Ultralow temperature bottom-mounted floating ball valve

Abstract

The utility model provides a kind of ultra-low temperature bottom-mounted floating ball valve, it is related to cryogenic ball valve technology, specifically discloses valve body, the valve seat structure being set in valve body and the ball body being installed in the channel center of valve seat structure, upper valve cover is installed on valve body, and the valve rod connected with ball body is installed in upper valve cover;Valve seat structure and the side wall opposite to the inner wall of valve body are provided with wedge surface, wedge structure is installed between valve seat structure and wedge surface, and wedge structure is used to limit the displacement of valve seat structure;The side of valve body away from upper valve cover is equipped with lower valve cover, and the adjusting structure for adjusting the installation position of wedge structure is equipped between lower valve cover and valve body, when low temperature shrinks, the displacement of wedge block is converted into radial compression force by adjusting adjusting structure driving wedge structure, offset the adverse effects brought by low temperature, realize the stability of sealing specific pressure and the persistence of sealing effect.

Description

Technical Field

[0001] This utility model relates to the field of cryogenic ball valve technology, and more specifically, to an ultra-low temperature bottom-mounted floating ball valve. Background Technology

[0002] Cryogenic top-mounted floating ball valves are widely used in small pipeline systems in cryogenic liquefied natural gas (LNG) projects, and also in cryogenic liquefied gases such as liquid nitrogen, liquid hydrogen, and liquid argon. A key challenge in valve design and manufacturing is maintaining low internal and external leakage rates under cryogenic conditions. Furthermore, an increasing number of applications mandate that cryogenic top-mounted ball valves meet ISO 15848 or other relevant standards and obtain low-leakage certification. Conventional cryogenic top-mounted floating ball valves struggle to meet the requirements of cryogenic, low-leakage conditions, and their limited lifespan necessitates frequent shutdowns for maintenance and replacement, disrupting normal production and potentially causing significant economic losses.

[0003] Existing cryogenic valves employ a side-mounted structure. The seal at the valve body and cover joint is affected by pipeline tensile stress. Prolonged operation at ambient and ultra-low temperatures can lead to elongation of the fasteners at the joint, insufficient clamping force of the sealing gasket, and easy seal failure. Furthermore, these valves use an integrated top-mounted structure with a forced seal on the valve seat. Excessive valve opening and closing cycles can cause seat wear and seal failure. Additionally, existing valve seat preload uses cylindrical springs. This design requires a relatively small valve diameter; otherwise, there is no space to install the corresponding cylindrical spring. If the cylindrical spring is too small, the provided preload is insufficient. Utility Model Content

[0004] The purpose of this utility model is to provide a cryogenic bottom-mounted floating ball valve, which addresses the shortcomings of existing technologies and solves the problems mentioned in the background.

[0005] The technical solution of this utility model is implemented as follows: The utility model provides a cryogenic bottom-mounted floating ball valve, including a valve body, a valve seat structure disposed within the valve body, and a ball installed at the center of the valve seat structure channel. An upper valve cover is installed above the valve body, and a valve stem connected to the ball is installed inside the upper valve cover. A wedge-shaped surface is formed on the side wall of the valve seat structure opposite to the inner wall of the valve body. The angle between the reverse extension line of the wedge-shaped surface and the axis of the valve stem is an acute angle. A wedge structure is installed between the valve seat structure and the wedge-shaped surface, and the wedge structure is used to limit the displacement of the valve seat structure. A lower valve cover is provided on the side of the valve body away from the upper valve cover, and an adjustment structure is provided between the lower valve cover and the valve body for adjusting the installation position of the wedge structure.

[0006] In some technical solutions of this utility model, the valve seat structure is partially embedded in the wedge-shaped structure, and a disc spring preload structure is installed between the valve seat structure and the wedge-shaped structure.

[0007] In some technical solutions of this utility model, the adjustment structure includes an internal hexagonal screw, and the wedge-shaped structure has an internal threaded hole on the end face near the lower valve cover. After the hexagonal screw is installed in the internal threaded hole, it abuts against the lower valve cover.

[0008] In some technical solutions of this utility model, a stop block is installed between the upper valve cover and the valve seat structure, and the valve stem passes through the stop block and is partially embedded in the ball.

[0009] In some technical solutions of this utility model, a support ring is fitted at one end of the valve seat structure near the wedge-shaped block, and both the lower valve cover and the upper valve cover abut against the support ring.

[0010] In some technical solutions of this utility model, the lower valve cover is partially embedded in the valve body, and a first sealing gasket is installed between the valve body and the valve cover.

[0011] In some technical solutions of this utility model, a thrust bearing is installed between the valve stem and the inner wall of the upper valve cover.

[0012] In some technical solutions of this utility model, a second sealing gasket is installed between the upper valve cover and the valve body.

[0013] In some technical solutions of this utility model, a drip tray is installed on the outer side of the upper valve cover.

[0014] In some technical solutions of this utility model, a packing gland is installed on the side of the upper valve cover away from the valve body, the valve stem extends outward after passing through the packing gland, and packing, O-ring and second sliding bearing are installed vertically downward between the valve stem and the inner wall of the upper valve cover.

[0015] Compared with the prior art, this utility model has at least the following advantages or beneficial effects: The valve body structure adopts an integrated bottom-mounted structure in which the valve seat structure is installed and removed from the bottom of the valve body. Through the disc spring pre-tightening structure and the wedge structure in conjunction with the wedge surface located in the inner cavity of the valve body, the above structure can drive the wedge structure (wedge block) by adjusting the adjustment structure when the valve body contracts at low temperature. This converts the axial displacement of the wedge block into radial clamping force, actively and controllably pressing the sealing valve seat against the ball, offsetting the adverse effects of low temperature, and achieving stable sealing pressure and long-lasting sealing effect. Furthermore, the valve seat structure is disassembled from the bottom of the valve body to form a bottom-mounted structure. When repairing internal leakage of the valve, it is not necessary to remove the upper valve cover and valve stem and other actuators, making maintenance simpler. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the ultra-low temperature bottom-mounted floating ball valve structure in this utility model.

[0017] Figure 2 for Figure 1 A partially enlarged structural diagram.

[0018] Figure 3 This is a cross-sectional view of the valve body in this utility model.

[0019] Figure 4 This is a schematic diagram of the assembly structure of the valve seat structure and the wedge structure in this utility model.

[0020] Figure 5 This is a schematic diagram of the wedge-shaped structure in this utility model.

[0021] Reference numerals: 1. Valve body; 2. Upper valve cover; 4. First sealing gasket; 5. Lower valve cover; 6. Ball; 7. Valve seat structure; 8. Support ring; 9. Disc spring preload structure; 10. Hex socket screw; 11. Wedge structure; 12. Second sealing gasket; 15. Valve seat; 16. Stop block; 17. Thrust bearing; 18. First sliding bearing; 19. Valve stem; 20. Drip tray; 21. Stuffing box; 22. Second sliding bearing; 23. O-ring; 24. Packing; 25. Packing gland; 26. Disc spring; 27. Bolt. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0024] Example This utility model provides a cryogenic bottom-mounted floating ball valve, such as... Figures 1-5As shown, there is a valve body 1, a valve seat structure 7 disposed within the valve body 1, and a ball 6 installed at the center of the channel of the valve seat structure 7. An upper valve cover 2 is installed above the valve body 1, and a valve stem 19 connected to the ball 6 is installed inside the upper valve cover 2. A wedge-shaped surface is provided on the side wall of the valve seat structure 7 opposite to the inner wall of the valve body 1. The cross-section of the chamber inside the valve body 1 used to install the valve body structure 1 is a right trapezoid, and the wedge-shaped surface is the hypotenuse of the right trapezoid, with its lower base located on one side of the lower valve cover 5. The angle between the reverse extension line of the wedge-shaped surface and the axis of the valve stem 19 is acute. A wedge-shaped structure 11 is installed between the valve seat structure 7 and the wedge-shaped surface. This structure utilizes the mechanical compensation mechanism of the wedge-shaped inclined surface. During low-temperature contraction, the wedge-shaped structure 11 (wedge block) is driven by adjusting the adjustment structure, converting the axial displacement of the wedge block into radial clamping force. This actively and controllably seals and fixes the valve seat structure 7 within the valve body 1, offsetting the adverse effects of low temperature and achieving stable sealing pressure and durable sealing effect. The wedge-shaped structure 11 is used to limit the displacement of the valve seat structure 7. A lower valve cover 5 is provided on the side of the valve body 1 away from the upper valve cover 2. An adjustment structure for adjusting the installation position of the wedge-shaped structure 11 is provided between the lower valve cover 5 and the valve body 1. The valve seat structure 7 is disassembled from the bottom of the valve body 1 to form a bottom-mounted structure. When repairing internal leakage of the valve, it is not necessary to remove the valve cover and the actuator, making maintenance simpler. In actual use, when the valve needs to be closed, the operator rotates the valve stem 19, which causes the ball 6 to rotate 90 degrees, thus misaligning the channel of the ball 6 with the channel of the valve seat structure 7, achieving a seal. In ultra-low temperature environments, the material shrinks. At this time, by adjusting the adjusting structure at the lower valve cover 5, the wedge structure 11 can be moved along its inclined surface. Since the reverse extension line of the wedge surface forms an acute angle with the axis of the valve stem 19, the movement of the wedge structure 11 will press the valve seat structure 7 towards the center of the ball 6, thereby compensating for the loss of preload caused by low-temperature shrinkage and ensuring a reliable seal between the valve seat structure 7 and the ball 6.

[0025] The valve seat structure 7 is assembled from two valve seats 15, and the two valve seats 15 form an installation space that matches the ball 6.

[0026] In some technical solutions of this utility model, the valve seat structure 7 is partially embedded in the wedge structure 11, and a disc spring preload structure 9, which is a disc spring, is installed between the valve seat structure 7 and the wedge structure 11. During pre-installation or low-temperature compensation, the disc spring preload structure 9 always applies an initial elastic preload force to the valve seat structure 7. Even at room temperature, basic sealing can be guaranteed. When the wedge structure 11 is adjusted to push the valve seat structure 7, the disc spring preload structure 9 is further compressed. Its elastic force and mechanical thrust work together to make the sealing force more stable and controllable. Furthermore, the elasticity of the preload structure can absorb some pressure and temperature fluctuations, reducing the impact on the ball 6 and the valve seat structure 7, making the sealing process smoother, improving sealing stability, and working in conjunction with the wedge structure 11 to enhance the reliability and adaptability of the entire compensation system.

[0027] In some technical solutions of this utility model, the adjusting structure includes an internal hexagon screw 10. An internal threaded hole is provided on the end face of the wedge structure 11 near the lower valve cover 5. The hexagon screw is installed in the internal threaded hole and abuts against the lower valve cover 5. Rotational motion is converted into linear motion using a threaded transmission pair (screw and internal threaded hole). The axial displacement of the wedge structure 11 is precisely controlled by the screw's insertion depth, thereby controlling its radial clamping degree on the valve seat structure 7. When low-temperature shrinkage compensation is required, the internal hexagon screw 10 is tightened using a tool. When the screw is screwed in or out, it is held in place by the subsequently installed lower valve cover 5. Since the lower valve cover 5 is fixed, the reaction force of the screw pushes the wedge structure 11 (through its mating internal threaded hole) into the valve body 1, thus achieving precise adjustment of its position. Furthermore, the threaded adjustment has self-locking properties; once the position is set, it will not change due to fluid pressure or vibration, ensuring the stability of the adjustment result.

[0028] In some technical solutions of this utility model, a stop block 16 is installed between the upper valve cover 2 and the valve seat structure 7, and the valve stem 19 passes through the stop block 16 and is partially embedded in the ball 6. The stop block 16 is embedded between the upper valve cover 2 and the valve seat structure 7. When the valve stem 19 drives the ball 6 to rotate, the stop block 16, as a fixed reference point, can restrict the movement of the valve stem 19 and the ball 6 in the non-rotational direction, ensure that the ball 6 rotates stably around the axis of the valve stem 19, constrain the axial and radial degrees of freedom of the valve stem 19, improve the stability of the rigid connection between the valve stem 19 and the ball 6, and ensure its precise movement trajectory.

[0029] In some technical solutions of this utility model, a support ring 8 is fitted at one end of the valve seat structure 7 near the wedge-shaped block, and both the lower valve cover 5 and the upper valve cover 2 abut against the support ring 8. The support ring 8 is fitted outside the valve seat structure 7. By abutting against the support ring 8, the upper and lower valve covers 5 provide axial positioning and support for the valve seat structure 7 and the wedge-shaped structure 11 assembly from both upper and lower directions, preventing axial movement or tilting within the valve cavity, improving the centering and stability of the valve seat structure 7, ensuring uniform contact between the ball 6 and the sealing surface of the valve seat structure 7, and avoiding uneven wear.

[0030] In some technical solutions of this utility model, the lower valve cover 5 is partially embedded in the valve body 1, and a first sealing gasket 4 is installed between the valve body 1 and the valve cover. The first sealing gasket 4 is pressed between the mating surfaces of the lower valve cover 5 and the valve body 1. When the valve is filled with a low-temperature medium, the gasket forms a static seal to prevent the medium from leaking from the bottom of the valve body 1.

[0031] In some technical solutions of this utility model, a thrust bearing 17 and a first sliding bearing 18 are sequentially installed vertically upward between the valve stem 19 and the inner wall of the upper valve cover 2. The thrust bearing 17 and the first sliding bearing 18 are installed on the side of the upper valve cover 2 near the valve body 1. When the valve stem 19 is rotated, it will be subjected to a certain axial force. The thrust bearing 17 installed between the valve stem 19 and the upper valve cover 2 will bear this axial load, making the rotation of the valve stem 19 easier and smoother.

[0032] In some technical solutions of this utility model, a second sealing gasket 12 is installed between the upper valve cover 2 and the valve body 1. The second sealing gasket 12 is pressed between the mating surfaces of the upper valve cover 2 and the valve body 1, forming an important static seal to prevent the medium in the valve cavity from leaking from the upper part of the valve body 1.

[0033] In some technical solutions of this utility model, a drip tray 20 is installed on the outer side of the upper valve cover 2. In ultra-low temperature environments, water vapor in the atmosphere will condense into frost or water on the surface of low-temperature components such as the upper valve cover 2. The drip tray 20 installed on the outer side of the upper valve cover 2 can collect this condensate and guide it to drip in a specific direction, avoiding random dripping of condensate which may cause corrosion or other problems.

[0034] The upper valve cover 2 and the lower valve cover are both fixed to both sides of the valve body by bolts.

[0035] In some technical solutions of this utility model, a packing gland 25 is installed on the side of the upper valve cover 2 opposite to the valve body 1. The valve stem 19 extends outward after passing through the packing gland 25. A packing 24, an O-ring 23, and a second sliding bearing 22 are sequentially installed vertically downwards between the valve stem 19 and the inner wall of the upper valve cover 2. The packing 24 fills the packing cavity 21 provided inside the upper valve cover 2. The packing gland 25 presses the packing 24, causing the packing 24 to expand and tightly wrap around the valve stem 19, forming a dynamic seal to prevent the medium from leaking outwards along the valve stem 19. The O-ring 23 provides an additional static seal. The second sliding bearing 22 supports the valve stem 19, making it more stable and reducing friction during rotation, improving the sealing reliability at the valve stem 19 and effectively preventing external leakage.

[0036] The packing gland 25 is fixed to the end of the upper valve cover 2 by bolts 27, and a disc spring 26 connected to the packing gland 25 is sleeved on the bolts 27.

[0037] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A cryogenic bottom-mounted floating ball valve, comprising a valve body (1), a valve seat structure (7) disposed within the valve body (1), and a ball (6) installed at the center of the channel of the valve seat structure (7), characterized in that, An upper valve cover (2) is installed above the valve body (1), and a valve stem (19) connected to the ball (6) is installed inside the upper valve cover (2); a wedge-shaped surface is provided on the side wall of the valve seat structure (7) opposite to the inner wall of the valve body (1), and a wedge-shaped structure (11) is installed between the valve seat structure (7) and the wedge-shaped surface, and the wedge-shaped structure (11) is used to limit the displacement of the valve seat structure (7); a lower valve cover (5) is provided on the side of the valve body (1) away from the upper valve cover (2), and an adjustment structure is provided between the lower valve cover (5) and the valve body (1) for adjusting the movement of the wedge-shaped structure (11) along the extension direction of the wedge-shaped surface.

2. The cryogenic bottom-mounted floating ball valve according to claim 1, characterized in that, The valve seat structure (7) is partially embedded in the wedge structure (11), and a disc spring preload structure (9) is installed between the valve seat structure (7) and the wedge structure (11).

3. A cryogenic bottom-mounted floating ball valve according to claim 1 or 2, characterized in that, The adjustment structure includes an internal hexagonal screw (10), and the wedge-shaped structure (11) has an internal threaded hole on its end face near the lower valve cover (5). The hexagonal screw is installed in the internal threaded hole and abuts against the lower valve cover (5).

4. The cryogenic bottom-mounted floating ball valve according to claim 1, characterized in that, A stop (16) is installed between the upper valve cover (2) and the valve seat structure (7), and the valve stem (19) passes through the stop (16) and is partially embedded in the ball (6).

5. A cryogenic bottom-mounted floating ball valve according to claim 2, characterized in that, The valve seat structure (7) is fitted with a support ring (8) at one end near the wedge block, and the lower valve cover (5) and the upper valve cover (2) both abut against the support ring (8).

6. A cryogenic bottom-mounted floating ball valve according to claim 1, characterized in that, The lower valve cover (5) is partially embedded in the valve body (1), and a first sealing gasket (4) is installed between the valve body (1) and the valve cover.

7. A cryogenic bottom-mounted floating ball valve according to claim 1, characterized in that, A thrust bearing (17) is installed between the valve stem (19) and the inner wall of the upper valve cover (2).

8. A cryogenic bottom-mounted floating ball valve according to claim 1, characterized in that, A second sealing gasket (12) is installed between the upper valve cover (2) and the valve body (1).

9. A cryogenic bottom-mounted floating ball valve according to claim 1, characterized in that, A drip tray (20) is installed on the outer side of the upper valve cover (2).

10. A cryogenic bottom-mounted floating ball valve according to claim 1, characterized in that, A packing gland (25) is installed on the side of the upper valve cover (2) away from the valve body (1). The valve stem (19) extends outward after passing through the packing gland (25). A packing (24), an O-ring (23) and a second sliding bearing (22) are installed vertically downward between the valve stem (19) and the inner wall of the upper valve cover (2).

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