Energy-saving six-eccentric metal seal butterfly valve

Abstract

The utility model provides an energy-saving type six-eccentric metal seal butterfly valve, including valve body, valve rod, valve seat and butterfly plate, the valve body forms the valve body flow channel, and the valve seat and butterfly plate are arranged in the valve body flow channel, one end of valve rod is connected with butterfly plate and is inserted into the valve body flow channel, six-eccentric seal structure and valve seat seal structure are arranged on the valve body, six-eccentric seal structure includes eccentricity structure and eccentric angle structure, eccentricity structure includes first eccentricity E1 and second eccentricity E2, and eccentric angle structure includes first eccentric angle beta, first eccentricity E1 is formed between valve rod and the valve body flow channel, second eccentricity E2 is formed between valve rod and the valve body, and the first eccentric angle beta is formed between valve seat and the valve body, the utility model not only retains the advantages of the current conventional three-eccentric butterfly valve, such as reliable sealing performance, long service life, no friction in opening and closing sealing, but also requires the energy-saving type six-eccentric butterfly valve to be short in opening and closing stroke, less in switch time, small in pressure loss, lower in energy loss and better in economic performance.

Description

Technical Field

[0001] This invention relates to the field of butterfly valve technology, specifically to an energy-saving six-eccentric metal-sealed butterfly valve. Background Technology

[0002] A butterfly valve is a type of valve that uses a disc-shaped opening and closing element to rotate approximately 90° to open, close, or regulate the flow of media. Butterfly valves are not only simple in structure, small in size, lightweight, economical in material consumption, small in installation dimensions, low in driving torque, and easy and quick to operate, but they also simultaneously possess excellent flow regulation and sealing characteristics, making them one of the fastest-growing valve types in the past decade. The use of butterfly valves is very widespread, and the variety and quantity used continue to expand, with trends towards high temperature, high pressure, large diameter, high sealing performance, long service life, excellent regulation characteristics, and multi-functionality. Their reliability and other performance indicators have reached a high level.

[0003] The superior performance of butterfly valves is closely related to their continuous eccentricity, evolution, and development. To meet the requirements of various working conditions, butterfly valves have successively evolved from concentric to single eccentric, double eccentric, triple eccentric, quadruple eccentric, and other multi-eccentric types.

[0004] Multi-eccentric butterfly valves, representing the pinnacle of valve technology, combine the strengths of various valve types while mitigating their weaknesses. They boast a maximum pressure rating of 2500 psi, temperature resistance ranging from -196℃ to 700℃, zero leakage, and a control ratio exceeding 100:1. Standard diameters are available up to DN6000, and various structural lengths and configurations are compatible, including wafer, lug, flange, ring, butt weld, jacket, and more. Furthermore, the wide range of material choices allows for smooth operation in high and low temperatures, as well as various corrosive media such as acids and alkalis. Particularly in large-diameter applications, their zero-leakage advantage is leading to their increasing replacement of bulky gate valves and ball valves in shut-off applications. Similarly, butterfly valves, with their superior control performance, are increasingly replacing cumbersome gate valves as control valves.

[0005] However, conventional butterfly valves are opened and closed by rotating the valve stem 90°. Therefore, the opening and closing strokes of a conventional butterfly valve are both one-quarter of a circumference, or 90°. For large-diameter butterfly valves, opening and closing requires a large torque. In order to easily open the butterfly valve at the handwheel input torque end, the speed ratio of its matching worm gear device will be very large, and the number of rotations of the handwheel or electric actuator will be large. This results in a long opening and closing time, sometimes taking about half an hour or even longer to open or close a single butterfly valve, which is very time-consuming and laborious.

[0006] Furthermore, in conventional butterfly valves, the valve seat diameter is smaller than the inner diameter of the flow channels at both ends of the valve body. When the butterfly plate is open, the thickness of the butterfly plate and the diameter of the valve shaft occupy about 1 / 3 of the flow channel area, leaving only 2 / 3 or even less of the actual flow area of ​​the medium passing through the valve seat. This reduction in flow channel area inevitably leads to a larger pressure loss in the butterfly valve, greater energy consumption in the entire pipeline, and increased operating costs, making it highly uneconomical.

[0007] Given the time-consuming and labor-intensive opening and closing process and the huge cost during use, there is a special need to design an energy-saving butterfly valve with a short opening and closing stroke, short switching time, low pressure loss, low energy consumption, and good economic efficiency. Summary of the Invention

[0008] In view of this, the purpose of this invention is to overcome the defects of existing conventional butterfly valves and provide an energy-saving six-eccentric butterfly valve that retains the advantages of conventional triple-eccentric butterfly valves, such as reliable sealing performance, long service life, and frictionless opening and closing sealing, while also requiring shorter opening and closing strokes, less switching time, less pressure loss, lower energy consumption, and better economic performance.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] An energy-saving six-eccentric metal-sealed butterfly valve includes a valve body, a valve stem, a valve seat, and a butterfly plate. A valve body flow channel is formed within the valve body. The valve seat and butterfly plate are disposed within the valve body flow channel. One end of the valve stem extends into the valve body flow channel and connects to the butterfly plate. A six-eccentric sealing structure and a valve seat sealing structure are provided on the valve body. The six-eccentric sealing structure includes an eccentricity structure and an eccentricity angle structure. The eccentricity structure includes a first eccentricity E1 and a second eccentricity E2. The eccentricity angle structure includes a first eccentricity angle β. The first eccentricity E1 is formed between the valve stem and the valve body flow channel, the second eccentricity E2 is formed between the valve stem and the valve body, and the first eccentricity angle β is formed between the valve seat and the valve body.

[0011] Preferably, the vertical distance between the centerline of the valve stem and the horizontal centerline of the valve body flow channel forms a first eccentricity E1, and the vertical distance between the centerline of the valve stem and the symmetrical centerline of the valve body structure length forms a second eccentricity E2.

[0012] Preferably, the valve seat sealing structure is a sealing ring disposed on a butterfly plate, the butterfly plate has a butterfly plate sealing surface, a sealing ring groove is formed on the butterfly plate sealing surface, the sealing ring is disposed in the sealing ring groove, and the angle between the radial plane of the valve seat and the center plane of the valve body structure length forms a first eccentric angle β.

[0013] Preferably, the eccentric angle structure further includes a second eccentric angle α, the angle between the center line of the inclined elliptical cone of the butterfly plate sealing surface and the center line of the butterfly plate forming the second eccentric angle α.

[0014] Preferably, the valve body has a split structure, comprising a left valve body and a right valve body, with a valve seat mounting groove formed between the left and right valve bodies. The valve seat mounting groove is inclined, and the valve seat is disposed within the valve seat mounting groove, with the valve seat corresponding to the valve seat mounting groove having an inclined structure.

[0015] Preferably, the left valve body is provided with a left end flange and a first middle flange, the right valve body is provided with a right end flange and a second middle flange, the valve seat mounting groove is provided between the first middle flange and the second middle flange, the first middle flange and the second middle flange are connected to form a middle flange, the middle flange is inclined, and both ends of the middle flange have an angle β with the corresponding left end flange and right end flange.

[0016] Preferably, the valve body flow channel has a medium inlet and a medium outlet at both ends. The valve body flow channel includes an inlet portion and a middle cavity portion near the medium inlet and an outlet portion near the medium outlet. The inner diameters of the inlet portion and the outlet portion are the same, and the inner diameter of the middle cavity portion is larger than the inner diameters of the inlet portion and the outlet portion.

[0017] Preferably, the eccentricity structure further includes a third eccentricity E3 and a fourth eccentricity E4. The third eccentricity E3 is formed by the perpendicular distance between the centerline of the valve stem and the plane of the sealing ring, and the fourth eccentricity E4 is formed by the distance between the centerline of the valve stem and the outer circle centerline of the butterfly plate.

[0018] Preferably, the first eccentricity E1 = 1 / 10 to 1 / 8 × DN mm, and the second eccentricity E2 = 1 / 10 to 1 / 8 × DN mm.

[0019] Preferably, the first eccentric angle β = 45° to 55° and the second eccentric angle α = 8° to 12°.

[0020] The beneficial effects of this invention are as follows: This invention forms a six-eccentric all-metal hard-on-hard sealing structure for the entire sealing system. The six eccentricities are the distances from the first eccentricity E1, the second eccentricity E2, the third eccentricity E3, the fourth eccentricity E4, the second eccentricity angle α, and the first eccentricity angle β. The third eccentricity E3 ensures that the valve stem does not penetrate the sealing ring, making the sealing ring a continuous and complete sealing ring. The fourth eccentricity E4 causes the valve stem center to deviate from the butterfly plate center, forming a cam effect, ensuring that there is no interference or friction between the sealing ring and the valve seat during the opening and closing of the butterfly plate. The first eccentricity E1 causes the valve stem to be offset to one side of the valve body flow channel center. When fully open, the butterfly plate is basically located at the center of the valve body flow channel, ensuring that the fluid in the upper and lower layers is uniform and stable without turbulence when the medium passes through the butterfly plate, minimizing pressure drop and energy loss. The second eccentricity E2 positions the valve stem off-center to one side of the valve body's structural length symmetry center. When the butterfly plate is fully open, it is positioned within the expanded central cavity of the valve body, ensuring maximum flow area and minimal pressure and energy loss. This eccentricity also minimizes the overall valve body length and maintains symmetry, saving installation space and cost. The second eccentricity angle α forms a perfectly fitted, obliquely shaped conical surface between the valve seat and the sealing ring. Due to the cam effect, the sealing ring does not interfere with or rub against the valve seat during the butterfly plate's opening and closing motion around the valve stem. The sealing ring and valve seat are in contact when closed and separate when open; the higher the pressure, the tighter the seal. The first eccentricity angle β, by obliquely positioning the valve seat and sealing ring at angle β, changes the butterfly valve's opening angle to 90°-β, typically reducing the opening and closing angle to 45°–55°. The stroke is at least half that of a conventional butterfly valve, and the opening and closing time is reduced by at least half, ensuring the butterfly valve is time-saving, labor-saving, and energy-efficient, exhibiting excellent economic performance. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Appendix Figure 1 This is a schematic diagram of the structure of the present invention;

[0023] Appendix Figure 2 For the appendix Figure 1 A cross-sectional view of the structure with AA fully open;

[0024] Appendix Figure 3 For the appendix Figure 1 A cross-sectional view of the structure with AA fully closed.

[0025] Figure label:

[0026] 1. Valve body, 2. Valve stem, 3. Valve seat, 4. Butterfly plate, 5. Valve body flow channel, 6. Sealing ring, 7. Butterfly plate sealing surface, 8. Sealing ring groove, 9. Pressure ring, 10. Screw, 11. Actuator, 12. Left valve body, 13. Right valve body, 14. Valve seat mounting groove, 15. Middle flange, 16. Left end flange, 17. First middle flange, 18. Right end flange, 19. Second middle flange, 20. Medium inlet, 21. Medium outlet, 22. Inlet section, 23. Middle cavity section, 24. Outlet section, E1. First eccentricity, E2. Second eccentricity, E3. Third eccentricity, E4. Fourth eccentricity, α. Second eccentricity angle, β. First eccentricity angle. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The present invention will now be further described with reference to the accompanying drawings.

[0029] This invention provides the following technical solution:

[0030] As attached Figures 1-3 As shown, this invention discloses an energy-saving six-eccentric metal-sealed butterfly valve, comprising a valve body 1, a valve stem 2, a valve seat 3, and a butterfly plate 4. A valve body flow channel 5 is formed within the valve body 1. The valve seat 3 and the butterfly plate 4 are disposed within the valve body flow channel 5. One end of the valve stem 2 extends into the valve body flow channel 5 and connects to the butterfly plate 4. A six-eccentric sealing structure and a valve seat sealing structure are provided on the valve body 1. The six-eccentric sealing structure includes an eccentricity structure and an eccentricity angle structure. The eccentricity structure includes a first eccentricity E1, a second eccentricity E2, a third eccentricity E3, and a fourth eccentricity E4. The eccentricity angle structure includes a first eccentricity angle β and a second eccentricity angle α. Specifically, this design, by setting a six-eccentric sealing structure, ensures that the butterfly valve, with its reliable sealing performance, long service life, and frictionless opening and closing, maintains the advantages of conventional eccentric butterfly valves by setting the third eccentricity E3, the fourth eccentricity E4, and the second eccentricity angle α. At the same time, by increasing the first eccentricity E1, the second eccentricity E2, and the first eccentricity angle β, the butterfly valve becomes an energy-saving six-eccentric butterfly valve with shorter opening and closing strokes, less switching time, less pressure loss, lower energy consumption, and better economic performance.

[0031] The vertical distance between the centerline of the valve stem 2 and the horizontal centerline of the valve body flow channel 5 forms a first eccentricity E1, which is 1 / 10 to 1 / 8 × DN mm. The vertical distance between the centerline of the valve stem 2 and the symmetrical centerline of the structural length of the valve body 1 forms a second eccentricity E2, which is 1 / 10 to 1 / 8 × DN mm. Specifically, the first eccentricity E1 positions the valve stem 2 off-center to one side of the valve body flow channel 5. When the butterfly plate 4 is fully open, it is essentially at the center of the valve body flow channel 5, ensuring that the fluid flow between the upper and lower layers is uniform and stable without turbulence when the medium passes through the butterfly plate 4, minimizing pressure drop and energy loss. The second eccentricity E2 positions the valve stem 2 off-center to one side of the symmetrical center of the valve body 1's structural length. When the butterfly plate 4 is fully open, it is located in the enlarged central cavity 23 of the right valve body 13. Excluding the flow channel area occupied by the butterfly plate 4 and valve stem 2, the actual flow channel area through which the medium passes is greater than or equal to the area of ​​the two ports (inlet 22 and outlet 24), ensuring minimal pressure loss and energy loss when fully open, significantly saving energy consumption in the pipeline system. This axial eccentricity ensures the overall valve body 1 structure is symmetrical and has the shortest length, saving installation space and cost.

[0032] The valve seat sealing structure is a sealing ring 6 mounted on the butterfly plate 4. The butterfly plate 4 has a butterfly plate sealing surface 7, on which a sealing ring groove 8 is formed. The sealing ring 6 is disposed within the sealing ring groove 8. The angle between the radial plane of the valve seat 3 and the center plane of the valve body 1 forms a first eccentric angle β, which is 45° to 55°. The angle between the center line of the oblique elliptical cone of the butterfly plate sealing surface 7 and the center line of the butterfly plate 4 forms a second eccentric angle α, which is 8° to 12°. Specifically, after the first eccentric angle β is adjusted to the angle corresponding to the conventional vertical oblique placement of the valve seat 3 (i.e., the second eccentric angle β), the opening angle of the butterfly plate 4 becomes 90° - β. The opening and closing angle is 45° to 55°, the stroke is only about half of the conventional stroke, the switching time is halved, the medium is quickly shut off, and the safety of the pipeline system is ensured. It saves time, effort, and energy, exhibiting excellent economic performance. The second eccentric angle α causes the sealing surfaces of the valve seat 3 and the sealing ring 6 to form obliquely tangent elliptical conical surfaces. During the opening and closing motion of the sealing ring 6 as the butterfly plate 4 rotates around the valve stem 2, there is no interference or friction throughout the entire switching process. The sealing ring 6 and the valve seat 3 are in close contact when closed and separate when open. There is no friction or wear between the sealing pairs, ensuring the reliability and long service life of the seal.

[0033] In this design, the sealing ring 6 is fixed to the butterfly plate 4 by the pressure ring 9 and screws 10. The valve stem 2 passes through the shaft hole on the butterfly plate 4 and the right valve body 13. The valve stem 2 and the butterfly plate 4 are fixedly connected by a flat key. The valve stem 2 is sealed and positioned at one end of the valve body 1 by a shaft end cap, and the other end passes through the valve body 1 and is connected to the actuator 11 on the bracket. Under the driving action of the actuator 11, the valve stem 2 rotates in the shaft hole of the valve body 1. At the same time, the valve stem 2 drives the butterfly plate 4 and the sealing ring 6 to rotate as a whole through the flat key connection, thereby realizing the opening and closing process. The sealing radial plane of the sealing pair of the butterfly plate 4 and the sealing ring 6 is parallel to the radial plane of the valve seat 3. Therefore, when the butterfly plate 4 and the sealing ring 6 are closed, they are also in an oblique state, forming an angle β with the vertical plane of the center of the valve body 1. Its opening and closing stroke is only 90°-β°, that is, 45°~55°.

[0034] The valve body 1 is a split structure, comprising a left valve body 12 and a right valve body 13. A valve seat mounting groove 14 is formed between the left valve body 12 and the right valve body 13. The valve seat mounting groove 14 is inclined, and the valve seat 3 is disposed within the valve seat mounting groove 14, with the valve seat 3 corresponding to the valve seat mounting groove 14 in an inclined structure. The valve body 1 is a two-piece split structure, composed of the left valve body 12 and the right valve body 13. Specifically, the left valve body 12 and the right valve body 13 are connected as a whole valve body 1 by a middle flange 15 and bolts. The middle flange 15 is inclined, forming an angle β with the corresponding left end flange 16 and right end flange 18. Therefore, the opening and closing angle stroke of the butterfly plate 4 will be reduced by the angle β, shortening the opening and closing time. The two valve bodies 1 are positioned and sealed by the valve seat 3 and a sealing gasket, forming a statically sealed whole.

[0035] The left valve body 12 is provided with a left end flange 16 and a first middle flange 17, and the right valve body 13 is provided with a right end flange 18 and a second middle flange 19. The valve seat mounting groove 14 is located between the first middle flange 17 and the second middle flange 19. The first middle flange 17 and the second middle flange 19 are connected to form a middle flange 15. The middle flange 15 is inclined, and both ends of the middle flange 15 have an angle β with the corresponding left end flange 16 and right end flange 18. Specifically, the valve seat 3 is clamped and fixed in the valve seat mounting groove 14 of the inclined middle flange 15 between the left valve body 12 and the right valve body 13. The two side planes of the valve seat 3 form a static seal with the valve body 1 through gaskets. The inclined first middle flange 17 and the second middle flange 19 are fixedly connected by bolts. The sealing ring 6 is clamped and fixedly connected to the butterfly plate 4 by a pressure ring 9 and screws 10. When closed, the radial planes of the sealing ring 6, butterfly plate 4, and valve seat 3 remain parallel and aligned, i.e., they are inclined at an angle β to the vertical plane perpendicular to the center of the valve body 1. The opening and closing stroke of the butterfly plate 4 is 90°-β. Both the sealing ring 6 and valve seat 3 are movable connections, ensuring on-site replacement, easy maintenance, and low operating costs. The inclined valve seat 3 design allows for an opening and closing angle of 45°–55°, with the minimum stroke being only half that of a standard butterfly valve. This results in short opening and closing times and significant energy savings.

[0036] The valve body flow channel 5 has a medium inlet 20 and a medium outlet 21 at both ends. The valve body flow channel 5 includes an inlet portion 22 and a central cavity portion 23 near the medium inlet 20, and an outlet portion 24 near the medium outlet 21. The inner diameters of the inlet portion 22 and the outlet portion 24 are the same, while the inner diameter of the central cavity portion 23 is larger than that of the inlet portion 22 and the outlet portion 24. Specifically, the internal volume of the central cavity portion 23 of the valve body flow channel 5 is larger than that of the inlet portion 22 and the outlet portion 24 at both ends. The volume of the enlarged central cavity portion 23 is greater than 40% of the volume of the inlet portion 22 and the outlet portion 24. When the butterfly plate 4 is opened, the flow cross-sectional area through the valve seat 3 is equal to or greater than the cross-sectional area of ​​the valve inlet and outlet portions 24. The medium passes through the butterfly plate 4 with almost no pressure drop, minimizing head loss and achieving the lowest energy consumption.

[0037] The perpendicular distance between the centerline of the valve stem 2 and the plane of the sealing ring 6 forms a third eccentricity E3, which is equal to 1 / 2 × valve stem shaft diameter + 20 mm. The distance between the centerline of the valve stem 2 and the outer circle centerline of the butterfly plate 4 forms a fourth eccentricity E4, which is 2–12 mm. Specifically, the third eccentricity E3 ensures that the valve stem 2 does not pass through the sealing ring 6, making the sealing ring 6 a continuous and complete sealing ring. The fourth eccentricity E4 causes the center of the valve stem 2 to deviate from the center of the butterfly plate 4, creating a cam effect and ensuring that there is no interference or friction between the sealing ring 6 and the valve seat 3 during the opening and closing of the butterfly plate 4.

[0038] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An energy-saving six-eccentric metal-sealed butterfly valve, characterized in that: The valve includes a valve body, a valve stem, a valve seat, and a butterfly plate. A valve body flow channel is formed within the valve body. The valve seat and butterfly plate are disposed within the valve body flow channel. One end of the valve stem extends into the valve body flow channel and connects to the butterfly plate. A six-eccentric sealing structure and a valve seat sealing structure are provided on the valve body. The six-eccentric sealing structure includes an eccentricity structure and an eccentricity angle structure. The eccentricity structure includes a first eccentricity E1 and a second eccentricity E2. The eccentricity angle structure includes a first eccentricity angle β. The first eccentricity E1 is formed between the valve stem and the valve body flow channel. The second eccentricity E2 is formed between the valve stem and the valve body. The valve seat and the valve body form a first eccentricity angle β. The eccentricity angle structure also includes a second eccentricity angle α. The angle between the center line of the inclined elliptical cone of the butterfly plate sealing surface and the center line of the butterfly plate forms the second eccentricity angle α. The eccentricity structure also includes a third eccentricity E3 and a fourth eccentricity E4. The perpendicular distance between the center line of the valve stem and the plane of the sealing ring forms the third eccentricity E3. The distance between the center line of the valve stem and the outer circle center line of the butterfly plate forms the fourth eccentricity E4.

2. The energy-saving six-eccentric metal-sealed butterfly valve according to claim 1, characterized in that: The vertical distance between the centerline of the valve stem and the horizontal centerline of the valve body flow channel forms the first eccentricity E1, and the vertical distance between the centerline of the valve stem and the symmetrical centerline of the valve body structure length forms the second eccentricity E2.

3. The energy-saving six-eccentric metal-sealed butterfly valve according to claim 1, characterized in that: The valve seat sealing structure is a sealing ring set on a butterfly plate. The butterfly plate has a butterfly plate sealing surface, and a sealing ring groove is opened on the butterfly plate sealing surface. The sealing ring is set in the sealing ring groove. The angle between the radial plane of the valve seat and the center plane of the valve body structure length forms a first eccentric angle β.

4. The energy-saving six-eccentric metal-sealed butterfly valve according to claim 1, characterized in that: The valve body has a split structure, comprising a left valve body and a right valve body, with a valve seat mounting groove formed between the left and right valve bodies. The valve seat mounting groove is inclined, and the valve seat is disposed within the valve seat mounting groove, with the valve seat corresponding to the valve seat mounting groove having an inclined structure.

5. The energy-saving six-eccentric metal-sealed butterfly valve according to claim 4, characterized in that: The left valve body is provided with a left end flange and a first middle flange, and the right valve body is provided with a right end flange and a second middle flange. The valve seat mounting groove is provided between the first middle flange and the second middle flange. The first middle flange and the second middle flange are connected to form a middle flange. The middle flange is inclined, and both ends of the middle flange have an angle β with the corresponding left end flange and right end flange.

6. The energy-saving six-eccentric metal-sealed butterfly valve according to claim 1, characterized in that: The valve body flow channel has a medium inlet and a medium outlet at both ends. The valve body flow channel includes an inlet section and a middle cavity section near the medium inlet and an outlet section near the medium outlet. The inner diameters of the inlet section and the outlet section are the same, and the inner diameter of the middle cavity section is larger than the inner diameters of the inlet section and the outlet section.

7. The energy-saving six-eccentric metal-sealed butterfly valve according to claim 1, characterized in that: The first eccentricity E1 = 1 / 10 to 1 / 8 × DN mm, and the second eccentricity E2 = 1 / 10 to 1 / 8 × DN mm.

8. The energy-saving six-eccentric metal-sealed butterfly valve according to claim 4, characterized in that: The first eccentric angle β = 45° to 55°, and the second eccentric angle α = 8° to 12°.

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