal valve seat 31 are made of corrosion-resistant alloy materials, and the arc surface 21 and the arc inclined surface 311 are welded with wear-resistant coatings.

[0023] In some embodiments of the present invention, the sealing assembly 3 further includes a limiting member 32 and an elastic member 33. The limiting member 32 is disposed on the side near the valve plate 2. The valve body 1 is provided with a first mounting groove. The limiting member 32 is disposed in the first mounting groove and extends partially to the flow channel 11. The limiting member 32 can abut against the first end face of the metal valve seat 31 to limit the sliding displacement of the metal valve seat 31. One end of the elastic element 33 is connected to the valve body 1, and the other end is connected to the second end of the metal valve seat 31. The elastic element 33 is adapted to drive the metal valve seat 31 to slide back and forth along the medium flow direction.

[0024] Specifically, by setting a first mounting groove and installing a limiting member 32 in the valve body 1, the limiting member 32 can abut against the first end face of the metal valve seat 31 during its movement, thereby physically limiting the stroke of the metal valve seat 31. This avoids sealing failure or structural interference caused by excessive valve seat slippage, significantly improving the stability and safety of valve operation. One end of the elastic member 33 is fixedly connected to the valve body 1, and the other end is connected to the metal valve seat 31, forming an elastic drive structure for the metal valve seat 31. This structure can automatically drive the valve seat to slide back and forth during the opening or closing of the valve plate 2, causing the metal valve seat 31 to retract in the sealed state and automatically move forward in the open state, further improving the valve's opening and closing response sensitivity and sealing fit.

[0025] Furthermore, it is understandable that the elastic element 33, while transmitting power, also has a vibration-absorbing and buffering function, which can reduce the impact force on the valve plate 2 during the opening and closing process, reduce the frequency of mechanical impact between the metal valve seat 31 and the limiting element 32, effectively slow down wear, and extend the overall service life of the valve. The synergistic effect of the limiting element 32 and the elastic element 33 enables the metal valve seat 31 to have better motion controllability and self-adaptability during actual operation, adapting to stable operation under different pressure and flow rate conditions, and enhancing the practical performance of the product under complex working conditions.

[0026] In some embodiments of the present invention, the elastic element 33 is a spring.

[0027] In some embodiments of the present invention, the limiting member 32 has a ring-shaped structure, and the portion of the limiting member 32 extending into the flow channel 11 is provided with a plurality of clearance holes.

[0028] Specifically, the limiting component 32 is designed as an integral circular structure, which effectively improves its mechanical stability in the radial and axial directions, avoiding structural deformation or damage due to local stress concentration, thereby ensuring the long-term stable and reliable limiting function of the metal valve seat 31. The clearance hole facilitates the removal of the limiting component 32 from the first mounting groove using tools such as hooks, thus facilitating replacement and improving maintenance efficiency.

[0029] In some embodiments of the present invention, the second end of the metal valve seat 31 is provided with a receiving cavity, and the elastic member 33 is disposed in the receiving cavity.

[0030] Specifically, by providing a receiving cavity within the metal valve seat 31 to house the elastic element 33, the situation where the elastic element 33 is exposed in the flow channel 11 of the valve body 1 is avoided. The overall structure is more compact, effectively saving internal space of the valve body 1, reducing the risk of assembly interference, and facilitating miniaturization and modular design. Placing the elastic element 33 within the receiving cavity avoids direct exposure to high-pressure fluids, impurity particles, or corrosive media, thereby reducing the risk of fatigue damage, corrosion wear, and other failures of the elastic element 33, significantly extending its service life and improving the overall operational reliability of the machine.

[0031] Understandably, the accommodating cavity effectively constrains and guides the elastic element 33, ensuring that its force direction is consistent with the sliding direction during operation. This prevents abnormal deformation such as skewness or twisting of the elastic element 33, thereby improving the response accuracy of the elastic reset action and the sealing fit. Since the elastic element 33 is centrally located within the accommodating cavity inside the metal valve seat 31, the elastic element 33 and the metal valve seat 31 form an integrated structural module. During later maintenance or replacement, the metal valve seat 31 and its built-in elastic element 33 can be completely disassembled and replaced, simplifying maintenance operations and improving operational efficiency.

[0032] In some embodiments of the present invention, under sealed conditions, the arc surface 21 and the arc inclined surface 311 fit and abut against each other, the limiting member 32 and the first end face of the metal valve seat 31 have a first gap, and the elastic member 33 is in a compressed state. In the conducting state, the arc surface 21 and the arc inclined surface 311 are separated from each other, the limiting member 32 abuts against the first end face of the metal valve seat 31, and the elastic member 33 is in a compressed state or in its original length state.

[0033] Specifically, in the sealed state, the arc surface 21 of the valve plate 2 and the arc inclined surface 311 of the metal valve seat 31 are tightly fitted, ensuring a stable surface contact seal. At this time, a first gap is maintained between the limiting member 32 and the first end face of the metal valve seat 31, which facilitates a complete and effective seal. In the open state, the metal valve seat 31 slides to the limiting member 32, achieving physical limitation, thereby effectively preventing excessive sliding of the metal valve seat 31, ensuring sufficient and safe movement space for the valve plate 2, preventing structural damage, and improving the operational reliability of the valve during opening and closing.

[0034] In the sealed state, the elastic element 33 is in a compressed state. In the open state, the elastic element 33 is in a compressed state or its original length state, so that the elastic element 33 always maintains a pre-tightening force or driving force on the metal valve seat 31. This helps the valve seat to slide smoothly back and forth with the cooperation of the valve plate 2, avoids jamming or lag, and improves the smoothness of opening and closing.

[0035] Understandably, the dynamic coordination structure of the limiting component 32, metal valve seat 31, and elastic component 33 is reasonably designed to avoid unexpected interference between components, reduce mechanical impact and wear, effectively extend the service life of key components such as the limiting component 32, metal valve seat 31, and elastic component 33, and improve the long-term operational stability of the entire butterfly valve system.

[0036] In some embodiments of the present invention, the flow channel 11 is provided with a stepped portion near the outlet end, and a guide groove is provided on the side of the stepped portion near the valve plate 2, and the first end of the metal valve seat 31 is installed in the guide groove.

[0037] Specifically, by providing a guide groove on the stepped portion and embedding the first end of the metal valve seat 31 within this groove, effective linear guidance and constraint are provided during the reciprocating sliding of the metal valve seat 31, preventing it from becoming skewed, wobbly, or otherwise unstable, thereby improving the stability of the sealing fit between the valve seat and the valve plate 2. The guide groove, as a partial embedding structure of the metal valve seat 31, effectively limits its installation position in the axial and radial directions. Combined with the reset thrust of the elastic element 33 and the stroke limitation of the limiting element 32, it forms a stable and reliable motion boundary, ensuring the trajectory stability and repeatability of the valve seat during opening and closing. Furthermore, the guide groove provides a smooth sliding support surface for the metal valve seat 31, reducing contact interference with other parts of the valve body 1 during sliding, effectively reducing friction and wear, and helping to extend the service life of the metal valve seat 31 and its mating parts, thus improving the overall durability of the machine.

[0038] The first end of the metal valve seat 31 is embedded in the guide groove, which can play an automatic alignment role during the assembly process, improving assembly efficiency and consistency. At the same time, during the later maintenance process, the metal valve seat 31 can be quickly disassembled and replaced through the guide structure, reducing maintenance complexity.

[0039] In some embodiments of the present invention, in the sealed state, there is a second gap between the second end face of the metal valve seat 31 and the step portion, and in the conducting state, there is a third gap between the second end face of the metal valve seat 31 and the step portion, the third gap being larger than the second gap.

[0040] Specifically, the second gap ensures that the metal valve seat 31 is not prematurely restricted when approaching a sealing state, facilitating a more precise fit between the valve seat and the valve plate 2. The increased third gap ensures that the metal valve seat 31 has sufficient clearance in the conducting state, preventing obstruction of the valve plate 2's movement and improving operational smoothness. Furthermore, the difference between the second and third gaps helps accommodate the influence of manufacturing tolerances, thermal expansion and contraction, or media pressure fluctuations on component positions during actual operation, thereby enhancing the overall valve system's anti-interference capability and dynamic fault tolerance, and strengthening its reliability in complex operating conditions.

[0041] Understandably, by clearly defining the clearance control under different states, a clear judgment standard can be provided for subsequent functions such as displacement detection and status monitoring. For example, the position of the metal valve seat 31 can be identified by a limit switch or sensor, thereby realizing intelligent judgment of the valve's sealing or conducting state and improving the level of automation control.

[0042] In some embodiments of the present invention, the inner ring end face of the metal valve seat 31 is flush with the stepped portion.

[0043] Specifically, by setting the inner ring end face of the metal valve seat 31 flush with the stepped portion of the valve body 1, a clear axial positioning reference can be formed during the assembly process, which helps to quickly achieve precise assembly of the metal valve seat 31, prevents axial misalignment during installation, and improves assembly efficiency and consistency.

[0044] In some embodiments of the present invention, the sealing assembly 3 further includes a sealing element, the metal valve seat 31 is in the form of a ring structure, the valve body 1 is provided with a second mounting groove at a position relative to the metal valve seat 31, the sealing element is disposed in the second mounting groove, and the outer ring end face of the metal valve seat 31 is sealed to the valve body 1 through the sealing element.

[0045] Specifically, if the metal valve seat 31 is in direct contact with the valve body 1, local sealing may be inadequate due to manufacturing tolerances, thermal expansion, or differences in surface roughness. By setting a second mounting groove in the valve body 1 and embedding a sealing element, a reliable static seal is formed between the outer ring end face of the metal valve seat 31 and the valve body 1, which can effectively prevent leakage of the medium in the non-opening and closing parts of the valve, improve the tightness of the overall sealing system, and meet the sealing requirements under harsh conditions such as high pressure or high temperature.

[0046] In some embodiments of the present invention, the sealing element includes a first sealing element 34 and a second sealing element 35, the first sealing element 34 and the second sealing element 35 being spaced apart along the flow direction of the medium, the first sealing element 34 being a flexible sealing element and the second sealing element 35 being a rigid sealing element.

[0047] Specifically, flexible and rigid seals are arranged sequentially along the direction of media flow, forming a graded sealing structure of either flexible in the front and rigid in the back, or rigid in the front and flexible in the back. This addresses different types of sealing requirements, giving the sealing system higher pressure resistance and durability, and effectively improving the overall sealing integrity. The first seal 34 is made of flexible material, possessing good elasticity and adaptability, capable of accommodating minor installation deviations and irregularities on the surface of the metal valve seat 31. It serves as a primary seal and impact buffer, preventing the rigid seal from failing due to excessive direct stress. The second seal 35 is a rigid structure with excellent structural stability and pressure and wear resistance. It provides reliable support and sealing under harsh conditions such as high pressure, high speed, or high frequency opening and closing, extending the service life of the sealing system. Specifically, the first seal 34 is an elastic sealing ring, made of rubber or silicone, while the second seal 35 is a graphite sealing ring, enabling sealing in the event of a fire.

[0048] Understandably, flexible and rigid seals can be replaced separately based on actual usage cycles, making maintenance more targeted and economical, reducing maintenance costs and downtime.

[0049] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An eccentric sealing butterfly valve, characterized in that, The utility model provides a valve body (1), the flow channel (11) is equipped in the valve body (1) for medium flow, the valve shaft is equipped in the valve body (1), the sealing assembly (3) is arranged in the flow channel (11) of the inlet end of valve body (1), the sealing assembly (3) includes metal valve seat (31), metal valve seat (31) is suitable for reciprocating sliding along the medium flow direction, metal valve seat (31) is equipped with circular arc inclined plane (311), the valve plate (2) is equipped in the valve body (1), the end of sealing assembly (3) is close to the circular arc surface (21) of valve plate (2) setting, valve plate (2) is installed eccentrically through valve shaft, valve shaft drives valve plate (2) rotation, so that valve plate (2) and sealing assembly (3) have the sealing state of circular arc surface (21) and circular arc inclined plane (311) mutual cooperation abutment and have the lead-through state of circular arc surface (21) and circular arc inclined plane (311) mutual separation. The sealing assembly (3) further includes a limiting piece (32) and a resilient piece (33), the limiting piece (32) is arranged near one side of the valve plate (2), the valve body (1) is provided with a first mounting groove, the limiting piece (32) is arranged in the first mounting groove and partially extends into the flow channel (11), the limiting piece (32) can abut against a first end surface of the metal valve seat (31) to limit the sliding displacement of the metal valve seat (31); One end of the resilient piece (33) is connected with the valve body (1), and the other end is connected with a second end of the metal valve seat (31), and the resilient piece (33) is suitable for driving the metal valve seat (31) to reciprocate along the medium flow direction. The limiting piece (32) has a circular ring structure, and the part of the limiting piece (32) extending into the flow channel (11) is provided with a plurality of avoiding holes.

2. The eccentric sealing butterfly valve according to claim 1, characterized in that The second end of the metal valve seat (31) is provided with a receiving cavity, and the resilient piece (33) is arranged in the receiving cavity. In the sealing state, the circular arc surface (21) and the circular arc inclined plane (311) are mutually attached and abutted, the limiting piece (32) and the first end surface of the metal valve seat (31) have a first gap therebetween, and the resilient piece (33) is in a compressed state; 3. The eccentric sealing butterfly valve according to claim 2, wherein, In the lead-through state, the circular arc surface (21) and the circular arc inclined plane (311) are mutually separated, the limiting piece (32) abuts against the first end surface of the metal valve seat (31), and the resilient piece (33) is in a compressed state or an original length state.

4. The eccentric sealing butterfly valve according to claim 2, wherein, The flow channel (11) is provided with a stepped portion near the outlet end, the stepped portion is provided with a guide groove near one side of the valve plate (2), and the first end of the metal valve seat (31) is arranged in the guide groove.

5. The eccentric sealing butterfly valve according to any one of claims 2 to 4, characterized in that In the sealing state, the second end surface of the metal valve seat (31) and the stepped portion have a second gap therebetween, in the lead-through state, the second end surface of the metal valve seat (31) and the stepped portion have a third gap therebetween, and the third gap is larger than the second gap. The inner ring end surface of the metal valve seat (31) is flush with the stepped portion.

6. The eccentric sealing butterfly valve according to claim 5, wherein, ​ 7. The eccentric sealing butterfly valve according to claim 6, characterized in that ​ 8. The eccentric sealing butterfly valve according to claim 6, wherein, ​ 9. The eccentric sealing butterfly valve according to claim 2, wherein, The sealing assembly (3) further comprises a sealing member, the metal valve seat (31) is in a ring structure, a second mounting groove is arranged on the valve body (1) relative to the position of the metal valve seat (31), and the sealing member is arranged in the second mounting groove, and the outer ring end face of the metal valve seat (31) is in sealing connection with the valve body (1) through the sealing member.

10. The eccentric sealing butterfly valve according to claim 9, characterized in that The sealing member comprises a first sealing member (34) and a second sealing member (35), the first sealing member (34) and the second sealing member (35) are arranged at intervals along the flow direction of the medium, the first sealing member (34) is a flexible sealing member, and the second sealing member (35) is a rigid sealing member.

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