A cryogenic soft-seal ball valve

Abstract

This utility model relates to an ultra-low temperature soft-seal ball valve, comprising: a ball valve body, a sealing structure sleeved on the inner wall of the ball valve body, and a venting structure located on one side of the center of the upper end face of the ball valve body. The beneficial effects of this utility model are: through the corresponding locking block and push-pull block via the push-pull groove, the locking block is precisely guided during installation by sliding the push-pull block along the push-pull groove. Simultaneously, the locking groove of the rubber sealing layer and the locking block form a concave-convex fit, and the dual positioning structure firmly constrains the position of the locking block. Even if the rubber sealing layer shrinks and deforms at ultra-low temperatures, the locking block will not experience radial displacement or axial movement, providing a stable reference support for subsequent multi-layer sealing. Furthermore, through a four-layer gradient sealing system consisting of a sealing ring, a waterproof layer, a sealing bonding layer, and a sleeve sealing layer, the functions of each layer complement and synergize, specifically resisting risks such as media penetration and moisture freezing and swelling, resulting in a lower sealing leakage rate and longer service life at ultra-low temperatures.

Description

Technical Field

[0001] This utility model relates to the field of ball valve technology, specifically to an ultra-low temperature soft-seal ball valve. Background Technology

[0002] With the increasing global demand for clean energy, the production and transportation of liquefied natural gas (LNG), as a clean and efficient energy source, are constantly expanding. The temperature of LNG is usually around 162°C, and ordinary valves cannot work properly under such extreme low temperature conditions. Therefore, special cryogenic soft-seal ball valves are needed to control and transport liquefied cryogenic media, which has driven the research and development of cryogenic soft-seal ball valves.

[0003] In the existing technology, most cryogenic soft-seal ball valves are either all-metal hard seal or non-metal soft seal. All-metal valve seats have greater friction in cryogenic environments and are prone to sealing failure after wear. Non-metal soft-seal valve seats have poor elasticity and greater shrinkage in cryogenic environments, which can also easily cause sealing failure. The elasticity of materials decreases sharply in cryogenic environments, making them brittle and prone to cracking. At the same time, the shrinkage rate of rubber and metal valve bodies is different, resulting in gaps between the sealing layer and the valve body. Utility Model Content

[0004] To address the shortcomings of existing technologies, this application provides an ultra-low temperature soft-seal ball valve, which solves the problems in existing technologies, such as the high friction of all-metal valve seats in ultra-low temperature environments, which easily leads to sealing failure after wear; the poor elasticity and large shrinkage of non-metallic soft-seal valve seats in ultra-low temperature environments, which also easily leads to sealing failure; the sharp decrease in material elasticity at ultra-low temperatures, which makes them brittle and prone to cracking; and the large difference in shrinkage rates between rubber and metal valve bodies, which leads to gaps between the sealing layer and the valve body.

[0005] This utility model provides the following technical solution: a cryogenic soft-seal ball valve, comprising: a ball valve body, a sealing structure sleeved on the inner wall of the ball valve body, and a venting structure provided on one side of the center of the upper end face of the ball valve body. The sealing structure includes a rubber sealing layer, which is sleeved on the inner wall of the ball valve body. The inner wall of the rubber sealing layer has a groove on both sides near the center. On one side of the two grooves, there are four push-pull grooves arranged in a ring on the inner wall of the rubber sealing layer. The sealing structure also has a block on both sides near the center.

[0006] As a preferred embodiment of this utility model, the two locking blocks are respectively adapted to the two rubber sealing layers, and the outer walls of the two locking blocks are provided with four push-pull blocks arranged in a ring. The eight push-pull blocks are slidably connected to the center of the eight push-pull grooves.

[0007] As a preferred embodiment of this utility model, a sealing ring is provided at one side of the center of the outer wall of each of the two card blocks, and a waterproof layer is provided on one side of each of the two sealing rings and on the outer wall of each of the two card blocks, and a sealing and bonding layer is provided on the outer wall of each of the two waterproof layers.

[0008] As a preferred embodiment of this utility model, a sealing layer is provided on the outer wall of each of the two sealing and bonding layers, and the two sealing layers are respectively adapted to the two locking blocks. An elastic layer is provided at the center of the inner wall of the sealing structure, and a sphere is provided at the center of the elastic layer.

[0009] As a preferred embodiment of this utility model, a through hole is provided at the center of one side wall of the ball, a valve seat is provided at the center of the upper end face of the ball valve body, and a valve stem is provided at the center of the upper end face of the ball. One end of the valve stem passes through the inner wall of the rubber sealing layer and the inner wall of the ball valve body to the upper end face of the ball valve body, and an actuator is fixedly connected to the end.

[0010] As a preferred embodiment of this utility model, the venting structure includes an air inlet and pressure inlet pipe, which is located at the center of the upper end face of the ball valve body on one side. A base plate is provided at the lower center of the air inlet and pressure inlet pipe. Multiple air inlet and pressure inlets are arranged in a ring on the upper end face of the base plate. One end of the air inlet and pressure inlet pipe passes through the upper end face of the ball valve body and the upper end face of the rubber sealing layer and extends into the interior of the rubber sealing layer.

[0011] As a preferred embodiment of this utility model, two push plates are arranged horizontally on one side of the center of the air intake and pressure pipe, a damper is provided between the two push plates, a compression spring is sleeved on the outside of the damper, and multiple exhaust pressure relief ports are arranged horizontally on one side of the center of the upper end face of the air intake and pressure pipe.

[0012] The beneficial effects of this utility model are: In this invention, the push-pull groove corresponds to the locking block and the push-pull block. During installation, the sliding of the push-pull block along the push-pull groove achieves precise guidance of the locking block. At the same time, the locking groove of the rubber sealing layer and the locking block form a concave-convex fit. The dual positioning structure can firmly constrain the position of the locking block. Even if the rubber sealing layer shrinks and deforms at ultra-low temperatures, the locking block will not experience radial displacement or axial movement, providing a stable reference support for subsequent multi-layer sealing. Furthermore, through the four-layer gradient sealing system of sealing ring, waterproof layer, sealing bonding layer and sleeve layer, the functions of each layer complement and synergize, specifically resisting the risks of media penetration and moisture freezing and swelling. The sealing leakage rate is lower and the service life is longer at ultra-low temperatures. In this invention, the arrangement of multiple air inlets and pressure inlets allows the pressure of the medium inside the valve to enter the pressure inlet pipe synchronously through multiple evenly distributed air inlets. Even if the medium flows inside the valve and causes local pressure fluctuations, the annularly distributed air inlets can average out the pressure, avoiding accidental pressure release caused by a single air inlet capturing local high pressure. At the same time, the design of multiple air inlets can also improve the pressure transmission speed, ensuring that the pressure relief structure can respond quickly when the pressure inside the valve changes, and avoiding excessive pressure accumulation. The addition of damping and compression springs between the two push plates forms a synergistic effect to prevent accidental pressure release due to local high pressure. The damping and spring work together to slow down the movement of the push plates, preventing component impact and avoiding splashing of low-temperature medium, thus achieving safe and stable pressure relief. Attached Figure Description

[0013] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional cross-sectional view of the present invention; Figure 3 This is a schematic diagram of the three-dimensional disassembled structure of this utility model; Figure 4 for Figure 2 Enlarged structural diagram at point A; In the diagram: 1. Ball valve body; 2. Sealing structure; 201. Rubber sealing layer; 202. Slot; 203. Push-pull groove; 204. Push-pull block; 205. Slot; 206. Sealing ring; 207. Waterproof layer; 208. Sealing bonding layer; 209. Sleeve sealing layer; 210. Elastic layer; 211. Ball; 212. Valve seat; 213. Valve stem; 214. Actuator; 3. Venting and exhaust structure; 301. Inlet and pressure inlet pipe; 302. Base plate; 303. Inlet and pressure inlet port; 304. Push plate; 305. Damping; 306. Compression spring; 307. Exhaust and pressure relief port. Detailed Implementation

[0014] To make the technical problems solved by this utility model, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0015] Example like Figures 1 to 4 As shown, an ultra-low temperature soft-seal ball valve includes: a ball valve body 1, a sealing structure 2 sleeved on the inner wall of the ball valve body 1, and a venting structure 3 provided on one side of the center of the upper end face of the ball valve body 1.

[0016] In this embodiment, the sealing structure 2 includes a rubber sealing layer 201, which is sleeved on the inner wall of the ball valve body 1. The inner wall of the rubber sealing layer 201 has grooves 202 on both sides near the center. Four push-pull grooves 203 are arranged in a ring on one side of each groove 202 and on the inner wall of the rubber sealing layer 201. The sealing structure 2 has blocks 205 on both sides near the center, which are respectively adapted to the two rubber sealing layers 201. Four push-pull blocks 204 are arranged in a ring on the outer wall of each block 205. The eight push-pull blocks 204 are slidably connected to the center of the eight push-pull grooves 203. A sealing ring 206 is provided on one side of the outer wall of each block 205. A waterproof layer 207 is fitted on the outer wall of each of the two locking blocks 205. A sealing and bonding layer 208 is fitted on the outer wall of each of the two waterproof layers 207. A sealing layer 209 is fitted on the outer wall of each of the two sealing and bonding layers 208. The two sealing layers 209 are adapted to each other with the two locking blocks 205 respectively. An elastic layer 210 is fitted at the center of the inner wall of the sealing structure 2. A ball 211 is provided at the center of the inner wall of the elastic layer 210. A through hole is provided at the center of one side wall of the ball 211. A valve seat 212 is provided at the center of the upper end face of the ball valve body 1. A valve stem 213 is provided at the center of the upper end face of the ball 211. One end of the valve stem 213 passes through the inner wall of the rubber sealing layer 201 and the inner wall of the ball valve body 1 and connects to the upper end face of the ball valve body 1. An actuator 214 is fixedly connected to the end.

[0017] The rubber sealing layer 201 is directly fitted onto the inner wall of the ball valve body 1, serving as the first sealing barrier. Its material is low-temperature resistant rubber such as EPDM and fluororubber, which maintains elasticity at ultra-low temperatures, preventing seal failure due to low-temperature embrittlement. When the locking block 205 is installed, the four push-pull blocks 204 on the outer side of the locking block 205 slide along the push-pull groove 203 on the inner side of the rubber sealing layer 201, ultimately ensuring precise engagement between the locking block 205 and the groove 202. Furthermore, the groove 202 structure ensures that the locking block 205 does not shift under low-temperature deformation, providing stable support for subsequent multi-layer sealing. The sealing ring 206, made of polytetrafluoroethylene composite material, directly adheres to the locking block 205, filling the tiny gaps between the locking block 205 and the rubber sealing layer 201, blocking the medium penetration path. The waterproof layer 207 addresses the potential presence of low-temperature condensate or water-containing media in ultra-low-temperature environments, preventing moisture from seeping into the rubber sealing layer 201 and causing freeze-thaw damage. The sealing bonding layer 208 possesses excellent... The low-temperature fit allows for synchronous bonding with the slight deformation of the rubber sealing layer 201, preventing gaps caused by low-temperature shrinkage. The outer sealing layer 209 serves as an outer protective layer, enhancing the impact resistance of the overall sealing structure 2 and further constraining the deformation range of the inner sealing element. The elastic layer 210, a low-temperature resistant elastomer, directly contacts the ball 211. When the ball 211 rotates, the elastic layer 210 can compensate for the gap between the ball 211 and the rubber sealing layer 201 through its own elasticity, while avoiding rigid friction between the ball 211 and the rubber sealing layer 201 at low temperatures. In addition, the through hole on one side of the ball 211 is used for media flow. The actuator 214 is electric or pneumatic and fixed to the upper end of the valve stem 213. When the actuator 214 receives the opening and closing signal, it will drive the valve stem 213 to rotate. The rotation of the valve stem 213 will directly drive the ball 211 to rotate inside the elastic layer 210. The valve seat 212 is used to support the valve stem 213 and also helps to seal the gap between the valve stem 213 and the body.

[0018] In this embodiment, the venting structure 3 includes an air intake and pressure inlet pipe 301, which is located at one side of the center of the upper end face of the ball valve body 1. A base plate 302 is located at the lower center of the air intake and pressure inlet pipe 301. Multiple air intake and pressure inlets 303 are arranged in a ring on the upper end face of the base plate 302. One end of the air intake and pressure inlet pipe 301 passes through the upper end face of the ball valve body 1 and the upper end face of the rubber sealing layer 201, and extends into the interior of the rubber sealing layer 201. Two push plates 304 are arranged laterally at one side of the center of the air intake and pressure inlet pipe 301. A damper 305 is provided between the two push plates 304. A compression spring 306 is sleeved on the outside of the damper 305. Multiple venting and pressure relief ports 307 are arranged laterally at one side of the center of the upper end face of the air intake and pressure inlet pipe 301.

[0019] The pressure inside the valve is transmitted through the base plate 302 at the bottom of the intake and pressure inlet pipe 301. Multiple intake and pressure inlets 303 on the base plate 302 ensure that the pressure inside the valve enters the intake and pressure inlet pipe 301 evenly, avoiding false triggering caused by localized pressure concentration. When the pressure inside the valve is lower than the set threshold, the spring force of the compression spring 306 is greater than the pressure inside the intake and pressure inlet pipe 301, pushing the two push plates 304 to fit tightly together, blocking the passage between the pressure inlet pipe and the outside. At this time, the exhaust pressure relief port 307 is in a closed state, ensuring no leakage of the medium. When the pressure inside the valve is higher than the set threshold, the pressure inside the intake and pressure inlet pipe 301 overcomes the spring force of the compression spring 306, pushing the two push plates 304 to move... When the valve is activated, the inside of the intake and pressure inlet pipe 301 is connected to the exhaust pressure relief port 307. Excess pressure inside the valve is discharged to the outside through multiple exhaust pressure relief ports 307 until the pressure inside the valve drops to a safe threshold. The function of the damper 305 is to slow down the movement speed of the push plate 304, to prevent the push plate 304 from hitting the pipe wall quickly due to a sudden increase in pressure, and to prevent the medium flow rate from being too fast and generating low-temperature splashing during the pressure relief process. When the pressure inside the valve drops to a safe threshold, the elastic force of the compression spring 306 takes over again, pushing the two push plates 304 to reset and fit together, closing the exhaust pressure relief port 307 again, restoring the valve to a sealed state, and realizing the adaptive adjustment of automatic pressure relief when the pressure is too high and automatic sealing when the pressure is normal.

[0020] Implementation plan: The rubber sealing layer 201 is directly fitted onto the inner wall of the ball valve body 1 as the first sealing barrier. Its material is low-temperature resistant rubber such as EPDM rubber and fluororubber, which can maintain elasticity at ultra-low temperatures and avoid sealing failure due to low-temperature embrittlement. When the locking block 205 is installed, the four push-pull blocks 204 on the outside of the locking block 205 will slide along the push-pull groove 203 on the inner side of the rubber sealing layer 201, so that the locking block 205 and the groove 202 are precisely fitted. In addition, the structure of the groove 202 can ensure that the locking block 205 does not shift under low-temperature deformation, providing stable support for subsequent multi-layer sealing. The sealing ring 206 is directly attached to the locking block 205 and is made of polytetrafluoroethylene composite material. It fills the tiny gap between the locking block 205 and the rubber sealing layer 201, blocking the medium penetration path. The waterproof layer 207 is for low-temperature condensate or water-containing media that may exist in the ultra-low temperature environment, preventing moisture from penetrating into the rubber sealing layer 201 and causing freeze-thaw damage.

[0021] The sealing layer 208 has excellent low-temperature adhesion and can fit synchronously with the slight deformation of the rubber sealing layer 201, avoiding gaps caused by low-temperature shrinkage. The sleeve layer 209 serves as an outer protective layer, enhancing the impact resistance of the overall sealing structure 2 and further constraining the deformation range of the inner sealing element. The elastic layer 210, a low-temperature resistant elastomer, directly contacts the ball 211. When the ball 211 rotates, the elastic layer 210 can compensate for the gap between the ball 211 and the rubber sealing layer 201 through its own elasticity. The gap is sealed to prevent rigid friction between the ball 211 and the rubber sealing layer 201 at low temperatures. In addition, the through hole on one side of the ball 211 is used for media flow. The actuator 214 is electric or pneumatic and is fixed to the upper end of the valve stem 213. When the actuator 214 receives the opening and closing signal, it will drive the valve stem 213 to rotate. The rotation of the valve stem 213 will directly drive the ball 211 to rotate inside the elastic layer 210. The valve seat 212 is used to support the valve stem 213 and at the same time help seal the gap between the valve stem 213 and the body.

[0022] The pressure inside the valve is transmitted through the base plate 302 at the bottom of the intake and pressure inlet pipe 301. Multiple intake and pressure inlets 303 on the base plate 302 ensure that the pressure inside the valve enters the intake and pressure inlet pipe 301 evenly, avoiding false triggering caused by localized pressure concentration. When the pressure inside the valve is lower than the set threshold, the spring force of the compression spring 306 is greater than the pressure inside the intake and pressure inlet pipe 301, pushing the two push plates 304 to fit tightly together, blocking the passage between the pressure inlet pipe and the outside. At this time, the exhaust pressure relief port 307 is in a closed state, ensuring no leakage of the medium. When the pressure inside the valve is higher than the set threshold, the pressure inside the intake and pressure inlet pipe 301 overcomes the spring force of the compression spring 306, pushing the two push plates 304 to move... When the valve is activated, the inside of the intake and pressure inlet pipe 301 is connected to the exhaust pressure relief port 307. Excess pressure inside the valve is discharged to the outside through multiple exhaust pressure relief ports 307 until the pressure inside the valve drops to a safe threshold. The function of the damper 305 is to slow down the movement speed of the push plate 304, to prevent the push plate 304 from hitting the pipe wall quickly due to a sudden increase in pressure, and to prevent the medium flow rate from being too fast and generating low-temperature splashing during the pressure relief process. When the pressure inside the valve drops to a safe threshold, the elastic force of the compression spring 306 takes over again, pushing the two push plates 304 to reset and fit together, closing the exhaust pressure relief port 307 again, restoring the valve to a sealed state, and realizing the adaptive adjustment of automatic pressure relief when the pressure is too high and automatic sealing when the pressure is normal.

[0023] Furthermore, the control method of this utility model is controlled by a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the art. Since this utility model is used to protect mechanical devices, the control method and circuit connection will not be explained in detail.

[0024] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0025] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. An ultra-low temperature soft-seal ball valve, characterized in that, include: The ball valve body has a sealing structure fitted on the inner wall of the ball valve body, and a venting structure is provided on one side of the center of the upper end face of the ball valve body. The sealing structure includes a rubber sealing layer, which is sleeved on the inner wall of the ball valve body. The inner wall of the rubber sealing layer has a groove on both sides near the center. On one side of the two grooves, there are four push-pull grooves arranged in a ring on the inner wall of the rubber sealing layer. The sealing structure has a block on both sides near the center. The two locking blocks are respectively adapted to the two rubber sealing layers. The outer walls of the two locking blocks are provided with four push-pull blocks arranged in a ring. The eight push-pull blocks are slidably connected to the center of the eight push-pull grooves. A sealing ring is provided at one side of the center of the outer wall of each of the two card blocks. A waterproof layer is fitted on one side of each sealing ring and on the outer wall of each of the two card blocks. A sealing and bonding layer is fitted on the outer wall of each of the two waterproof layers. Both sealing layers have a sealing layer on their outer sidewalls, and the two sealing layers are adapted to each other with the two locking blocks. An elastic layer is fitted at the center of the inner sidewall of the sealing structure, and a sphere is located at the center of the elastic layer.

2. The cryogenic soft-seal ball valve according to claim 1, characterized in that, A through hole is provided at the center of one side wall of the ball, a valve seat is provided at the center of the upper end face of the ball valve body, and a valve stem is provided at the center of the upper end face of the ball. One end of the valve stem passes through the inner wall of the rubber sealing layer and the inner wall of the ball valve body to the upper end face of the ball valve body, and an actuator is fixedly connected to the end.

3. An ultra-low temperature soft-seal ball valve according to claim 1, wherein The venting and exhaust structure includes an air inlet and pressure inlet pipe, which is located on one side of the center of the upper end face of the ball valve body. A base plate is located at the lower center of the air inlet and pressure inlet pipe. Multiple air inlet and pressure inlets are arranged in a ring on the upper end face of the base plate. One end of the air inlet and pressure inlet pipe passes through the upper end face of the ball valve body and the upper end face of the rubber sealing layer, leading to the interior of the rubber sealing layer.

4. An ultra-low temperature soft-seal ball valve according to claim 3, wherein Two push plates are arranged horizontally on one side of the center inside the intake manifold, with a damper between the two push plates and a compression spring sleeved on the outside of the damper. Multiple exhaust pressure relief ports are arranged horizontally on one side of the center of the upper end face of the intake manifold.

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