Ultra-low temperature ball valve seal pressure adjustable valve seat structure

Abstract

The application provides a super-low-temperature ball valve sealing specific pressure adjustable valve seat structure and relates to the technical field of ball valves.The super-low-temperature ball valve sealing specific pressure adjustable valve seat structure mainly comprises an adjustable valve seat, an adjusting and limiting mechanism and a shaft end sealing mechanism.The adjustable valve seat comprises a valve cover, a Leluo triangular adjusting rod, a spring seat, a cylindrical spring, a supporting ring, a seal ring I, a valve seat, a sealing ring and a ball.The Leluo triangular adjusting rod, the spring seat, the cylindrical spring, the supporting ring, the seal ring I, the valve seat and the sealing ring are all installed inside the valve seat cavity in the valve cover.The sealing ring is installed inside the valve seat and forms a sealing pair with the ball.In the application, the Leluo triangular adjusting rod structure can realize the on-site sealing specific pressure adjustment of the super-low-temperature ball valve product.Compared with other sealing specific pressure increasing modes such as medium force or structural potential energy, the application has the characteristics of "active adjustment, online adjustment and multiple adjustment".

Description

Technical Field

[0001] This invention relates to the field of ball valve technology, specifically to a cryogenic ball valve with an adjustable sealing pressure valve seat structure. Background Technology

[0002] Cryogenic ball valves, such as the double ball valve for cryogenic large loading and unloading arms used in LNG receiving terminals, are an important branch of ball valve products. They are widely used in cryogenic media conditions such as LNG, liquid hydrogen, and liquid oxygen, with a minimum operating temperature of -253℃.

[0003] Under the influence of cryogenic media, non-metallic materials used for sealing, such as polytetrafluoroethylene (PTFE) and polychlorotrifluoroethylene (PTFE), undergo "vitrification," causing cryogenic ball valves that meet sealing requirements at room temperature to leak under cryogenic conditions. Due to the special nature of the media, cryogenic ball valves with conventional seat structures cannot be adjusted online for sealing pressure after leakage. If offline maintenance is required, the pipeline must be vented. Furthermore, because media such as LNG are flammable and explosive, gas replacement of the pipeline is necessary, resulting in a large workload and high replacement costs.

[0004] A search revealed an existing patent (publication number: CN217874291U) that discloses a sealing structure between a sealing ring and a valve seat in a cryogenic ball valve. The structure includes a first annular groove extending axially inward from the end of the valve seat of the cryogenic ball valve, which is used to assemble and install the sealing ring. A second annular groove extending axially inward from the bottom of the first annular groove has multiple pressure inlet holes connected to it. These pressure inlet holes can communicate with the upstream medium cavity of the valve seat. The second annular groove is used to install a plug. Although this patented technology improves the valve seat structure of traditional cryogenic ball valves and fully utilizes the sealing principle of the plug adapting to the medium pressure to achieve a seal between the sealing ring and the valve seat, thus solving the leakage risks of traditional cryogenic ball valves, it has a problem that the sealing ring and the ball can only be sealed when the working specific pressure is greater than the initial sealing specific pressure. Therefore, in the initial stage of valve closure, the medium pressure range before the valve is established, and there is still a possibility of slight medium leakage when the pressure is low. As a result, this structure mainly uses the deformation of the plug under medium pressure to provide additional sealing specific pressure. However, at low temperatures, because the molecular chains are more tightly arranged and the free volume between molecules is reduced, the intermolecular interaction is enhanced, which greatly increases the force required for the plug deformation. Therefore, it is more difficult to achieve sealing using medium pressure at low temperatures.

[0005] Therefore, those skilled in the art have provided a valve seat structure with adjustable sealing pressure for cryogenic ball valves to solve the problems mentioned in the background art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a valve seat structure with adjustable sealing pressure for cryogenic ball valves. This structure can adjust the sealing pressure of the sealing pair of cryogenic ball valves within a range under cryogenic conditions, thus solving the leakage risks present in traditional cryogenic ball valves. However, there is a problem that the sealing ring and the ball can only be sealed when the working pressure is greater than the initial sealing pressure. Therefore, in the initial stage of valve closure, the pressure range of the medium before the valve is established, and there is still a possibility of minor leakage of the medium when the pressure is low.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An adjustable sealing pressure valve seat structure for cryogenic ball valves mainly includes an adjustable valve seat, an adjustment and limiting mechanism, and a shaft end sealing mechanism. The adjustable valve seat includes a valve cover, a Leylow triangular adjusting rod, a spring seat, a cylindrical spring, a support ring, a plug sealing ring I, a valve seat, a sealing ring, and a ball. The Leylow triangular adjusting rod, spring seat, cylindrical spring, support ring, plug sealing ring I, valve seat, and sealing ring are all installed inside the valve seat cavity in the valve cover. The sealing ring is installed inside the valve seat and forms a sealing pair with the ball. The plug sealing ring I is installed on the outer ring side of the valve seat and is limited by the support ring. The cylindrical spring is installed inside the spring seat and provides the initial sealing pressure to the sealing ring. The Leylow triangular adjusting rod is installed on the back of the spring seat. The contact size between the Leylow triangular adjusting rod and the spring seat is adjusted by adjusting the angle of the adjustment and limiting structure, thereby compressing or extending the cylindrical spring. The sealing pressure between the sealing ring and the ball is adjusted by the compression and extension of the cylindrical spring. Through the above technical solution, the Lelo triangular adjusting rod structure can realize the on-site sealing pressure adjustment of cryogenic ball valve products. Compared with other methods of increasing sealing pressure, such as using medium force or structural potential energy, it has the characteristics of "active adjustment, online adjustment, and multiple adjustments". Furthermore, by adjusting the angle of the adjusting and limiting structure, the contact size between the Lelo triangular adjusting rod and the spring seat is adjusted, thereby compressing or extending the cylindrical spring. The sealing pressure between the sealing ring and the ball is adjusted by the compression and extension of the cylindrical spring.

[0008] Furthermore, the adjustment and limiting mechanism includes an adjustment and limiting cover, a nut, a stud, a limiting plate, and a Leroy triangular adjustment rod. The adjustment and limiting cover is provided with a limiting groove at every 10° position and is connected to the valve cover through the nut and stud. The above technical solution, by setting a limiting groove and connecting it to the valve cover with nuts and studs to limit and fix the adjustment and limiting pressure plate, can better perform adjustment and limiting.

[0009] Furthermore, one side of the limiting piece is installed on the head of the Lelo triangular adjusting rod through the adjusting rod slot on the Lelo triangular adjusting rod, and the other side is set inside the limiting groove of the adjusting and limiting pressure cover. By rotating the Lelo triangular adjusting rod counterclockwise, the limiting piece can be made to cooperate with the limiting groove at different angles to achieve the adjustment and limiting effect of the Lelo triangular adjusting rod. With the above technical solution, by rotating the Leylow triangle adjusting rod counterclockwise, the limiting plate can be matched with the limiting groove at different angles to achieve the adjustment and limiting effect of the Leylow triangle adjusting rod, resulting in better performance.

[0010] Furthermore, the shaft end sealing mechanism includes an adjusting and limiting gland, a nut, a stud, a V-type packing assembly, a packing gasket, a Pansei sealing ring II, and a Leylow triangular adjusting rod. The adjusting and limiting gland is provided with a limiting groove at every 10° position and is connected to the valve cover through the nut and stud. The V-type packing assembly is pressed by the adjusting and limiting gland to form a shaft end seal. The above technical solution achieves better shaft end sealing by adjusting and tightening the limiting gland and forming a shaft end seal between it and the V-type packing assembly.

[0011] Furthermore, the packing gasket is installed at the bottom of the V-type packing assembly to separate the V-type packing assembly from the plug sealing ring II; By using the above technical solution, the V-type packing assembly and the Pan-Seal Ring II can be separated by packing gaskets, thus avoiding conflict between them.

[0012] Furthermore, the Pansei sealing ring II is installed inside the valve cover and utilizes the built-in spring and medium force inside the Pansei sealing ring II to achieve a double shaft end sealing effect. The above technical solution utilizes the built-in spring and medium force inside the Pan-Seal Ring II to achieve a double shaft end seal effect, further improving the sealing effect.

[0013] Furthermore, in addition to using a Reilly triangle, the Reilly triangle adjusting rod can also be designed using any variable radius structure such as an ellipse; Through the above technical solution, the Lelo triangular adjusting rod is more flexible in use and can be applied to different ball valves, thus offering greater flexibility in use.

[0014] Working Principle: This cryogenic ball valve with adjustable sealing pressure seat structure utilizes a Leylow triangular adjusting rod to achieve on-site adjustment of the sealing pressure of cryogenic ball valves. Compared to other methods of increasing sealing pressure using medium force or structural potential energy, it features "active adjustment, online adjustment, and multiple adjustments." Furthermore, throughout the product's lifespan, it compensates for insufficient sealing pressure caused by the effects of cryogenic media, wear of the sealing ring, and fatigue stress of the cylindrical spring, preventing leaks. It is also easier to maintain, has a longer service life, and can allow for range-based adjustment of the sealing pressure of the cryogenic ball valve's sealing pair under cryogenic conditions.

[0015] This invention provides a valve seat structure with adjustable sealing specific pressure for cryogenic ball valves. It offers the following advantages: This invention provides an adjustable sealing pressure valve seat structure for cryogenic ball valves. By utilizing the Leylow triangular adjusting rod structure, the sealing pressure of cryogenic ball valves can be adjusted on-site. Compared with other methods of increasing sealing pressure, such as using medium force or structural potential energy, it has the characteristics of "active adjustment, online adjustment, and multiple adjustments".

[0016] This invention provides an adjustable sealing pressure valve seat structure for cryogenic ball valves, which can compensate for insufficient sealing pressure of the sealing pair caused by the action of cryogenic media, wear of the sealing ring switch, and fatigue stress of the cylindrical spring throughout the product's entire life cycle, thus avoiding sealing leakage, making maintenance easier, and extending service life.

[0017] This invention provides a valve seat structure with adjustable sealing pressure for cryogenic ball valves, which can meet the requirement of range adjustment of the sealing pressure of the sealing pair of cryogenic ball valves under cryogenic conditions. Attached Figure Description

[0018] Figure 1 This is a structural diagram of the adjustable sealing pressure valve seat of the present invention; Figure 2 This is a schematic diagram of the adjustable valve seat structure of the present invention; Figure 3 This is a schematic diagram of the adjustment and limiting mechanism of the present invention; Figure 4 This is a schematic diagram of the shaft end sealing mechanism of the present invention; Among them, 1. Adjustable valve seat; 1-1. Valve cover; 1-2. Leroy triangular adjusting rod; 1-3. Spring seat; 1-4. Cylindrical spring; 1-5. Support ring; 1-6. Pan-seal sealing ring I; 1-7. Valve seat; 1-8. Sealing ring; 1-9. Ball; 2. Adjustment and limiting mechanism; 2-1. Adjustment and limiting gland; 2-2. Nut; 2-3. Stud; 2-4. Limiting plate; 3. Shaft end sealing mechanism; 3-1. V-type packing assembly; 3-2. Packing gasket; 3-3. Pan-seal sealing ring II. Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0020] like Figure 1-4 As shown, this embodiment of the invention provides a cryogenic ball valve with an adjustable sealing pressure valve seat structure. This structure mainly includes an adjustable valve seat 1, an adjustment and limiting mechanism 2, and a shaft end sealing mechanism 3. The adjustable valve seat 1 includes a valve cover 1-1, a Leylow triangular adjusting rod 1-2, a spring seat 1-3, a cylindrical spring 1-4, a support ring 1-5, a plug sealing ring I 1-6, a valve seat 1-7, a sealing ring 1-8, and a ball 1-9. The Leylow triangular adjusting rod 1-2, spring seat 1-3, cylindrical spring 1-4, support ring 1-5, plug sealing ring I 1-6, valve seat 1-7, and sealing ring 1-8 are all installed inside the valve seat cavity in the valve cover 1-1. The sealing ring 1-8 is installed... The sealing ring I1-6 is installed inside the valve seat 1-7 and forms a sealing pair with the ball 1-9. The sealing ring I1-6 is installed on the outer ring side of the valve seat 1-7 and is limited by the support ring 1-5. The cylindrical spring 1-4 is installed inside the spring seat 1-3 and provides the initial sealing pressure to the sealing ring 1-8. The Leylow triangular adjusting rod 1-2 is installed on the back of the spring seat 1-3. The contact size between the Leylow triangular adjusting rod 1-2 and the spring seat 1-3 is adjusted by adjusting the angle of the limiting structure 2, thereby compressing or extending the cylindrical spring 1-4. The sealing pressure between the sealing ring 1-8 and the ball 1-9 is adjusted by the compression and extension of the cylindrical spring 1-4. The Lelo triangular adjusting rod 1-2 structure enables on-site adjustment of the sealing pressure of cryogenic ball valves. Compared with other methods of increasing sealing pressure, such as using medium force or structural potential energy, it features "active adjustment, online adjustment, and multiple adjustments." Furthermore, by adjusting the angle of the adjusting and limiting structure 2, the contact size between the Lelo triangular adjusting rod 1-2 and the spring seat 1-3 is adjusted, thereby compressing or extending the cylindrical spring 1-4. The compression and extension of the cylindrical spring 1-4 adjust the sealing pressure between the sealing ring 1-8 and the ball 1-9.

[0021] The adjustment and limiting mechanism 2 includes an adjustment and limiting cover 2-1, a nut 2-2, a stud 2-3, a limiting piece 2-4, and a Leroy triangular adjustment rod 1-2. The adjustment and limiting cover 2-1 is provided with a limiting groove at every 10° position and is connected to the valve cover 1-1 through the nut 2-2 and the stud 2-3. By providing the limiting groove and connecting it to the valve cover 1-1 through the nut 2-2 and the stud 2-3, the adjustment and limiting cover 2-1 is limited and fixed, which can better perform adjustment and limiting.

[0022] One side of the limiting piece 2-4 is installed in the head of the Lero triangular adjusting rod 1-2 via the adjusting rod slot on the Lero triangular adjusting rod 1-2, and the other side is set inside the limiting groove of the adjusting and limiting pressure cover 2-1. By rotating the Lero triangular adjusting rod 1-2 counterclockwise, the limiting piece 2-4 can be matched with the limiting groove at different angles to achieve the adjustment and limiting effect of the Lero triangular adjusting rod 1-2. This method of adjusting and limiting the Lero triangular adjusting rod 1-2 counterclockwise results in better performance.

[0023] The shaft end sealing mechanism 3 includes an adjusting and limiting gland 2-1, a nut 2-2, a stud 2-3, a V-type packing assembly 3-1, a packing gasket 3-2, a Pansei sealing ring II 3-3, and a Leroy triangular adjusting rod 1-2. The adjusting and limiting gland 2-1 is provided with limiting grooves at every 10° position and is connected to the valve cover 1-1 through the nut 2-2 and the stud 2-3. The V-type packing assembly 3-1 is pressed by the adjusting and limiting gland 2-1 to form a shaft end seal. The shaft end seal is formed between the adjusting and limiting gland 2-1 and the V-type packing assembly 3-1, which can better seal the shaft end.

[0024] The packing gasket 3-2 is installed at the bottom of the V-type packing assembly 3-1 to separate the V-type packing assembly 3-1 and the plug sealing ring II 3-3. By separating the V-type packing assembly 3-1 and the plug sealing ring II 3-3 through the packing gasket 3-2, it is possible to avoid conflict between them.

[0025] The Pansai sealing ring II3-3 is installed inside the valve cover 1-1 and achieves a double shaft end seal effect by utilizing the built-in spring and medium force inside the Pansai sealing ring II3-3. This further improves the sealing effect.

[0026] In addition to using the Lelo triangle shape, the Lelo triangle adjusting rod 1-2 can also be designed with any variable radius structure, such as an ellipse. The Lelo triangle adjusting rod 1-2 is more flexible in use and can be applied to different ball valves, making it more adaptable to different applications.

[0027] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cryogenic ball valve with an adjustable sealing pressure valve seat structure, the structure mainly comprising an adjustable valve seat (1), an adjustment and limiting mechanism (2), and a shaft end sealing mechanism (3), characterized in that: The adjustable valve seat (1) includes a valve cover (1-1), a Leylow triangular adjusting rod (1-2), a spring seat (1-3), a cylindrical spring (1-4), a support ring (1-5), a plug sealing ring I (1-6), a valve seat (1-7), a sealing ring (1-8), and a ball (1-9). The Leylow triangular adjusting rod (1-2), spring seat (1-3), cylindrical spring (1-4), support ring (1-5), plug sealing ring I (1-6), valve seat (1-7), and sealing ring (1-8) are all installed inside the valve seat cavity in the valve cover (1-1). The sealing ring (1-8) is installed inside the valve seat (1-7) and forms a sealing pair with the ball (1-9). The sealing ring I (1-6) is installed on the outer ring side of the valve seat (1-7) and is limited by the support ring (1-5). The cylindrical spring (1-4) is installed inside the spring seat (1-3) and provides the initial sealing pressure to the sealing ring (1-8). The Lelo triangular adjusting rod (1-2) is installed on the back of the spring seat (1-3). The contact size between the Lelo triangular adjusting rod (1-2) and the spring seat (1-3) is adjusted by adjusting the angle of the limiting structure (2), thereby compressing or extending the cylindrical spring (1-4). The sealing pressure between the sealing ring (1-8) and the ball (1-9) is adjusted by the compression and extension of the cylindrical spring (1-4). The adjustment and limiting mechanism (2) includes an adjustment and limiting cover (2-1), a nut (2-2), a stud (2-3), a limiting piece (2-4), and a Leroy triangular adjustment rod (1-2). The adjustment and limiting cover (2-1) is provided with limiting grooves at every 10° position and is connected to the valve cover (1-1) through the nut (2-2) and the stud (2-3). The limiting piece (2-4) is installed on one side of the Lelo triangular adjusting rod (1-2) through the adjusting rod slot on the Lelo triangular adjusting rod (1-2), and the other side is set inside the limiting groove of the adjusting and limiting pressure cover (2-1). By rotating the Lelo triangular adjusting rod (1-2) counterclockwise, the limiting piece (2-4) can be matched with the limiting groove at different angles to achieve the adjustment and limiting effect of the Lelo triangular adjusting rod (1-2). The shaft end sealing mechanism (3) includes an adjusting and limiting gland (2-1), a nut (2-2), a stud (2-3), a V-type packing assembly (3-1), a packing gasket (3-2), a Pansei sealing ring II (3-3), and a Leroy triangular adjusting rod (1-2). The adjusting and limiting gland (2-1) is provided with a limiting groove at every 10° position and is connected to the valve cover (1-1) through the nut (2-2) and the stud (2-3). The V-type packing assembly (3-1) is pressed by the adjusting and limiting gland (2-1) to form a shaft end seal.

2. The adjustable sealing pressure valve seat structure for cryogenic ball valve according to claim 1, characterized in that: The packing gasket (3-2) is installed at the bottom of the V-type packing assembly (3-1) to separate the V-type packing assembly (3-1) from the plug sealing ring II (3-3).

3. The adjustable sealing pressure valve seat structure for cryogenic ball valve according to claim 1, characterized in that: The Pansei sealing ring II (3-3) is installed inside the valve cover (1-1) and achieves a double shaft end sealing effect by utilizing the built-in spring and medium force inside the Pansei sealing ring II (3-3).

Images