JP4689177B2 - Sealing device - Google Patents

Description

  The present invention relates to a sealing device used to prevent leakage of fluids such as high-temperature steam, gas, oil, water, etc. in machinery and equipment, pressure vessels, piping, and the like.

  In recent years, expanded graphite having high heat resistance, flexibility and elasticity has been widely used as a material for forming sealing materials such as gaskets, and in terms of stress relaxation and chemical resistance, conventional asbestos is used. Excellent performance compared to materials made of

  The gasket has a sheet shape, a spiral shape, and the like. As the sheet gasket, the expanded graphite powder is supplied from a hopper or the like between a pair or several pairs of continuously arranged rolling rolls and rolled. The expanded graphite sheet thus obtained is punched into a gasket shape, or if necessary, a metal foil or the like is further bonded to one or both sides of the expanded graphite sheet and then punched into a gasket shape is widely used.

  As a spiral-shaped gasket, a tape-shaped metal ribbon (hoop material) whose cross section has been formed in a substantially V-shape in advance and a filler material that is slit into a slit by expanding an expanded graphite sheet are stacked on top of each other. It is widely known that the coil is wound in a spiral shape, the start and end of the winding are fixed by spot welding, and the inner side, the outer side, or both are further reinforced by a metal ring as required.

  Such a gasket using expanded graphite can be used in an inert atmosphere even at a high temperature exceeding 700 ° C., but in the presence of oxygen, it is oxidized (combusted) by oxygen, so the operating temperature range Is limited. For example, it is limited to 400 ° C. or lower in air and 650 ° C. or lower in water vapor.

  Therefore, in order to widen the operating temperature range of the expanded graphite sealing material, it is necessary to suppress and prevent oxidation of the expanded graphite.

  As a technique for improving the oxidation resistance of expanded graphite itself, Japanese Patent Laid-Open No. 01-089744 (Patent Document 1) discloses a technique for converting the surface of expanded graphite to β-type silicon carbide. No. (Patent Document 2) discloses a technique for adding expanded, boron-based, or iron oxide-based flame retardant to expanded graphite, and Japanese Patent Application Laid-Open No. 09-317894 (Patent Document 3) discloses expanded graphite. Disclosed in Japanese Patent Laid-Open No. 10-310762 (Patent Document 4) and Japanese Patent Laid-Open No. 10-226573 (Patent Document). 5) discloses a technique for treating graphite with phosphoric acid, and Japanese Patent Application Laid-Open No. 58-181713 (Patent Document 6) discloses a technique for depositing a metal, a metal oxide or the like on expanded graphite particles. ing

  By using these techniques, the oxidation of expanded graphite is somewhat suppressed, but it is difficult to extend the operating temperature range to 700 ° C.

  Many techniques for preventing oxidation of a gasket using expanded graphite by blocking the expanded graphite from oxygen are also disclosed.

Regarding a sheet-like gasket, Japanese Patent Application Laid-Open No. 57-009358 (Patent Document 7) discloses a technique for cutting off oxygen by grommeting the edge of an expanded graphite sheet with a metal plate. Patent Document 8) discloses a technique for blocking oxygen by laminating a carbon fiber sheet on expanded graphite and covering the surface with nickel or the like.

  About a spiral-shaped gasket, Unexamined-Japanese-Patent No. 01-224571 (patent document 9) and Unexamined-Japanese-Patent No. 11-351399 (patent document 10) hold | maintain a filler in a spiral shape with a metal strip with a cross-sectional wave shape. Disclosed is a technology for shielding expanded graphite fillers from oxygen by combining filler materials made of inorganic materials excluding asbestos (eg, mica tape with an organic content of 5% or less) inside and outside the spiral gasket. JP-A-11-013888 (Patent Document 11) discloses a technique for blocking oxygen by coating an expanded graphite filler material with a metal foil.

  In addition, regarding gland packing that is not a gasket, Japanese Patent Laid-Open No. 05-060245 (Patent Document 12) describes that grommet processing is applied to both ends of an expanded graphite tape with metal foil or the like, and the packing is wound in a spiral shape. Is disclosed in Japanese Patent Application Laid-Open No. 2001-349439 (Patent Document 13), on both end surfaces of an expanded graphite packing, a metal foil tape is formed by pressure molding. Thus, a technique for blocking contact between oxygen and expanded graphite is disclosed.

When these techniques are used, if oxygen can be reliably shut off, a sealing material such as a gland packing can be used for a long time even at a high temperature exceeding 700 ° C. In addition, since the sealing performance of the inorganic material itself is not sufficient, there is a problem that it cannot be used for a long time. Further, even when the above-described technique for improving the oxidation resistance of the expanded graphite itself and the above-described technique for shielding from expanded oxygen are combined, the sealing performance at a high temperature is not significantly improved.
Japanese Unexamined Patent Publication No. 01-083974 Japanese Patent Laid-Open No. 10-130625 JP 09-317894 A Japanese Patent Laid-Open No. 10-310762 JP-A-10-226573 Japanese Laid-Open Patent Publication No. 58-181713 JP-A-57-009358 JP 05-042626 A JP-A-01-224571 JP-A-11-351399 JP-A-11-013888 JP 05-060245 A JP 2001-349439 A

  The present invention is intended to solve the problems associated with the prior art as described above, and is a sealing device capable of maintaining stable sealing performance over a long period of time even at a use temperature exceeding 700 ° C. in the presence of oxygen. The purpose is to provide.

  The sealing device according to the present invention includes a mounting groove for a blocking material on at least one of an inner circumferential side and an outer circumferential side of a mounting groove of an expanded graphite sealing member formed between a first member and a second member. In the mounting groove, a blocking material that softens or melts according to a high temperature state during use is disposed, and the first member and the second member are fastened to each other. .

  In the present invention, it is preferable that the mounting groove for the blocking material is formed across the first member and the second member.

  In the present invention, it is preferable that the first member and the second member are flange joints, and the expanded graphite sealing member is an expanded graphite gasket.

In the present invention, the blocking material is preferably a metal (i) having a melting point in the range of 200 to 650 ° C. or a metal (ii) having an annealing temperature in the range of 300 to 700 ° C.

  ADVANTAGE OF THE INVENTION According to this invention, the sealing device which can maintain the stable sealing performance over a long period of time, for example under the use temperature exceeding 700 degreeC in oxygen presence is provided.

  Hereinafter, a sealing device according to the present invention will be specifically described with reference to the drawings.

FIG. 1 shows a sealing device (first sealing device) according to a first preferred embodiment of the present invention, in which a first flange joint as a first member and a second flange joint as a second member are shown. A mounting groove for a blocking material is formed on the inner peripheral side and the outer peripheral side of the mounting groove of an expanded graphite gasket as an expanded graphite sealing member formed therebetween, and in accordance with the high temperature state during use in this mounting groove In this embodiment, a blocking material that softens or melts is disposed.

  FIG. 2 shows a sealing device (second sealing device) according to the second preferred embodiment of the present invention, and only on the inner peripheral side of the mounting groove of the expanded graphite gasket as the expanded graphite sealing member, An embodiment is shown in which a mounting groove for a blocking material is formed and the blocking material is disposed in the mounting groove.

  FIG. 3 shows a sealing device (third sealing device) according to a third preferred embodiment of the present invention, which is cut off only on the outer peripheral side of the mounting groove of the expanded graphite gasket as the expanded graphite sealing member. An embodiment is shown in which a mounting groove for the material is formed and the blocking material is disposed in the mounting groove.

  1-3, the same code | symbol is attached | subjected to the same member.

1 to 3, there is a large gap (gap) 90 (90A, 90B, 90C, 90D) between the first flange joint and the second flange joint for convenience of explanation. In the state of use, the first flange joint 20 and the second flange joint 30 are firmly tightened by a fastener 110 such as a bolt, and in actuality, cannot be visually recognized. There are only very small voids.
[First sealing device]
First, the first sealing device shown in FIG. 1 will be described. In the first sealing device 10, an expanded graphite gasket formed between the first flange joint 20 and the second flange joint 30 of the pipe body 1. A mounting groove (inner peripheral side mounting groove) 60 for the blocking material 62 is formed on the inner peripheral side of the mounting groove 50 of 52, and also for the blocking material 72 on the outer peripheral side of the mounting groove 50 of the expanded graphite gasket 52. Mounting grooves (outer peripheral mounting grooves) 70 are formed.

  FIG. 1 shows a state in which blocking members 62 and 72 that are softened or melted according to a high temperature state during use are disposed in the mounting grooves 60 and 70.

Among these blocking materials 62 and 72, the blocking material (inner peripheral blocking material) 62 located on the inner peripheral side of the mounting groove 50 of the expanded graphite gasket 52 flows through the inside 80 of the tubular body 1 under a positive pressure. The internal fluid 100 is softened or melted by the heat of the high-temperature internal fluid 100 to prevent the internal fluid 100 from directly contacting the expanded graphite gasket 52, thereby preventing oxidative deterioration of the expanded graphite gasket 52.

Further, a blocking material (outer peripheral blocking material) 72 positioned on the outer peripheral side of the mounting groove 50 of the expanded graphite gasket 52 is a high-temperature internal fluid 100 that circulates under the positive pressure (pressurization) inside the tube body 1. Heat is quickly transmitted through the metal flange to soften or melt, thereby closing and sealing the outer peripheral side gap 90B, and preventing external fluid from directly contacting the expanded graphite gasket 52. Thus, the oxidative deterioration of the expanded graphite gasket 52 is prevented.

In a use state of the sealing device 10 having such a configuration, for example, water vapor, which is the internal fluid 100, moves from top to bottom toward the paper surface or under pressure at a high temperature exceeding 700 ° C. (eg, 800 ° C.). It flows in the pipe body 1 at an arbitrary speed in the reverse direction. At this time, the inner peripheral side blocking material 62 is
An expanded graphite gasket that is heated and softened or melted by the heat of the internal fluid 100 and deforms and moves freely under the positive pressure (pressurization) of the internal fluid 100, but is a solid sealing material 52 exists behind it so as to back up when viewed from the internal fluid 100 side, so that the internal fluid 100 or the gap 90D located on the inner peripheral side of the inner peripheral blocking member 62 and the outer peripheral side of the inner peripheral blocking member 62 Between the internal fluid 100 and the expanded graphite gasket 52. The air gap 90C is stored in the inner peripheral side mounting groove 60 and in the vicinity thereof in an equilibrium state with substantially no pressure difference between the internal fluid 100 and the expanded graphite gasket 52. Direct contact is blocked. When the inner peripheral blocking material 62 is formed of the metal (ii) that is only softened by the heat of the internal fluid, the internal fluid 100 flows into the gap 90C and the pressure difference is eliminated. However, since the amount of the fluid 100 that flows in is extremely small, the expanded graphite gasket 52 cannot be oxidized and lost.

  In addition, the pipe body 1 is, for example, a pipe of a mechanical instrument, a pressure vessel, and the like as long as fluid such as high-temperature steam, gas, oil, water, etc., particularly high-pressure, high-temperature fluid is contained or circulated therein. It is not limited to piping etc. which extend from a container to various machine tools.

  Also, the cross-sectional shapes of the mounting groove 50 for the expanded graphite gasket 52, the inner peripheral mounting groove 60 for the blocking material 62, and the outer peripheral mounting groove 70 for the blocking material 72 are not particularly limited. As shown, the cross section may be rectangular, and the cross section may be V-shaped, U-shaped, or the like. Also, their dimensions are not particularly limited.

  In addition, the inner peripheral mounting groove 60 and the outer peripheral mounting groove 70 are the first flange joint 20 and the second flange joint 30 from the viewpoint of easiness of flange processing and reduction of the manufacturing cost of the tube body 1. It may be formed only on either one (not shown).

In the embodiment as shown in FIG. 1, the expanded graphite gasket 52 is not oxidized or deteriorated. Therefore, even if a pressure difference occurs between the inner peripheral side gap portion 90C and the outer peripheral side gap portion 90B of the expanded graphite gasket 52, the expanded graphite gasket 52 is substantially free. Fluid (internal fluid 100 and / or external fluid) having a pressure difference between the inner peripheral side and the outer peripheral side of the expanded graphite gasket 52 can be tightly sealed (blocked) for a long period of time without being deformed or collapsed. .

In the sealing device 10 having such a configuration, the temperature of the fluid 100 under a positive pressure flowing through the inside of the tube body 1 is as high as 400 to 800 ° C., and an oxidant component such as oxygen is contained in the internal fluid 100. The inner peripheral side blocking material 62 softens and melts by receiving the heat of the internal fluid 100, and casts into the gap 90C to close the gap, thereby expanding with the internal fluid 100. In order to block direct contact with the graphite gasket 52, the expanded graphite gasket 52 located outside the inner peripheral side blocking material 62 is held in an inert atmosphere, and as a result, expanded graphite even at a high temperature exceeding 700 ° C. The gasket 52 is not oxidized and can be used satisfactorily at such high temperatures.

  At this time, high heat exceeding 700 ° C. of the internal fluid 100 is directly transmitted to the expanded graphite gasket 52 through the flanges 20 and 30, but the expanded graphite gasket 52 is not in direct contact with oxygen or the like. Oxidation degradation is not promoted because it is placed in an active atmosphere.

Further, in this sealing device 10, an outer peripheral side blocking material 72 is also disposed on the outer peripheral side of the expanded graphite gasket 52, but in such a sealing device 10, the outside 82 of the tubular body 1 contains oxygen. Even if an external fluid (not shown) such as air is circulated, the outer peripheral surface of the pipe including the flange portion is often sealed with a heat insulating material (heat insulating material) not shown. Also, it is rare that an external fluid having a temperature higher than that of the internal fluid 100 is allowed to flow. In many cases, the high temperature of the internal fluid 100 is directly radiated through the flanges 20 and 30, and the external fluid also becomes hotter than the outside air temperature. Therefore, the external fluid does not become hotter than the flange temperature.
The outer peripheral side blocking material 72 is softened or melted by the heat to prevent the external fluid from directly contacting the expanded graphite gasket 52, thereby preventing the oxidative deterioration of the expanded graphite gasket 52.

  Further, the materials, dimensions, shapes, etc. of the inner peripheral side blocking material 62 and the outer peripheral side blocking material 72 used at this time depend on the temperature and type of the internal fluid 100 and the external fluid, the flow velocity, the cross-sectional shape of the tube body 1 and the like. The inner peripheral side blocking material 62 and the outer peripheral side blocking material 72 may be the same member or different members. Further, the planar shape of the blocking members 62 and 72 may be any of a circular ring shape, an elliptical ring shape, a rectangular ring shape, and the like.

  According to the sealing device 10 having such a configuration, even in the presence of oxygen, since the oxidation (combustion) of the expanded graphite gasket 52 is prevented by oxygen, the operating temperature range is expanded to 400 to 800 ° C., and 700 ° C. Can be exceeded. For example, even if the internal fluid 100 is high-temperature air of 400 to 800 ° C. or high-temperature water vapor of 600 to 800 ° C., the sealing device 10 of the present invention can be used continuously for a long time and exhibits excellent sealing performance. it can.

  By the way, the larger the distance r1 (diameter direction distance) between the expanded graphite gasket 52 and the inner peripheral blocking material 62 and the distance r2 between the expanded graphite gasket 52 and the outer peripheral blocking material 72, the larger the dimensions of the expanded graphite gasket 52. Since the margin is increased, tightening workability is improved. However, from the viewpoint of improving the oxidation resistance of the expanded graphite gasket 52, the smaller the margins r1 and r2, the softer and molten the inner peripheral blocking member 62 and outer peripheral blocking member 72 are, so that the gaps 90 are completely filled. As a result, the expanded graphite gasket 52 is preferably isolated from the internal fluid 100 and the external fluid.

The smaller the distance r1 (diameter direction distance) between the inner peripheral side blocking material 62 and the expanded graphite gasket 52 and the distance r2 between the outer peripheral side blocking material 72 and the expanded graphite gasket 52, the more preferable. Is preferably about 2 to 5 mm.
<Blocking material 62, 72>
The blocking members 62 and 72 are appropriately selected according to the type and temperature of the internal fluid 100 that flows through the tube 1 under positive pressure and the external fluid that flows outside the tube 1 under positive pressure (pressurization). But
Considering the use under high-temperature air conditions of 400 to 800 ° C. and high-temperature steam conditions of 600 to 800 ° C., which has been considered difficult in the past, a metal having a melting point in the range of 200 to 650 ° C. (i ) Or a metal that is a metal (ii) having an annealing temperature in the range of 300 to 700 ° C.

  In addition, as long as it has the said characteristic and function in a metal in this invention, it is needless to say that an alloy is included as evident in the said illustration.

  Note that “annealing” is to heat a metal hardened by cold working at a temperature equal to or higher than the recrystallization temperature, and the temperature of the internal fluid 100 or the external fluid in contact is higher than the annealing temperature (recrystallization temperature). If so, the metal is considered softened. As a result, direct contact between the high temperature and high pressure internal fluid 100 or external fluid and the expanded graphite gasket 52 can be prevented, and oxidation (combustion) deterioration of the expanded graphite gasket 52 can be prevented.

In the present invention, the metal (i) having a melting point in the range of 200 to 650 ° C.
Duralumin [melting point: about 650 ° C.] which is a copper-based aluminum alloy (aluminum (Al) / copper (Cu) / magnesium (Mg) -based alloy, No. 2000 series),
Al—Si—Cu—Mg based Y alloy [melting point: 550 to 640 ° C.],
Silmine (example: Al-Si 13 alloy) [melting point: 575-585 ° C],
White metal (alloy composition is, for example, lead-antimony-copper type or tin-antimony-copper type 1 to 10 type white metal [melting point: about 240 to 355 ° C.],
As-containing lead baby bit [melting point: 247-353 ° C.],
Solder For example, Pb—Sn solder (melting point: 183 to 301 ° C.), sn—Bi—Pb solder (trade name: Bi130 solder) [melting point: 99 to 139 ° C.], Pb-free tin-silver-copper solder (Trade name: Sn97C) [melting point: 218 to 219 ° C.] and the like.
Examples of the metal (ii) having an annealing temperature in the range of 300 to 700 ° C. include fourty-six brass [melting point: 905 ° C., annealing temperature: 425 to 600 ° C.], three-seven brass [melting point: 950 ° C., annealing temperature: 425. ˜700 ° C.], (white, bronze) and the like. Western white and other copper alloys also have an annealing temperature substantially the same as that of the brass.
Of these metals (ii), the lower the melting point or softening point, the better.

In the present invention, from the viewpoint of what kind of melting point and annealing temperature of the metal (alloy), what kind of temperature and what kind of internal fluid has good sealing properties, the metal (alloy) is as follows. It is desirable to select one that satisfies the following conditions.
1) The metal only needs to be melted at the use temperature of the internal fluid.
2) As a metal, what is necessary is just to soften even if it does not melt | dissolve under use temperature.
3) As a metal, the metal 1) in the molten state is better than the metal 2) in the softened state at the use temperature. (The molten state can theoretically completely shut off the fluid.)
4) For example, if the internal fluid 100 is air as described above, such as air at a high temperature, such as 400 ° C. or higher, at least 400 ° C., the metal needs to melt or soften. It should be noted that there is no problem even if the metal melts or softens below 400 ° C.
5) For example, if the internal fluid 100 is a high temperature vapor as described above, eg, 600 ° C. or higher, the metal must melt or soften at least about 600 ° C. It should be noted that there is no problem if it is melted or softened below about 600 ° C.
6) Considering the above points comprehensively, a specific temperature of 600 ° C. or higher (temperature of 600 ° C. + α, α> 0 ° C.) is the upper limit of the melting point or annealing temperature of the metal.
7) It goes without saying that the metal used for the heat insulating material is a material having no boiling point in the operating temperature range (up to about 800 ° C.). Since this condition is satisfied for ordinary metals, in practice, the condition to be provided for the metal used as the heat insulating material is that the lower the melting point / annealing temperature, the better. This is because the effect of the invention extends to a low temperature region as much as it is low. Therefore, the lower limit of the melting point / annealing temperature of the metal is not particularly limited. Note that “(the lowest melting point / annealing temperature of an actual metal) −α (α> 0 ° C.)” can be set as the lower limit, but there is no particular technical significance.

In the present invention, since the expanded graphite gasket 52 and the blocking materials 62 and 72 are used in combination, the sealing performance of the expanded graphite gasket 52 under high temperature and high pressure is further improved, and in the presence of oxygen. There is provided a sealing device capable of maintaining a stable sealing performance over a long period of time even at a use temperature exceeding 700 ° C.
<Internal fluid 100, external fluid>
Note that the types and states of the internal fluid 100 and the external fluid include oxygen, air, water vapor, hot water, and the like, as described above, such as a liquid or gas that functions as an oxidizing agent for the expanded graphite gasket 52. However, it is not limited to these as long as it has fluidity.

Both the internal fluid 100 and the external fluid need to circulate in the tube 1 or outside the tube 1 in a “positive pressure (pressurized) state”.
If the high-temperature fluid 100 flows through the inside of the tube body 1 in the “negative pressure (depressurized) state”, the shielding material 62 softened and melted by the heat passes through the gap portion 90D between the flanges 20 and 30 to the tube body. 1 flows into the internal fluid 100 and mixes with the internal fluid 100 to cause contamination of the internal fluid 100, and the gasket made of expanded graphite under the heat and oxidizing atmosphere of the internal fluid 100 due to the loss of the inner peripheral side blocking material 62. As a result of direct exposure of 52, the expanded graphite gasket 52 is promoted to be oxidized and deteriorated in sealing performance.

  Similarly, when a high-temperature external fluid exists in the “negative pressure state” outside the tube body 1, the shielding material 72 softened and melted by the heat passes through the gap portion 90 (90 </ b> A) between the flanges 20 and 30. As a result, it flows out of the tube 1 and mixes with the external fluid, which may contaminate the external fluid, and the expanded graphite gasket 52 is directly exposed to the heat and oxidizing atmosphere of the external fluid. As a result, the expanded graphite gasket 52 is oxidized and deteriorated, and the sealing performance is impaired.

Moreover, the temperature of the internal fluid 100 or the external fluid is usually in a range from room temperature to over 700 ° C. up to 800 ° C. In the sealing device 10 of the present invention, the expanded graphite gasket 52 is used in an inert atmosphere due to the inner peripheral side blocking material 62 and the outer peripheral side blocking material 72 being interposed. It can be used even at high temperatures exceeding. For example, even under conditions where oxygen is present in the internal fluid 100 and the external fluid, the expanded graphite gasket 52 is not oxidized (combusted) by oxygen, so the operating temperature range is not limited. Even if the fluid is air, it can be used in this air at a temperature of 400 ° C. or higher, for example, 400 to 800 ° C., and also in water vapor at a temperature of 650 ° C. or higher, for example, 650 to 800 ° C. Can be used.
[Second sealing device]
Next, the second sealing device shown in FIG. 2 will be described. In the second sealing device 10A, the first flange joint 20 as the first member of the tube body 1 and the second flange as the second member. A mounting groove (inner peripheral side mounting groove) 60 for the blocking material 62 is formed only on the inner peripheral side of the mounting groove 50 of the expanded graphite gasket 52 as an expanded graphite sealing member formed between the flange joints 30. Except for the point, it is the same as that of the case of the 1st sealing device 10 shown in the said FIG. In other words, in this sealing device 10 </ b> A, compared to the first sealing device 10, the mounting groove for the blocking material 72 (on the outer peripheral side of the mounting groove 50 of the expanded graphite gasket 52 as the expanded graphite sealing member ( The outer peripheral side mounting groove) 70 is not provided, and the blocking member 72 is not provided.
Such a sealing device 10A is similar to the case where the internal fluid 100 is the first sealing device 10, and the external fluid is a non-oxidizing high-temperature (eg, 400 to 700 ° C.) pressurized fluid that does not contain oxygen or the like. Or when the expanded graphite gasket 52 is air having a temperature of 400 ° C. or lower so as not to cause oxidative deterioration.
[Third sealing device]
Next, the third sealing device shown in FIG. 3 will be described. In the third sealing device 10B, the first flange joint 20 as the first member of the pipe body 1 and the second flange as the second member. A mounting groove (inner peripheral side mounting groove) 70 for the blocking material 72 is formed only on the outer peripheral side of the mounting groove 50 of the expanded graphite gasket 52 as the expanded graphite sealing member formed between the flange joints 30. Except for this point, the second sealing device 10 is the same as the first sealing device 10 shown in FIG. In other words, in this sealing device 10B, compared to the first sealing device 10, the mounting groove for the blocking material 62 is provided on the inner peripheral side of the mounting groove 50 of the expanded graphite gasket 52 as the expanded graphite sealing member. (Outer peripheral side mounting groove) 60 is the same as that of the sealing device 10 except that the blocking member 62 is not provided.
Such a sealing device 10 </ b> A can be suitably used when the internal fluid 100 and the external fluid in the second sealing device 10 </ b> A are interchanged, and is similar to the case where the external fluid is the first sealing device 10. It is preferably used when the internal fluid 100 is a non-oxidizing high-temperature pressurized fluid that does not contain oxygen or the like, or air at a temperature of 400 ° C. or less that does not cause oxidative deterioration of the expanded graphite gasket 52. .
[Manufacture of sealing devices]
Such sealing devices 10, 10 </ b> A, and 10 </ b> B can be easily manufactured by appropriately combining conventionally known methods. That is, the inner peripheral side mounting groove 60 and / or the outer peripheral side mounting groove 70 are formed on the inner peripheral side and / or outer peripheral side of the expanded graphite gasket disposed in the flange portion, and the inner peripheral side blocking is formed there. The first flange joint 20 and the second flange joint 30 may be firmly fastened by the fasteners 110 such as bolts and nuts in a state where the material 62 and / or the outer peripheral side blocking material 72 are mounted.

  The inner peripheral side mounting groove 60 and the outer peripheral side mounting groove 70 are formed between the first flange joint 20 and the second flange joint 30 so that the inner peripheral side blocking member 62 and the outer peripheral side blocking member 70 are formed. It is desirable from the standpoint that 72 can be stored and present in a large amount in the mounting grooves 60 and 70 and contact with the expanded graphite gasket 52 can be reliably prevented.

  Also, the distance r1 (distance in the radial direction) between the expanded graphite gasket 52 and the inner peripheral blocking material 62 and the distance r2 between the expanded graphite gasket 52 and the outer peripheral blocking material 72 are large. For example, r1 and r2 are 5 When the thickness is about -10 mm, a wide margin can be taken when tightening the expanded graphite gasket 52, and the flange fastening workability is improved. However, from the viewpoint of improving the oxidation resistance of the expanded graphite gasket 52, the smaller the margins r1 and r2, the softer and molten the inner peripheral blocking member 62 and outer peripheral blocking member 72 are, so that the gaps 90 are completely filled. As a result, since the expanded graphite gasket 52 is well shielded from the internal fluid 100 and the external fluid, the margins r1 and r2 are preferably as small as possible. For example, each of r1 and r2 is about 2 to 5 mm. It is desirable to set to.

  In the above description, the first member and the second member are flange joints, and the expanded graphite sealing member is an expanded graphite gasket as an example. It is not limited to the aspect which concerns. For example, a tank composed of a tank body and a lid positioned on the tank body, which are joined to each other by a fastener from the outside of the tank, and an opening edge of the tank body as a first member; In addition, a structure in which the opening edge portion of the lid body as the second member does not have a flange portion is included (not shown).

[The invention's effect]
According to the present invention, between the internal fluid in which oxygen is present and the expanded graphite gasket as the expanded graphite sealing material, or between the external fluid in which oxygen is present and the expanded graphite gasket as the expanded graphite sealing material. Since the specific barrier material is interposed therebetween, a sealing device is provided that can maintain a stable sealing performance over a long period of time even at a use temperature exceeding 700 ° C. in the presence of oxygen.

As described above in detail, the sealing device according to the present invention can maintain a stable sealing performance over a long period of time even at a use temperature exceeding 700 ° C. in the presence of oxygen. It is preferably used as a sealing device or the like used to prevent leakage of fluid such as high-temperature steam, gas, oil, water, etc. at the flange portion.

FIG. 1 is a partially cutaway sectional view of a first sealing device according to a preferred embodiment of the present invention. FIG. 2 is a partially cutaway cross-sectional view of a second sealing device according to a preferred embodiment of the present invention. FIG. 3 is a partially cutaway cross-sectional view of a third sealing device according to a preferred embodiment of the present invention.

Explanation of symbols

1 ... Tube,
10... First sealing device,
10A: Second sealing device,
10B: Third sealing device,
20... First flange joint,
30 ... the second flange joint,
50... Mounting groove for expanded graphite gasket,
52... Expanded graphite gasket,
60... Mounting groove (inner circumferential side mounting groove) for the blocking material 62,
62 ..blocking material (inner peripheral side blocking material),
70... Mounting groove for the shielding material (outer peripheral mounting groove)
72 .. blocking material (outer peripheral side blocking material),
80... Inside of tube (internal fluid passage),
82... Fluid outside the tube,
90 ... the gap between the flanges,
90A: the outer peripheral side gap of the outer peripheral side blocking material,
90B... A gap between flanges located between the expanded graphite gasket and the outer peripheral side blocking material,
90C: a gap between the flanges located between the expanded graphite gasket and the inner peripheral side blocking material,
90D: a gap between flanges located on the inner peripheral side of the inner peripheral blocking material,
90D '... the gap between the flanges located on the inner peripheral side of the expanded graphite gasket and leading to the flow path of the internal fluid,
100: Internal fluid,
110... Fasteners such as bolts and nuts
r1... Distance between the expanded graphite gasket and the inner peripheral blocking material,
r2: Distance between the expanded graphite gasket and the outer peripheral blocking material.

Claims (2)

400 at least at a positive pressure on the inner peripheral side or outer peripheral side of the mounting groove for the expanded graphite gasket formed between the first member and the second member constituting the flange joint and provided with the expanded graphite gasket. A mounting groove for a blocking material is formed on a side in contact with a fluid having a high temperature of ˜800 ° C. , and a blocking material that softens or melts according to a high temperature state during use is disposed in the mounting groove. The first member and the second member are fastened together,
The shielding material is a metal having a melting point of 200 to 650 ° C or a metal having an annealing temperature of 300 to 700 ° C;
The mounting groove for the blocking material is formed between the first member and the second member, and
2. A sealing device according to claim 1, wherein a mounting groove for the expanded graphite gasket is formed in one of the first member and the second member.   The sealing device according to claim 1, wherein a distance between the mounting groove for the expanded graphite gasket and the mounting groove for the blocking material is 2 to 5 mm.

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