High-pressure wedge type flat gate valve

Abstract

The utility model discloses a high-pressure wedge-type flat gate valve, relates to the field of flat gate valves, and aims to solve the problems that one-way sealing of a traditional flat gate valve cannot adapt to two-way pressure, a sealing pair is easy to wear and lacks a self-compensation mechanism, and leakage risks exist. The bidirectional multi-stage sealing valve comprises a valve body, a valve seat, double parallel valve plates, a valve rod and a valve cover, the double parallel valve plates are matched through wedge angle inclined faces of a left wedge block and a right wedge block, wedge caulking is achieved through horizontal displacement driven by the valve rod, and a bidirectional multi-stage sealing pair is formed; sTL alloy is overlaid on the sealing faces of the valve seat and the double parallel valve plates respectively, hardness difference exists between the valve seat and the double parallel valve plates, and STL alloy layers are overlaid on the matched inclined faces of the left wedge block and the right wedge block. The valve can effectively improve the sealing performance, compensate the abrasion of the sealing surface and prolong the service life, is suitable for high-pressure working conditions, and remarkably reduces the leakage risk and the operation and maintenance cost of a system.

Description

Technical Field

[0001] This utility model relates to the field of flat gate valves, and in particular to a high-pressure wedge flat gate valve. Background Technology

[0002] In high-pressure and high-temperature environments such as petroleum, chemical, and energy industries, slab gate valves are key control devices in media conveying systems, and their sealing reliability and operational stability are of paramount importance. Traditional slab gate valves generally adopt a unidirectional rigid sealing structure. Unidirectional sealing cannot adapt to bidirectional pressure environments. The sealing pair is prone to wear due to frequent opening and closing, media erosion, and high-temperature deformation, leading to increased sealing gaps, increased leakage risk, and a lack of wear self-compensation mechanism. After long-term operation, the probability of seal failure increases significantly. Utility Model Content

[0003] The technical problem to be solved and the technical task proposed by this utility model is to improve and refine the existing technical solutions, and to provide a high-pressure wedge-type flat gate valve with the aim of improving sealing performance. To this end, this utility model adopts the following technical solution.

[0004] A high-pressure wedge-type flat gate valve includes a valve body, a valve seat, double parallel valve plates, a valve stem, and a valve cover. The valve seats are mirror-symmetrically distributed on both sides of the double parallel valve plates within the valve body. The valve cover is located at the upper end of the valve body. The valve stem passes through the valve cover from top to bottom and enters the valve body cavity. The double parallel valve plates include a left valve plate and a right valve plate. A left wedge is located on the right side of the left valve plate, and a right wedge is located on the left side of the right valve plate. The upper end of the left wedge is connected to the valve stem. The left and right wedges engage with each other via a wedge angle bevel, generating horizontal displacement under the drive of the valve stem to open or release the double parallel valve plates. The sealing surfaces of the valve seat and the double parallel valve plates are respectively overlaid with STL alloy layers, and there is a hardness difference between the two. By overlaying STL alloys of different hardnesses on both sides of the sealing surfaces, the wear of the contact area can be reduced, the coefficient of friction can be reduced, and the smoothness of opening and closing can be improved. The double parallel valve plates are wedge-tightened through a wedge linkage mechanism, forming a bidirectional multi-stage sealing pair. Horizontal displacement compensates for the wear of the sealing surfaces, extending the valve's service life and effectively improving sealing performance. STL alloy, or Stellite Alloys.

[0005] As a preferred technical means, the mating inclined surfaces of the left and right wedges are both overlaid with an STL alloy layer. The STL alloy overlay on the inclined surfaces can withstand the friction generated by frequent relative sliding, reduce wedge wear, ensure stable wedge clamping force, and the high-temperature oxidation resistance of STL alloy is suitable for high-temperature working conditions, avoiding wedge jamming due to thermal expansion.

[0006] As a preferred technical approach, the STL alloy layer has a thickness ranging from 2 to 4 mm. Optimizing the thickness range ensures sufficient wear resistance and lifespan, avoids the risk of weld overlay cracking, and controls manufacturing costs.

[0007] As a preferred technical approach: the right wedge has a rectangular hole running through it from left to right, and the STL alloy layer of the right wedge is disposed on the inclined surfaces on both sides of the rectangular hole. The position of the STL alloy layer on the left wedge corresponds to the position of the STL alloy layer on the right wedge. Alloy is deposited only on critical friction surfaces, reducing material waste and lowering manufacturing costs.

[0008] As a preferred technical means, the left and right wedges are fitted with a wedge-shaped inclined surface with an angle of 15-20 degrees to the vertical. This angle range is greater than the critical angle for friction self-locking, ensuring smooth movement of the wedges during valve opening and closing, while efficiently converting the axial force of the valve stem into the sealing force of the valve plate.

[0009] As a preferred technical means: a guide plate is fixed to each of the left and right sides of the upper part of the left wedge block by fasteners. When the left wedge block moves downward, the lower part of the guide plate extends into the annular groove of the double parallel valve plate to guide and position the left wedge block and the double parallel valve plate. The left wedge block achieves guiding and positioning when it moves downward.

[0010] As a preferred technical approach: a valve cover cylinder is welded to the valve cover, a valve cover flange is welded to the upper end of the valve cover cylinder, and multiple evenly distributed valve cover stiffeners are welded to the outer periphery of the valve cover cylinder. The lower ends of the valve cover stiffeners are welded to the valve cover, and the upper ends of the valve cover stiffeners are welded to the valve cover flange. This structure effectively improves the rigidity of the valve cover structure, prevents high-pressure deformation, and is suitable for high-pressure operating conditions.

[0011] As a preferred technical approach: a stuffing box is installed on top of the flange on the valve cover, and a bellows is fitted over the middle of the valve stem, forming a double-sealing structure with the packing sealing structure inside the stuffing box. Through the packing sealing structure and the bellows sealing structure, a static and dynamic double-sealing structure is achieved, effectively adapting to high-pressure sealing conditions and sealing conditions involving toxic and harmful media.

[0012] As a preferred technical approach: the upper end of the valve stem is connected to a pneumatic actuator, and the lower end is connected to a left wedge block. The pneumatic actuator is fixed by a rigid frame formed by welding the lower plate blank of the support, the support cylinder, and the upper plate blank of the support. The support cylinder is provided with a maintenance window. Welding the rigid frame avoids coupling with pipeline vibration, ensuring a small fluctuation range in the actuator's output force. The maintenance window allows direct inspection and repair of vulnerable parts such as the valve stem nut and anti-rotation mechanism without disassembling the actuator, making maintenance convenient and shortening maintenance time.

[0013] As a preferred technical means, metal spiral wound gaskets are used for sealing between the valve cover and the valve body, and at the connection between the flange on the valve cover and the stuffing box. The metal spiral wound gaskets can withstand pressures of over 60 MPa, have a rebound rate of ≥40%, compensate for minor deformations of the flange surface, are suitable for high-pressure conditions with a wide temperature range, meet the requirements of extreme conditions, and reduce the risk of seal failure caused by thermal cycling.

[0014] Beneficial effects: By welding STL alloys of different hardnesses onto both sides of the sealing surface, the wear of the valve can be reduced, the coefficient of friction can be lowered, and the smoothness of opening and closing can be improved. The double parallel valve plates are wedge-tightened through the wedge linkage mechanism, forming a bidirectional multi-stage sealing pair. The wear of the sealing surface is compensated by horizontal displacement, which extends the service life of the valve and effectively improves the sealing performance. By welding STL alloy layers onto the mating inclined surfaces of the left and right wedges, the friction generated by frequent relative sliding can be withstood, reducing wedge wear and ensuring stable wedge tightening force. The high-temperature oxidation resistance of STL alloy is suitable for high-temperature conditions, avoiding wedge jamming caused by thermal expansion. Through the wedge self-compensation structure, multi-sealing structure and rigid force transmission path, the sealing performance, reliability and maintenance convenience are effectively improved. It is especially suitable for high-pressure toxic media and can significantly reduce the risk of system leakage and operation and maintenance costs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the main structure of this utility model.

[0016] Figure 2 This is a schematic diagram of the right-side structure of this utility model.

[0017] Figure 3 yes Figure 2 A schematic diagram of the AA section.

[0018] Figure 4 yes Figure 3 Enlarged schematic diagram of part B.

[0019] Figure 5 yes Figure 3 Enlarged schematic diagram of part C.

[0020] Figure 6 This is an exploded view of the left and right wedge blocks of this utility model.

[0021] In the diagram: 1. Valve body; 2. Valve seat; 3. Double parallel valve plate; 4. Valve stem; 5. Valve cover; 6. Valve cover cylinder; 7. Valve cover upper flange; 8. Valve cover stiffener; 9. Lifting lug; 10. Stuffing box; 11. Stuffing gasket; 12. Stuffing; 13. Stuffing spacer; 14. Stuffing sleeve; 15. Stuffing pressure plate; 16. Bellows; 17. Upper sealing ring; 18. Lower sealing ring; 19. Metal spiral wound gasket; 20. Opening and closing nut flat steel clamp; 21. Pneumatic actuator; 22. Bracket upper plate blank; 23. Cylindrical pin; 24. Bracket lower plate blank; 25. Bracket cylinder; 26. Left wedge; 27. Right wedge; 28. Guide plate; 29. ​​STL alloy layer. Detailed Implementation

[0022] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings.

[0023] Example 1

[0024] like Figure 1-5As shown, a high-pressure wedge-type flat gate valve includes a valve body 1, a valve seat 2, double parallel valve plates 3, a valve stem 4, and a valve cover 5. The valve seats 2 are mirror-symmetrically distributed on both sides of the double parallel valve plates 3 within the valve body 1. The valve cover 5 is located at the upper end of the valve body 1, and a valve cover cylinder 6 is welded to the valve cover 5. A valve cover flange 7 is welded to the upper end of the valve cover cylinder 6. Four evenly distributed vertical valve cover stiffeners 8 are welded around the outer periphery of the valve cover cylinder 6. The lower end of the valve cover stiffeners 8 is welded to the valve cover 5, and the upper end of the valve cover stiffeners 8 is welded to the valve cover flange 7. The valve cover stiffeners 8 enhance the structural rigidity of the valve cover 5 and prevent deformation under high pressure. Two lifting lugs 9 are welded to the middle of the valve cover cylinder 6 along its height, providing conditions for hoisting the valve as a whole or in sections. A stuffing box 10 is installed on the upper flange 7 of the valve cover. Inside the stuffing box 10, a stuffing gasket 11, two sets of packing 12, a packing spacer 13, a packing compression sleeve 14, and a packing pressure plate 15 are installed sequentially. The packing 12 is tightened using spring washers, type 2 hexagonal nuts, and fully threaded studs. A bellows 16 is fitted in the middle of the valve stem 4. An upper sealing ring 17 is located at the upper end of the bellows 16, and a lower sealing ring 18 is located at the lower end. The lower sealing ring 18 is fixed to the valve stem 4. The upper sealing ring 17 is located inside the space between the stuffing box 10 and the upper flange 7 of the valve cover. A metal spiral wound gasket 19 is used for sealing the connection between the upper sealing ring 17 and the stuffing box 10. A metal spiral wound gasket 19 is also used for sealing the connection between the upper sealing ring 17 and the upper flange 7 of the valve cover. Through the sealing structures of the packing 12 and the bellows 16, a static and dynamic dual-sealing structure is achieved. The upper end of the valve stem 4 is connected to the pneumatic actuator 21 via the opening and closing nut flat steel clamp 20. The valve stem 4 passes downward through the packing 12 structure, the upper sealing ring 17, the valve cover upper flange 7, and the valve cover cylinder 6 in sequence before entering the inner cavity of the valve body 1. The opening and closing nut flat steel clamp 20 is positioned and fixed by the cylindrical pin 23 and the internal hexagonal head screw. The pneumatic actuator 21 is fixed by a rigid frame formed by welding the lower plate blank 24 of the bracket, the bracket cylinder 25, and the upper plate blank 22 of the bracket. The bracket cylinder 25 is provided with a maintenance window for easy maintenance. The double parallel valve plate 3 includes a left valve plate and a right valve plate. A left wedge 26 is provided on the right side of the left valve plate, and a right wedge 27 is provided on the left side of the right valve plate. The upper end of the left wedge 26 is connected to the valve stem 4. The upper left and right sides of the left wedge 26 are connected and fixed with a guide plate 28 by four sets of type 2 hexagonal nuts and fully threaded bolts. When the left wedge 26 moves down, the lower part of the guide plate 28 extends into the annular groove of the double parallel valve plate 3 to guide and position the left wedge 26 and the double parallel valve plate 3. The left wedge 26 and the right wedge 27 are engaged by the wedge angle bevel and generate horizontal displacement under the drive of the valve stem 4 to open or release the double parallel valve plate 3. The sealing surfaces of the valve seat 2 and the double parallel valve plate 3 are respectively overlaid with STL alloy, and there is a hardness difference between the two.

[0025] To ensure smooth wedge movement during valve opening and closing, the left wedge 26 and right wedge 27 are fitted with a wedge-angled inclined surface with an angle of 15° to the vertical. This angle is greater than the friction self-locking critical angle, ensuring smooth wedge movement during valve opening and closing, while efficiently converting the axial force of the valve stem 4 into valve plate sealing force.

[0026] When the pneumatic actuator 21 controls the valve stem 4 to move downwards, it drives the left wedge block 26 to move downwards as well. The left wedge block 26, through the wedge angle and inclined surface engagement, changes the direction of force, pushing the right wedge block 27 to move laterally. Through action and reaction forces, the left and right valve plates of the double parallel valve plates 3 seal the sealing surface between themselves and the valve seat 2. If this sealing surface wears due to long-term use, the wedge block will automatically move downwards accordingly, synchronously pressing the sealing surface to form a bidirectional, multi-stage sealing pair, achieving a self-compensating structure for the sealing surface. By welding STL alloys of different hardnesses onto both sides of the sealing surface, wear and friction coefficients can be reduced, improving opening and closing smoothness. Through the multi-sealing structure and rigid force transmission path, sealing performance, reliability, and ease of maintenance are effectively improved. It is especially suitable for high-pressure toxic media, significantly reducing system leakage risk and maintenance costs.

[0027] Example 2

[0028] Unlike the above embodiment, as Figure 6 As shown, the mating bevels of the left wedge 26 and the right wedge 27 are both overlaid with an STL alloy layer 29. The STL alloy overlay on the bevels can withstand the friction generated by frequent relative sliding, reduce wedge wear, and ensure stable wedge clamping force. The high-temperature oxidation resistance of the STL alloy is suitable for high-temperature working conditions, preventing wedge jamming due to thermal expansion.

[0029] The STL alloy layer 29 has a thickness of 3mm. This thickness optimization ensures sufficient wear resistance life, avoids the risk of weld overlay cracking, and controls manufacturing costs.

[0030] Example 3

[0031] Unlike Embodiment 1 or 2 above, as Figure 6 As shown, the right wedge 27 has a rectangular hole running through it from left to right. The STL alloy layer 29 of the right wedge 27 is disposed on the inclined surfaces on both sides of the rectangular hole. The position of the STL alloy layer on the left wedge 26 corresponds to the position of the STL alloy layer 29 on the right wedge 27. Alloy is deposited only on critical friction surfaces, reducing material waste and lowering manufacturing costs.

[0032] The high-pressure wedge-type flat gate valve shown above is a specific embodiment of this utility model, which has demonstrated the substantial features and progress of this utility model. According to actual use needs, equivalent modifications in shape, structure, etc. can be made to it under the guidance of this utility model, all of which are within the protection scope of this solution.

Claims

1. A high-pressure wedge-type flat gate valve, comprising a valve body, valve seats, double parallel valve plates, a valve stem, and a valve cover, wherein the valve seats are mirror-symmetrically distributed on both sides of the double parallel valve plates within the valve body, the valve cover is disposed at the upper end of the valve body, and the valve stem passes through the valve cover from top to bottom and enters the inner cavity of the valve body, characterized in that: The dual parallel valve plate includes a left valve plate and a right valve plate. A left wedge is provided on the right side of the left valve plate, and a right wedge is provided on the left side of the right valve plate. The upper end of the left wedge is connected to the valve stem. The left wedge and the right wedge are engaged by a wedge angle bevel, and under the drive of the valve stem, they generate horizontal displacement to open or release the dual parallel valve plate. The valve seat and the sealing surface of the dual parallel valve plate are respectively overlaid with STL alloy layer, and there is a hardness difference between the two.

2. The high-pressure wedge-type flat gate valve according to claim 1, characterized in that: The mating bevels of the left and right wedges are both overlaid with an STL alloy layer.

3. A high-pressure wedge-type flat gate valve according to claim 2, characterized in that: The STL alloy layer has a thickness of 2-4 mm.

4. A high-pressure wedge-type flat gate valve according to claim 2, characterized in that: The right wedge has a rectangular hole running through it from left to right. The STL alloy layer of the right wedge is located on the inclined surfaces on both sides of the rectangular hole of the right wedge. The position of the STL alloy layer on the left wedge corresponds to the position of the STL alloy layer on the right wedge.

5. A high-pressure wedge-type flat gate valve according to claim 4, characterized in that: The left and right wedges are connected by a wedge-shaped inclined surface with an angle of 15-20 degrees to the vertical.

6. A high-pressure wedge-type flat gate valve according to claim 5, characterized in that: The left wedge has a guide plate fixed to each of its upper left and right sides by fasteners. When the left wedge moves down, the lower part of the guide plate extends into the annular groove of the double parallel valve plate to guide and position the left wedge and the double parallel valve plate.

7. A high-pressure wedge-type flat gate valve according to claim 6, characterized in that: A valve cover cylinder is welded to the valve cover, and a valve cover flange is welded to the upper end of the valve cover cylinder. Multiple valve cover stiffeners are welded around the outer periphery of the valve cover cylinder. The lower end of the valve cover stiffener is welded to the valve cover, and the upper end of the valve cover stiffener is welded to the valve cover flange.

8. A high-pressure wedge-type flat gate valve according to claim 7, characterized in that: A stuffing box is provided on the top of the flange of the valve cover, and a bellows is sleeved in the middle of the valve stem, forming a double sealing structure with the packing sealing structure in the stuffing box.

9. A high-pressure wedge-type flat gate valve according to claim 8, characterized in that: The upper end of the valve stem is connected to a pneumatic actuator, and the lower end is connected to a left wedge block. The pneumatic actuator is fixed by a rigid frame formed by welding the lower plate blank of the bracket, the bracket cylinder, and the upper plate blank of the bracket. The bracket cylinder is provided with a maintenance window.

10. A high-pressure wedge-type flat gate valve according to claim 9, characterized in that: Metal spiral wound gaskets are provided for sealing between the valve cover and the valve body, and at the connection between the flange on the valve cover and the stuffing box.

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