JPH0659661U - Spiral wound gasket - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a spiral gasket having good sealing property at high temperature and excellent smoothness of the gasket contact surface. [Structure] In a spiral gasket constituted by superposing a filler material 10 on a hoop material 11 and winding it in a spiral shape, the filler material 10 is made of an inorganic fiber other than asbestos fiber and has a bulk density of 0.8 g / cm ³ or less. An inorganic fiber sheet 14 is used, this sheet is impregnated with an inorganic filler 15, and the gasket contact surface is rubbed with the inorganic filler. [Effect] The inorganic fiber sheet and the inorganic filler impregnated with the inorganic fiber sheet improve the sealability at high temperatures. Also,
A film is formed on the gasket contact surface by rubbing the inorganic filler, and is smoothed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a spiral gasket that prevents fluid leakage by being clamped between fixed joint surfaces such as machine tools, pressure vessels and pipes, and clamped with bolts or other means to prevent fluid leakage.

[0002]

[Prior art]

 In general, this type of spiral gasket is formed by spirally winding a plurality of corrugated metal hoop materials and strip-shaped filler materials in a superposed state. As the filler material, asbestos paper, swelling graphite sheet, fluororesin sheet, and paper based on inorganic fiber other than asbestos fiber are used.

[0003]

[Problems to be solved by the device]

 The use of asbestos in the spiral wound gasket that uses asbestos paper as the filler material has become a problem in terms of environmental hygiene, so its use has been restricted. Further, the filler material made of asbestos paper does not always have sufficient sealing property at high temperature, and its improvement is an issue. On the other hand, the spiral gasket using a swollen graphite sheet follows the trend of higher pressure due to the recent technological level improvement, and the sealing property is better than that of asbestos paper, but when used in a high temperature oxidizing atmosphere, it is oxidized. There is a problem in the range of use due to the risk of burning.

A spiral gasket using a fluororesin sheet cannot be used at a high temperature because of decomposition of the fluororesin. Spiral gaskets that use paper based on inorganic fibers other than asbestos fibers (ceramic fibers, glass fibers, metal fibers, etc.) contain organic fibers and organic binders because the paper is made by the papermaking method, There is a problem with sex.

In consideration of the sealing property, the above-mentioned filler materials have a certain bulk density (for example, about 1.0 g / cm ³ for a paper having an inorganic fiber as a base material), and have a very low porosity. When a filler material or gasket contact surface is further impregnated or applied with a filler, a filler (non-porous material) is used, so that the filler remains only near the gasket contact surface and is impregnated to the inside. The problem is that it is impossible. 3 (A) and 3 (B) schematically show partially enlarged cross sections of the spiral wound gasket after the filler is impregnated or applied. In the figure, 1 is a gasket body, 2 is a hoop material, 3 is a filler material, and 4 is a filler material.

[0006]

[The purpose of the device]

 The main object of the present invention is to provide a spiral gasket having good sealing property at high temperature and excellent smoothness of the gasket contact surface.

[0007]

[Means for Solving the Problems]

A first invention of the present application is a spiral gasket constituted by superposing a filler material on a hoop material and spirally winding the filler material, wherein the filler material is an inorganic fiber other than asbestos fiber and has a bulk density of 0.8 g / cm ³ or less. The gist is that the inorganic fiber sheet is used and the inorganic fiber sheet is impregnated with an inorganic filler. A second invention of the present application is characterized in that the spiral gasket according to the first invention is constituted by rubbing a filler material on a gasket contact surface.

[0008]

[Action]

 According to the above configuration, since the filler material is made of porous inorganic fiber sheet having a relatively small bulk density, the inorganic filler is impregnated deep inside the filler material, which is excellent in heat resistance and sealing property. A spiral gasket is formed. Further, by using the one in which the inorganic filler is rubbed on the gasket contact surface, a spiral gasket having excellent smoothness on the gasket contact surface is formed.

[0009]

【Example】

 1 to 2 (A) and (B) show an embodiment of the present invention. FIG. 1 is a cross-sectional view of a spiral gasket, and FIGS. 2A and 2B are structural views schematically showing a partially enlarged cross section of a gasket. In the figure, 10 is a spiral gasket body, 11 is a hoop material, 12 is a filler material, and 13 is an outer ring.

The filler material 12 is formed by impregnating an inorganic fiber sheet 14 excluding asbestos fibers with a powdery inorganic filler material 15.

Examples of the inorganic fibers used in the inorganic fiber sheet 14 include ceramic fibers, aluminum fibers, glass fibers, and metal fibers. Examples of the shape of the inorganic fiber sheet include paper (papermaking paper), woven cloth, non-woven cloth, and felt.

The inorganic fiber sheet 14 has a bulk density of 0. It is preferably 8 g / cm ³ or less. The bulk density of this inorganic fiber sheet varies slightly depending on the fibers used, but is preferably in the range of 0.15 to 0.80 g / cm ³ .

As the impregnated amount of the filler, for example, in the case of an inorganic fiber sheet having a bulk density of 0.2 g / cm ³ , the bulk density after filling is 0.7 g / cm ³ , and the bulk density is 0.8 g / cm ^3. In the case of the above inorganic fiber sheet, the bulk density after filling can be 1.1 g / cm ³ .

Suitable examples of the inorganic filler 15 include graphite, talc, kaolin, mica and vermiculite, but other inorganic minerals can also be used. These inorganic fillers are used as powders (average particle size 5 to 20 μ), and these are dispersed in a dispersion liquid (ethanol, water, etc.) (solid content concentration 30% to 50%) and impregnated into the inorganic fiber sheet 14. Let If the powder particle size of the inorganic filler is less than 5 μ, the bulk density of the filler material does not become large enough to allow sealing, and if it is 20 μ or more, the penetration into the filler material becomes poor.

As the inorganic filler, flat powder is particularly effective for sealing property, but is not limited thereto.

The impregnation treatment with the inorganic filler dispersion may be performed before or after winding the inorganic fiber sheet. Further, the impregnated amount is slightly different depending on the filler used, but in the case of paper, for example, it can be 200 to 300 g per 1 m ² .

As described above, when the inorganic fiber sheet material, which is the base material of the filler material, is impregnated with the inorganic filler, a spiral gasket excellent in sealing property at high temperature can be obtained. By rubbing the powdered inorganic filler on the gasket contact surface, the gasket sealing property is further improved, and the gasket contact surface is excellent in smoothness, and a gasket that is well compatible with the flange surface can be obtained.

As described above, in the spiral-shaped gasket formed by stacking the hoop material and the filler material on each other and winding the hoop material and the filler material, the hoop material or the filler material is exposed at the gasket contact surface. Although it is not necessarily a smooth surface, rubbing the inorganic filler to form a rubbed layer (membrane layer) of the filler on the gasket contact surface makes the gasket contact surface smooth. At the same time, the sealing property can be improved.

When rubbing the powdered inorganic filler, the soft filler is more compatible with the flange and effective in improving the sealing property. Also, if it is impossible to rub the powder as it is, it is better to use a mud-like one with a little water added. Hereinafter, experimental examples of the present invention will be shown together with comparative examples.

Example 1 Ceramic fiber paper (bulk density 0.2 g / cm ³ ) was used as a filler material, and this was wound with a hoop material, and the gasket contact surface was impregnated with graphite powder dispersed in an ethanol solution. Then, the powder surface was rubbed with the graphite powder to obtain a spiral gasket body.

Comparative Example 1 A conventional asbestos paper was used as a filler material, and this was wound with a hoop material to obtain a spiral gasket body.

Comparative Example 2 As a filler material, a paper having an inorganic fiber as a base material other than the conventional asbestos fiber was used, and this was wound with a hoop material to obtain a spiral gasket main body.

Comparative Example 3 Only the ceramic fiber paper of Example 1 was used as the filler material and this was wound with the hoop material to obtain a spiral gasket.

A spiral type gasket with an outer ring (JPI class 3004B) in which an outer ring is provided on the gasket body of the above-mentioned examples and comparative examples is used as a sample, and it is sandwiched by a predetermined flange and a predetermined tightening surface pressure (1100fkg / Cm ² ), heat this in an electric furnace at 400 ° C for 5 hours, cool to room temperature, add a predetermined internal pressure (21 fkg / cm ² ) using N ₂ gas, and replace the leak amount for 10 minutes with water. The test results measured in Table 1 are shown in Table 1 below. In order to measure the sealability of only the main body of the sample, the outer ring was provided with four grooves on each side.

[0025]

[Table 1]

[0026]

[Effect of device]

 As is clear from the above description, according to the present invention, it is possible to obtain a spiral gasket having a sealing property close to room temperature as it is at room temperature as well as at room temperature and excellent in smoothness of the gasket contact surface. You can That is, as is clear from the above-mentioned test results, it can be used practically at 400 ° C, and even if it is higher than that, it is good in a range where there is no sudden deterioration due to heat of the inorganic fiber sheet and the inorganic filler. It is possible to maintain a good sealing property. For example, when a glass fiber cloth is used as the inorganic fiber sheet, it is considered that there is no problem up to a glass softening point of about 600 ° C. and a ceramic fiber paper up to 1000 to 1500 ° C. It is considered that there is no problem with the inorganic filler as long as it does not undergo a particularly rapid shrinkage or a dehydration reaction at high temperatures.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a spiral gasket showing an embodiment of the present invention.

FIG. 2 is a schematic partially enlarged cross-sectional view of a gasket.

FIG. 3 is a schematic partially enlarged cross-sectional view of a conventional spiral gasket.

[Explanation of symbols]

 10 Body of spiral gasket 11 Hoop material 12 Filler material 13 Outer ring 14 Inorganic fiber sheet 15 Inorganic filler

Claims (2)

[Scope of utility model registration request] 1. A spiral type gasket comprising a hoop material and a filler material superposed on each other and wound in a spiral shape, wherein the filler material is made of an inorganic fiber other than asbestos fiber and has a bulk density of 0.8.
A spiral gasket, wherein an inorganic fiber sheet of g / cm ³ or less is used, and the inorganic fiber sheet is impregnated with an inorganic filler. 2. A spiral gasket, which is formed by stacking a filler material on a hoop material and spirally winding the filler material, wherein the filler material is an inorganic fiber other than asbestos fiber and has a bulk density of 0.8.
A spiral gasket, wherein an inorganic fiber sheet of g / cm ³ or less is used, the inorganic fiber sheet is impregnated with an inorganic filler, and the gasket contact surface is rubbed with the inorganic filler.