Dynamic self-compensation sealing structure for butterfly valve

Abstract

The invention provides a dynamic self-compensation sealing structure for a butterfly valve, which comprises a butterfly valve body, flange connecting holes, a sealing pipe, a fixed fluted disc, a valve rod, an operating handle, a butterfly valve plate, a bottom bracket, a limiting ring and a sealing valve seat, and the flange connecting holes are formed in the outer edges of the front side and the rear side of the butterfly valve body; the sealing pipe is integrally cast in the middle of the upper portion of the butterfly valve body. Through the design of the dynamic self-compensation sealing assembly, the pressurization spring can automatically adjust the elastic force according to the abrasion or deformation condition of a sealing element, a sealing gap is compensated in real time, the leakage problem caused by aging and abrasion of the sealing element of a traditional sealing structure is effectively avoided, and the sealing service life of the butterfly valve is prolonged; the cooperative guide structure of the limiting ring and the bottom bracket ensures that the sealing valve seat stably moves in the dynamic compensation process, the valve clamping stagnation phenomenon caused by deviation of the sealing valve seat is avoided, and the valve opening and closing resistance is reduced.

Description

Technical Field

[0001] This invention belongs to the field of valve sealing technology, and particularly relates to a dynamic self-compensating sealing structure for butterfly valves. Background Technology

[0002] A butterfly valve, also known as a flap valve, is a simple regulating valve used for on / off control of low-pressure pipeline media. A butterfly valve is characterized by its closing element (valve disc or butterfly plate) being a circular plate that rotates around the valve shaft to open and close. Butterfly valves can be used to control the flow of various types of fluids, including air, water, steam, various corrosive media, mud, oil, liquid metals, and radioactive media.

[0003] Butterfly valves, commonly used for shutting off and regulating fluids, are widely applied in various industries such as petroleum, chemical, water treatment, and power. During the use of butterfly valves, sealing performance is one of the key indicators of their operational reliability. Traditional butterfly valves typically employ a fixed sealing structure, meaning the seal between the sealing element and the butterfly disc is essentially fixed after installation. However, during long-term use, factors such as the scouring effect of the fluid medium, thermal expansion and contraction of components due to temperature changes, and mechanical wear during valve operation can easily cause deformation, aging, or wear of the sealing element, leading to increased sealing gaps and fluid leakage.

[0004] In addition, Chinese patent publications CN104964044A (a double eccentric butterfly valve) discloses the application of polytetrafluoroethylene (PTFE), CN203223372U (a combined air valve), CN106122492A (a self-regulating butterfly valve), and CN115264086A (a low-emission bidirectional pressure-lined PTFE butterfly valve) all disclose technical features related to butterfly valves. In the prior art, some butterfly valves address leakage by replacing sealing elements, but this requires downtime, impacting production efficiency and increasing maintenance costs. Others attempt to improve sealing by increasing the sealing preload, but this method cannot dynamically adjust to changes in the sealing gap. Even slight wear on the sealing elements can still lead to leakage, and excessive preload increases valve opening and closing resistance, reducing operational flexibility and service life.

[0005] Therefore, it is essential to invent a dynamic self-compensating sealing structure for butterfly valves. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a dynamic self-compensating sealing structure for butterfly valves, solving the issues of poor sealing effect between the valve plate and valve body, and the lack of automatic compensation and adjustment function in existing butterfly valves. A dynamic self-compensating sealing structure for butterfly valves includes a butterfly valve body, a flange connection hole, a sealing tube, a fixed gear disc, a valve stem, an operating handle, a butterfly valve disc, a bottom support, a limiting ring, and a sealing valve seat. The flange connection hole is located on the outer edges of the front and rear sides of the butterfly valve body. The sealing tube is integrally cast in the upper middle position of the butterfly valve body. The valve stem passes through the sealing tube and the interior of the butterfly valve body and is engaged with the butterfly valve disc. The fixed gear disc is engaged at the upper end of the sealing tube. The operating handle is threaded to the upper end of the valve stem. The butterfly valve disc is disposed inside the butterfly valve body and is engaged with the sealing valve seat. The bottom support is embedded in the lower middle position of the butterfly valve body. The limiting ring is integrally cast longitudinally inside the butterfly valve body at a position slightly to the left. The sealing valve seat is longitudinally embedded in the middle position inside the butterfly valve body.

[0007] Preferably, the outer edge of the butterfly valve disc is provided with a groove edge, the upper and lower parts of the front side of the butterfly valve disc are integrally cast with connecting reinforcing ribs, the middle position of both sides of the butterfly valve disc is integrally provided with a flow guiding protrusion, and the outer edge of the butterfly valve disc is integrally provided with a leak-proof edge.

[0008] Preferably, a pressure-boosting spring is embedded on the inner side of the sealing valve seat, and a leak-proof sealing gasket is glued to the outer edge of the sealing valve seat.

[0009] Preferably, the left side of the operating handle is provided with a locking tooth, which can be engaged with a locking hole on the fixed gear plate.

[0010] Preferably, the limiting ring is located on the left side of the sealing valve seat, and the sealing valve seat is located on the left side of the butterfly valve disc.

[0011] Preferably, the stiffness range of the pressure-boosting spring is 5-20 N / mm, and the spring stiffness gradually increases from the low-pressure zone to the high-pressure zone according to the working pressure of the butterfly valve; the leak-proof sealing gasket is made of polytetrafluoroethylene and nitrile rubber composite material, and its side near the butterfly valve disc is provided with a wavy sealing pattern, and the pattern depth is 0.5-1.5 mm, so as to increase the sealing contact area and sealing friction.

[0012] Preferably, the limiting ring is made of metal, and its inner side is provided with a guide slope with an inclination angle of 15°-30°, and the surface roughness of the guide slope is not greater than Ra0.8μm.

[0013] Preferably, the bottom support includes a base and a guide sleeve. The base is fixedly connected to the bottom inner wall of the butterfly valve body. The guide sleeve is fixedly installed at the center of the base. The guide sleeve has a guide hole that mates with the valve stem. The inner wall of the guide hole is coated with a lubricating coating. The top of the guide sleeve is provided with a buffer pad that contacts the bottom of the sealing valve seat. The buffer pad is made of elastic polyurethane material.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Significantly improves sealing reliability and durability: Through the design of the dynamic self-compensating sealing component, the pressure spring can automatically adjust its elasticity according to the wear or deformation of the sealing element, and compensate for the sealing gap in real time. This effectively avoids leakage problems caused by aging and wear of sealing elements in traditional sealing structures, extending the sealing life of the butterfly valve by 3-5 times. At the same time, the multi-structure collaborative sealing design of the butterfly valve disc forms multiple sealing defenses, further reducing the risk of leakage. Experimental tests show that under working pressure of 0.1-4.0MPa and temperature of -20℃-150℃, the leakage of this sealing structure can be controlled below 0.01L / h, which is far below the leakage limit specified by national standards.

[0015] 2. Improve the operational flexibility and structural stability of the butterfly valve: The coordinated guiding structure of the limit ring and the bottom support ensures smooth movement of the sealing valve seat during dynamic compensation, avoiding valve jamming caused by sealing valve seat misalignment, reducing valve opening and closing resistance, and reducing the operating torque of the operating handle by 20%-30%, thus improving the operational flexibility of the valve; the setting of connecting reinforcing ribs not only enhances the structural strength of the butterfly valve disc and prevents the disc from deforming under the action of high-pressure fluid, but also guides the fluid, reduces the impact of the fluid on the disc, reduces vibration and noise during the operation of the butterfly valve, and improves the overall structural stability of the butterfly valve.

[0016] 3. Reduced maintenance costs and wide applicability: This sealing structure enables dynamic self-compensation of the sealing element, reducing the number of downtime maintenance due to seal failure and lowering maintenance costs. Furthermore, through the gradient design of the pressure spring stiffness and the rational selection of sealing materials, this sealing structure is suitable for various fluid media such as water, oil, and gas, and can operate stably under different pressure and temperature conditions. Its wide applicability meets the needs of multiple industries, including petroleum, chemical, water treatment, and power.

[0017] 4. Optimize fluid flow characteristics: The design of the guide protrusion changes the flow trajectory of the fluid inside the butterfly valve, reduces eddy currents and turbulence in the sealing area, reduces the scouring and wear of the sealing elements by the fluid, and at the same time reduces the fluid flow resistance, thereby reducing the flow resistance coefficient of the butterfly valve by 15%-20%, improving fluid delivery efficiency and reducing energy consumption. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the open state of the present invention.

[0019] Figure 2 This is a schematic diagram of the closed state of the present invention.

[0020] Figure 3 This is a schematic diagram of a portion of the internal structure of the present invention.

[0021] Figure 4 This is a partial structural schematic diagram of the sealing valve seat of the present invention.

[0022] Figure 5 This is a front view structural schematic diagram of the butterfly valve disc of the present invention.

[0023] Figure 6 This is a top view of the butterfly valve disc of the present invention.

[0024] In the picture: 1. Butterfly valve body; 2. Flange connection hole; 3. Sealing pipe; 4. Fixed gear disc; 5. Valve stem; 6. Operating handle; 7. Butterfly valve disc; 711. Groove edge; 712. Connecting reinforcing rib; 713. Flow guide protrusion; 714. Leak-proof edge; 8. Bottom support; 9. Limit ring; 10. Sealing seat; 101. Pressure boosting spring; 102. Leak-proof sealing gasket. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings: Example

[0026] As attached Figure 1 To be continued Figure 2 As shown, this invention provides a dynamic self-compensating sealing structure for a butterfly valve, comprising a butterfly valve body 1, a flange connection hole 2, a sealing tube 3, a fixed gear disc 4, a valve stem 5, an operating handle 6, a butterfly valve disc 7, a bottom support 8, a limiting ring 9, and a sealing valve seat 10. The butterfly valve body 1 is cast from cast steel, and after casting, it undergoes annealing to eliminate internal stress. Then, its internal sealing surface and flange connection surface are machined to ensure a surface roughness of no more than Ra 1.6 μm. The flange connection hole 2 is drilled using a drilling machine and then tapped, with a thread accuracy of 6H. The sealing tube 3 is made of seamless stainless steel, and its inner and outer walls are polished to a surface roughness of no more than Ra 0.8 μm. The fixed gear disc 4 is machined from 45# steel, and its teeth are machined by wire cutting to ensure tooth accuracy. The valve stem 5 is made of stainless steel and chrome-plated with a chrome layer thickness of 0.05-0.1 mm to improve wear resistance and corrosion resistance. The operating handle 6 is die-cast from aluminum alloy and anodized. The butterfly valve disc 7 is stamped from stainless steel, and the groove edge 711, connecting reinforcing rib 712, flow guiding protrusion 713, and leak-proof edge 714 are CNC machined. The leak-proof edge 714 is formed by rubber and metal composite injection molding. The bottom support 8 and the limiting ring 9 are both made of stainless steel, and the guide slope of the limiting ring 9 is ground. The sealing valve seat 10 is made of stainless steel, and a leak-proof sealing gasket 102 is attached to its inner side. The leak-proof sealing gasket 102 is made of polytetrafluoroethylene and nitrile rubber composite material and is fixedly connected to the sealing valve seat 10 by high-temperature vulcanization. The pressure spring 101 is made of spring steel and heat-treated after winding to ensure that the spring stiffness meets the design requirements.

[0027] In the above implementation scheme, specifically, the outer edge of the butterfly valve disc 7 is provided with a groove edge 711, the upper and lower parts of the front side of the butterfly valve disc 7 are integrally cast with connecting reinforcing ribs 712, the middle position of both sides of the butterfly valve disc 7 is integrally provided with a flow guiding protrusion 713, and the outer edge of the butterfly valve disc 7 is integrally provided with a leak-proof edge 714.

[0028] In the above implementation scheme, specifically, a pressure-boosting spring 101 is embedded on the inner side of the sealing valve seat 10, and a leak-proof sealing gasket 102 is glued to the outer edge of the sealing valve seat 10.

[0029] In the above implementation scheme, specifically, the left side of the operating handle 6 is provided with a locking tooth, which can be engaged with the locking hole opened on the fixed gear plate 4.

[0030] In the above implementation scheme, specifically, the limiting ring 9 is located on the left side of the sealing valve seat 10, and the sealing valve seat 10 is located on the left side of the butterfly valve disc 7.

[0031] In the above implementation scheme, specifically, the stiffness range of the pressure boosting spring 101 is 5-20 N / mm, and the spring stiffness gradually increases from the low pressure zone to the high pressure zone according to the working pressure of the butterfly valve; the leak-proof sealing gasket 102 is made of polytetrafluoroethylene and nitrile rubber composite material, and its side near the butterfly valve disc 7 is provided with a wavy sealing pattern, and the pattern depth is 0.5-1.5 mm, so as to increase the sealing contact area and sealing friction.

[0032] In the above implementation scheme, specifically, the limiting ring 9 is made of metal, and its inner side is provided with a guide slope with an inclination angle of 15°-30°, and the surface roughness of the guide slope is not greater than Ra0.8μm.

[0033] In the above implementation scheme, specifically, the bottom support 8 includes a base and a guide sleeve. The base is fixedly connected to the bottom inner wall of the butterfly valve body 1. The guide sleeve is fixedly installed at the center of the base. The guide sleeve has a guide hole that cooperates with the valve stem. The inner wall of the guide hole is provided with a lubricating coating. The top of the guide sleeve is provided with a buffer pad that contacts the bottom of the sealing valve seat 10. The buffer pad is made of elastic polyurethane material.

[0034] The working process of this invention is as follows: When the butterfly valve needs to be closed, the operator rotates the operating handle 6, which drives the valve stem 5 to rotate. The valve stem 5 drives the butterfly valve disc 7 to rotate inside the sealing tube 3 to the closed position. During the rotation of the butterfly valve disc 7, the leak-proof edge 714 of the butterfly valve disc 7 gradually contacts the leak-proof sealing gasket 102. As the butterfly valve disc 7 continues to rotate, the leak-proof sealing gasket 102 is compressed, pushing the sealing valve seat 10 towards the limiting ring 9, thereby compressing the pressure spring 101. When the butterfly valve disc 7 is fully closed, the pressure spring 101 is in a compressed state, and the generated elastic force is transmitted to the leak-proof sealing gasket 102 through the sealing valve seat 10, so that the leak-proof sealing gasket 102 and the leak-proof edge 714 of the butterfly valve disc 7 are tightly fitted. At the same time, the groove edge 711 of the butterfly valve disc 7 and the sealing valve seat 10 form an embedded seal, achieving a preliminary seal.

[0035] During the operation of the butterfly valve, if the anti-leakage sealing gasket 102 experiences wear or deformation, causing an increase in the sealing gap, the pressure-boosting spring 101 will automatically extend under its elastic force, pushing the sealing valve seat 10 and the anti-leakage sealing gasket 102 towards the butterfly valve disc 7 to fill the sealing gap and achieve dynamic self-compensating sealing. Simultaneously, the guide slope of the limit ring ensures that the sealing valve seat 10 moves smoothly along a preset direction, preventing the sealing valve seat 10 from shifting. When the butterfly valve needs to be opened, the operating handle 6 is rotated in the opposite direction, causing the valve stem 5 to rotate the butterfly valve disc 7. The pressure on the anti-leakage sealing gasket 102 gradually decreases, the pressure-boosting spring 101 gradually returns to its original state, and the sealing valve seat 10 returns to its initial position under the action of the pressure-boosting spring 101, completing the valve opening process.

[0036] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dynamic self-compensating sealing structure for butterfly valves, characterized in that, The dynamic self-compensating sealing structure for butterfly valves includes a butterfly valve body (1), a flange connection hole (2), a sealing tube (3), a fixed toothed disc (4), a valve stem (5), an operating handle (6), a butterfly valve disc (7), a bottom support (8), a limiting ring (9), and a sealing valve seat (10). The operating handle (6) is threaded to the upper end of the valve stem (5). The butterfly valve disc (7) is located inside the butterfly valve body (1) and fits against the sealing valve seat (10). The bottom support (8) is embedded in the lower middle position of the butterfly valve body (1). The limiting ring (9) is longitudinally integrally cast in the left position inside the butterfly valve body (1). The sealing valve seat (10) is longitudinally embedded in the middle position inside the butterfly valve body (1). A pressure-boosting spring (101) is embedded on the inner side of the sealing valve seat (10), and a leak-proof sealing gasket (102) is glued to the outer edge of the sealing valve seat (10).

2. The dynamic self-compensating sealing structure for butterfly valves as described in claim 1, characterized in that, The flange connection hole (2) is opened on the outer edge of the front and rear sides of the butterfly valve body (1); the sealing tube (3) is integrally cast in the middle of the upper part of the butterfly valve body (1); the valve stem (5) passes through the sealing tube (3) and the interior of the butterfly valve body (1) and is engaged with the butterfly valve disc (7); the fixed toothed disc (4) is engaged at the upper end of the sealing tube (3).

3. The dynamic self-compensating sealing structure for butterfly valves as described in claim 1, characterized in that, The butterfly valve disc (7) has a groove edge (711) on its outer edge, and the upper and lower parts of the front of the butterfly valve disc (7) are integrally cast with connecting reinforcing ribs (712). The butterfly valve disc (7) has a flow guiding protrusion (713) integrally provided in the middle of both sides, and the butterfly valve disc (7) has an anti-leakage edge (714) integrally provided on its outer edge.

4. The dynamic self-compensating sealing structure for butterfly valves as described in claim 1, characterized in that, The left side of the operating handle (6) is provided with a locking tooth, which can be engaged with the locking hole opened on the fixed gear plate (4).

5. The dynamic self-compensating sealing structure for butterfly valves as described in claim 1, characterized in that, The limiting ring (9) is located on the left side of the sealing valve seat (10), and the sealing valve seat (10) is located on the left side of the butterfly valve disc (7).

6. The dynamic self-compensating sealing structure for a butterfly valve as described in claim 1, characterized in that, The stiffness range of the pressure boosting spring (101) is 5-20 N / mm, and the spring stiffness gradually increases from the low pressure zone to the high pressure zone according to the working pressure of the butterfly valve; the leak-proof sealing gasket (102) is made of polytetrafluoroethylene and nitrile rubber composite material, and a wave-shaped sealing pattern is provided on the side near the butterfly valve disc (7), and the pattern depth is 0.5-1.5 mm, so as to increase the sealing contact area and sealing friction.

7. The dynamic self-compensating sealing structure for butterfly valves as described in claim 1, characterized in that, The limiting ring (9) is made of metal and has a guide slope with an inclination angle of 15°-30° on its inner side. The surface roughness of the guide slope is not greater than Ra0.8μm.

8. The dynamic self-compensating sealing structure for a butterfly valve as described in claim 1, characterized in that, The bottom support (8) includes a base and a guide sleeve. The base is fixedly connected to the bottom inner wall of the butterfly valve body (1). The guide sleeve is fixedly installed at the center of the base. The guide sleeve has a guide hole that cooperates with the valve stem. The inner wall of the guide hole is provided with a lubricating coating. The top of the guide sleeve is provided with a buffer pad that contacts the bottom of the sealing valve seat (10). The buffer pad is made of elastic polyurethane material.

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