valve

Abstract

To provide a valve capable of improving maintainability, and efficiently performing cold insulation / heat insulation of a transferred fluid or heating the same.SOLUTION: A valve 10 has: a jacket portion 30 covering an outer side of a valve main body 11; a cylindrical portion 20 connected to the valve main body 11 at one end side and opened at the other end side; a valve rod 60 rotating a valve element 12; a bonnet 65 rotatably holding the valve rod 60, and detachable to the valve main body 11; and a cover body 40 formed integrally with the bonnet 65, and attachable to and detachable from the other end side of the cylindrical portion 20. The jacket portion 30 has a cylindrical portion-side covering portion 32 for partially or fully covering an outer side of the cylindrical portion 20, the cover body 40 has a projecting portion 42 which projects toward an inner side of the cylindrical portion 20 and can be fitted to the cylindrical portion 20, the projecting portion 42 has an inner pipe 45 through which the valve rod 60 can pass and has a hollow partition chamber 43 disposed around the inner pipe 45, and the inside of the partition chamber 43 can be decompressed. A heat medium can be introduced to the inside of the partition chamber 43.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a valve. More specifically, it relates to a valve having a jacket structure suitable for transferring low-temperature or high-temperature fluids.

Background Art

[0002] Conventionally, various valves have been used to transfer various fluids. The valve needs to be maintained when inspections, cleaning, or malfunctions occur. During the maintenance, it is necessary to remove the valve from the connected piping or the like. Therefore, there is a problem of poor maintainability.

[0003] Therefore, a swing check valve (hereinafter referred to as a valve) provided with an opening for maintenance and having improved maintainability is known (for example, Patent Document 1). The valve described in Patent Document 1 has an opening for maintenance provided at the upper part of the valve body and has a maintenance cover that can be opened and closed at the upper part of the opening. Therefore, the valve described in Patent Document 1 enables maintenance without removing it from the piping.

[0004] By the way, when transferring cryogenic fluids such as liquid hydrogen (boiling point: -253°C) and liquid helium (boiling point: -269°C), in order to prevent the fluid from vaporizing, it is necessary to provide a vacuum jacket for heat insulation outside the valve and piping (hereinafter referred to as valve etc.) to reduce the heat input from the outside air to the fluid. However, even when a vacuum jacket is provided outside the valve etc., if a part of the outer surface of the valve etc. that is below the boiling point of liquid oxygen (-183°C) is exposed to the outside air, there is a concern that oxygen in the air will liquefy and liquid oxygen will be generated. Therefore, it is necessary to attach a vacuum jacket to the parts that may be below the boiling point of liquid oxygen to isolate them from the outside air.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Utility Model Publication No. 57-80769 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, if the valve described in Patent Document 1 is covered with a jacket, the maintenance opening and maintenance cover are also covered, which presents a problem as maintenance becomes impossible. To solve this problem, as shown in Figure 8, it is necessary to extend the maintenance opening 83 and maintenance cover 84 of the valve 80 together with the jacket 85 to a position where liquid oxygen is not generated. Therefore, the maintenance opening 83 needs to be provided at a position that is significantly separated above the opening 82 of the valve body 81.

[0007] Therefore, as shown in Figure 8, when the valve body 81 is extended upward, fluid enters the interior of the extended portion, and due to heat input from the upper side, the vaporized low-temperature gas becomes more susceptible to convection, as shown by the dashed arrows in the figure. In this way, the convection of the vaporized low-temperature fluid cools the maintenance cover 84, etc., raising concerns that liquid oxygen may be generated outside the maintenance cover 84, etc. Therefore, it was necessary to provide the maintenance opening 83 and maintenance cover 84, etc., at a very high position (a position far away from the valve body 86 and piping 87) where they would not be affected by convection. As a result, there was a problem of poor maintainability. Thus, with conventional valves, it was difficult to solve the conflicting problems of efficiently keeping the fluid being transferred cool while maintaining maintainability.

[0008] Therefore, the present invention aims to provide a valve that improves the maintainability of the valve and can not only efficiently cool the fluid being transferred, but also keep it warm or even heat it. [Means for solving the problem]

[0009] (1) The valve of the present invention, provided to solve the above-mentioned problems, comprises: a jacket portion covering the outside of a valve body; a cylindrical portion having one end connected to the valve body and the other end open; a valve element disposed inside the valve body; a valve stem connected to the valve element and causing the valve element to rotate or reciprocate; a bonnet that holds the valve stem so as to be able to rotate or reciprocate and is detachably provided to the valve body; and a lid integrally formed with the bonnet and detachably provided to the other end of the cylindrical portion to seal that other end; wherein the jacket portion has a cylindrical portion side covering portion that covers part or all of the outside of the cylindrical portion; the lid has a projection that protrudes from the back side toward the inside of the cylindrical portion and can be fitted into the inside of the cylindrical portion; the projection has an inner tube through which the valve stem can pass and a hollow chamber disposed around the inner tube; and the chamber is capable of reducing pressure inside.

[0010] The valve described above has a cylindrical portion connected at one end to the valve body, with the other end of the cylindrical portion being open. The other end of the cylindrical portion is sealed with a removable cover. Therefore, by removing the cover, it is possible to access the inside of the valve body through the cylindrical portion. As a result, the valve described above can improve the maintainability of the inside of the valve body (e.g., cleaning, repair, inspection, etc.).

[0011] Furthermore, the valve described above has a projection on the underside of the cover, which can be fitted into the inside of the cylindrical part, and has a hollow chamber inside. The chamber is also designed to be able to reduce pressure inside. Here, the pressure reduction described above should ideally be reduced to the point where the inside of the chamber becomes a vacuum (insulated state). As a result, the valve described above can shield from heat input from the other end of the cylindrical part (for example, the upper side), allowing the height of the cylindrical part (cover) to be set lower, and the length of the valve stem and bonnet to be shortened. Consequently, access to the inside of the valve (for example, the seal part) becomes easier, and improvements in maintainability and miniaturization of the valve can be expected.

[0012] Furthermore, the valve described above can be reliably insulated from the outside air by its lid (chamber) and jacket. Therefore, the valve described above can suppress the generation of liquid oxygen even when transferring cryogenic fluids such as liquid hydrogen, liquid helium, and liquid nitrogen. Also, even when transferring high-temperature fluids, the valve described above can prevent the high-temperature part from being directly exposed to the outside. The pressure inside the chamber can be reduced, for example, by providing a suction port in the chamber and exhausting the air inside the chamber through the suction port using a vacuum pump or the like. In addition, since the valve body and the jacket portion of the bonnet of the valve described above are independent of each other, it is possible to remove the bonnet for maintenance while maintaining the pressure (e.g., vacuum level) of the valve body's jacket portion.

[0013] (2) The valve of the present invention, provided to solve the above-mentioned problems, comprises: a jacket portion covering the outside of a valve body; a cylindrical portion having one end connected to the valve body and the other end open; a valve element disposed inside the valve body; a valve stem connected to the valve element and causing the valve element to rotate or reciprocate; a bonnet that holds the valve stem so as to be able to rotate or reciprocate and is detachably provided to the valve body; and a lid integrally formed with the bonnet and detachably provided to the other end of the cylindrical portion to seal the other end, wherein the jacket portion has a cylindrical portion side covering portion that covers part or all of the outside of the cylindrical portion; the lid has a projection that protrudes from the back side toward the inside of the cylindrical portion and can be fitted into the inside of the cylindrical portion; the projection has an inner tube through which the valve stem can pass and a hollow compartment disposed around the inner tube, and a heat transfer medium can be introduced into the compartment.

[0014] The valve described above has a cylindrical portion connected at one end to the valve body, with the other end of the cylindrical portion being open. The other end of the cylindrical portion is sealed with a removable cover. Therefore, by removing the cover, it is possible to access the inside of the valve body through the cylindrical portion. Thus, the valve described above can improve the maintainability of the inside of the valve body (e.g., cleaning, repair [including replacement of internal parts], inspection, etc.).

[0015] Furthermore, the valve described above has a projection on the underside of the lid, which can be fitted into the inside of the cylindrical part and has a hollow chamber inside. The chamber is also designed to allow the introduction of a heat transfer medium. The heat transfer medium can be, for example, steam or heat transfer oil. Therefore, the valve described above can efficiently keep the valve warm or heated while ensuring maintainability. Here, various means can be employed to introduce the heat transfer medium, such as providing an inlet in the chamber and sealing the heat transfer medium into the chamber from the inlet, or providing a separate outlet in addition to the inlet and circulating the heat transfer medium within the chamber.

[0016] (3) In the valve of the present invention described above, it is preferable that the partition chamber is formed such that at least a portion of it overlaps with the covering portion on the cylindrical part side.

[0017] The valve described above, with this configuration, can reliably keep a fluid (including vaporized gas) cool, warm, or heated. In other words, the valve of the present invention can suppress the transfer of the temperature of a fluid (e.g., liquid hydrogen, liquid helium, liquid nitrogen) to the outside air through the valve. As a result, the valve can suppress the generation of liquid oxygen. Furthermore, even when transferring high-temperature fluids, the valve can suppress direct exposure of high-temperature parts to the outside.

[0018] (4) The jacket structure of the present invention described above is preferably such that a part or the entire inner wall of the partition is covered with at least one of either a low-radiation insulating sheet or a multilayer insulating material consisting of a low-radiation insulating sheet and a spacer material.

[0019] The jacket structure described above can suppress heat transfer by radiation, thereby further improving thermal insulation.

[0020] (5) The valve of the present invention described above preferably has a sealing portion formed between the inner wall at one end of the cylindrical portion and the outer wall of the protruding portion.

[0021] The valve described above, with this configuration, can seal the gap between the inner wall at one end of the cylindrical portion and the outer wall of the protruding portion. As a result, fluids (e.g., liquid hydrogen, liquid helium, liquid nitrogen) that enter the space between the lower part of the protruding portion (separation chamber) and the valve body are retained in that space as a gas. Here, since gas has lower thermal conductivity and heat transfer coefficient than liquid, the heat insulation effect in the space is enhanced. Consequently, the valve described above, in synergy with the jacket portion, can be set to a lower height for the cylindrical portion. This improves the maintainability of the valve described above. Furthermore, since the valve described above can suppress the ingress of low-temperature liquids into the cylindrical portion, the cooling of the lid portion 41 can be suppressed. As a result, the valve described above can suppress the generation of liquid oxygen. In addition, even when transferring high-temperature fluids, the valve described above can suppress direct exposure of high-temperature parts to the outside.

[0022] (6) In the valve of the present invention as described above, the sealing portion is such that the sealing performance is enhanced when the pressure on the valve body side is higher than the pressure on the cylindrical portion side, and the sealing performance is reduced when the pressure on the cylindrical portion side is higher than the pressure on the valve body side.

[0023] With the above-described valve configured as such, when the internal pressure on the piping side increases, the sealing performance is enhanced, and the gap between the lid body and the cylindrical portion can be reliably sealed. Therefore, the above-described valve can suppress the intrusion of low-temperature liquid into the cylindrical portion and the cooling of the lid portion, and thus can suppress the generation of liquid oxygen. On the other hand, if by any chance the fluid passes through the seal portion and enters the gap between the lid body and the cylindrical portion, and the fluid vaporizes to increase the internal pressure in the cylindrical portion, the sealing performance is reduced, and the pressure can be released to the piping side. Therefore, it is possible to prevent abnormal pressure increase caused by providing the seal portion. Further, the above-described jacket structure can suppress the direct exposure of the high-temperature portion to the outside even when transferring a high-temperature fluid.

[0024] (7) The valve of the present invention described above has a bearing holder independent of the bonnet and a bearing that can be held by the bearing holder. The bearing holder is arranged on the lower side of the protruding portion and may support the valve rod rotatably via the bearing.

[0025] In the above-described valve, a bearing holder is arranged independently of the bonnet, and the valve rod is supported rotatably via a bearing held by the bearing holder. Therefore, the centering of the valve rod can be performed with the bonnet removed. Therefore, according to the above-described valve, the assembly property and the maintainability are improved. Further, in the above-described valve, by removing the bonnet together with the lid body and taking out the bearing holder from the valve body, all parts such as the valve element and the seal inside the valve body can be taken out, so that the maintainability can be improved.

[0026] (8) The valve of the present invention described above may have a drive portion that rotationally drives or linearly drives the valve rod, and the valve rod may be formed by being divided into a plurality of parts.

[0027] Since the valve rod of the valve described above is formed by being divided into a plurality of parts, for example, centering can be performed with only the first valve rod on the side connected to the valve body. That is, the valve described above can perform centering of the first valve rod with the lid body or the bonnet removed. Therefore, according to the valve described above, the assemblability and maintainability are improved. Also, the connection of other valve rods connected to the first valve rod and the attachment of each valve rod to the lid body or the like may be performed after the centering of the first valve rod.

[0028] Also, since the valve rod of the valve described above can be divided, the lifting cost of a crane or the like when removing the bonnet can be set low. Therefore, the maintainability is improved. Also, since the maintenance space above the valve body can be minimized, the installation space of the valve can be made compact while maintaining the maintainability.

Effects of the Invention

[0029] According to the present invention, it is possible to provide a valve that improves maintainability and can efficiently cool, heat-insulate, or heat the fluid to be transferred.

Brief Description of the Drawings

[0030] [Figure 1] It is a side-direction cross-sectional view of a jacket structure according to a first embodiment applicable to the valve of the present invention. [Figure 2] It is an enlarged view around the seal portion in FIG. 1. [Figure 3] It is a side-direction cross-sectional view of a jacket structure according to a second embodiment applicable to the valve of the present invention. [Figure 4] It is a cross-sectional view taken along the arrow A-A direction in FIG. 3. [Figure 5] It is a side-direction cross-sectional view of the valve of the present invention employing a jacket structure according to a third embodiment. [Figure 6] It is an enlarged view of the upper part of the valve body in FIG. 5. [Figure 7] It is a side-direction cross-sectional view of a valve according to a modified example of the present invention. [Figure 8]This is an explanatory diagram of a valve in a conventional check valve. [Modes for carrying out the invention]

[0031] First, the first and second embodiments of the jacket structures 1A and 1B, which form the basic structure of the valve 10 of the present invention, will be described below. Next, the valves 10C and 10D of the present invention, which employ the jacket structures 1A and 1B, will be described in detail as a third embodiment and its modified form. ≪First Embodiment≫ The jacket structure 1A (collectively referred to as jacket structure 1) according to the first embodiment will be described below with reference to Figure 1. In the first embodiment, the case in which jacket structure 1A is used in a swing-type check valve 10A (also referred to as valve 10A, and collectively referred to as valve 10) will be described. Furthermore, the case in which the fluid transferred in the piping 2 and check valve 10A is a cryogenic fluid such as liquid hydrogen, liquid helium, or liquid nitrogen will be described.

[0032] As shown in Figure 1, the check valve 10A employing a jacket structure 1A comprises a valve body 11 as a housing, piping 2 connected to the valve body 11, a cylindrical portion 20 positioned on the upper part of the valve body 11, a jacket portion 30 covering the valve body 11 and piping 2, etc., and a cover 40 that seals the upper part of the cylindrical portion 20, etc.

[0033] The valve body 11 is formed as a housing with an internal space. The valve body 11 has pipes 2 connected to both ends of the lower end in the horizontal direction (horizontal direction in the illustration) by welding or the like. The valve body 11 contains a valve element 12 and a swing arm 13 for swinging the valve element 12.

[0034] The valve body 11 has a maintenance opening 14 at its upper end. Below the opening 14 are the valve element 12 and the swing arm 13, and the opening 14 allows access to these components. Therefore, workers can easily inspect and repair (including replacing internal parts) the check valve 10A and the piping 2 through the opening 14.

[0035] Furthermore, a flange 15 for attaching the swing arm 13 is fixed to the opening 14. The flange 15 has an opening that communicates with the opening 14. In addition, an arm support portion 15A is formed on the lower side of the flange 15, extending downward along the opening edge of the opening 14.

[0036] The oscillating arm 13 is rotatably supported at its base end by an arm support portion 15A located above the valve body 12. The oscillating arm 13 can rotate vertically together with the valve body 12, which is subjected to fluid pressure.

[0037] The valve body 12 is formed as a disc-shaped member of a size capable of closing the flow path of the valve body 11, and a seal (not shown) is provided on the contact surface between the valve body 12 and the valve body 11. The seal can be of various forms, such as being provided as a separate part, having a surface treatment applied to the valve body 12 and / or the valve body 11, or having a machined surface formed on the valve body and / or the valve body 11. The tip of the swing arm 13 is connected to the back side (inside the valve body 11) of the valve body 12. Therefore, when the valve body 12 receives fluid pressure and the swing arm 13 rotates, the valve body 12 swings between a closed position that closes the valve body 11 and an open position that opens the flow path of the valve body 11.

[0038] The cylindrical portion 20 has one end, which serves as the base, connected to the upper part of the valve body 11, and the other end is open to the outside of the valve body 11. The cylindrical portion 20 is formed in a cylindrical shape and is positioned to surround the opening 14 of the valve body 11. Therefore, an operator can access the inside of the valve body 11 through the cylindrical portion 20. The other end (upper end) of the cylindrical portion 20 has a screw hole for fixing the cover 40, which will be described later. In addition, the protruding portion 42 of the cover 40, which will be described later, can be fitted into the inside of the cylindrical portion 20.

[0039] The jacket portion 30 has an internal space and is designed to cover at least the outside of the piping 2. In this embodiment, the jacket portion 30 covers the valve body 11 and the cylindrical portion 20 from the outside, in addition to the piping 2. The jacket portion 30 also has a cylindrical portion side covering portion 32 that covers the outside of the cylindrical portion 20.

[0040] The jacket portion 30 is connected to a vacuum pump (not shown) via a suction port (not shown) as appropriate, and the inside can be depressurized by driving the vacuum pump. Here, the depressurization described above should ideally be reduced to, for example, until the internal space of the jacket portion 30 becomes a thermally insulated state (vacuum state). Note that the jacket portion 30 may not only be connected to a vacuum pump, but may also be sealed in a depressurized state beforehand to achieve a thermally insulated state.

[0041] In this embodiment, the cylindrical cover portion 32 is formed on the outside of the cylindrical portion 20, extending from one end (base end) of the cylindrical portion 20 toward the other end. In this embodiment, the cylindrical cover portion 32 is formed integrally with the cylindrical portion 20. In this embodiment, the internal space of the cylindrical cover portion 32 communicates with the internal space of the piping 2 and the jacket portion 30 of the valve body 11. Note that the cylindrical cover portion 32 may be formed independently of the cylindrical portion 20, not just integrally with it. Furthermore, when connecting the piping 2 to the middle part of the cylindrical portion 20, an opening can be provided in the cylindrical cover portion 32, and the piping 2 and the cylindrical cover portion can be connected to the cylindrical portion 20 and the jacket portion 30 on the piping 2 side through this opening. As will be described in detail later, the internal space of the cylindrical cover portion 32 should be formed at a height that overlaps at least a part with the partition 43 of the lid 40.

[0042] The cover 40 comprises a plate-shaped cover portion 41, a protruding portion 42 that can be fitted inside the cylindrical portion 20, and a compartment 43 formed inside the protruding portion 42. The cover 40 is designed to seal the other end (open end) of the cylindrical portion 20. In other words, the cover 40 also functions as a closing flange (maintenance cover).

[0043] The lid portion 41 is formed in a disc shape and is approximately the same size as the outer diameter of the cylindrical portion 20. The outer circumference of the lid portion 41 is fixed to the cylindrical portion 20 by a plurality of screw members 41A. In other words, the lid 40 is detachably fixed to the cylindrical portion 20 by the screw members 41A. Therefore, by removing the lid 40, an operator can access the inside of the valve body 11. The lid portion 41 and the cylindrical portion 20 are sealed by a sealing member, and by fixing the lid portion 41 to the cylindrical portion 20, the other end (open end) of the cylindrical portion 20 is sealed. In addition, the lid portion 41 has a suction port 41B that communicates with the partition chamber 43, which will be described later.

[0044] The protrusion 42 is formed to protrude from the back side of the lid 41 toward the inside of the cylindrical portion 20. The protrusion 42 is formed in a circular shape and has a diameter equal to or slightly smaller than the inner diameter of the cylindrical portion 20. Therefore, the protrusion 42 can be fitted inside the cylindrical portion 20. In addition, a hollow partition 43 is formed inside the protrusion 42. Because the protrusion 42 is configured as described above, it is possible to suppress contact between the cryogenic fluid and the high-temperature fluid and the lid 41. This ensures that the cryogenic fluid and high-temperature fluid are properly insulated from the lid 41. The shape and size of the protrusion 42 can be formed in various shapes and sizes depending on the composition and temperature of the fluid.

[0045] Furthermore, a sealing portion 50 is formed between the outer wall at the lower end of the protruding portion 42 and the inner wall at one end of the cylindrical portion 20 (the valve body 11 side).

[0046] The sealing portion 50 seals the gap between the protruding portion 42 and the inner wall of the cylindrical portion 20, preventing the fluid being transferred from leaking to the outside. The sealing portion 50 is positioned to surround the outer circumference of the protruding portion 42. Figure 2 is an enlarged view of the area around the sealing portion 50. As shown in Figure 2, the sealing portion 50 comprises a U-shaped member 51 and a spring 52 fitted into the U-shaped member 51.

[0047] The spring 52 is compressed during installation, applying a constant load to the sealing surface of the U-shaped member 51. When the pressure (internal pressure) on the piping 2 side, i.e., the check valve 10A side, increases, the pressure acts in a direction that opens the U-shaped member 51, increasing the sealing surface pressure and improving the sealing performance. On the other hand, when the pressure on the cylindrical portion 20 side, i.e., the open end side (other end side) of the cylindrical portion 20, increases, the pressure acts in a direction that closes the U-shaped member 51, reducing the sealing performance. In this embodiment, the open side of the U-shaped member 51 is positioned horizontally so as to face the protrusion 42, but the U-shaped member 51 can be positioned in various directions and locations depending on the pressure. For example, the U-shaped member 51 may be positioned in an inverted U shape along the vertical direction. Furthermore, the sealing portion 50 can be of various forms as long as it can seal the space between the protrusion 42 and the cylindrical portion 20.

[0048] Thus, since the jacket structure 1A has a sealing portion 50, it can reliably seal the gap between the lid 40 and the cylindrical portion 20 even when the pressure of the fluid passing through the piping 2 (including the check valve 10A) increases. Therefore, the jacket structure 1A can suppress the intrusion of low-temperature liquid into the cylindrical portion 20 and the cooling of the lid 41, thereby suppressing the generation of liquid oxygen. Furthermore, even when transferring high-temperature fluid, the jacket structure 1A can suppress direct exposure of high-temperature parts to the outside.

[0049] Next, the partition chamber 43 formed in the protruding portion 42 will be described with reference to Figure 1. The partition chamber 43 is formed in a circular shape along the radially inward side of the protruding portion 42, leaving the thickness of the outer wall of the protruding portion 42. Therefore, the partition chamber 43 can cover almost the entire radially inward area of ​​the cylindrical portion 20 from above. The partition chamber 43 is in communication with the suction port 41B formed in the lid portion 41. A vacuum pump (not shown) is connected to the suction port 41B via a port 44 that is detachable or connected by welding or the like.

[0050] The pressure inside the partition chamber 43 is reduced by exhausting the air inside the partition chamber 43 through the suction port 41B using the vacuum pump. Here, the degree of pressure reduction (vacuum) can be, for example, a vacuum state that provides thermal insulation. The port 44 can seal the suction port 41B after the pressure reduction is complete. This maintains a vacuum state inside the partition chamber 43. The partition chamber 43 may be formed to a thickness that provides thermal insulation depending on the temperature of the fluid being transferred.

[0051] The partition chamber 43 is formed such that at least a portion of it overlaps with the cylindrical side covering portion 32 of the jacket portion 30. Therefore, the valve body 11 is covered by the jacket portion 30 over its entire outer surface. As a result, the inside of the valve body 11 is kept cool. It is preferable that part or all of the inner wall of the partition chamber 43 be covered with at least one of either a low-radiation insulating sheet or a multi-layer insulating material consisting of a low-radiation insulating sheet and a spacer material. This allows the jacket structure 1 described above to suppress heat transfer by radiation, thereby further improving its thermal insulation performance.

[0052] The above example illustrates the case of transporting cryogenic fluids, but the jacket structure 1A described above can also be applied to high-temperature fluids such as molten wax. In such cases, the inside of the partition chamber 43 can be insulated as described above, or a heat transfer medium can be introduced into the partition chamber 43. For example, steam or heat transfer oil can be used as the heat transfer medium. In this way, the jacket structure 1A described above can maintain or heat the inside of the partition chamber 43 to a high temperature by introducing a heat transfer medium into the partition chamber 43. Here, various means can be employed to introduce the heat transfer medium, such as providing an inlet in the partition chamber 43 and sealing the heat transfer medium into the partition chamber from the inlet, or providing a separate outlet in addition to the inlet and circulating the heat transfer medium within the partition chamber.

[0053] The above describes the configuration of the first embodiment of the jacket structure 1A that can be used in the valve 10 of the present invention. By adopting the above-described configuration of the jacket structure 1A, the valve 10 can achieve, for example, the following effects.

[0054] Valve 10 has one end of a cylindrical portion 20 connected to the valve body 11, with the other end of the cylindrical portion 20 being open. The other end of the cylindrical portion 20 is sealed with a removable cover 40. Therefore, by removing the cover 40, it is possible to access the inside of the valve 10 and the piping 2 through the cylindrical portion 20. Thus, according to the valve 10 of the present invention, the maintainability (e.g., cleaning, repair [including replacement of internal parts], inspection, etc.) of the inside of the valve body 11 and the piping 2 is improved.

[0055] Furthermore, as described above, the valve 10 has a cover 40 with a projection 42 on its back side, the projection 42 being able to be fitted inside the cylindrical portion 20, and having a hollow compartment 43 inside. The compartment 43 is also designed to allow for pressure reduction inside. Therefore, the valve 10 can shield against heat input from the other end of the cylindrical portion 20 (for example, the upper side), thus allowing the length of the cylindrical portion 20 to be shortened. As a result, improved maintainability and miniaturization of the valve 10 can be expected.

[0056] Furthermore, the valve 10 described above, with its cover 40 (separation chamber 43) and jacket portion 30, can reliably insulate the check valve 10A, piping 2, etc., from the outside air. Therefore, the valve 10 can suppress the generation of liquid oxygen even when transferring cryogenic fluids such as liquid hydrogen, liquid helium, and liquid nitrogen. Also, even when transferring high-temperature fluids, the valve 10 can prevent the high-temperature parts from being directly exposed to the outside.

[0057] Furthermore, since the valve 10 described above is formed such that at least a portion of the partition chamber 43 overlaps with the cylindrical side covering portion 32, it can reliably keep the fluid (including vaporized gas) cool, warm, or heated. In other words, the valve 10 described above can further suppress the transmission of the fluid temperature to the outside air via the piping 2 and the valve 10.

[0058] Furthermore, since the valve 10 described above has a sealing portion 50 formed between the inner wall at one end of the cylindrical portion 20 and the outer wall of the protruding portion 42, it can seal (seal) the gap between the inner wall at one end of the cylindrical portion 20 and the outer wall of the protruding portion 42. As a result, cryogenic fluid that enters the space between the lower part of the protruding portion 42 (separation chamber 43) and the valve body 11 is held in that space as a gas.

[0059] Here, since gas has lower thermal conductivity and heat transfer coefficient than liquid, the heat insulation effect within the space is enhanced. Therefore, the valve 10 described above, through a synergistic effect with the jacket portion 30, allows the height of the cylindrical portion 20 to be set lower. As a result, the valve 10 described above can improve maintainability. In addition, the valve 10 described above can suppress the ingress of low-temperature liquid into the cylindrical portion 20, thereby suppressing the cooling of the lid portion 41. Therefore, the valve 10 described above can effectively suppress the generation of liquid oxygen. Furthermore, even when transferring high-temperature fluid, the valve 10 described above can effectively suppress direct exposure of high-temperature parts to the outside.

[0060] Next, a jacket structure 1B according to a second embodiment that can be used in the valve 10 of the present invention will be described in detail with reference to Figures 3 and 4.

[0061] ≪Second Embodiment≫ In the second embodiment, we will describe a case in which a jacket structure 1B (collectively referred to as jacket structure 1) is used in a butterfly valve 10B (also referred to as valve 10B, and collectively referred to as valve 10) having a long valve stem 60. Note that the same components as in the first embodiment will not be described. Also, please note that the same reference numerals are used for components as in the first embodiment. Furthermore, in the second embodiment, as in the first embodiment, we will describe the case in which cryogenic fluids such as liquid hydrogen, liquid helium, or liquid nitrogen are transferred as the fluid.

[0062] Figure 3 is a cross-sectional view of the jacket structure 1B from the side, and Figure 4 is a cross-sectional view taken in the direction of arrow AA in Figure 3. As shown in Figures 3 and 4, the butterfly valve 10B comprises a valve body 11 as a housing, a valve element 12, a valve stem 60 connected to the valve element 12, and a bonnet 65 arranged on the outer circumference of the valve stem 60. Piping 2 is connected to both sides of the valve body 11 in the horizontal direction.

[0063] In the second embodiment, the opening 14 is formed not directly above the valve body 12, but on the upper surface of the valve body 11, offset towards the piping 2 side. Furthermore, one end of the cylindrical portion 20 is connected to the upper part of the valve body 11 above the opening 14. Therefore, a worker can access the inside of the valve body 11 through the opening 14 from the other end (upper end) of the cylindrical portion 20. In addition, in the second embodiment, since the cylindrical portion 20 is provided above and adjacent to the valve body 12, the seal 12A can be easily replaced. Furthermore, maintenance of the valve body 12 (e.g., cleaning, repair, inspection, etc.) can be performed together with the valve body 11. Details of the cylindrical portion 20 are the same as in the first embodiment, so a description will be omitted.

[0064] A lid 40 is detachably fixed to the other end (open end) of the cylindrical portion 20. The jacket portion 30, which is provided to cover the cylindrical portion 20, and the lid 40 fixed to the other end of the cylindrical portion 20 are the same as in the first embodiment, so their description will be omitted.

[0065] The upper end of the valve body 12 is connected to the valve stem 60. The valve body 12 is rotatably supported by the valve body 11. A seal 12A is installed between the outer circumference of the valve body 12 and the inner circumference of the valve body 11, so that the valve body 11 can be closed by closing the valve body 12. Various forms of seal 12A can be used, such as one installed on the valve body 12 side, one installed on the valve body 11 side, or one installed on both the valve body 12 and the valve body 11.

[0066] The valve stem 60 is rotatably supported on the valve body 11 via a bearing 16A. Furthermore, a drive unit 66, such as a gear, cylinder, or motor, is connected to the upper end of the valve stem 60. Therefore, the valve stem 60 is rotationally driven by the drive unit 66, causing the valve body 12 to rotate between a closed position that closes the valve body 11 and an open position that opens the flow path of the valve body 11. In the case of a gate valve or globe valve where the valve body 12 moves up and down, the drive unit 66 can be used to reciprocate the valve body 12 up and down via the valve stem 60.

[0067] Furthermore, a bonnet 65 is erected so as to extend upward and cover the outer circumference of the valve stem 60. The bonnet 65 rotatably holds the valve stem 60 via appropriate bearings (not shown).

[0068] The jacket portion 30 is provided to cover the piping 2, the cylindrical portion 20, and the valve body 11, similar to the first embodiment. In addition, in the second embodiment, the jacket portion 30 is arranged to extend upward from the base end side (valve body 11 side) of the bonnet 65. Therefore, the jacket portion 30 provided on the outer circumference of the bonnet 65 can suppress the generation of liquid oxygen in the lower part of the bonnet 65. The above describes the configuration of the jacket structure 1B according to the second embodiment that can be used in the valve 10 of the present invention, and the jacket structure 1B according to the second embodiment also provides the same effects as the first embodiment.

[0069] Furthermore, by adopting the above-described configuration, the jacket structure 1A according to the first embodiment and the jacket structure 1B according to the second embodiment can be mounted on various parts of various pipes 2 and fluid equipment (various valves, flow meters, strainers, etc.). This improves the thermal insulation of the pipes 2 and fluid equipment, as well as improves maintainability.

[0070] Next, the butterfly valve 10C according to the third embodiment of the present invention will be described in detail below with reference to Figure 5.

[0071] ≪Third Embodiment≫ In the third embodiment, a case will be described in which a jacket structure 1C (collectively referred to as jacket structure 1) is employed in a butterfly valve 10C (also referred to as valve 10C, and collectively as valve 10) which has a bonnet 65 similar to the butterfly valve 10B in the second embodiment. The main differences of the third embodiment from the second embodiment are that the partition chamber 43 is located above the valve body 12 and the valve stem 60 is divided into a first valve stem 61 and a second valve stem 62. The same components as in the first and second embodiments will not be described. Also, please note that the same reference numerals are used for the same components as in the first and second embodiments. In the third embodiment as well, the description will be based on the assumption that a cryogenic fluid such as liquid hydrogen, liquid helium, or liquid nitrogen is being transferred as the fluid, similar to the first and second embodiments.

[0072] As shown in Figure 5, the butterfly valve 10C comprises a valve body 11 as a housing, a valve element 12, a cylindrical portion 20, a valve stem 60 connected to the valve element 12, and a bonnet 65 arranged around the outer circumference of the valve stem 60. Piping 2 is connected to both sides of the valve body 11 in the horizontal direction.

[0073] In the third embodiment, the opening 14 is formed on the valve body 11. One end (base end) of the cylindrical portion 20 is connected to the upper part of the opening 14 on the valve body 11. A cover 40 is provided on the other end (upper end) of the cylindrical portion 20, which is the open end, and closes the other end of the cylindrical portion 20.

[0074] In the third embodiment, a bearing holder 16 is provided below the protrusion 42 of the cover 40. Figure 6 is an enlarged view of the upper part of the valve body 11. The bearing holder 16 has an opening into which a bearing 16A is fitted. The bearing holder 16 is formed in a plate shape and is detachably fixed to the opening edge of the opening 14 with bolts or the like. The upper side (protrusion 42 side) and the lower side (valve body 12 side) of the bearing holder 16 are in communication, and the vaporized fluid (gas) from inside the valve body 11 can flow into the protrusion 42 side.

[0075] As shown in Figure 5, the butterfly valve 10C has a cylindrical bonnet 65 that rotatably holds the valve stem 60. In the third embodiment, the bonnet 65 is integrally formed with the cover 40. Therefore, the bonnet 65 is detachably attached to the valve body 11 integrally with the cover 40. The bonnet 65 is formed to extend upward and rotatably holds the valve stem 60 via a bearing 65A.

[0076] Furthermore, an inner tube 45 is formed in the protruding portion 42 so as to surround the valve stem 60. The inner tube 45 is formed integrally with the bonnet 65 by extending the bonnet 65 downward. As a result, the inner tube 45 is in communication with the inside of the bonnet 65. The inner tube 45 is also intended to function as a partition wall separating the compartment 43. Therefore, in the third embodiment, the compartment 43 has a donut shape. Note that the inner tube 45 is not limited to being formed integrally with the bonnet 65; a divided bonnet 65 may be connected to the upper end of the inner tube 45.

[0077] The valve stem 60 is erected so as to penetrate the cover 40. The valve stem 60 is divided into a first valve stem 61 located on the lower side (valve body 12 side) and a second valve stem 62 located above the first valve stem 61. The first valve stem 61 and the second valve stem 62 are detachably connected to each other by appropriate means such as a key or pin, and can rotate as a single unit. Therefore, when the drive unit 66 is driven, the valve stem 60 rotates, and the valve body 12 is opened and closed.

[0078] The lower end of the first valve stem 61 is connected to the upper end of the valve body 12. The first valve stem 61 is shorter than the second valve stem 62. The upper end of the first valve stem 61 is rotatably supported by the bearing 16A of the bearing holder 16. The upper end of the first valve stem 61 also protrudes upward via the bearing 16A. As described above, the upper end of the first valve stem 61 is detachably connected to the lower end of the second valve stem 62. The upper end of the first valve stem 61 is housed in the inner tube 45 of the partition chamber 43.

[0079] The second valve stem 62 has a hollow section 62A formed from the lower end to the upper end to reduce the heat transfer area. The hollow section 62A communicates with the inside of the valve body 11 and allows the inflow of vaporized fluid (gas) inside the valve body 11. Therefore, the hollow section 62A can suppress the inflow of low-temperature liquids with a high heat transfer coefficient by allowing the inflow of gas. As a result, the hollow section 62A can suppress freezing of the gland packing section 67 of the second valve stem 62. The lower end of the second valve stem 62 is housed in the inner tube 45, and the upper end above the cover 40 is rotatably held inside the bonnet 65. The second valve stem 62 is detachable from the bonnet 65.

[0080] As described above, in the butterfly valve 10C (valve 10) according to the third embodiment, the valve stem 60 is divided into a first valve stem 61 and a second valve stem 62. For example, the first valve stem 61 can be aligned with respect to the bearing 16A of the bearing holder 16 by itself. In other words, the first valve stem 61 of the butterfly valve 10C can be aligned with the cover 40 and bonnet 65 removed. Therefore, the butterfly valve 10C improves ease of assembly and maintenance. Furthermore, as in the third embodiment, aligning the first valve stem 61 is made shorter than the second valve stem 62. The connection of the first valve stem 61 and the second valve stem 62 and the attachment of the cover 40 (bonnet 65) can be done after aligning the first valve stem 61. Furthermore, in the butterfly valve 10C according to the third embodiment described above, all parts such as the valve body 12 and seal 12A located inside the valve body 11 can be removed by removing the bonnet 65 together with the cover 40 and removing the bearing holder 16 from the valve body 11, thereby improving maintainability.

[0081] Furthermore, in the butterfly valve 10C according to the third embodiment, the jacket portion 30 of the valve body 11 and the partition chamber 43 of the bonnet 65 are independent of each other, so it is possible to remove the bonnet 65 for maintenance while maintaining the pressure (e.g., vacuum level) of the jacket portion 30 of the valve body 11. Therefore, by adopting the butterfly valve 10C of the present invention, maintainability is improved.

[0082] Furthermore, in the third embodiment, the butterfly valve 10C has a separable valve stem 60, allowing for a lower lifting height for cranes and other equipment when removing the bonnet 65. This improves maintainability. Additionally, the maintenance space above the valve body 11 can be minimized, allowing for a compact installation space for the valve 10 while maintaining maintainability. Other effects and advantages are the same as those of the first and second embodiments, so their explanation will be omitted.

[0083] The above describes the configuration of the butterfly valve 10C of the present invention according to the third embodiment. Next, a modified example of the butterfly valve 10D of the third embodiment will be described in detail with reference to Figure 7.

[0084] ≪Variations≫ In the modified example, a case will be described in which a jacket structure 1D (collectively referred to as jacket structure 1) is adopted for a butterfly valve 10D (collectively referred to as valve 10) which has a bonnet 65 similar to the butterfly valve 10C of the third embodiment. The butterfly valve 10D in the modified example has the same configuration as the third embodiment except that a second compartment 43B is arranged to extend along the outer circumference of the bonnet 65, so the description of the similar parts will be omitted. Also, please note that the same reference numerals are used for the same components as in the first and second embodiments. Furthermore, in the modified example of the third embodiment, as in the first and second embodiments, it will be described as a cryogenic fluid such as liquid hydrogen, liquid helium, or liquid nitrogen being transferred as the fluid.

[0085] As shown in Figure 7, the second compartment 43B is formed to extend upward from the upper surface of the lid 40 and also to extend along the outer circumference of the bonnet 65. That is, the second compartment 43B is positioned to cover at least a portion of the outer circumference of the bonnet 65. The second compartment 43B is also in communication with the compartment 43 (also referred to as the first compartment 43A) formed on the lower surface of the lid 40. A port 44 can be connected to the upper part of the second compartment 43B by means of attachment or welding. Therefore, the first compartment 43A and the second compartment 43B can be subjected to reduced pressure (e.g., a vacuum) by using a suitable vacuum pump (not shown) via the port 44. In this way, the modified butterfly valve 10D can improve the heat insulation, including the outer circumference of the bonnet 65. As a result, the butterfly valve 10D can reduce the heat input from the outside air to the fluid and suppress the vaporization of the fluid.

[0086] The above describes various embodiments and modifications of the valve 10 and the jacket structure 1 that can be used in the valve 10 according to the present invention. However, the valve 10 of the present invention is not limited to those of the embodiments described above, and can be modified in various ways.

[0087] In this embodiment, the valve 10 is exemplified as a butterfly valve, but the valve 10 of the present invention can utilize various types of valves, such as a rotary ball valve, a gate valve or globe valve in which the valve body moves up and down. When a gate valve or globe valve is used as the valve 10, the valve stem 60 can be reciprocated up and down by the drive unit 66. In this embodiment, the cylindrical portion 20 is exemplified as being integrally formed with the valve body 11, but the cylindrical portion 20 may be formed independently of the valve body 11, not just integrally formed with the valve body 11 or piping 2. In such cases, the cylindrical portion 20 can be joined to the valve body 11 or piping 2 by welding or the like. Furthermore, the cylindrical portion 20 is not limited to a cylindrical shape, but its shape and size can be changed as appropriate to match the shape of the valve body 11. For example, the cylindrical portion 20 may be formed in an elliptical or rectangular shape.

[0088] In this embodiment, the jacket portion 30 is arranged to cover at least the pipe 2, but the portion forming the jacket portion 30 can be arranged in various locations depending on the fluid equipment to which the jacket structure 1 is applied and the temperature of the fluid being transferred. Furthermore, the shape and size of the jacket portion 30 can be various depending on the fluid equipment to which it is applied and the temperature of the fluid being transferred. In this embodiment, the jacket portion 30 has a cylindrical portion side covering portion 32 that extends from one end (base end) of the cylindrical portion 20 toward the other end so as to cover the outside of the cylindrical portion 20, but the cylindrical portion side covering portion 32 can be formed in various shapes and lengths (sizes) to match the shape and size of the cylindrical portion 20. When forming the cylindrical portion side covering portion 32, it is desirable to connect it to the jacket portion 30, but the cylindrical portion side covering portion 32 may be formed independently. In such a case, it is desirable to form the cylindrical portion side covering portion 32 starting from one end (base end) of the cylindrical portion 20 in order to suppress the base end of the cylindrical portion 20 from being exposed to the outside air. Furthermore, when connecting pipe 2 to the middle section of the cylindrical section 20, an opening for connecting pipe 2 can be provided in the cylindrical section-side covering section 32, and pipe 2 and the jacket section 30 on the pipe 2 side can be connected through this opening. Also, the cylindrical section-side covering section 32 may cover part or all of the cylindrical section 20, and various forms can be used depending on the structure of the fluid equipment or pipe 2 connected to the cylindrical section 20.

[0089] Furthermore, the shape and size of the lid 40 (including the protruding portion 42 and the partition chamber 43) can be of various shapes and sizes, as long as they fit into the cylindrical portion 20. In addition, the partition chamber 43 can be of various forms, such as one in which the inside is pre-vacuumed, or one in which the pressure is reduced as needed by a vacuum pump, as in this embodiment.

[0090] In this embodiment, the example illustrates the transfer of cryogenic fluids such as liquid hydrogen, liquid helium, or liquid nitrogen, but the valve 10 of the present invention can be used for various fluids. For example, the valve 10 of the present invention can also be used to transfer high-temperature waxes, oils, etc. In such cases, it is desirable to introduce a heat transfer medium into the partition chamber 43. Thus, the jacket structure 1 of the present invention can effectively maintain the temperature or heat the fluid even when transferring high-temperature fluids, and can also suppress direct exposure of high-temperature parts. Furthermore, when introducing a heat transfer medium into the partition chamber 43, an inlet for introducing the heat transfer medium and an outlet for discharging the heat transfer medium may be provided. This allows the valve 10 to continuously introduce the heat transfer medium from the inlet to the outlet of the partition chamber 43, thereby effectively maintaining the temperature or heating the fluid.

[0091] In this embodiment, at least a portion of the partition chamber 43 is formed to overlap with the cylindrical side covering portion 32 of the jacket portion 30. However, the partition chamber 43 is not limited to one that overlaps with the cylindrical side covering portion 32; various forms can be adopted. For example, the partition chamber 43 may be formed so as not to overlap with the cylindrical side covering portion 32.

[0092] In this embodiment, a sealing portion 50 is formed between the inner wall of one end (base end) of the cylindrical portion 20 and the outer wall of the protruding portion 42. However, the sealing portion 50 may be provided only if necessary, and a configuration without a sealing portion 50 is also possible. Furthermore, the sealing portion 50 is not limited to one whose sealing performance changes in response to changes in internal and external pressure, as in this embodiment; various types of sealing members can be used. For example, the sealing portion 50 may have a constant sealing performance.

[0093] In this embodiment, the valve stem 60 of the valve 10 is shown as being divided into a first valve stem 61 and a second valve stem 62. However, it is possible to use valve stems 60 of various forms and lengths, such as those that are not divided or those that are divided into two or more parts. Furthermore, the lengths of the first valve stem 61 and the second valve stem 62 can be changed as appropriate, and the hollow portion 62A provided in the second valve stem 62 may be provided as needed.

[0094] In this embodiment, a valve 10 equipped with a bearing holder 16 is illustrated, but the bearing holder 16 may be provided only if necessary, and a configuration without the bearing holder 16 is also possible. Furthermore, in this embodiment, a valve 10 in which the bonnet 65 is integrally formed with the cover 40 is illustrated, but the bonnet 65 may be integrally formed with the cover 40 if necessary. For example, the bonnet 65 may be formed independently of the cover 40.

[0095] In this embodiment, a valve 10 is used as an example, but the jacket structure 1 that can be used in the valve 10 of the present invention can be used in various fluid devices. For example, the jacket structure 1 can be used in measuring instruments that measure the state of fluid, such as flow meters, and in piping components such as strainers. Furthermore, the jacket structure 1 that can be used in the valve 10 of the present invention can be used for one or more combinations of various fluid devices. Thus, the jacket structure 1 according to this embodiment improves the maintainability of various fluid devices, including the valve 10, flow meter, and strainer, and can efficiently cool, heat, or warm these fluid devices. Therefore, the jacket structure 1 according to this embodiment is expected to enhance the versatility of the valve 10, flow meter, and strainer.

[0096] The above describes various embodiments and modifications of the jacket structure 1 according to the present invention. However, the present invention is not limited to those exemplified in the embodiments and modifications described above, and it will be readily apparent to those skilled in the art that other embodiments may exist in the spirit and teachings thereof, without departing from the scope of the claims. [Industrial applicability]

[0097] The valve of the present invention can be used as various types of valves such as butterfly valves, ball valves, gate valves, globe valves, etc., capable of keeping the internal fluid cool, warm, or heated. [Explanation of symbols]

[0098] 1: Jacket structure 1A: Jacket structure 1B: Jacket structure 1C: Jacket structure 1D: Jacket structure 10: Valve 10A: Check valve 10B: Butterfly valve 10C: Butterfly valve 10D: Butterfly valve 11: Valve body 12: Valve body 14: Opening 16: Bearing holder 16A: Bearing 20:Cylinder part 30: Jacket section 32: Covering part on the cylindrical section side 40: Lid 42:Protrusion 43: Compartment 45: Inner tube 50: Seal part 60: Valve stem 61:First valve stem 62:Second valve stem 62A: Hollow part 65: Hood 66: Drive unit 67: Gland packing section

Claims

1. The jacket portion covers the outside of the valve body, A cylindrical portion having one end connected to the valve body and the other end open, A valve body disposed inside the valve body, A valve stem connected to the valve body and causing the valve body to rotate or reciprocate, The valve stem is held so as to be rotatable or reciprocable, and a bonnet is provided that is detachably attached to the valve body, It has a lid which is integrally formed with the bonnet and is detachably provided on the other end of the cylindrical portion to seal the other end, The jacket portion has a cylindrical portion covering part or all of the outside of the cylindrical portion, The lid has a projection that protrudes from the back side toward the inside of the cylindrical portion and is fitted into the inside of the cylindrical portion. The aforementioned protrusion is integrally formed with the cover and has an inner tube through which the valve stem can pass, as well as a hollow compartment arranged around the inner tube. The valve is characterized in that the chamber can be depressurized from the outside through a suction port provided in the lid.

2. The jacket portion covers the outside of the valve body, A cylindrical portion having one end connected to the valve body and the other end open, A valve body disposed inside the valve body, A valve stem connected to the valve body and causing the valve body to rotate or reciprocate, The valve stem is held so as to be rotatable or reciprocable, and a bonnet is provided that is detachably attached to the valve body, It has a lid which is integrally formed with the bonnet and is detachably provided on the other end of the cylindrical portion to seal the other end, The jacket portion has a cylindrical portion covering part or all of the outside of the cylindrical portion, The lid has a projection that protrudes from the back side toward the inside of the cylindrical portion and is fitted into the inside of the cylindrical portion. The valve is characterized in that the protruding portion is integrally formed with the cover and has an inner tube through which the valve stem can pass, and has a hollow compartment arranged around the inner tube, and a heat transfer medium can be introduced into the compartment.

3. A jacket portion that covers the outside of the valve body, A cylindrical portion having one end connected to the valve body and the other end open, A valve body disposed inside the valve body, A valve stem connected to the valve body and causing the valve body to rotate or reciprocate, The valve stem is held so as to be rotatable or reciprocable, and a bonnet is provided that is detachably attached to the valve body, It has a lid which is integrally formed with the bonnet and is detachably provided on the other end of the cylindrical portion to seal the other end, The jacket portion has a cylindrical portion covering part or all of the outside of the cylindrical portion, The lid has a projection that protrudes from the back side toward the inside of the cylindrical portion and is fitted into the inside of the cylindrical portion. The aforementioned protrusion has an inner tube through which the valve stem can pass, and a hollow compartment arranged around the inner tube. The aforementioned compartment is capable of reducing internal pressure, A valve characterized in that a sealing portion is formed between the inner wall at one end of the cylindrical portion and the outer wall of the protruding portion.

4. The valve according to any one of claims 1 to 3, characterized in that at least a portion of the partition chamber is formed to overlap with the covering portion on the cylindrical portion side.

5. The valve according to any one of claims 1 to 4, characterized in that part or all of the inner wall of the partition is covered with at least one of a low-radiation insulating sheet or a multilayer insulating material consisting of a low-radiation insulating sheet and a spacer material.

6. The valve according to any one of claims 1, 2, 4, or 5, characterized in that a sealing portion is formed between the inner wall at one end of the cylindrical portion and the outer wall of the protruding portion.

7. The valve according to claim 6, characterized in that the sealing portion has improved sealing performance when the pressure on the valve body side is higher than the pressure on the cylindrical portion side, and reduced sealing performance when the pressure on the cylindrical portion side is higher than the pressure on the valve body side.

8. The aforementioned bonnet and a bearing holder separate from it, The bearing has a bearing that can be held in the bearing holder, The valve according to any one of claims 1 to 7, characterized in that the bearing holder is disposed below the protruding portion and rotatably supports the valve stem via the bearing.

9. The valve stem has a drive unit that rotates or reciprocates the valve stem, The valve according to any one of claims 1 to 8, characterized in that the valve stem is formed in a plurality of parts.

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