Pneumatic two-eccentric hard sealing butterfly valve

Abstract

The utility model belongs to the technical field of pneumatic sealing butterfly valves, and aims to provide a pneumatic two-eccentric hard sealing butterfly valve which comprises a pneumatic piston type executing mechanism, and a support is connected below the pneumatic piston type executing mechanism. A connecting rod is arranged in the support, and a connecting sleeve is arranged below the connecting rod. The connecting sleeve is connected with a valve rod; the valve rod is eccentrically connected with the valve plate; the lower portion of the support is connected with the valve body, padding is arranged at the position of a step in the valve body, a padding gland is arranged above the padding, a padding pressing plate is arranged above the padding gland, and the padding pressing plate is fixedly connected with the valve body through a double-end stud; the valve plate is positioned at the hollow part in the valve body, and a hard sealing ring is arranged at the contact surface of the valve plate and the valve body; a bottom cover is further arranged at the bottom of the valve body. The butterfly valve has the advantages of being compact in structure, accurate in flow control, small in adjustment abrasion, good in sealing effect and the like, and can be widely applied to the technical field of butterfly valve production in the industries of petrochemical engineering, electric power, water treatment, metallurgy and the like.

Description

Technical Field

[0001] This utility model belongs to the field of pneumatic sealing butterfly valve technology, specifically relating to a pneumatic double eccentric hard seal butterfly valve. Background Technology

[0002] A butterfly valve, also known as a flap valve, is a relatively simple regulating valve. It opens and closes by rotating around a valve shaft and is typically used for on / off control of low-pressure pipeline media. The double eccentric butterfly valve is a further improvement on the single eccentric butterfly valve. Its valve stem centerline is offset from both the center of the butterfly plate and the center of the valve body, effectively solving the problem of high friction and wear in traditional butterfly valves during opening and closing. Double eccentric butterfly valves are widely used in industries such as petrochemicals, power generation, water treatment, and metallurgy.

[0003] Patent application number "202322960463.X" describes a hard-seal butterfly valve, including a valve body and a butterfly plate disposed inside the valve body. The butterfly plate is connected to a valve stem, and the end of the valve stem away from the butterfly plate extends out of the valve body and connects to an actuator. The valve body has a valve seat that seals with the butterfly plate. Its triple-eccentric structure allows the butterfly plate to disengage from the valve seat instantly upon opening, achieving frictionless operation between the butterfly plate and the valve seat, reducing wear on both and maintaining good valve sealing. Patent application number "201822034820.9" describes a quadruple-eccentric hard-seal butterfly valve, including a valve body. A top cover is installed at the top of the valve body, and a high-lift manifold is installed at the top of the top cover via a middle flange. A transmission box is installed at the top of the high-lift manifold, and a transmission shaft is installed inside the transmission box. Its quadruple-eccentric design makes the sealing cone surface more uniform, homogenizing the sealing surface pressure, resulting in good bidirectional sealing performance and increased sealing reliability. However, most existing double eccentric butterfly valves are hydraulically driven or manually controlled, resulting in high control costs. Furthermore, they often employ soft-seal structures, leading to issues such as inaccurate flow rates due to high sealing elasticity and short lifespan. Therefore, the structure of existing double eccentric butterfly valves needs further improvement. Utility Model Content

[0004] The purpose of this utility model is to overcome the shortcomings of the existing technology and provide a pneumatic double eccentric hard seal butterfly valve, which has the characteristics of compact structure, precise flow control, low adjustment wear and good sealing effect. It can be widely used in the field of butterfly valve production technology in industries such as petrochemical, power, water treatment and metallurgy.

[0005] To achieve the above objectives, this utility model adopts the following technical solution: a pneumatic double eccentric hard-seal butterfly valve, comprising a pneumatic piston actuator, with a bracket connected below the pneumatic piston actuator; a connecting rod is provided inside the bracket, and a connecting sleeve is provided below the connecting rod; the connecting sleeve connects to the valve stem, and the valve stem is eccentrically connected to the valve plate; a valve body is connected below the bracket, and packing is provided at the step inside the valve body, a packing gland is provided above the packing, and a packing pressure plate is provided above the packing gland, the packing pressure plate being fixedly connected to the valve body by double-ended studs; the valve plate is located in the hollow part inside the valve body, and a hard sealing ring is provided at the contact surface between the two; a bottom cover is also provided at the bottom of the valve body.

[0006] As an improvement, the pneumatic piston actuator is equipped with a switch feedback device on the top, an air inlet opening hole on the left side of the front, and an air inlet closing hole on the right side.

[0007] As an improvement, a packing pad is provided below the packing material. The packing pad is a chromium-containing metal pad with a thickness of 3-5 mm.

[0008] As an improvement, the valve stem connecting bushing is located at the step inside the valve body, and a split ring support block is provided below the bushing.

[0009] As an improvement, the hard sealing ring has a U-shaped structure, and the contact surface with the valve plate has an arc-shaped structure.

[0010] As an improvement, a pressure plate is provided in the U-shaped groove of the hard sealing ring. The pressure plate is fixedly connected to the valve body by bolts and presses down the hard sealing ring. The hard sealing ring is made of 304 stainless steel hardened material.

[0011] As an improvement, a high-temperature flexible sealing gasket is provided at the connection between the bottom cover and the valve body. The high-temperature flexible sealing gasket is made of graphite composite stainless steel wire and has a thickness of 1.5~3.5mm.

[0012] As an improvement, a set of four hexagonal socket screws are provided under the bottom cover.

[0013] The beneficial effects achieved by this utility model are as follows: A pneumatic double eccentric hard-seal butterfly valve has the characteristics of compact structure, precise flow control, low adjustment wear, and good sealing effect; by setting the valve stem and valve plate to be eccentrically connected, a double eccentric structure is formed inside the butterfly valve, which reduces the problem of large wear in the butterfly valve during flow regulation. Furthermore, the use of hard 304 stainless steel sealing rings on the contact surface between the valve body and the valve plate further improves the butterfly valve's wear resistance and high-temperature resistance to media, extending the butterfly valve's service life; by setting a high-temperature flexible sealing gasket at the connection between the bottom cover and the valve body, the overall sealing performance of the butterfly valve is improved, and the flexible gasket can also play a buffering role. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the pneumatic double eccentric hard seal butterfly valve of this utility model.

[0015] In the diagram: 1. Pneumatic piston actuator; 2. Bracket; 3. Connecting rod; 4. Connecting sleeve; 5. Valve stem; 6. Valve plate; 7. Valve body; 8. Packing; 9. Packing gland; 10. Packing pressure plate; 11. Double-ended stud; 12. Hard sealing ring; 13. Bottom cover; 14. Switch feedback device; 15. Air inlet opening hole; 16. Air inlet closing hole; 17. Packing gasket; 18. Bushing; 19. Split ring support block; 20. Pressure plate; 21. Bolt; 22. High-temperature flexible sealing gasket; 23. Socket head screw. Detailed Implementation

[0016] The preferred embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0017] like Figure 1 As shown, a pneumatic double eccentric hard-seal butterfly valve of this embodiment includes a pneumatic piston actuator 1, with a bracket 2 connected below the pneumatic piston actuator 1; a connecting rod 3 is provided inside the bracket 2, and a connecting sleeve 4 is provided below the connecting rod 3; the connecting sleeve 4 is connected to a valve stem 5, and the valve stem 5 is eccentrically connected to a valve plate 6; a valve body 7 is connected below the bracket 2, and a packing 8 is provided at the step inside the valve body 7, a packing gland 9 is provided above the packing 8, and a packing pressure plate 10 is provided above the packing gland 9, and the packing pressure plate 10 is fixedly connected to the valve body 7 by a double-ended stud 11; the valve plate 6 is located in the hollow part inside the valve body 7, and a hard sealing ring 12 is provided at the contact surface between the two; a bottom cover 13 is also provided at the bottom of the valve body 7.

[0018] Furthermore, the pneumatic piston actuator 1 is provided with a switch feedback device 14 on the top, an air inlet opening hole 15 on the left side of the front, and an air inlet closing hole 16 on the right side; specifically, the switch feedback device 14 can also be a valve positioner, which plays a role in accurately controlling the valve opening degree, thereby accurately controlling the flow rate; specifically, the air inlet opening hole 15 and the air inlet closing hole 16 are responsible for controlling the air intake, and are responsible for providing a suitable and constant air source to the pneumatic piston actuator 1.

[0019] Furthermore, a packing pad 17 is provided below the packing 8. The packing pad 17 is a chromium-containing metal gasket with a thickness of 3-5 mm, preferably 5 mm. Specifically, the packing pad 17 is located at the step inside the valve body 7 and is tightly fitted to the valve body 7.

[0020] Furthermore, the valve stem 5 is connected to the bushing 18, which is located at the step inside the valve body 7. A split ring support block 19 is provided below the bushing 18. Specifically, the split ring support block 19 is made of metal and has a thickness of 5~15mm.

[0021] Furthermore, the hard sealing ring 12 has a U-shaped structure, and the contact surface with the valve plate 6 has an arc-shaped structure; specifically, a pressure plate 20 is provided in the U-shaped groove of the hard sealing ring 12, and the pressure plate 20 is fixedly connected to the valve body 7 by bolts 21, pressing the hard sealing ring 12. The hard sealing ring is made of 304 stainless steel hardened material, thereby effectively improving the wear resistance and high temperature resistance of the butterfly valve, and extending the service life of the butterfly valve.

[0022] Furthermore, a high-temperature flexible sealing gasket 22 is provided at the connection between the bottom cover 13 and the valve body 7. The high-temperature flexible sealing gasket 22 is made of graphite composite stainless steel wire and has a thickness of 1.5~3.5mm, preferably 2mm. The compressibility of the high-temperature flexible sealing gasket 22 improves the overall sealing performance of the butterfly valve and provides a good buffer for the overall installation of the butterfly valve, preventing the connecting parts from being crushed or deformed. Specifically, four hexagon socket head cap screws 23 are provided below the bottom cover 13. The size of the hexagon socket head cap screws 23 is preferably M6*20mm. The bottom cover 13 and the valve body 7 are fixedly connected by the hexagon socket head cap screws 23.

[0023] This utility model of a pneumatic double eccentric hard-seal butterfly valve features a compact structure, precise flow control, low adjustment wear, and excellent sealing performance. By eccentrically connecting the valve stem and valve plate, a double eccentric structure is formed inside the butterfly valve, reducing the problem of excessive wear during flow regulation. Furthermore, the use of a hard 304 stainless steel sealing ring on the contact surface between the valve body and the valve plate further enhances the butterfly valve's wear resistance and high-temperature resistance, extending its service life. The addition of a high-temperature flexible sealing gasket at the connection between the bottom cover and the valve body improves the overall sealing performance of the butterfly valve, while the flexible gasket also acts as a buffer. This design is widely used in butterfly valve manufacturing in industries such as petrochemicals, power, water treatment, and metallurgy, and is particularly suitable for high-temperature media.

[0024] Finally, it should be noted that the above examples are merely specific embodiments of this utility model. Obviously, this utility model is not limited to the above embodiments and can have many variations. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of this utility model should be considered within the protection scope of this utility model.

Claims

1. A pneumatic double eccentric hard-seal butterfly valve, comprising a pneumatic piston actuator (1), wherein a support (2) is connected below the pneumatic piston actuator (1); characterized in that, The bracket (2) is provided with a connecting rod (3) inside, and a connecting sleeve (4) is provided below the connecting rod (3); the connecting sleeve (4) is connected to the valve stem (5), and the valve stem (5) is eccentrically connected to the valve plate (6); the bracket (2) is connected to the valve body (7) below, and a packing (8) is provided at the step inside the valve body (7), a packing gland (9) is provided above the packing (8), and a packing pressure plate (10) is provided above the packing gland (9). The packing pressure plate (10) is fixedly connected to the valve body (7) by a double-headed stud (11); the valve plate (6) is located in the hollow part inside the valve body (7), and a hard sealing ring (12) is provided at the contact surface between the two; a bottom cover (13) is also provided at the bottom of the valve body (7).

2. The pneumatic double eccentric hard-seal butterfly valve according to claim 1, characterized in that, The pneumatic piston actuator (1) is provided with a switch feedback device (14) on the top, an air intake opening hole (15) on the left side of the front, and an air intake closing hole (16) on the right side.

3. The pneumatic double eccentric hard-seal butterfly valve according to claim 1, characterized in that, A packing pad (17) is provided below the packing (8). The packing pad (17) is a chromium-containing metal pad with a thickness of 3~5mm.

4. The pneumatic double eccentric hard-seal butterfly valve according to claim 1, characterized in that, The valve stem (5) is connected to the bushing (18), which is located at the step inside the valve body (7). A split ring support block (19) is provided below the bushing.

5. The pneumatic double eccentric hard-seal butterfly valve according to claim 1, characterized in that, The hard sealing ring (12) has a U-shaped structure and the contact surface with the valve plate (6) has an arc-shaped structure.

6. The pneumatic double eccentric hard-seal butterfly valve according to claim 5, characterized in that, The hard sealing ring (12) has a pressure plate (20) in its U-shaped groove. The pressure plate (20) is fixedly connected to the valve body (7) by bolts (21) and presses down the hard sealing ring (12). The hard sealing ring (12) is made of 304 stainless steel hardened material.

7. The pneumatic double eccentric hard-seal butterfly valve according to claim 1, characterized in that, A high-temperature flexible sealing gasket (22) is provided at the connection between the bottom cover (13) and the valve body (7). The high-temperature flexible sealing gasket (22) is made of graphite composite stainless steel wire and has a thickness of 1.5~3.5mm.

8. The pneumatic double eccentric hard-seal butterfly valve according to claim 7, characterized in that, The bottom cover (13) is provided with four hexagonal screws (23).

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