Bidirectional zero-leakage hard sealing four-eccentric center butterfly valve

Abstract

The utility model relates to the technical field of butterfly valves, and discloses a two-way zero-leakage hard sealing four-eccentric butterfly valve which comprises a valve body, a valve plate is installed in the middle of an inner cavity of the valve body, and the left side of the valve plate is a sealing side. A sealing ring pressing ring, a sealing ring and a first gasket are sequentially fixed to the side face of the valve plate through a first screw on the left side of the valve plate to form a sealing side, a valve seat is installed in a valve seat groove in the left side of the valve plate of an inner cavity of the valve body, and the valve seat is fixed to a valve cavity seat groove through a second screw, a valve seat pressing ring arranged on the outer side and a second gasket arranged on the inner side. The valve plate and the valve seat are matched to form inner sealing, namely the valve cavity is in a fully-closed state, and a lower valve rod is inserted into the valve plate from the bottom. The butterfly valve does not generate plastic deformation under high pressure, does not have the phenomena of stamping stress, welding stress, elastic annealing or bite breakage and embrittlement under high temperature or low temperature, solves the problem of leakage caused by an unreasonable sealing surface structure of a traditional butterfly valve, and is reliable in sealing performance.

Description

Technical Field

[0001] The utility model relates to the technical field of butterfly valves, in particular to a two-way zero-leakage hard-sealed four-eccentric butterfly valve. Background Art

[0002] The three-eccentric butterfly valve is a widely used industrial valve. It adopts a three-eccentric structure, so that it will not rub when it is switched, ensuring its reliability and durability. The three-eccentric butterfly valve has the advantages of simple structure, small size, light weight, strong corrosion resistance, excellent fluid control ability, and good sealing performance, making it widely used in chemical, pharmaceutical, metallurgical, electric power and other fields. However, its scope of application is relatively narrow. It cannot be used to treat high-concentration solid particle media, nor can it be used to treat media with high viscosity. In addition, it also has certain restrictions on the temperature and pressure of the medium. In addition, its reliability is still low, especially in the case of high temperature, high pressure and frequent switching, it is prone to failure, and there is a problem that it cannot achieve two-way zero leakage. Therefore, there is an urgent need for a high-performance valve that fundamentally changes the sealing structure. It is no longer a sealing pair compression seal, but a torsion seal, which mainly relies on the sealing specific pressure generated by the torsion extrusion of the sealing pair to achieve the sealing effect; in the sealing structure, it can be realized that when the medium flows forward or backward, the medium pressure can partially act on the seal, so that the valve can achieve two-way sealing during operation, high temperature and high pressure resistance, wear resistance, thereby extending the service life of the valve. Utility Model Content

[0003] The utility model aims to provide a two-way zero-leakage hard-sealed four-eccentric butterfly valve to solve the problems raised in the above-mentioned background technology.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] 14. The invention relates to a two-way zero-leakage hard-sealed four-eccentric butterfly valve, comprising a valve body, a valve plate is installed in the middle of the valve body cavity, and the left side of the valve plate is a sealing side, the left side of the valve plate is fixed to the side of the valve plate by a first screw to form a sealing side, a valve seat is installed in the valve seat groove on the left side of the valve plate in the valve body cavity, the valve seat is fixed to the valve cavity seat groove by a second screw and a valve seat pressure ring is provided on the outside and a second gasket is provided on the inside, an inner seal can be formed by the cooperation between the valve plate and the valve seat, that is, the valve cavity is fully closed, a valve stem is inserted from the top of the valve plate, a lower valve stem is inserted from the bottom of the valve plate, a first pin is installed on the right side of the valve plate, a shaft bushing is provided at the bottom of the valve body, the bottom of the shaft bushing is arranged on the top of the lower end cover directly below through a third gasket, the lower The bottom of the end cover is connected to the bottom of the valve body through a plurality of first bolts passing through a first gasket, the top of the valve body is sleeved with a packing pad, the top of the packing pad is provided with a packing, the top of the packing is provided with a packing press sleeve, the top of the packing press sleeve is installed with a packing pressure plate, the top of the packing pressure plate is installed with a first full-threaded stud, the upper end of the first full-threaded stud is threadedly connected with a first nut, a turbine transmission device is arranged directly above the packing pressure plate, the bottom of the turbine transmission device is provided with a connecting plate, the bottom of the connecting plate is connected with a second full-threaded stud, the lower end of the second full-threaded stud is threadedly connected with a second nut, the connecting plate and the packing pressure plate are connected by a second pin, and a second washer is arranged on the second full-threaded stud and between the connecting plate and the second nut.

[0006] As a preferred technical solution of the utility model, a key is embedded on the side surface of the valve stem near the top.

[0007] As a preferred technical solution of the present utility model, the number of the first pins is set to be multiple.

[0008] As a preferred technical solution of the present utility model, the number of the second pins is set to be multiple.

[0009] As a preferred technical solution of the utility model, the material of the filler is flexible graphite.

[0010] As a preferred technical solution of the utility model, the materials of the first gasket, the second gasket and the third gasket are all 304 plus flexible graphite.

[0011] Compared with the prior art, the utility model has the following beneficial effects:

[0012] 1. The utility model does not produce plastic deformation under high pressure, and does not have stamping stress, welding stress, elastic annealing or biting and brittle cracking at high or low temperatures, which solves the leakage caused by the unreasonable sealing surface structure of traditional butterfly valves and improves the reliability of sealing performance.

[0013] 2. In the process of opening and closing the butterfly plate, the utility model realizes the friction-free and jam-free between the butterfly plate sealing ring and the valve seat sealing surface. The pressure angle on the sealing surface is greater than the friction angle. The "radial dynamic balance sealing system" design is adopted to reduce the opening resistance of the butterfly plate. During the opening and closing process, the butterfly plate sealing surface can be instantly and quickly completed along the 360° circumference of each point, point by point contact and point by point separation, and the closing contact automatically matches the sealing action quickly and accurately. The all-metal hard-sealed butterfly valve adopts an integral metal seal on the sealing surface, and the elliptical cross-section sealing ring is machined to form a sealing pair with the metal sealing surface of the valve seat. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0015] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0016] Figure 2 It is a schematic diagram of the four-eccentric geometric shape of the utility model;

[0017] Figure 3 This is a schematic diagram of the bidirectional sealing design structure of the utility model.

[0018] In the figure: 1, valve body; 2, valve seat pressure ring; 3, second gasket; 4, valve seat; 5, sealing ring; 6, first gasket; 7, valve plate; 8, first screw; 9, sealing ring pressure ring; 10, second screw; 11, third gasket; 12, lower end cover; 13, first gasket; 14, first bolt; 15, lower valve stem; 16, bushing; 17, first pin; 18, valve stem; 19, packing pad; 20, packing; 21, packing sleeve; 22, packing pressure plate; 23, first full-thread stud; 24, first nut; 25, second nut; 26, second full-thread stud; 27, second gasket; 28, key; 29, turbine transmission device; 30, connecting plate; 31, second pin. DETAILED DESCRIPTION

[0019] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than to limit the utility model. It should also be noted that, for ease of description, only the parts related to the utility model are shown in the accompanying drawings. The different types of section lines in the drawings in the embodiments of the utility model are not marked according to the national standard, nor are there any requirements for the materials of the components, but are used to distinguish the cross-sectional views of the components in the drawings.

[0020] See also Figure 1-3, a two-way zero-leakage hard-sealed four-eccentric butterfly valve, comprising a valve body 1, a valve plate 7 is installed in the middle of the inner cavity of the valve body 1, and the left side of the valve plate 7 is a sealing side, and the left side of the valve plate 7 is fixed to the side of the valve plate 7 by a first screw 8 in sequence, forming a sealing side, a valve seat 4 is installed in the valve seat groove on the left side of the valve plate 7 in the inner cavity of the valve body 1, and the valve seat 4 is fixed to the valve cavity seat groove by a second screw 10 and a valve seat pressure ring 2 is provided on the outside and a second gasket 3 is provided on the inside, and an inner seal can be formed by the cooperation between the valve plate 7 and the valve seat 4, that is, the valve cavity is fully closed, a valve stem 18 is inserted from the top of the valve plate 7, a lower valve stem 15 is inserted from the bottom of the valve plate 7, a first pin 17 is installed on the right side of the valve plate 7, a shaft bushing 16 is provided at the bottom of the valve body 1, and the bottom of the shaft bushing 16 is arranged on the top of the lower end cover 12 directly below through a third gasket 11, and the bottom of the lower end cover 12 is fixed by a third gasket 11. A plurality of first bolts 14 pass through the first gasket 13 and are connected to the bottom of the valve body 1. A packing pad 19 is sleeved on the top of the valve body 1. A packing 20 is arranged on the top of the packing pad 19. A packing sleeve 21 is arranged on the top of the packing 20. A packing pressing plate 22 is installed on the top of the packing pressing plate 21. A first full-threaded stud 23 is installed on the top of the packing pressing plate 22. The upper end of the first full-threaded stud 23 is threadedly connected to the first nut 24. A turbine transmission device 29 is arranged just above the packing pressing plate 22. A connecting plate 30 is arranged at the bottom of the turbine transmission device 29. A second full-threaded stud 26 is connected to the bottom of the connecting plate 30. A second nut 25 is threadedly connected to the lower end of the second full-threaded stud 26. The connecting plate 30 and the packing pressing plate 22 are connected by a second pin 31. A second gasket 27 is arranged on the second full-threaded stud 26 and between the connecting plate 30 and the second nut 25.

[0021] A key 28 is embedded on the side surface of the valve stem 18 near the top.

[0022] The number of the first pins 17 is plural.

[0023] The number of the second pins 31 is set to be plural.

[0024] The filler 20 is made of flexible graphite.

[0025] Among them, the materials of the first gasket 6, the second gasket 3 and the third gasket 11 are all 304 plus flexible graphite.

[0026] Four eccentric geometric shapes: 1. Axial eccentricity, the valve's rotation center deviates from the contact plane with the sealing surface, forming an eccentricity; 2. Radial eccentricity, the valve's rotation center and the pipeline center are not on the same center line; 3. Angular eccentricity, the valve sealing surface center and the pipeline center form an angle; 4. Angular eccentricity, the short side meshing line of the sealing surface and the center line of the flow channel form an angle. The fourth eccentricity is a variable arbitrary value, and its meshing angle is also a variable arbitrary value. According to the working conditions, various reasonable meshing angles can be designed in different environments to make the valve easier to open. The size of the second eccentricity can be designed to be smaller, from the previous eccentricity of more than ten millimeters to 2-3 millimeters, and the second eccentric moment is also greatly reduced, so the torque of the valve opening is also greatly reduced. The actuator equipped with the valve drive can be more energy-saving and economical. The price of the whole machine is much more economical than other eccentric butterfly valves under the same working conditions.

[0027] The sealing pair adopts metal-to-metal hard-to-hard sealing. The valve seat / sealing ring is made entirely of metal material, and the valve seat and sealing ring are hardened by heat treatment or surfacing. They have the advantages of anti-erosion, wear resistance, high temperature and high pressure resistance, and long service life. They solve the problems of the common three-eccentric butterfly valve, such as the multi-layer sealing structure is easy to erode and the service life is short, and the U-ring sealing structure butterfly valve, the elastic sealing ring is easy to fail, the sealing surface hardness is poor, and the design defects of easy wear are solved, thus avoiding the problems of butterfly valve internal leakage, short service life, and few applicable working conditions caused by this.

[0028] It implements two-way sealing and can withstand pressure in both positive and negative directions. No internal leakage occurs evenly when bearing pressure in either positive or negative directions, and meets the standard zero leakage requirements.

[0029] When the medium flows forward, the force applied by the driving device to the valve stem drives the valve plate, causing the valve plate sealing surface to generate a forced sealing force acting on the valve seat sealing surface. At the same time, the medium pressure generates an auxiliary sealing force, causing the valve plate sealing surface to press against the valve seat sealing surface to form a good seal.

[0030] When the medium flows in the opposite direction, the preload force and the piston effect of the medium push the valve seat sealing surface to the valve plate sealing surface to form a good seal.

[0031] In order to prevent the butterfly plate from deformation, valve stem dislocation and sealing surface biting caused by the influence of liquid pressure and temperature, two independent thrust rings are installed on the upper and lower sides of the butterfly plate respectively, so as to ensure the normal operation of the valve under any working conditions. In order to prevent sudden accidents caused by the valve stem breaking and flying out due to unknown reasons, independent valve stem anti-flying structures are designed at the inner and outer sides of the lower end of the valve.

[0032] During the design process, special consideration was given to the application issues in the field of regulation. The sealing principle of the four-eccentric butterfly valve was fully utilized to achieve an opening angle design with no dead zone, thus eliminating the common opening jump phenomenon when opening ordinary valves, and eliminating the unregulatory phenomenon caused by various unstable factors such as friction within the low opening range of the valve, that is, eliminating the dead zone (insensitive zone), which means that the valve can enter the adjustable area almost from 0 opening to 90 opening.

[0033] The valve adopts a detachable sealing sub-structure design. The valve plate sealing surface is independent of the valve plate, and the valve seat is independent of the valve body, so the valve plate sealing ring and the valve seat can be replaced separately. When the valve plate sealing ring or the valve seat seal is damaged, only the valve plate sealing ring or the valve seat needs to be replaced, which greatly reduces the maintenance cost, maintenance man-hours and maintenance difficulty.

[0034] The sealing pair fixing method adopts balanced distribution fixing, which not only has accurate positioning, but also makes each bolt bear force evenly, eliminating the loosening of the sealing pair caused by uneven force and avoiding valve leakage. In the problem of valve leakage, traditionally, people often focus on the leakage of the valve seat, that is, internal leakage, while ignoring the leakage of the packing part, that is, external leakage; in the packing seal and other structures to prevent external leakage, the dynamic load standard design is adopted, and the combined packing sealing system is adopted to ensure that the maximum leakage rate of the valve is ≤20PPM, so that the packing is permanently sealed and the maintenance-free time of the packing is extended. The packing is pressed with a combined elastic gasket to continuously provide the pre-tightening force required for packing pressing, avoid valve leakage, and make the valve safer to use, especially suitable for toxic and harmful media in the chemical industry.

[0035] During the opening and closing process of the butterfly plate, the butterfly valve achieves no friction or jamming between the butterfly plate sealing ring and the valve seat sealing surface. The pressure angle on the sealing surface is greater than the friction angle. The "radial dynamic balance sealing system" design is adopted to reduce the opening resistance of the butterfly plate. During the opening and closing process, the butterfly plate sealing surface can be quickly completed instantly along the 360° circumference of each point, point by point, and the sealing action of closing contact automatically matches can be achieved quickly and accurately. Since the sealing surface of the all-metal hard-sealed butterfly valve adopts an integral metal seal, the elliptical cross-section sealing ring is machined and formed into a sealing pair with the metal sealing surface of the valve seat. This sealing structure does not produce plastic deformation under high pressure, and there is no stamping stress, welding stress, elastic annealing or biting brittle cracking at high or low temperatures. It solves the leakage caused by the unreasonable structure of the sealing surface of the traditional butterfly valve and the reliability of the sealing performance. The content not described in detail in this description belongs to the existing technology known to professional and technical personnel in this field.

[0036] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the concept of the utility model. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) by each other to form a technical solution.

Claims

1. A two-way zero-leakage hard-sealed four-eccentric butterfly valve, comprising a valve body (1), characterized in that: A valve plate (7) is installed in the middle of the inner cavity of the valve body (1), and the left side of the valve plate (7) is a sealing side. The left side of the valve plate (7) is fixed by a first screw (8) to the side of the valve plate (7) by a sealing ring pressure ring (9), a sealing ring (5) and a first gasket (6) in sequence to form a sealing side. A valve seat (4) is installed in the valve seat groove on the left side of the valve plate (7) in the inner cavity of the valve body (1). The valve seat (4) is fixed to the valve cavity seat groove by a second screw (10) and a valve seat pressure ring (2) is provided on the outer side and a second gasket (3) is provided on the inner side. The valve body (1) and the valve seat (4) cooperate to form an inner seal, that is, the valve cavity is in a fully closed state. A valve stem (18) is inserted from the top of the valve plate (7), and a lower valve stem (15) is inserted from the bottom of the valve plate (7). A first pin (17) is installed on the right side of the valve plate (7). A shaft bushing (16) is provided at the bottom of the valve body (1). The bottom of the shaft bushing (16) is arranged on the top of the lower end cover (12) directly below through a third gasket (11). The bottom of the lower end cover (12) is fastened by a plurality of first bolts (14) passing through the third gasket (11). A gasket (13) is connected to the bottom of the valve body (1); a packing pad (19) is sleeved on the top of the valve body (1); a packing (20) is arranged on the top of the packing pad (19); a packing gland (21) is arranged on the top of the packing (20); a packing gland (22) is installed on the top of the packing gland (21); a first full-thread stud (23) is installed on the top of the packing gland (22); a first nut (24) is threadedly connected to the upper end of the first full-thread stud (23); and a first nut (24) is threadedly connected to the upper end of the packing gland (22). A turbine transmission device (29) is arranged directly above the turbine transmission device (29), a connecting plate (30) is arranged at the bottom of the turbine transmission device (29), a second fully threaded stud (26) is connected to the bottom of the connecting plate (30), a second nut (25) is threadedly connected to the lower end of the second fully threaded stud (26), the connecting plate (30) and the packing pressure plate (22) are connected via a second pin (31), and a second washer (27) is arranged on the second fully threaded stud (26) and between the connecting plate (30) and the second nut (25).

2. A two-way zero-leakage hard-sealed four-eccentric butterfly valve according to claim 1, characterized in that: A key (28) is embedded on the side surface of the valve stem (18) close to the top.

3. A two-way zero-leakage hard-sealed four-eccentric butterfly valve according to claim 1, characterized in that: The number of the first pins (17) is plural.

4. A two-way zero-leakage hard-sealed four-eccentric butterfly valve according to claim 1, characterized in that: The number of the second pins (31) is plural.

5. A two-way zero-leakage hard-sealed four-eccentric butterfly valve according to claim 1, characterized in that: The material of the filler (20) is flexible graphite.

6. A two-way zero-leakage hard-sealed four-eccentric butterfly valve according to claim 1, characterized in that: The first gasket (6), the second gasket (3) and the third gasket (11) are all made of 304 plus flexible graphite.

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