Low-temperature ball valve

Abstract

A low-temperature ball valve comprises a valve body, a valve rod, a valve clack, a valve seat, a water inlet flow channel and a water outlet flow channel, the valve clack is arranged at the bottom of the valve rod and used for controlling connection and disconnection of the water inlet flow channel and the water outlet flow channel, a sealing assembly used for being in sealing connection with the valve clack is arranged on the valve seat, and the sealing assembly comprises an installation cavity formed in the valve seat. A spring is mounted in the mounting cavity, the other end of the spring extends out of the mounting cavity to be connected with a pressurizing ring capable of horizontally reciprocating, a fixing ring is arranged on the pressurizing ring, a sealing ring used for abutting against the valve clack to form sealing connection is mounted on the fixing ring, and a limiting ring is arranged outside the sealing ring. One end of the limiting ring is embedded with the sealing ring, and the other end is fixedly connected with the fixing ring through a bolt.

Description

Technical Field

[0001] The utility model relates to a cryogenic ball valve, belonging to the field of ball valves. Background Art

[0002] Generally, ball valves are used in fluid transportation systems such as powder and liquid, and the opening and closing of the orifice are achieved by rotating the ball.

[0003] In ultra-low temperature environments (such as fluid conditions with extremely low temperatures like liquefied natural gas (LNG), liquid nitrogen, and liquid oxygen), the application requirements for ball valves are more stringent. In the prior art, in order to ensure the sealing performance between the ball and the valve seat, multiple components such as a retaining ring, gasket, valve seat ring, and spring are usually combined. Although this design can achieve the sealing requirements to a certain extent, it also brings the following significant problems:

[0004] Traditional ultra-low temperature ball valves usually involve the combination of multiple metal and non-metal components, such as retaining rings, sealing gaskets, spring-loaded elements, valve seat rings, etc. The installation relationships of these components are complex, and precise positioning and press-fitting are required in multiple processes during the assembly process, increasing the difficulty of manufacturing and assembly.

[0005] In a rapidly switching environment between ultra-low temperature and normal temperature, due to the difference in the thermal expansion coefficients of various component materials (such as metals and polymer materials), the following problems are likely to occur: loosening of the fit, resulting in internal leakage; extrusion damage between materials, causing damage to the sealing surface; after long-term use, due to thermal fatigue caused by alternating heat and cold, the sealing performance significantly decreases. Especially in ultra-low temperature applications, seal failure not only affects the normal operation of the equipment but may also pose major safety hazards. Content of the Utility Model

[0006] The purpose of the utility model is to provide a cryogenic ball valve to overcome the shortcomings and deficiencies existing in the prior art.

[0007] A cryogenic ball valve, comprising a valve body, a valve stem, a valve flap, a valve seat, an inlet water flow channel and an outlet water flow channel. The valve flap is arranged at the bottom of the valve stem and is used to control the on-off of the inlet water flow channel and the outlet water flow channel. A sealing component for sealing connection with the valve flap is arranged on the valve seat. The sealing component includes a mounting cavity arranged on the valve seat, a spring is installed in the mounting cavity, the other end of the spring extends out of the mounting cavity and is connected with a pressure ring capable of horizontal reciprocating movement. A fixing ring is arranged on the pressure ring, and a sealing ring for abutting against the valve flap to form a sealing connection is installed on the fixing ring. A limiting ring is arranged outside the sealing ring, one end of the limiting ring is fitted with the sealing ring, and the other end is fixedly connected with the fixing ring through a bolt. By arranging a spring in the mounting cavity and connecting one end of the spring to the pressure ring, the pressure ring is always pushed to move the fixing ring and the sealing ring towards the valve flap under the action of elastic force. Even in a low-temperature environment, due to material shrinkage or small displacement of the valve flap, the sealing gap can be compensated in real time, ensuring the close fit between the sealing ring and the valve flap, thereby significantly improving the sealing reliability and preventing leakage. The elastic floating structure of the pressure ring and the overall mobility of the sealing component can effectively absorb the dimensional changes caused by the difference in thermal expansion and contraction between metal and non-metal materials, avoiding the cracking or failure problems caused by stress concentration in the traditional fixed sealing structure, and ensuring that the ball valve can still work stably in the environment of frequent switching between ultra-low temperature and normal temperature. One end of the limiting ring is fitted with the sealing ring, and the other end is fixedly connected with the fixing ring through a bolt, which can effectively limit the axial or radial displacement of the sealing ring in the environment of high-pressure and high-speed fluid scouring, ensuring that the sealing ring is always in the correct position, and improving the anti-fatigue performance and service life of the overall sealing component.

[0008] Preferably, a sealing inclined surface for abutting against the valve flap to form a sealing connection is arranged on the sealing ring. The sealing inclined surface forms a conical or spherical surface fit with the surface of the valve flap, which can realize the gradual transition from line contact to surface contact, increase the effective sealing contact area, and thus improve the sealing reliability. The inclined surface structure will generate an axial component force under the action of the medium pressure, causing the sealing ring to further press the valve flap, realizing pressure self-tightening. As the pressure increases, the sealing becomes tighter, preventing leakage under high pressure.

[0009] Preferably, a first fixing groove is provided at the bottom of the sealing ring, and a second fixing groove is provided at the bottom of the fixing ring. The first fixing groove and the second fixing groove are communicated, and a support ring is installed inside. The through groove formed by the first fixing groove and the second fixing groove provides precise axial and radial positioning for the support ring, effectively preventing the support ring from shifting under high pressure or vibration conditions, so as to ensure that the sealing ring always obtains uniform support. The support ring is filled in the through groove, which can expand the stress-bearing surface at the bottom of the sealing ring, making the deformation of the sealing ring more controllable and the stress distribution more uniform when the sealing ring is pressed, thereby significantly improving the sealing reliability and reducing the leakage risk. There is a certain clearance margin between the through groove and the support ring, which can compensate for the dimensional changes caused by thermal expansion and contraction, ensuring that the support ring and the sealing ring always maintain good contact and maintain long-term stable sealing in the alternating environment of ultra-low temperature and normal temperature.

[0010] Preferably, a first limiting groove is provided on the outer side of the sealing ring, and one end of the limiting ring extends into the first limiting groove to be connected with the sealing ring in a limiting manner. The first limiting groove and the limiting ring are engaged to form a mechanical stop edge, which can accurately position the sealing ring in the radial direction and prevent it from radially shifting or falling off under the action of pressure or fluid erosion. The limiting ring is integrally structured with the sealing ring by being embedded in the limiting groove, so that the sealing ring always maintains a predetermined position during operation, ensuring that the sealing surface continuously fits tightly and improving the overall sealing performance.

[0011] Furthermore, the bottom of the limiting ring is inclined, and a first sealing cavity is formed by the bottoms of the fixing ring, the sealing ring and the limiting ring. A packing is installed in the first sealing cavity. The inclined bottom of the limiting ring makes the first sealing cavity in a conical or inclined groove shape. After being pressed, the packing can be evenly distributed along the inclined surface, avoiding concentrated stress points, thereby improving the sealing efficiency and reliability of the sealing cavity. The inclined structure, combined with the compressible characteristics of the packing, can automatically adjust the position of the packing and the sealing pressure when the valve flap is opened / closed, compensating for the gap changes caused by wear or thermal expansion, and ensuring continuous tight sealing. The inclined limiting ring, the fixing ring and the sealing ring integrally enclose the sealing cavity, and high-efficiency sealing can be achieved without additional gaskets or complex processing, reducing the number of parts and processing costs.

[0012] Furthermore, bolt holes are provided on the limiting ring, and the limiting ring is fixedly connected to the fixing ring by bolts through the bolt holes. The bolt passes through the bolt hole of the limiting ring and is tightened on the fixing ring, which can firmly lock the limiting ring in the axial direction, preventing the limiting ring from loosening or shifting under high pressure or fluid impact, and ensuring the long-term stable operation of the sealing assembly. The bolt connection allows fine-tuning of the pressing state between the limiting ring, the sealing ring and the fixing ring through the tightening torque, realizing the adjustment of the pre-pressing strength of the packing or the sealing ring in the sealing cavity to adapt to different working conditions.

[0013] Preferably, a first step is provided on the fixing ring, the pressing ring is L-shaped, a second sealing cavity is formed among the pressing ring, the first step and the valve seat, and a sealing ring is arranged in the second sealing cavity. The second sealing cavity formed by enclosing the L-shaped pressing ring with the first step and the valve seat, together with the sealing ring in the cavity, can provide an independent seal outside the first sealing cavity, significantly reducing the risk of bilateral leakage. The sealing ring in the second sealing cavity is compressed and expanded under the action of the medium pressure, further enhancing the sealing fit with the pressing ring and the valve seat, realizing the pressure self-tightening effect, and the sealing is more reliable as the system pressure increases. The sealing ring material can be selected from elastomers or composite materials, which can maintain elasticity and sealing performance in the range from ultra-low temperature to normal temperature, and effectively compensate for the thermal expansion difference in cooperation with the double-cavity structure to ensure long-term stable operation.

[0014] Further, a third step is provided on the outer side of the fixing ring, and a fourth step for cooperating with the third step is provided on the valve seat. The third step and the fourth step are meshed with each other, which can reliably position the fixing ring in the radial direction, prevent it from generating radial movement under the action of medium pressure or vibration, and thus ensure the structural stability of the sealing assembly. The step cooperation can be used as a positioning reference during the assembly process, enabling the fixing ring to be automatically aligned with the valve seat during installation, reducing the dependence on the experience of assembly workers, and improving production efficiency and assembly consistency.

[0015] The beneficial effects of the present utility model are as follows: By arranging a spring in the installation cavity and connecting one end of the spring to the pressing ring, the pressing ring is always pushed to move the fixing ring and the sealing ring towards the valve flap under the action of the elastic force. Even in a low-temperature environment, due to material shrinkage or slight displacement of the valve flap, the sealing gap can be compensated in real time to ensure the tight fit between the sealing ring and the valve flap, thereby significantly improving the sealing reliability and preventing leakage. The elastic floating structure of the pressing ring, combined with the overall mobility of the sealing assembly, can effectively absorb the dimensional changes caused by the thermal expansion and contraction differences between metal and non-metal materials, avoiding the cracking or failure problems caused by stress concentration in traditional fixed sealing structures, and ensuring that the ball valve can still work stably in an environment where the temperature frequently switches between ultra-low temperature and normal temperature. One end of the limiting ring is fitted with the sealing ring, and the other end is fixedly connected to the fixing ring through a bolt, which can effectively limit the axial or radial displacement of the sealing ring in an environment of high-pressure and high-speed fluid erosion, ensure that the sealing ring is always in the correct position, and improve the anti-fatigue performance and service life of the overall sealing assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, obtaining other drawings based on these drawings still belongs to the scope of the present utility model.

[0017] Figure 1 This is the main structure diagram of the present utility model;

[0018] Figure 2 is Figure 1 the enlarged detail view of part A in

[0019] In the figure, 1 is the valve body; 2 is the valve stem; 3 is the valve flap; 4 is the valve seat; 41 is the installation cavity; 42 is the spring; 43 is the fourth step; 5 is the pressure ring; 6 is the fixing ring; 61 is the second fixing groove; 62 is the first step; 63 is the second sealing cavity; 64 is the sealing ring; 65 is the third step; 7 is the sealing ring; 71 is the sealing inclined surface; 72 is the first fixing groove; 73 is the first limiting groove; 8 is the limiting ring; 81 is the first sealing cavity; 82 is the packing; 83 is the bolt hole; 9 is the support ring; 10 is the water inlet channel; 11 is the water outlet channel. Specific embodiments

[0020] To make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0021] It should be noted that all the expressions using "first" and "second" in the embodiments of the present utility model are used to distinguish two entities or parameters with the same name but different, so "first" and "second" are only for the convenience of expression and should not be construed as a limitation on the embodiments of the present utility model. This will not be further elaborated in the subsequent embodiments.

[0022] The directional and positional terms mentioned in the present utility model, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "top", "bottom", "side", etc., are only with reference to the directions or positions in the accompanying drawings. Therefore, the directional and positional terms used are for the purpose of explaining and understanding the present utility model, rather than a limitation on the protection scope of the present utility model.

[0023] Such as Figure 1-2As shown in the figure, this is an embodiment of a cryogenic ball valve of the present utility model, which includes a valve body 1, a valve stem 2, a valve disc 3, a valve seat 4, an inlet water flow channel 10 and an outlet water flow channel 11. The valve disc 3 is arranged at the bottom of the valve stem 2 to control the on-off of the inlet water flow channel 10 and the outlet water flow channel 11. A sealing assembly for sealing connection with the valve disc 3 is arranged on the valve seat 4. The sealing assembly includes an installation cavity 41 arranged on the valve seat 4. A spring 42 is installed in the installation cavity 41. The other end of the spring 42 extends out of the installation cavity 41 and is connected with a pressure ring 5 that can perform horizontal reciprocating motion. A fixing ring 6 is arranged on the pressure ring 5. A sealing ring 7 for abutting against the valve disc 3 to form a sealing connection is installed on the fixing ring 6. A limiting ring 8 is arranged outside the sealing ring 7. One end of the limiting ring 8 is fitted with the sealing ring 7, and the other end is fixedly connected with the fixing ring 6 through a bolt. By arranging the spring 42 in the installation cavity 41 and connecting one end of the spring 42 to the pressure ring 5, the pressure ring 5 is always pushed to move the fixing ring 6 and the sealing ring 7 towards the valve disc 3 under the action of elastic force. Even in a low-temperature environment, due to material shrinkage or minor displacement of the valve disc 3, the sealing gap can be compensated in real time, ensuring the close fit between the sealing ring 7 and the valve disc 3, thereby significantly improving the sealing reliability and preventing leakage. The elastic floating structure of the pressure ring 5 and the overall mobility of the sealing assembly can effectively absorb the dimensional changes caused by the thermal expansion and contraction differences between metal and non-metal materials, avoiding the cracking or failure problems caused by stress concentration in the traditional fixed sealing structure, and ensuring that the ball valve can still work stably in the environment of frequent switching between ultra-low temperature and normal temperature. One end of the limiting ring 8 is fitted with the sealing ring 7, and the other end is fixedly connected with the fixing ring 6 through a bolt, which can effectively limit the axial or radial displacement of the sealing ring 7 in the environment of high-pressure and high-speed fluid erosion, ensuring that the sealing ring 7 is always in the correct position, and improving the anti-fatigue performance and service life of the overall sealing assembly.

[0024] A sealing inclined surface 71 for abutting against the valve disc 3 to form a sealing connection is arranged on the sealing ring 7. The sealing inclined surface 71 forms a conical or spherical surface fit with the surface of the valve disc 3, which can realize the gradual transition from line contact to surface contact, increasing the effective sealing contact area, thereby improving the sealing reliability. The inclined surface structure will generate an axial component force under the action of the medium pressure, causing the sealing ring 7 to further press the valve disc 3, realizing pressure self-tightening. As the pressure increases, the sealing becomes tighter, preventing leakage under high pressure.

[0025] The bottom of the sealing ring 7 is provided with a first fixing groove 72, and the bottom of the fixing ring 6 is provided with a second fixing groove 61. The first fixing groove 72 and the second fixing groove 61 are communicated, and a support ring 9 is installed inside. The through groove formed by the first fixing groove 72 and the second fixing groove 61 provides precise axial and radial positioning for the support ring 9, effectively preventing the support ring 9 from shifting under high pressure or vibration conditions, so as to ensure that the sealing ring 7 always obtains uniform support. The support ring 9 is filled in the through groove, which can expand the stress-bearing surface at the bottom of the sealing ring 7, make the deformation of the sealing ring 7 more controllable when it is pressurized, and the stress distribution more uniform, thus significantly improving the sealing reliability and reducing the leakage risk. The through groove and the support ring 9 are matched with a certain clearance margin, which can compensate for the dimensional changes caused by thermal expansion and contraction, and ensure that the support ring 9 and the sealing ring 7 always maintain good contact and maintain long-term stable sealing in the alternating environment of ultra-low temperature and normal temperature.

[0026] The outer side of the sealing ring 7 is provided with a first limiting groove 73, and one end of the limiting ring 8 extends into the first limiting groove 73 to be connected with the sealing ring 7 in a limiting manner. The first limiting groove 73 and the limiting ring 8 are engaged to form a mechanical stop edge, which can accurately position the sealing ring 7 in the radial direction and prevent it from radially shifting or falling off under the action of pressure or fluid erosion. The limiting ring 8 is integrally structured with the sealing ring 7 by being embedded in the limiting groove, so that the sealing ring 7 always maintains a predetermined position during the working process, ensuring that the sealing surface is continuously and tightly fitted, and improving the overall sealing performance.

[0027] The bottom of the limiting ring 8 is inclined, and a first sealing cavity 81 is formed by the bottoms of the fixing ring 6, the sealing ring 7 and the limiting ring 8. A packing 82 is installed in the first sealing cavity 81. The inclined bottom of the limiting ring 8 makes the first sealing cavity 81 in a conical or inclined groove shape. After being pressurized, the packing 82 can be evenly distributed along the inclined surface, avoiding concentrated stress points, thereby improving the sealing efficiency and reliability of the sealing cavity. The inclined structure cooperates with the compressible characteristics of the packing 82, which can automatically adjust the position and sealing pressure of the packing 82 when the valve flap 3 is opened / closed, compensate for the gap changes caused by wear or thermal expansion, and ensure continuous tight sealing. The inclined limiting ring 8 and the fixing ring 6 and the sealing ring 7 integrally enclose the sealing cavity, and high-efficiency sealing can be achieved without additional gaskets or complex processing, reducing the number of parts and processing costs.

[0028] The limiting ring 8 is provided with bolt holes 83, and the limiting ring 8 is fixedly connected to the fixing ring 6 by bolts through the bolt holes 83. The bolt passes through the bolt holes 83 of the limiting ring 8 and is tightened on the fixing ring 6, which can firmly lock the limiting ring 8 in the axial direction and prevent the limiting ring 8 from loosening or shifting under high pressure or fluid impact, ensuring the long-term stable operation of the sealing assembly. The bolt connection allows fine-tuning of the pressing state between the limiting ring 8 and the sealing ring 7 and the fixing ring 6 through the tightening torque, so as to adjust the preloading strength of the packing 82 or the sealing ring 7 in the sealing cavity to meet the requirements of different working conditions.

[0029] A first step 62 is provided on the fixing ring 6. The pressing ring 5 is L-shaped. A second sealing cavity 63 is formed between the pressing ring 5, the first step 62 and the valve seat 4. A sealing ring 64 is provided in the second sealing cavity 63. The second sealing cavity 63 formed by the L-shaped pressing ring 5, the first step 62 and the valve seat 4, together with the sealing ring 64 in the cavity, can provide an independent seal outside the first sealing cavity 81, significantly reducing the risk of bilateral leakage. The sealing ring 64 in the second sealing cavity 63 is compressed and expanded under the action of the medium pressure, further enhancing the sealing fit between the pressing ring 5 and the valve seat 4, achieving a pressure self-tightening effect, and the seal is more reliable as the system pressure increases. The material of the sealing ring 64 can be selected from elastomers or composite materials, which can maintain elasticity and sealing performance in the range from ultra-low temperature to normal temperature, effectively compensating for the difference in thermal expansion with the double-cavity structure to ensure long-term stable operation.

[0030] A third step 65 is provided on the outer side of the fixing ring 6. The valve seat 4 is provided with a fourth step 43 for cooperating with the third step 65. The third step 65 and the fourth step 43 are engaged with each other, which can reliably position the fixing ring 6 in the radial direction, preventing it from generating radial movement under the action of medium pressure or vibration, thereby ensuring the structural stability of the sealing assembly. The step cooperation can be used as a positioning reference during the assembly process, enabling the fixing ring 6 to automatically align with the valve seat 4 during installation, reducing the dependence on the experience of assembly workers, and improving production efficiency and assembly consistency.

[0031] The foregoing disclosure is only for the preferred embodiments of the present invention, and of course cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

[0032] Although the present invention has been described with reference to several specific embodiments, it should be understood that the present invention is not limited to the specific embodiments disclosed. The present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A cryogenic ball valve, characterized in that: It includes a valve body, a valve stem, a valve flap, a valve seat, an inlet water flow channel and an outlet water flow channel. The valve flap is arranged at the bottom of the valve stem and is used to control the on-off of the inlet water flow channel and the outlet water flow channel. A sealing component for sealing connection with the valve flap is arranged on the valve seat. The sealing component includes an installation cavity arranged on the valve seat. A spring is installed in the installation cavity. The other end of the spring extends out of the installation cavity and is connected with a pressure ring capable of horizontal reciprocating movement. A fixing ring is arranged on the pressure ring. A sealing ring for abutting against the valve flap to form a sealing connection is installed on the fixing ring. A limiting ring is arranged outside the sealing ring. One end of the limiting ring is fitted with the sealing ring, and the other end is fixedly connected with the fixing ring through a bolt.

2. The cryogenic ball valve according to claim 1, wherein: A sealing inclined surface for abutting against the valve flap to form a sealing connection is arranged on the sealing ring.

3. The cryogenic ball valve according to claim 1, characterized in that: A first fixing groove is arranged at the bottom of the sealing ring, and a second fixing groove is arranged at the bottom of the fixing ring. The first fixing groove and the second fixing groove are communicated, and a support ring is installed inside.

4. The cryogenic ball valve according to claim 1, wherein: A first limiting groove is arranged on the outer side of the sealing ring. One end of the limiting ring extends into the first limiting groove and is in limiting connection with the sealing ring.

5. The cryogenic ball valve according to claim 4, characterized in that: The bottom of the limiting ring is inclined. A first sealing cavity is formed by the bottoms of the fixing ring, the sealing ring and the limiting ring. Packing is installed in the first sealing cavity.

6. The cryogenic ball valve according to claim 1 or 5, characterized in that: A bolt hole is arranged on the limiting ring. The limiting ring is fixedly connected with the fixing ring through the bolt hole by a bolt.

7. The cryogenic ball valve according to claim 1, wherein: A first step is arranged on the fixing ring. The pressure ring is L-shaped. A second sealing cavity is formed among the pressure ring, the first step and the valve seat. A sealing ring is arranged in the second sealing cavity.

8. The cryogenic ball valve according to claim 7, wherein: A third step is arranged on the outer side of the fixing ring. A fourth step for cooperating with the third step is arranged on the valve seat.

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