A high-temperature resistant piston-type bidirectional hard-seal butterfly valve

Abstract

This utility model relates to a high-temperature resistant piston-type bidirectional hard-seal butterfly valve, comprising a valve body, valve seat, valve stem, butterfly plate, bracket, and transmission mechanism. Its key feature is that the valve seat is a piston-type elastic valve seat composed of a piston-type sealing seat, piston ring, thrust plate, and spring. Under low-pressure conditions, the spring pushes the piston-type sealing seat to press tightly against the butterfly plate sealing surface, ensuring reliable bidirectional sealing performance under low pressure. Under high-temperature conditions, the spring's extension and contraction automatically absorbs the expansion between the piston-type sealing seat and the butterfly plate, preventing them from jamming due to high-temperature expansion and reducing the opening torque under high-temperature conditions. A piston-type sealing structure is formed between the valve seat and the inner wall of the valve body passage, with a V-shaped sealing ring installed in the V-shaped sealing groove between the thrust plate and the piston ring. The medium pressure and spring force press the V-shaped sealing ring, automatically compensating for wear and improving the sealing performance between the valve seat and the valve body. It has advantages such as reliable sealing performance and low opening and closing torque.

Description

Technical Field

[0001] This utility model belongs to the field of valves, and in particular relates to a high-temperature resistant piston-type bidirectional hard-seal butterfly valve. Background Technology

[0002] Bidirectional hard-seal butterfly valves generally employ a floating seat structure, such as the high-temperature resistant bidirectional hard-seal butterfly valve with announcement number CN211371314U. In this valve, the seat and baffle are installed together between the three-ring valve and the radial step of the valve body outlet channel. A sealing ring is pressed between the outer surface of the seat and the inner wall of the valve body outlet channel by the baffle. When the medium flows in the forward direction, the valve stem presses the butterfly plate against the seat to achieve a sealing fit. When the medium flows in the reverse direction, the fluid pressure pushes the seat and baffle towards the valve stem to press against the butterfly plate, achieving a bidirectional sealing function. However, the main disadvantages of this type of bidirectional hard-seal butterfly valve are: under low-pressure conditions, the reverse medium pressure exerts a small thrust on the butterfly plate and baffle, insufficient to press the seat against the butterfly plate for sealing, resulting in poor reverse sealing performance; under high-temperature conditions, the sealing surface between the butterfly plate and the seat is prone to seizure due to high-temperature expansion, leading to a large opening torque and requiring a high-power transmission mechanism; and the sealing ring between the outer surface of the seat and the inner wall of the valve body outlet channel is prone to wear and leakage during use. Utility Model Content

[0003] This utility model addresses the shortcomings of existing technologies by providing a high-temperature resistant piston-type bidirectional hard-seal butterfly valve that can increase the clamping force between the valve seat and the butterfly plate under low-pressure conditions, automatically absorb the high-temperature expansion of the butterfly plate and the valve seat to prevent the sealing surfaces from jamming, and has good bidirectional sealing performance, low opening torque, and reliable sealing performance between the valve seat and the valve body.

[0004] The technical solution for realizing this utility model is as follows: A high-temperature resistant piston-type bidirectional hard-seal butterfly valve includes a valve body, valve seat, valve stem, butterfly plate, bracket, and transmission mechanism. The valve body, valve stem, and butterfly plate form a triple-eccentric structure. The butterfly plate is fixedly installed in the middle of the valve stem and is integrally placed within the valve body cavity. The upper end of the valve stem is connected to the transmission mechanism. The valve seat is characterized by being a piston-type resilient valve seat, comprising a piston-type sealing seat, a piston ring, and a thrust plate. The piston-type sealing seat has a radially annular outer step, within which an axial spring cavity is provided. A spring is provided; the thrust plate and the piston ring face each other with an annular shoulder and an annular groove to form a piston-like structure, which is installed on the radial annular outer step of the piston-like sealing seat by a pressure plate; an inner annular inclined surface and an outer annular inclined surface are respectively provided on both sides of the annular shoulder of the thrust plate and the annular groove of the piston ring; an inverted trapezoidal sealing groove is formed between the outer annular inclined surface of the thrust plate and the piston ring, and a positive trapezoidal sealing groove is formed between the inner annular inclined surface of the thrust plate and the piston ring; an inverted trapezoidal sealing ring is set in the inverted trapezoidal sealing groove, and a positive trapezoidal sealing ring is set in the positive trapezoidal sealing groove.

[0005] The preferred embodiment is that the bracket consists of an upper bracket and a lower bracket. The lower flange of the upper bracket is fixedly connected to the upper flange of the valve body, and the upper flange of the upper bracket is fixedly connected to the transmission mechanism. An upper bearing device is provided between the upper flange of the upper bracket and the valve stem, and an air-cooling window is provided between the upper flange and the lower flange of the upper bracket. The lower bracket is fixedly installed at the lower end of the valve body via an upper mounting plate. A lower packing seal device and a lower bearing device are respectively provided between the upper mounting plate and the lower mounting plate of the lower bracket and the valve stem. An air-cooling window is provided between the upper mounting plate and the lower mounting plate.

[0006] The preferred embodiment is that the upper bearing device consists of an upper tapered bearing sealed and installed in the bearing housing of the upper bracket through an upper cover plate; the lower bearing device consists of a lower tapered bearing sealed and installed in the bearing mounting cavity of the lower mounting plate through a lower cover plate; dustproof graphite rings are respectively provided between the upper cover plate, the bearing housing and the valve stem, and a lower dustproof graphite ring is provided between the lower mounting plate and the valve stem; grease inlets connecting the upper tapered bearing and the lower tapered bearing are respectively provided on the bearing housing and the lower mounting plate.

[0007] The preferred embodiment is that the lower packing sealing device consists of a grease-filled sealing ring in the middle of the lower packing, and is pressed into the packing cavity between the upper mounting plate and the valve stem by the lower packing gland.

[0008] The preferred design is that the butterfly plate adopts a double-plate truss structure, with the valve stem passing through the middle of the double plates and fixedly connected by a pin.

[0009] The advantages of this utility model compared with the prior art are: 1. The valve seat adopts a piston-type elastic valve seat. Under low-pressure conditions, the spring pushes the piston-type sealing seat to press and seal with the butterfly plate sealing surface, ensuring reliable bidirectional sealing performance under low pressure. 2. Under high-temperature conditions, the expansion of the piston-type sealing seat and the butterfly plate is automatically absorbed by the extension and contraction of the spring, preventing them from jamming due to high-temperature expansion and reducing the opening torque under high-temperature conditions. 3. A piston-type sealing structure is formed by setting a trapezoidal sealing ring in the trapezoidal sealing groove between the valve seat and the valve body passage. The medium pressure and spring force push the thrust plate and piston ring to press the trapezoidal sealing ring into the trapezoidal sealing groove, automatically compensating for the wear of the trapezoidal sealing ring and improving the sealing performance between the valve seat and the valve body. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the structure of this utility model.

[0011] Figure 2 This is a utility model Figure 1 Enlarged view of the local structure at point A in the middle.

[0012] Figure 3 This is a utility model Figure 1 Enlarged view of the local structure at point B in the middle.

[0013] In the diagram: 1 Lower tapered bearing, 2 Lower dustproof graphite ring, 3 Lower bracket, 4 Grease sealing ring, 5 Valve body, 6 Butterfly plate, 7 Pin, 8 Piston ring, 9 Positive trapezoidal sealing ring, 10 Thrust plate, 11 Pressure plate, 12 Spring, 13 Piston-type sealing seat, 14 Upper packing, 15 Dustproof graphite ring, 16 Upper tapered bearing, 17 Transmission mechanism, 18 Valve stem, 19 Radial annular outer step, 20 Axial spring cavity, 21 Annular groove, 22 Annular shoulder, 23 Inverted trapezoidal sealing ring, 24 Upper bracket, 25 Lower flange, 26 Upper flange, 27 Upper mounting plate, 28 Lower mounting plate, 29 Upper cover plate, 30 Bearing housing, 31 Lower cover plate, 32 Grease port, 33 Lower packing gland, 34 Lower packing, 35 Upper packing gland. Detailed Implementation

[0014] like Figure 1The high-temperature resistant piston-type bidirectional hard-seal butterfly valve shown includes a valve body 5, a valve seat, a valve stem 18, a butterfly plate 6, a bracket, and a transmission mechanism 17. The valve body 5, valve stem 18, and butterfly plate 6 form a triple eccentric structure. The butterfly plate 6 is fixedly installed in the middle of the valve stem 18 and is integrally placed in the inner cavity of the valve body 5. The upper end of the valve stem 18 is connected to the transmission mechanism 17 for transmission. The transmission mechanism 17 drives the valve stem 18 to rotate, which in turn drives the butterfly plate 6 to rotate 90º in the inner cavity of the valve body 5, realizing the opening and closing operation between the butterfly plate 6 and the valve seat. An upper packing 14 is provided between the upper end of the valve body 5 and the valve stem 18. The upper packing 14 is press-fitted by an upper packing gland 35 between the shaft hole of the valve body 5 and the outer surface of the valve stem 18. Its characteristic is that... The valve seat adopts a piston-type resilient valve seat, which includes a piston-type sealing seat 13, a piston ring 8, and a thrust plate 10. The piston-type sealing seat 13 has a radial annular outer step 19, and an axial spring cavity 20 is provided in the radial annular outer step 19. A spring 12 is installed in the axial spring cavity 20. The axial spring cavity 20 is formed by a circular groove set at the middle position of the radial annular outer step 19, and the spring 12 is evenly installed in the circumferential direction in the circular groove. Alternatively, it can be formed by a number of axial circular holes evenly set at the middle position of the radial annular outer step 19, and a spring 12 is installed in each circular hole. The thrust plate 10 faces the piston ring 8. The piston-like structure is formed by the interplay of an annular shoulder 22 and an annular groove 21. A pressure plate 11 is mounted on the radial annular outer step 19 of the piston-like sealing seat 13. This means the annular shoulder 22 of the thrust plate 10 and the annular groove 21 of the piston ring 8 are movably fitted together, allowing the piston ring 8 to move axially between the radial annular outer step 19 and the thrust plate 10. The annular shoulder 22 and the annular groove 21 can be interchangeably disposed on the thrust plate 10 and the piston ring 8. Inner annular inclined surfaces and outer annular inclined surfaces are respectively provided on both sides of the annular shoulder 22 of the thrust plate 10 and on both sides of the annular groove 21 of the piston ring 8. The outer annular inclined surface of the thrust plate 10 and the outer annular inclined surface of the piston ring 8... The surfaces of the piston ring 8 and the inner annular inclined surface of the thrust plate 10 form an inverted trapezoidal sealing groove, while the inner annular inclined surface of the piston ring 8 forms a positive trapezoidal sealing groove. An inverted trapezoidal sealing ring 23 is installed within the inverted trapezoidal sealing groove, and a positive trapezoidal sealing ring 9 is installed within the positive trapezoidal sealing groove. When the inverted trapezoidal sealing ring 23 and the positive trapezoidal sealing ring 9 wear, the spring 12 and the medium pressure together push the piston ring 8 towards the thrust plate 10, radially expanding the inverted trapezoidal sealing ring 23 to press against the inner wall of the valve body 5 passage for sealing. The positive trapezoidal sealing ring 9 is radially compressed to press against the outer surface of the piston-type sealing seat 13 for sealing, achieving automatic compensation sealing between the valve seat and the valve body 5, thus improving the sealing reliability between them. Figure 2As shown, the inverted trapezoidal sealing ring 23 and the regular trapezoidal sealing ring 9 are made of graphite rings, which have a fireproof sealing function. Under low-pressure conditions, the spring 12 increases the preload of the sealing pair; under high-pressure conditions, in the reverse working state, the reverse medium pressure enters between the piston ring 8 and the radial annular outer step 19, pushing the piston-type sealing seat 13 and the butterfly plate 6 to press and seal; in the forward working state, the valve stem 18 presses the butterfly plate 6 and the piston-type sealing seat 13 to seal; under high-temperature conditions, the spring 12 absorbs the high-temperature expansion of the butterfly plate 6 and the valve seat to prevent them from jamming.

[0015] The support consists of an upper support 24 and a lower support 3. The lower flange 25 of the upper support 24 is fixedly connected to the upper end of the valve body 5, and the upper flange 26 of the upper support 24 is fixedly connected to the transmission mechanism 17. An upper bearing device is provided between the upper flange 26 of the upper support 24 and the valve stem 18. A cooling window is provided between the upper flange 26 and the lower flange 25 of the upper support 24 to reduce the temperature of the medium conducted to the upper bearing device. The lower support 3 is fixedly installed at the lower end of the valve body 5 through an upper mounting plate 27. A lower packing seal device and a lower bearing device are respectively provided between the upper mounting plate 27 and the lower mounting plate 28 of the lower support 3 and the valve stem 18. A cooling window is provided between the upper mounting plate 27 and the lower mounting plate 28 to reduce the temperature of the medium conducted to the lower bearing device. The upper bearing device and the lower bearing device position the upper and lower ends of the valve stem 18 vertically, which can significantly reduce the rotational friction of the valve stem 18.

[0016] The upper bearing assembly consists of an upper tapered bearing 16 sealed within the bearing housing 30 of the upper bracket 24 via an upper cover plate 29. The bearing housing 30 is welded to the center hole of the upper flange 26, or it can be an integral structure with the upper flange 26. The lower bearing assembly consists of a lower tapered bearing 1 sealed within the bearing mounting cavity of the lower mounting plate 28 via a lower cover plate 31. Dustproof graphite rings 15 are respectively provided between the upper cover plate 29 and the bearing housing 30 and the valve stem 18 to prevent dust from entering the upper tapered bearing 16, and a lower dustproof graphite ring 2 is provided between the lower mounting plate 28 and the valve stem 18 to prevent dust from entering the lower tapered bearing 1. Figure 3 As shown, the bearing housing 30 and the lower mounting plate 28 are respectively provided with grease inlets 32 that connect the upper tapered bearing 16 and the lower tapered bearing 1. Grease can be injected into the upper tapered bearing 16 and the lower tapered bearing 1 through the grease inlets 32 to improve lubrication.

[0017] The lower packing sealing device consists of a grease-filled sealing ring 4 set in the middle of the lower packing 34, and is pressed into the packing cavity between the upper mounting plate 27 and the valve stem 18 by the lower packing gland 33. Sealing grease is injected into the grease-filled sealing ring 4 to form a composite sealing structure with the lower packing 24.

[0018] The butterfly plate 6 adopts a double flat truss structure. The valve stem 18 passes through the middle of the double flat plates and is fixedly connected by the pin 7. It has high strength, large flow area and low flow resistance.

Claims

1. A high-temperature-resistant piston-type bidirectional hard-seal butterfly valve, comprising a valve body (5), a valve seat, a valve rod (18), a butterfly plate (6), a support, and a transmission mechanism (17), wherein a three-eccentric structure is formed among the valve body (5), the valve rod (18), and the butterfly plate (6), the butterfly plate (6) is fixedly installed in the middle of the valve rod (18) and is placed in the inner cavity of the valve body (5), and the upper end of the valve rod (18) is in transmission connection with the transmission mechanism (17); characterized in that: The valve seat adopts a piston-type elastic valve seat, which includes a piston-type sealing seat (13), a piston ring (8), and a thrust plate (10). The piston-type sealing seat (13) is provided with a radial annular outer step (19), and an axial spring cavity (20) is provided in the radial annular outer step (19). A spring (12) is provided in the axial spring cavity (20). The thrust plate (10) and the piston ring (8) face each other with an annular shoulder (22) and an annular groove (21) in the middle. It has a piston-like structure, with a pressure plate (11) installed on the radial annular outer step (19) of the piston-type sealing seat (13); an inner annular inclined surface and an outer annular inclined surface are provided on both sides of the annular shoulder (22) of the thrust plate (10) and on both sides of the annular groove of the piston ring (8), respectively. The outer annular inclined surface and the inner annular inclined surface of the two form an inverted trapezoidal sealing groove and a positive trapezoidal sealing groove, respectively. An inverted trapezoidal sealing ring (23) is provided in the inverted trapezoidal sealing groove, and a positive trapezoidal sealing ring (9) is provided in the positive trapezoidal sealing groove. ​ 2. The high-temperature resistant piston-type bidirectional hard-seal butterfly valve according to claim 1, characterized in that: The bracket consists of an upper bracket (24) and a lower bracket (3). The lower flange (25) of the upper bracket (24) is fixedly connected to the upper end of the valve body (5), and the upper flange (26) is fixedly connected to the transmission mechanism (17). An upper bearing device is provided between the upper flange (26) and the valve stem (18), and a wind-cooling window is provided between the upper flange (26) and the lower flange (25). The lower bracket (3) is fixedly installed at the lower end of the valve body (5) through an upper mounting plate (27). A lower packing sealing device and a lower bearing device are respectively provided between the upper mounting plate (27) and the lower mounting plate (28) of the lower bracket (3) and the valve stem (18). A wind-cooling window is provided between the upper mounting plate (27) and the lower mounting plate (28).

3. The high-temperature resistant piston-type bidirectional hard-seal butterfly valve according to claim 2, characterized in that: The upper bearing assembly consists of an upper tapered bearing (16) sealed and installed in the bearing housing (30) of the upper bracket (24) through an upper cover plate (29); the lower bearing assembly consists of a lower tapered bearing (1) sealed and installed in the bearing mounting cavity of the lower mounting plate (28) through a lower cover plate (31); a dustproof graphite ring (15) is provided between the upper cover plate (29) and the bearing housing (30) and the valve stem (18), and a lower dustproof graphite ring (2) is provided between the lower mounting plate (28) and the valve stem (18); a grease inlet (32) connecting the upper tapered bearing (16) and the lower tapered bearing (1) is provided on the bearing housing (30) and the lower mounting plate (28), respectively.

4. The high-temperature resistant piston-type bidirectional hard-seal butterfly valve according to claim 3, characterized in that: The lower packing sealing device consists of a grease-filled sealing ring (4) set in the middle of the lower packing (34), and is pressed into the packing cavity between the upper mounting plate (27) and the valve stem (18) by the lower packing gland (33).

5. The high-temperature resistant piston-type bidirectional hard-seal butterfly valve according to claim 1, 2, 3, or 4, characterized in that: The butterfly plate (6) adopts a double flat truss structure, and the valve stem (18) passes through the middle of the double flat plate and is fixedly connected by a pin (7).

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