Low-temperature fixed ball valve

Abstract

The low-temperature fixed ball valve is characterized by further comprising a bottom shaft, a long neck type valve cover and a pressure relief hole, wherein the bottom shaft penetrates through a main valve body, is arranged at the bottom of a ball body and is used for reducing the rotating friction resistance of the ball body; the long neck type valve cover is arranged outside a valve rod; the bottom shaft is arranged at the bottom of the ball body, so that the ball body has upward supporting force, the friction resistance during rotation of the ball body is reduced, the operation torque of the valve rod is reduced, and the ball body can be opened and closed flexibly even in a low-temperature environment; through the arrangement of the long-neck valve cover, the stuffing box is far away from a low-temperature area, the influence degree of a low-temperature medium on valve rod sealing stuffing is reduced, the sealing performance of the ball valve is improved, and meanwhile cold energy loss is reduced. The pressure relief hole is formed in the ball body, so that the ball body can be prevented from automatically relieving pressure by virtue of the function of the valve seat when the medium in the cavity of the valve body is abnormally boosted due to temperature rise, and an overpressure protection function is achieved.

Description

Technical Field

[0001] This utility model relates to the field of cryogenic ball valve technology, specifically a cryogenic fixed ball valve. Background Technology

[0002] As one of the key valves in LNG plants, cryogenic ball valves currently on the market suffer from several drawbacks. The short length of the valve cover mounted on the valve stem makes the stuffing gland susceptible to the effects of the cryogenic medium, leading to stuffing gland failure. This results in poor sealing performance, short service life, limited applicability, and, in particular, easy wear and leakage of the sealing surface after long-term use. These issues affect the valve's opening and closing life and shut-off tightness, severely hindering its normal operation and failing to meet the ever-growing demands of automated control. Therefore, a cryogenic fixed ball valve is proposed. Utility Model Content

[0003] The main purpose of this utility model is to provide a solution that can effectively address the problems in the background art.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a cryogenic fixed ball valve, comprising a main valve body, a secondary valve body connected to the main valve body, a ball disposed within the main valve body and the secondary valve body, a valve stem passing through the main valve body and connected to the ball, a bracket disposed at the top of the valve stem, and an actuator disposed on the bracket and connected to the valve stem, characterized in that: it further comprises a bottom shaft passing through the main valve body and disposed at the bottom of the ball to reduce the rotational frictional resistance of the ball, a long-neck valve cover disposed outside the valve stem, and a pressure relief hole disposed on the ball.

[0005] Preferably, the bottom of the sphere is provided with a shaft hole that matches the bottom shaft.

[0006] Preferably, an upstream valve seat, a pressure ring, a sealing ring, a retaining ring, an energy storage sealing ring, and a gasket are provided between the ball and the secondary valve body.

[0007] Preferably, a downstream valve seat and a butterfly spring are provided between the ball and the main valve body.

[0008] Preferably, the bottom of the main valve body is provided with a lower cover for fixing the bottom shaft.

[0009] Preferably, a nut is provided between the main valve body and the valve cover, and a nut is provided between the bracket and the valve cover.

[0010] Preferably, the connection points between nut one and the main valve body and nut two and the bracket are both provided with fixing pins.

[0011] Preferably, the nut two is provided with a packing gasket, an energy storage sealing ring, a retaining ring, and a stuffing box from bottom to top to increase the sealing performance between the valve stem and the nut two.

[0012] Preferably, the valve stem is provided with a connecting shaft and a sleeve adapted to the connecting shaft.

[0013] Preferably, the bracket is provided with a pressure sleeve for fixing the stuffing box, and both the pressure sleeve and the main valve body are provided with bushings connected to the valve stem.

[0014] This invention has the following advantages: By setting a bottom shaft at the bottom of the ball, the ball has an upward supporting force, reducing the frictional resistance when the ball rotates, thereby reducing the operating torque of the valve stem. Even in low-temperature environments, the ball can still open and close flexibly. By setting a long-neck valve cover, the stuffing box is kept away from the low-temperature zone, reducing the impact of the low-temperature medium on the valve stem sealing packing, increasing the sealing performance of the ball valve, and also reducing cold energy loss. By setting a pressure relief hole on the ball, when the medium in the valve body cavity experiences abnormal pressure rise due to temperature increase, the ball can automatically relieve pressure by relying on the valve seat function, playing an overpressure protection function.

[0015] The dual sealing design of the sealing ring and the energy storage sealing ring increases the sealing performance of the valve seat and reduces the loss of cold energy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0017] Figure 2 This is a left view of the sphere of this utility model;

[0018] Figure 3 This is a partial enlarged view of A of this utility model;

[0019] Figure 4 This is a partial enlarged view (B) of this utility model;

[0020] Figure 5 This is a partial enlarged view of C of this utility model.

[0021] Legend: 1. Main valve body; 2. Secondary valve body; 3. Ball; 4. Valve stem; 5. Bracket; 6. Actuator; 7. Bottom shaft; 8. Valve cover; 9. Pressure relief hole; 10. Shaft hole; 11. Upstream valve seat; 12. Pressure ring; 13. Sealing ring; 14. Retaining ring; 15. Energy storage sealing ring; 16. Washer; 17. Downstream valve seat; 18. Butterfly spring; 19. Lower cover; 20. Nut 1; 21. Nut 2; 22. Fixing pin; 23. Stuffing box; 24. Stuffing gasket; 25. Connecting shaft; 26. Connecting sleeve; 27. Pressure sleeve; 28. Shaft sleeve. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0023] like Figure 1-5 As shown, a cryogenic fixed ball valve includes a main valve body 1, a secondary valve body 2 connected to the main valve body 1, a ball 3 disposed within the main valve body 1 and the secondary valve body 2, a valve stem 4 passing through the main valve body 1 and connected to the ball 3, a bracket 5 disposed at the top of the valve stem 4, and an actuator 6 disposed on the bracket 5 and connected to the valve stem 4. The valve is characterized by further including a bottom shaft 7 passing through the main valve body 1 and disposed at the bottom of the ball 3 to reduce the rotational frictional resistance of the ball 3, a long-necked valve cover 8 disposed outside the valve stem 4, and a pressure relief hole 9 disposed on the ball 3; the bottom of the ball 3 is provided with a shaft hole 10 adapted to the bottom shaft 7; through... A bottom shaft 7 is provided at the bottom of the ball 3 to provide upward support for the ball 3, reducing the frictional resistance when the ball 3 rotates, thereby reducing the operating torque of the valve stem 4. Even in low-temperature environments, the ball 3 can still open and close flexibly. The long-neck valve cover 8 keeps the stuffing box 23 away from the low-temperature zone, reducing the impact of the low-temperature medium on the sealing packing of the valve stem 4, increasing the sealing performance of the ball valve, and also reducing cold energy loss. By providing a pressure relief hole 9 on the ball 3, when the medium in the valve body cavity experiences abnormal pressure rise due to temperature increase, the ball 3 can automatically relieve pressure by relying on the valve seat function, providing overpressure protection.

[0024] In one embodiment, an upstream valve seat 11, a pressure ring 12, a sealing ring 13, a retaining ring 14, an energy storage sealing ring 15, and a gasket 16 are provided between the ball 3 and the secondary valve body 2; a downstream valve seat 17 and a butterfly spring 18 are provided between the ball 3 and the main valve body 1; the double sealing arrangement of the sealing ring 13 and the energy storage sealing ring 15 increases the sealing performance of the valve seat and reduces the loss of cold energy.

[0025] In one embodiment, the bottom of the main valve body 1 is provided with a lower cover 19 for fixing the bottom shaft 7.

[0026] In one embodiment, a nut 20 is provided between the main valve body 1 and the valve cover 8, and a nut 21 is provided between the bracket 5 and the valve cover 8; a fixing pin 22 is provided at the connection between the nut 20 and the main valve body 1 and the nut 21 and the bracket 5; the nut 21 is provided with a packing gasket 24, an energy storage sealing ring 15, a retaining ring 14 and a stuffing box 23 from bottom to top to increase the sealing performance of the valve stem 4 nut 21.

[0027] In one embodiment, the valve stem 4 is provided with a connecting shaft 25 and a connecting sleeve 26 adapted to the connecting shaft 25; the bracket 5 is provided with a pressure sleeve 27 for fixing the stuffing box 23, and both the pressure sleeve 27 and the main valve body 1 are provided with a bushing 28 connected to the valve stem 4.

[0028] In one embodiment, the actuator may be a manual turntable, a pneumatic hydraulic cylinder, or an electric hydraulic cylinder.

[0029] In use, this utility model drives the actuator 6 to rotate the connecting shaft 25 and the valve stem 4. The valve stem 4 drives the ball 3 to rotate. When the ball 3 rotates, it is supported by the bottom shaft 7 to prevent friction between the ball 3 and the upstream valve seat 11 and the downstream valve seat 17, which would affect the opening and closing of the valve. In addition, the valve stem 4 reduces the coefficient of friction between the valve stem 4 and the pressure sleeve 27 and the main valve body 1 through the bushing 28, so that the valve stem 4 can open and close quickly. When the valve is in the closed position, the valve stem 4 drives the ball 3 to rotate, so that the pressure relief hole 9 on the ball 3 points to the downstream valve seat 17, and the air is released through the valve seat.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A cryogenic fixed ball valve, comprising a main valve body (1), a secondary valve body (2) connected to the main valve body (1), a ball (3) disposed within the main valve body (1) and the secondary valve body (2), a valve stem (4) passing through the main valve body (1) and connected to the ball (3), a bracket (5) disposed on the top of the valve stem (4), and an actuator (6) disposed on the bracket (5) and connected to the valve stem (4), characterized in that: It also includes a bottom shaft (7) that passes through the main valve body (1) and is located at the bottom of the ball (3) to reduce the frictional resistance of the ball (3) rotation, a long-neck valve cover (8) located outside the valve stem (4), and a pressure relief hole (9) located on the ball (3).

2. The cryogenic fixed ball valve according to claim 1, characterized in that: The bottom of the sphere (3) is provided with a shaft hole (10) that is adapted to the bottom shaft (7).

3. A cryogenic fixed ball valve according to claim 1, characterized in that: The ball (3) and the sub-valve body (2) are provided with an upstream valve seat (11), a pressure ring (12), a sealing ring (13), a retaining ring (14), an energy storage sealing ring (15), and a gasket (16).

4. A cryogenic fixed ball valve according to claim 1, characterized in that: A downstream valve seat (17) and a butterfly spring (18) are provided between the ball (3) and the main valve body (1).

5. A cryogenic fixed ball valve according to claim 4, characterized in that: The bottom of the main valve body (1) is provided with a lower cover (19) for fixing the bottom shaft (7).

6. A cryogenic fixed ball valve according to claim 1, characterized in that: The main valve body (1) is provided with a nut (20) between the valve cover (8) and the bracket (5) is provided with a nut (21) between the valve cover (8).

7. A cryogenic fixed ball valve according to claim 6, characterized in that: The connection between nut one (20) and the main valve body (1) and nut two (21) and the bracket (5) is provided with a fixing pin (22).

8. A cryogenic fixed ball valve according to claim 7, characterized in that: The nut 2 (21) is provided with a packing gasket (24), an energy storage sealing ring (15), a retaining ring (14) and a stuffing box (23) from bottom to top to increase the sealing performance between the valve stem (4) and the nut 2 (21).

9. A cryogenic fixed ball valve according to claim 1, characterized in that: The valve stem (4) is provided with a connecting shaft (25) and a connecting sleeve (26) adapted to the connecting shaft (25).

10. A cryogenic fixed ball valve according to claim 1, characterized in that: The bracket (5) is provided with a pressure sleeve (27) for fixing the stuffing box (23), and both the pressure sleeve (27) and the main valve body (1) are provided with a bushing (28) connected to the valve stem (4).

Images