Low-temperature top-mounted fixed ball valve

Abstract

The utility model discloses a low-temperature top-mounted fixed ball valve, which particularly relates to the field of ball valves, and comprises a step surface and a sealing surface which are sequentially arranged on a valve body from a middle cavity to an end part, the outer diameters of the step surface and the sealing surface are gradually reduced, a sealing ring is arranged between the head of a valve seat body and the sealing surface of a ball body, and a sealing pressing ring is tightly attached to the sealing ring. The valve seat is fixed on the valve seat body in a threaded connection manner; the valve seat assembly comprises a valve seat body, a plate spring, a fireproof graphite ring, a low-temperature energy storage ring, a valve seat pressing ring and a fastening screw. A pre-tightening nut is in threaded connection with the step face of the valve seat assembly and abuts against the end, away from the ball, of the plate spring. The sealing pressing ring is arranged on the valve seat sealing ring and is fixedly connected through the threads, so that the sealing ring is effectively prevented from deviating when a medium flows, the sealing performance is ensured, and potential safety hazards are reduced. The sealing ring can keep a stable sealing state in the using process, the reliability and safety of the valve are greatly improved, and the defects in the prior art are overcome.

Description

Technical Field

[0001] The utility model relates to the technical field of ball valves, and more specifically to a low-temperature top-loading fixed ball valve. Background Art

[0002] With the rapid development of petroleum and chemical industry, especially the widespread application of liquefied natural gas (LNG) as a new energy source, the requirements for valves working under low temperature conditions are becoming more and more stringent. Ball valves are widely used due to their advantages such as small fluid resistance, convenient operation, reliable sealing, and rapid opening and closing. In comparison, top-entry ball valves have the advantages of fewer external leakage points, simple structure, and less influence of pipeline stress. At the same time, they are easy to disassemble on the pipeline and convenient and quick to maintain, which is more popular with customers. Therefore, the market needs a high-performance top-entry cryogenic ball valve with reliable valve seat sealing, safety and fire protection, and low cost under low temperature conditions;

[0003] When a large flow of medium flows through an existing fixed ball valve, the valve seat is often impacted and vibrated by the medium, causing the sealing ring to shift and forming a gap between the sealing surface. In severe cases, leakage may even occur, directly affecting the normal use of the valve and causing safety hazards. Therefore, how to maintain the stability of the valve seat sealing ring under low temperature conditions and prevent it from shifting has become an urgent problem to be solved. Utility Model Content

[0004] In order to overcome the above-mentioned defects of the prior art, an embodiment of the utility model provides a low-temperature top-mounted fixed ball valve. By arranging a sealing pressure ring on the valve seat sealing ring and fixing it with a threaded connection, the utility model effectively prevents the sealing ring from shifting when the medium flows, ensures the sealing performance, and solves the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a low-temperature top-loading fixed ball valve, including a valve body, a valve cover, a ball, a valve stem, a valve seat assembly I, a valve seat assembly II, a pre-tightening nut, a support shaft, a spiral wound gasket, a gasket, a packing pad, a packing, a packing sleeve, a packing pressure plate, a bracket, a cylindrical pin, a thrust pad, a wear-reducing pad, a support pressure ring, a loose-proof sheet, an anti-rotation block, a spring, a leaf spring, a fireproof graphite ring, an anti-rotation seat ring, a valve seat pressure ring, bolts and nuts and a disc spring, a disc spring, a key, a bearing, a sealing pressure ring, a valve seat sealing ring, and a positioning pin; the valve body is from the middle cavity A step surface and a sealing surface with decreasing outer diameters are sequentially arranged toward the end, a sealing ring is arranged between the head of the valve seat body and the sealing surface of the ball, and the sealing pressure ring is tightly attached to the sealing ring and fixed to the valve seat body by a threaded connection; the valve seat assembly comprises a valve seat body, a leaf spring, a fireproof graphite ring, a low-temperature energy storage ring, a valve seat pressure ring and a fastening screw; a pre-tightening nut is threadedly connected on the step surface of the valve seat assembly, and the pre-tightening nut is attached to one end of the leaf spring away from the ball; an anti-rotation seat ring assembly is arranged in the valve body, facing the rear end face of the valve seat assembly, and a locating pin inserted into the valve seat assembly is arranged in the anti-rotation seat ring assembly.

[0006] In a preferred embodiment, a sealing groove and a connecting thread groove are provided on the head of the valve seat body, a sealing ring cooperating with the ball is arranged in the sealing groove, the sealing pressure ring is tightly attached to the sealing ring, and a boss is provided therebetween, and the outer circle of the sealing pressure ring and the connecting thread groove in the valve seat body form a threaded engagement structure; the sealing ring realizes a sealing combination with the valve seat sealing groove and the ball sealing surface.

[0007] In a preferred embodiment, the leaf spring, the fireproof graphite ring, the low-temperature energy storage ring, and the valve seat pressure ring are sequentially sleeved on the sealing surface from the head to the tail of the valve seat body, and the valve seat pressure ring is fastened to the tail of the valve seat body with screws;

[0008] The anti-rotation seat ring assembly is welded and fixed to the valve body, and a pin hole which is coaxial with the positioning pin and has clearance fit is arranged at the tail of the valve seat, and the positioning pin corresponds to the pin hole one by one.

[0009] In a preferred embodiment, the pre-tightening nut has a dovetail groove structure, and the pre-tightening nut is driven to rotate by turning a wrench so that the valve seat sealing surface is matched with the ball for sealing. After reaching the expected position, the valve seat assembly is fixed to the valve body with a locking sheet and a screw, so that the valve seat assembly remains sealed during use;

[0010] The sealing surface of the sphere is built-up with hard alloy, and a spiral wound gasket is arranged between the valve cover and the valve body.

[0011] In a preferred embodiment, a support pressure ring is arranged between the valve body and the valve cover, and a low-temperature energy storage ring is provided on the support pressure ring. The low-temperature energy storage ring is tightly attached to the contact surface of the valve cover and fits with the inner wall of the top of the valve body to realize a sealing combination, and then is fastened to the bottom of the valve cover with bolts to prevent the support pressure ring structure from moving; multiple seals are adopted between the valve body and the valve cover, and a low-temperature energy storage ring is added on the basis of the wound gasket.

[0012] In a preferred embodiment, a flexible graphite filler, an O-ring, and a low-temperature energy storage sealing ring are provided between the valve stem and the valve cover; and a friction-reducing pad and a thrust pad are provided between the valve stem and the valve cover.

[0013] In a preferred embodiment, a spring and a cushion block are provided at the contact point between the bottom of the ball and the support shaft. Under the self-weight of the ball, the spring and the cushion block are used to adjust the height of the ball and make the center line of the ball and the valve seat assembly and the center of the valve body on the same center line;

[0014] A plurality of transmission pins are arranged at the connection between the valve stem and the sphere.

[0015] Technical effects and advantages of the utility model:

[0016] 1. In the utility model, the valve seat sealing ring and the sealing pressure ring are fixed by threaded connection, which effectively prevents the sealing ring from deflecting when the medium flows, ensures the sealing performance, and reduces safety hazards. The sealing ring can maintain a stable sealing state during use, which improves the reliability and safety of the valve;

[0017] 2. The utility model ensures that the valve seat assembly does not move when subjected to force, maintains concentricity with the ball, prevents wear of the sealing surface, and prolongs the service life through the design of the anti-rotation seat ring assembly and the positioning pin. This design can provide stable support during the flow of the medium and the operation of the valve to ensure the sealing effect between the valve seat and the ball;

[0018] 3. The multiple seal design and top loading structure are adopted to reduce leakage points, realize online maintenance, and ensure reliable sealing and convenient maintenance operations under low temperature conditions. The multiple seal design provides multi-level protection, improves the sealing reliability of the valve under extreme conditions, and the top loading structure makes maintenance easier and faster, reducing downtime and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is an overall cross-sectional view of the low-temperature top-mounted fixed ball valve of the utility model.

[0020] Figure 2 For this utility model Figure 1 Cross-sectional view of the lower part of the structure.

[0021] Figure 3 For this utility model Figure 1 A cross-sectional view of the upper structure.

[0022] Figure 4 It is a connection diagram and matching annotation diagram of the low-temperature top-mounted fixed ball valve and valve seat assembly of the utility model.

[0023] Figure 5 It is a schematic diagram of the pre-tightening nut of the low-temperature upper fixed ball of the utility model.

[0024] Figure 6 It is a schematic diagram of the valve stem of the low-temperature top-mounted fixed ball valve of the utility model.

[0025] Figure 7 It is a schematic diagram of the upper valve cover of the low-temperature top-mounted fixed ball valve of the utility model.

[0026] The accompanying drawings are marked as follows: 1. valve body; 2. valve cover; 3. ball; 4. valve stem; 5. valve seat assembly I; 6. valve seat assembly II; 7. pre-tightening nut; 8. support shaft; 9. spiral wound gasket; 10. gasket block; 11. packing pad; 12. packing; 13. packing sleeve; 14. packing pressure plate; 15. bracket; 16. cylindrical pin; 17. thrust pad; 18. wear-reducing pad; 19. support pressure ring; 20. anti-loosening sheet; 21. anti-rotation block; 22. spring; 23. leaf spring; 24. fireproof graphite ring; 25. anti-rotation seat ring; 26. valve seat pressure ring; 27. bolts, nuts and disc springs; 28. key; 29. ​​bearing; 30. sealing pressure ring; 31. valve seat sealing ring; 32. positioning pin. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] Refer to the instruction manual Figure 1-7A low-temperature top-loading fixed ball valve according to an embodiment of the utility model comprises a valve body 1, a valve cover 2, a ball 3, a valve stem 4, a valve seat assembly I5, a valve seat assembly II6, a pre-tightening nut 7, a support shaft 8, a spiral wound gasket 9, a cushion block 10, a packing pad 11, a packing 12, a packing sleeve 13, a packing pressure plate 14, a bracket 15, a cylindrical pin 16, a thrust pad 17, a friction reducing pad 18, a support pressure ring 19, an anti-loosening sheet 20, an anti-rotation block 21, a spring 22, a leaf spring 23, a fireproof graphite ring 24, an anti-rotation seat ring 25, a valve seat pressure ring 26, a bolt nut and a disc spring 27, a disc spring, a key 28, a bearing 29, a sealing pressure ring 30, a valve seat sealing ring 31, a positioning Pin 32; the valve body 1 is provided with a step surface and a sealing surface with decreasing outer diameter in sequence from the middle cavity to the end direction; a sealing ring is provided between the head of the valve seat body and the sealing surface of the ball 3, and the sealing pressure ring 30 is tightly against the sealing ring and fixed to the valve seat body by a threaded connection; the valve seat assembly includes a valve seat body, a leaf spring 23, a fireproof graphite ring 24, a low-temperature energy storage ring, a valve seat pressure ring 26 and a fastening screw; the pre-tightening nut 7 is threadedly connected on the step surface of the valve seat assembly, and the pre-tightening nut 7 is abutted against the end of the leaf spring 23 away from the ball 3; an anti-rotation seat ring 25 assembly facing the rear end face of the valve seat assembly is provided in the valve body 1, and a positioning pin 32 inserted into the valve seat assembly is provided in the anti-rotation seat ring 25 assembly.

[0029] A sealing groove and a connecting thread groove are provided on the head of the valve seat body. A sealing ring cooperating with the ball 3 is arranged in the sealing groove. The sealing pressure ring 30 is tightly against the sealing ring, and a boss is provided therebetween. The outer circle of the sealing pressure ring 30 and the connecting thread groove in the valve seat body form a threaded engagement structure. The sealing ring, the valve seat sealing groove, and the sealing surface of the ball 3 are sealed together to enhance its stability and avoid a gap caused by offset between the sealing ring and the valve seat.

[0030] Among them, the leaf spring 23, the fireproof graphite ring 24, the low-temperature energy storage ring, and the valve seat pressure ring 26 are sequentially sleeved on the sealing surface from the head to the tail of the valve seat body, and the valve seat pressure ring 26 is fastened to the tail of the valve seat body with screws; the anti-rotation seat ring 25 assembly is welded and fixed to the valve body 1, and the tail of the valve seat is provided with a pin hole which is coaxial with the locating pin 32 and has a clearance fit, and the locating pin 32 corresponds to the pin hole one by one, and is used to stabilize the valve seat assembly.

[0031] Among them, the pre-tightening nut 7 has a dovetail groove structure, and the pre-tightening nut 7 is driven to rotate by turning the wrench to make the valve seat sealing face and seal with the ball 3. After reaching the expected position, the anti-loosening plate 20 and screws are used to fix it on the valve body 1, so that the valve seat assembly remains sealed during use and provides a certain pre-tightening force; the sealing surface of the ball 3 is welded with hard alloy, and through hardening treatment, its wear resistance and impact resistance are enhanced, and its service life is extended. A spiral wound gasket 9 is provided between the valve cover 2 and the valve body 1, which plays the role of the first sealing.

[0032] A support pressure ring 19 is arranged between the valve body 1 and the valve cover 2, and a low-temperature energy storage ring is arranged on the support pressure ring 19. The low-temperature energy storage ring is tightly attached to the contact surface of the valve cover 2 and fits with the top inner wall of the valve body 1 to achieve a sealing combination, and then is fastened to the bottom of the valve cover 2 with bolts to prevent the support ring 19 from structural movement; multiple seals are adopted between the valve body 1 and the valve cover 2, and a low-temperature energy storage ring is added on the basis of the spiral wound gasket 9 to ensure the reliability and safety of the sealing of the contact surface between the valve body 1 and the valve cover 2, which plays a second sealing role.

[0033] A flexible graphite packing 12, an O-ring, and a low-temperature energy storage sealing ring are provided between the valve stem 4 and the valve cover 2. Multiple seals ensure the safety and reliability of the sealing of the valve stem 4. A friction-reducing pad 18 and a thrust pad 17 are provided between the valve stem 4 and the valve cover 2. The valve stem 4 can effectively reduce the friction with the contact surface of the valve cover 2 during the opening or closing process, reduce the opening and closing operating torque, ensure the normal operation of the valve, and extend the service life of the valve.

[0034] A spring 22 and a cushion block 10 are provided at the contact point between the bottom of the ball 3 and the support shaft 8. Under the self-weight of the ball 3, the spring 22 and the cushion block 10 are used to adjust the height of the ball 3 and make the center line of the ball 3 and the center of the valve seat assembly and the valve body 1 on the same center line, which plays a role of automatic centering; at the same time, the cushion block 10 and the spring 22 can appropriately buffer and offset part of the self-weight of the ball 3, thereby ensuring the sealing and safety of the valve during use;

[0035] Among them, a plurality of transmission pins are provided at the connection between the valve stem 4 and the ball 3. When the valve is running, the transmission pins are connected to transmit torque, thereby improving the connection strength between the valve stem 4 and the ball 3, avoiding the valve stem 4 from being squeezed and deformed due to the head, resulting in the valve not being opened and closed properly, reducing the gap caused by wear, and ensuring the sealing and safety of the valve during opening and closing. The valve as a whole adopts a top-mounted structure, which reduces leakage points and enables online maintenance.

[0036] Working principle: The low-temperature top-loading fixed ball valve of the utility model achieves reliable sealing performance and convenient operation through optimized structural design. The step surface and sealing surface in the valve body 1 decrease step by step, so that a tight seal is formed between the head of the valve seat body and the sealing surface of the ball 3. The sealing pressure ring 30 is fixed to the valve seat body through a threaded connection, which further enhances the sealing effect and effectively prevents the sealing ring 31 from deflecting during the flow of the medium, thereby ensuring the stability of the seal.

[0037] An anti-rotation seat ring 25 assembly is arranged in the valve body 1, and a positioning pin 32 is inserted into the valve seat assembly, so that the valve seat assembly will not be displaced when subjected to the force of the medium, and the concentricity with the ball 3 is maintained to prevent the wear of the sealing surface. In addition, the pre-tightening nut 7 is fixed with the anti-loosening sheet 20 and the screw through the dovetail groove structure, so that the valve seat sealing surface and the ball 3 are always closely matched, and a stable pre-tightening force is provided to prevent the sealing failure;

[0038] A multiple sealing design is adopted between the valve cover 2 and the valve body 1, including a spiral wound gasket 9 and a low-temperature energy storage ring, to ensure reliable sealing of the contact surface. A flexible graphite filler 12, an O-ring and a low-temperature energy storage sealing ring are arranged between the valve stem 4 and the valve cover 2. The multiple sealing structure ensures the sealing safety and reliability of the valve stem 4. At the same time, a friction-reducing pad 18 and a thrust pad 17 are arranged between the valve stem 4 and the valve cover 2, which effectively reduce friction and operating torque during the opening and closing process of the valve, thereby extending the service life.

[0039] In order to ensure the stability of the ball 3 during use, a spring 22 and a cushion block 10 are provided at the contact point between the bottom of the ball 3 and the support shaft 8. By adjusting the height of the ball 3, its center line is kept consistent with the center line of the valve seat assembly and the valve body 1, so as to achieve automatic centering and ensure the sealing and safety of the valve. In addition, the spring 22 and the cushion block 10 can properly buffer the dead weight of the ball 3, so as to further ensure the sealing and safety during use. The overall top-loading structure design reduces leakage points and can realize online maintenance, which is convenient for users to operate and maintain, and ensures the reliable operation of the valve under various working conditions.

[0040] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change;

[0041] Secondly: In the drawings of the embodiments disclosed in the present utility model, only the structures related to the embodiments disclosed in the present utility model are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present utility model can be combined with each other;

[0042] Finally: The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A low-temperature top-loading fixed ball valve, comprising a valve body (1), a valve cover (2), a ball (3), a valve stem (4), a valve seat assembly I (5), a valve seat assembly II (6), a pre-tightening nut (7), a support shaft (8), a spiral wound gasket (9), a cushion block (10), a packing pad (11), a packing (12), a packing gland (13), a packing pressure plate (14), a bracket (15), a cylindrical pin (16), a thrust pad (17), a friction reducing pad (18), a support pressure ring (19), an anti-loosening sheet (20), an anti-rotation block (21), a spring (22), a leaf spring (23), a fireproof graphite ring (24), an anti-rotation seat ring (25), a valve seat pressure ring (26), bolts and nuts and a disc spring (27), a key (28), a bearing (29), a sealing pressure ring (30), a valve seat sealing ring (31), and a positioning pin (32); characterized in that: The valve body (1) is provided with a step surface and a sealing surface with decreasing outer diameters in sequence from the middle cavity to the end; the valve seat assembly includes a valve seat body, a leaf spring (23), a fireproof graphite ring (24), a low-temperature energy storage ring, a valve seat pressure ring (26) and a fastening screw, a sealing ring is provided between the head of the valve seat body and the sealing surface of the ball (3), and the sealing pressure ring (30) is tightly attached to the sealing ring and fixed to the valve seat body by a threaded connection; a pre-tightening nut (7) is threadedly connected to the step surface of the valve seat assembly, and the pre-tightening nut (7) is attached to one end of the leaf spring (23) away from the ball (3); an anti-rotation seat ring (25) assembly is provided in the valve body (1) and is directly opposite to the rear end face of the valve seat assembly, and a positioning pin (32) inserted into the valve seat assembly is provided in the anti-rotation seat ring (25) assembly.

2. A cryogenic top entry fixed ball valve according to claim 1, characterized in that: The head of the valve seat body is provided with a sealing groove and a connecting thread groove, a sealing ring matched with the ball (3) is arranged in the sealing groove, the sealing pressure ring (30) is tightly attached to the sealing ring, and a boss is arranged therebetween, the outer circle of the sealing pressure ring (30) and the connecting thread groove in the valve seat body form a threaded engagement structure; the sealing ring, the valve seat sealing groove, and the sealing surface of the ball (3) are sealed together.

3. A low temperature top entry fixed ball valve according to claim 2, characterized in that: The leaf spring (23), the fireproof graphite ring (24), the low-temperature energy storage ring, and the valve seat pressure ring (26) are sequentially sleeved on the sealing surface from the head to the tail of the valve seat body, and the valve seat pressure ring (26) is fastened to the tail of the valve seat body by screws; The anti-rotation seat ring (25) assembly is welded and fixed to the valve body (1), and a pin hole coaxial with the positioning pin (32) and having a clearance fit is provided at the tail of the valve seat, and the positioning pin (32) corresponds to the pin hole one by one.

4. A low temperature top entry fixed ball valve according to claim 3, characterized in that: The pre-tightening nut (7) has a dovetail groove structure, and the pre-tightening nut (7) is driven to rotate by turning a wrench, so that the valve seat sealing surface is matched with the ball (3) for sealing. After reaching the expected position, the valve seat assembly is fixed to the valve body (1) by a locking plate (20) and a screw, so that the valve seat assembly remains sealed during use; The sealing surface of the ball (3) is built-up with hard alloy, and a spiral wound gasket (9) is provided between the valve cover (2) and the valve body (1).

5. A low temperature top entry fixed ball valve according to claim 4, characterized in that: A support pressure ring (19) is arranged between the valve body (1) and the valve cover (2), and a low-temperature energy storage ring is arranged on the support pressure ring (19). The low-temperature energy storage ring is tightly attached to the contact surface of the valve cover (2) and fits with the inner wall of the top of the valve body (1) to achieve a sealing combination, and is then fastened to the bottom of the valve cover (2) with bolts to prevent the support pressure ring (19) from moving. Multiple seals are adopted between the valve body (1) and the valve cover (2), and a low-temperature energy storage ring is added on the basis of the spiral wound gasket (9).

6. A cryogenic top entry fixed ball valve according to claim 5, characterized in that: A flexible graphite filler (12), an O-ring, and a low-temperature energy storage sealing ring are provided between the valve stem (4) and the valve cover (2); and a friction-reducing pad (18) and a thrust pad (17) are provided between the valve stem (4) and the valve cover (2).

7. A cryogenic top entry fixed ball valve according to claim 6, characterized in that: A spring (22) and a cushion block (10) are provided at the contact point between the bottom of the ball (3) and the support shaft (8). Under the self-weight of the ball (3), the spring (22) and the cushion block (10) are used to adjust the height of the ball (3) and to make the center line of the ball (3) and the center of the valve seat assembly and the valve body (1) on the same center line; A plurality of transmission pins are provided at the connection between the valve stem (4) and the sphere (3).

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