Seal for double eccentric butterfly valve

Abstract

The utility model provides a kind of sealing of double eccentric butterfly valve, it is characterized by including valve handle, horizontal rotary lever, butterfly valve seat, metal sealing ring, fixed plate, butterfly plate, transmission case, vertical rotary lever, one end of the horizontal rotary lever is fixedly connected with valve handle, one end of the horizontal rotary lever is inserted into transmission case and is rotationally connected with transmission case, transmission structure in the transmission case is connected with the horizontal rotary lever, the horizontal rotary lever is connected with the vertical rotary lever by transmission structure in the transmission case, the vertical rotary lever is inserted into butterfly valve seat and is sealingly rotationally connected with butterfly valve seat, one side of the butterfly valve seat is fixedly connected with fixed plate by bolt, the fixed plate is connected with butterfly valve seat by bolt, so that butterfly valve seat and metal sealing ring are detachably connected, the metal sealing ring is interference fit with butterfly plate. By setting fixed plate, metal sealing ring and the cooperation of butterfly plate, the wear of metal sealing ring in interference fit with butterfly plate is reduced, and the service life of butterfly valve is improved.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, and in particular to a sealing method for a double eccentric butterfly valve. Background Technology

[0002] Double eccentric butterfly valve sealing is a core technology in industrial fluid control, suitable for low-pressure, medium-high temperature, and corrosive media conditions in various industries such as petrochemicals and power energy. Its double eccentric design enables rapid separation of the sealing surface during opening and closing, reducing frictional losses. Currently, flexible seals suffer from limitations in temperature resistance, fluoroplastics and other materials are susceptible to micro-cracks and peeling due to thermo-mechanical-chemical coupling, and have poor creep resistance. Metal hard seals, on the other hand, face problems such as weak reverse pressure sealing, stringent requirements for the accuracy of the closing position, and susceptibility to seal failure due to thermal expansion and contraction under low-temperature conditions. These two sealing methods are suitable for different media scenarios and remain core supporting technologies for critical pipelines in refining plants, power plant flues, and other applications.

[0003] Patent CN217463248U discloses a double eccentric butterfly valve with good sealing performance. It includes a double eccentric butterfly valve body, a valve stem vertically and movably connected inside the valve body, a sealing misalignment disc fixedly mounted on the surface of the valve stem, a convex sealing ring fixedly connected to the surface of the sealing misalignment disc, and a concave sealing ring fixedly connected to the inner wall of the double eccentric butterfly valve body, contacting the surface of the convex sealing ring. Misalignment fixing grooves are provided on both sides of the double eccentric butterfly valve body, and a sealing misalignment ring is fitted onto the surface of the valve stem, contacting the inner wall of the misalignment fixing groove. This invention solves the problem of poor sealing performance in existing double eccentric butterfly valves, where gaps easily form at the movable connection between the valve stem and the valve body, and at the movable connection between the valve disc and the valve body, resulting in reduced sealing performance.

[0004] However, this device has the following drawbacks: The device still cannot avoid the problem of reduced sealing performance caused by wear of the flexible seal due to the switching disc of the double eccentric butterfly valve, which requires operators to replace the flexible sealing ring regularly. This device still cannot avoid the problem of wear caused by friction between the butterfly plate and the inner wall of the valve body when the butterfly plate of the double eccentric butterfly valve is switched, which leads to reduced sealing performance and reduced service life of the butterfly valve. Utility Model Content

[0005] In view of the above technical problems, this utility model provides a sealing method for a double eccentric butterfly valve that is easy to replace and maintain.

[0006] This utility model provides a sealing method for a double eccentric butterfly valve, characterized by comprising a valve handle, a horizontal rotating rod, a butterfly valve seat, a metal sealing ring, a fixing plate, a butterfly plate, a transmission box, and a vertical rotating rod. One end of the horizontal rotating rod is fixedly connected to the valve handle, and the other end extends into the transmission box and is rotatably connected to it. A bevel gear pair is provided inside the transmission box. The input gear of the bevel gear pair inside the transmission box is fixedly connected to the horizontal rotating rod, and the output gear of the bevel gear pair inside the transmission box is fixedly connected to the vertical rotating rod. The vertical rotating rod extends into the butterfly valve seat and is rotatably connected to it with a sealing seal. A fixing plate is fixedly connected to one side of the butterfly valve seat by bolts. The fixing plate, through bolts, engages with the butterfly valve seat to allow for a detachable connection between the butterfly valve seat and the metal sealing ring. The metal sealing ring and the butterfly plate are interference-fitted.

[0007] An elastic sealing ring is provided on the side wall of the butterfly valve seat near the fixed plate. Bolt holes are provided around the butterfly valve seat. The butterfly valve seat is connected to the fixed plate through the bolt holes and bolts. A metal sealing ring is interference-fitted between the fixed plate and the butterfly valve seat.

[0008] The inner ring of the metal sealing ring is provided with a sealing structure, the outer ring of the sealing structure is provided with a sealing groove, and the outer ring of the sealing groove is provided with a mounting plate. The mounting plate is clamped to the butterfly valve seat by a fixing plate and the butterfly valve seat in an interference fit. The sealing groove is clamped to the elastic sealing ring by the fixing plate and the butterfly valve seat in an interference fit.

[0009] The metal sealing ring is formed using a special stamping process.

[0010] The beneficial effects of this utility model are as follows: By setting up a fixed plate, a metal sealing ring, and a butterfly plate, the metal sealing ring is pressed by the fixed plate when the valve is closed, and forms an interference fit with the butterfly plate to achieve an actual sealing effect. This avoids the problem of reduced service life of conventional double eccentric butterfly valves caused by the interference fit between the butterfly plate and the inner wall of the valve body. Because the metal sealing ring has a certain degree of elasticity, it reduces the wear caused by the interference fit between the metal sealing ring and the butterfly plate, thus improving the service life of the butterfly valve. Even if the sealing performance deteriorates, the leakage problem can be quickly solved by replacing the metal sealing ring. By setting an elastic sealing ring between the metal sealing ring and the butterfly valve seat, the butterfly valve possesses both a hard metal seal and a flexible sealing function. Unlike conventional double eccentric butterfly valves where the elastic sealing ring is positioned around the circumference of the butterfly plate, this elastic sealing ring achieves sealing immediately upon installation. It primarily serves as a supplementary sealing method to the hard metal seal and does not move with the butterfly valve's opening and closing. This avoids the problem of excessive wear and failure of the flexible seal caused by valve operation, thus improving the butterfly valve's sealing performance and extending its service life. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the overall sealing structure of a double eccentric butterfly valve according to the present invention; Figure 2 This is a schematic diagram of the sealing structure of a double eccentric butterfly valve according to the present invention. Figure 3 This is a cross-sectional structural diagram of the sealing portion of a double eccentric butterfly valve according to the present invention. Figure 4 This is a schematic cross-sectional view of the sealing butterfly valve seat of a double eccentric butterfly valve according to the present invention. Figure 5 This is a schematic cross-sectional view of the metal sealing ring structure of a double eccentric butterfly valve according to this utility model.

[0012] Reference numerals: 1 - Valve handle; 2 - Horizontal rotating rod; 3 - Butterfly valve seat; 31 - Elastic sealing ring; 32 - Screw hole; 4 - Metal sealing ring; 41 - Sealing structure; 42 - Sealing groove; 43 - Mounting plate; 5 - Fixing plate; 6 - Butterfly plate; 7 - Transmission box; 8 - Vertical rotating rod. Detailed Implementation Example 1

[0013] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings.

[0014] like Figure 1 , 2 As shown in Figure 3, a sealing method for a double eccentric butterfly valve is characterized by comprising: a valve handle 1, a horizontal rotating rod 2, a butterfly valve seat 3, a metal sealing ring 4, a fixing plate 5, a butterfly plate 6, a transmission box 7, and a vertical rotating rod 8. One end of the horizontal rotating rod 2 is fixedly connected to the valve handle 1, and the other end extends into the transmission box 7 and is rotatably connected to it. A bevel gear pair is provided inside the transmission box 7. The input gear of the bevel gear pair inside the transmission box 7 is fixedly connected to the horizontal rotating rod 2, and the output gear of the bevel gear pair inside the transmission box 7 is fixedly connected to the vertical rotating rod 8. The vertical rotating rod 8 extends into the butterfly valve seat 3 and is rotatably connected to it with a sealing seal. A fixing plate 5 is fixedly connected to one side of the butterfly valve seat 3 by bolts. The fixing plate 5 is bolted to the butterfly valve seat 3, allowing the butterfly valve seat 3 to be detachably connected to the metal sealing ring 4. The metal sealing ring 4 is interference-fitted with the butterfly plate 6.

[0015] like Figure 4 As shown, an elastic sealing ring 31 is provided on the side wall of the butterfly valve seat 3 near the fixed plate 5. Bolt holes 32 are arranged around the butterfly valve seat 3. The butterfly valve seat 3 is connected to the fixed plate 5 through the bolt holes 32 and the bolts. A metal sealing ring 4 is interference-fitted between the fixed plate 5 and the butterfly valve seat 3.

[0016] like Figure 3 ,5 As shown, the inner ring of the metal sealing ring 4 is provided with a sealing structure 41, the outer ring of the sealing structure 41 is provided with a sealing groove 42, and the outer ring of the sealing groove 42 is provided with a mounting plate 43. The mounting plate 43 is clamped to the fixing plate 5 and the butterfly valve seat 3 through an interference fit. The sealing groove 42 is clamped to the elastic sealing ring 31 through the fixing plate 5 and the butterfly valve seat 3 through an interference fit. Example 2

[0017] In use, this utility model is as follows: by rotating the valve handle 1, the horizontal rotating rod 2 is driven to rotate, which in turn drives the vertical rotating rod 8 to rotate through the internal transmission structure of the transmission box 7, which in turn drives the butterfly plate 6, which is fixedly connected to the vertical rotating rod 8, to rotate, thereby opening or closing the valve.

[0018] Furthermore, when the valve is closed, turning the valve handle 1 drives the butterfly plate 6 to rotate through the above transmission process. During the closing process of the butterfly plate 6, the butterfly plate 6 gradually comes into contact with the metal sealing ring 4 and finally rotates to the position, at which point the circumference of the butterfly plate 6 and the metal sealing ring 4 are completely in contact to form a seal.

[0019] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. The various components mentioned in this utility model are common technologies in the existing field. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A sealing method for a double eccentric butterfly valve, characterized in that: The device includes a valve handle, a horizontal rotating rod, a butterfly valve seat, a metal sealing ring, a fixing plate, a butterfly plate, a transmission box, and a vertical rotating rod. One end of the horizontal rotating rod is fixedly connected to the valve handle, and the other end extends into the transmission box and is rotatably connected to it. The transmission box contains a bevel gear pair. The input gear of the bevel gear pair in the transmission box is fixedly connected to the horizontal rotating rod, and the output gear of the bevel gear pair in the transmission box is fixedly connected to the vertical rotating rod. The vertical rotating rod extends into the butterfly valve seat and is rotatably connected to it with a sealing seal. A fixing plate is fixedly connected to one side of the butterfly valve seat by bolts. The fixing plate, through bolts, engages with the butterfly valve seat to allow for a detachable connection between the butterfly valve seat and the metal sealing ring. The metal sealing ring and the butterfly plate are interference-fitted.

2. The sealing of a double eccentric butterfly valve according to claim 1, characterized in that... An elastic sealing ring is provided on the side wall of the butterfly valve seat near the fixed plate. Bolt holes are provided around the butterfly valve seat. The butterfly valve seat is connected to the fixed plate through the bolt holes and bolts. A metal sealing ring is interference-fitted between the fixed plate and the butterfly valve seat.

3. The sealing of a double eccentric butterfly valve according to claim 1, characterized in that... The inner ring of the metal sealing ring is provided with a sealing structure, the outer ring of the sealing structure is provided with a sealing groove, and the outer ring of the sealing groove is provided with a mounting plate. The mounting plate is clamped to the butterfly valve seat by a fixing plate and the butterfly valve seat in an interference fit. The sealing groove is clamped to the elastic sealing ring by the fixing plate and the butterfly valve seat in an interference fit.

4. The sealing of a double eccentric butterfly valve according to claim 3, characterized in that... The metal sealing ring is formed using a special stamping process.

5. The sealing of a double eccentric butterfly valve according to claim 3, characterized in that... The sealing structure of the metal sealing ring is interference-fitted with the butterfly plate when the butterfly valve is closed, and the sealing structure will undergo elastic deformation when it is in contact with the butterfly plate.

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