Serrated metal washers

Abstract

A sawtooth metal gasket and a metal toothed gasket having the sawtooth metal gasket, wherein the sawtooth metal gasket has concentric sawtooth convex and concave portions (1a) and (1b) formed on both sides, the pitch of the convex portions (3) constituting the sawtooth convex and concave portions (1a) and (1b) being 1.2 mm to 1.8 mm, a flat portion (L) having a width of 50 μm to 180 μm being formed at the top (T) of the convex portion (3), a concave portion (4) constituting the sawtooth convex and concave portions (1a) and (1b) having a depth of 0.3 mm to 0.8 mm, and a circular arc having a radius of 0.2 mm to 0.6 mm being formed at the bottom (B) of the concave portion (4).

Description

Technical Field

[0001] The present invention relates to a sawtooth metal gasket. More specifically, the present invention relates to a sawtooth metal gasket and a metal profile gasket (Kammprofile Gasket) having the sawtooth metal gasket. The sawtooth metal gasket and the metal profile gasket having the sawtooth metal gasket of the present invention can be suitably used in, for example, pipe flanges, towers, tanks, heat exchangers, autoclaves, valve covers, metal sealing mechanisms, etc., which use fluids such as water vapor at high temperature and high pressure. Background Art

[0002] In order to improve the sealing efficiency, the serrated gasket forms concentric serrated concave and convex parts on both sides of the gasket, reducing the effective contact area with the flange, etc. The serrated gasket is generally used for example in valve covers, pipe flanges, sealing covers of pressure vessels, etc.

[0003] As a serrated gasket with high cost reduction effect, a serrated gasket is proposed, which is installed between a first flange component and a second flange component, and the serrated convex and concave parts formed on the gasket body are respectively embedded in the sealing surface on the first flange component side and the sealing surface on the second flange component side, thereby exerting sealing performance, wherein the gasket body is composed of a metal sealing part body formed with the serrated convex and concave parts and a metal positioning part formed on the outer peripheral side of the sealing part body, and the positioning part is composed of a plurality of divided bodies divided along the circumferential direction (for example, see patent document 1).

[0004] In addition, as a serrated gasket with a sheet layer including a sheet layer of expanded graphite or the like and capable of preventing particles of the sheet layer of expanded graphite or the like generated by crushing when the gasket is compressed from entering a fluid passage, a serrated gasket with a sheet layer is proposed, which comprises a gasket body having concentric serrated convex and concave portions formed on both sides, and a sheet layer stacked in a manner covering the serrated convex and concave portions, the gasket body and the sheet layer being mounted in an integrated state on a joint portion of the fluid passage, and the serrated convex and concave portions being covered when a first member and a second member constituting the joint portion are fastened together. The sawtooth-shaped convex-concave portion is embedded in the above-mentioned first component and the above-mentioned second component by the above-mentioned sheet layer, thereby exerting a sealing force, wherein, when the distance from the first convex portion that constitutes the above-mentioned sawtooth-shaped convex-concave portion and is closest to the above-mentioned fluid channel to the second convex portion that is second closest is set to a, and the distances from the above-mentioned second convex portion to the third convex portion, the third convex portion to the fourth convex portion, the fourth convex portion to the fifth convex portion, and the n-1th convex portion to the nth convex portion are set to b, a≥2b, and the radially inner side end portion of the above-mentioned sheet layer is arranged between the above-mentioned first convex portion and the above-mentioned second convex portion (for example, see patent document 2).

[0005] The serrated gasket has an excellent cost reduction effect, and the serrated gasket with sheet layers has an excellent effect of preventing particles of the sheet layers generated by breaking when the gasket is compressed from entering the fluid channel.

[0006] In recent years, in order to prevent fluid leakage from between flanges even when a metal toothed gasket is installed between flanges of a pipe and a high-pressure fluid is introduced into the pipe, the surface pressure between the flanges is required to be above 80 MPa. It is hoped that a metal toothed gasket with excellent durability and excellent sealing properties will be developed even under this surface pressure.

[0007] However, in the metal toothed gasket represented by the existing serrated gasket with a sheet layer, when the thickness of the sheet layer is 0.6 mm to 1.5 mm, for example, when the metal toothed gasket is installed between the flanges of the piping and the flanges are tightened in such a way that the surface pressure of the surface where the metal toothed gasket and the flange meet is above 80 MPa, the sealing between the convex part of the serrated gasket and the flange cannot be fully ensured due to the thickness of the sheet layer existing on the convex part of the serrated gasket.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent No. 4842023

[0011] Patent Document 2: Japanese Patent No. 4877673 Summary of the invention

[0012] Problems to be solved by the invention

[0013] The present invention is made in view of the above-mentioned prior art, and its subject is to provide a metal toothed gasket and a serrated metal gasket that can be suitable for the metal toothed gasket, wherein a metal toothed gasket with an elastic sheet thickness of 0.6mm to 1.5mm is installed between the flanges of the piping, and when the flanges are tightened in such a way that the surface pressure of the surface where the metal toothed gasket and the flange meet is above 80MPa, the sealing between the convex part of the serrated gasket and the flange can be fully ensured, and the durability under the surface pressure is excellent.

[0014] Means for solving problems

[0015] The present invention relates to:

[0016] (1) A sawtooth metal gasket having concentric sawtooth convex and concave portions formed on both surfaces, wherein the pitch of the convex portions constituting the sawtooth convex and concave portions is 1.2 mm to 1.8 mm, a flat portion having a width of 50 μm to 180 μm is formed on the top of the convex portions, a concave portion constituting the sawtooth convex and concave portions has a depth of 0.3 mm to 0.8 mm, and an arc having a radius of 0.2 mm to 0.6 mm is formed at the bottom of the concave portion;

[0017] (2) The sawtooth metal gasket described in (1) above, wherein the groove area in the cross section of the concave portion constituting the sawtooth concave-convex portion is 0.25 mm 2 ~0.80mm 2 ;and

[0018] (3) A metal toothed gasket comprising the serrated metal washer described in (1) or (2) above, wherein an elastic sheet having a thickness of 0.6 mm to 1.5 mm is attached to the serrated concave and convex portions formed on both surfaces of the serrated metal washer.

[0019] Effects of the Invention

[0020] According to the present invention, a metal toothed gasket and a serrated metal gasket suitable for use with the metal toothed gasket are provided, wherein a metal toothed gasket having an elastic sheet thickness of 0.6 mm to 1.5 mm is installed between flanges of a piping, and when the flange is tightened in such a manner that the surface pressure of the surface where the metal toothed gasket and the flange meet is 80 MPa or more, the sealing performance between the protrusion of the serrated gasket and the flange can be fully ensured, and the durability under the surface pressure is excellent. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 1 is a schematic top view showing one embodiment of the serrated metal washer of the present invention.

[0022] Figure 2 yes Figure 1 A schematic cross-sectional view of section AA of a serrated metal washer is shown.

[0023] Figure 3 yes Figure 2 A cross-sectional view of a serrated metal gasket shows a partial enlarged view of the serrated concave and convex portion.

[0024] Figure 4 This is a schematic plan view showing one embodiment of the metal toothed pad of the present invention.

[0025] Figure 5 yes Figure 4 A schematic cross-sectional view of the BB portion of the metal toothed pad is shown. DETAILED DESCRIPTION

[0026] The sawtooth metal washer of the present invention is a metal washer having concentric sawtooth-shaped concave and convex portions formed on both surfaces of the sawtooth metal washer.

[0027] The serrated metal gasket of the present invention is characterized in that the pitch of the convex parts constituting the above-mentioned serrated convex and concave parts is 1.2mm~1.8mm, a flat part with a width of 50μm~180μm is formed on the top of the convex part, the depth of the concave part constituting the above-mentioned serrated convex and concave parts is 0.3mm~0.8mm, and an arc with a radius of 0.2mm~0.6mm is formed at the bottom of the concave part.

[0028] Since the serrated metal gasket of the present invention has the above-mentioned structure, it has excellent durability and excellent sealing performance even when the surface pressure when fastened to a flange or the like is 80 MPa.

[0029] Hereinafter, the serrated metal washer of the present invention will be described in detail based on the drawings, but the present invention is not limited to the embodiments described in the drawings.

[0030] Figure 1 1 is a schematic top view showing one embodiment of the serrated metal washer of the present invention. Figure 2 yes Figure 1 A schematic cross-sectional view of section AA of a serrated metal washer is shown. Figure 3 yes Figure 2 A cross-sectional view of a serrated metal gasket shows a partial enlarged view of the serrated concave and convex portion.

[0031] like Figure 1 As shown, the sawtooth metal gasket 1 of the present invention comprises a concentric sawtooth convex-concave portion 1a and a flat plate-shaped flange portion 2 formed integrally with the concave-convex portion 1a, and its planar shape is a disc.

[0032] The material of the serrated metal gasket 1 varies depending on the purpose of the serrated metal gasket 1, and therefore cannot be determined uniformly, and is preferably determined appropriately according to the purpose. From the perspective of ensuring the sealing performance provided by the serrated metal gasket 1, the material of the serrated metal gasket 1 is preferably a metal selected from the group consisting of aluminum, aluminum alloy, stainless steel, nickel-chromium-iron heat-resistant and corrosion-resistant alloy, carbon steel, lead, gold, silver, copper, nickel, tantalum, chrome-molybdenum steel, monel alloy, titanium and magnesium alloy, more preferably a metal selected from the group consisting of aluminum, aluminum alloy, stainless steel and nickel-chromium-iron heat-resistant and corrosion-resistant alloy, and further preferably aluminum or stainless steel.

[0033] Examples of the aluminum alloy include aluminum-iron alloys, aluminum-copper alloys, aluminum-manganese alloys, aluminum-magnesium alloys, aluminum-zinc alloys, and aluminum-nickel alloys, but the present invention is not limited to the above examples.

[0034] Examples of the stainless steel include SUS304, SUS316, SUS430, SUS630, SUS631, SUS633, and SUS420J2, but the present invention is not limited to the above examples.

[0035] In addition, examples of metals other than magnesium used for the magnesium alloy include lithium, calcium, aluminum, zinc, titanium, manganese, zirconium, yttrium, tantalum, neodymium, and niobium, but the present invention is not limited to the above examples.

[0036] exist Figure 1 In the schematic top view of the serrated metal washer 1 shown, the outer diameter of the serrated metal washer 1 and the inner diameter of the opening at the center portion vary depending on the purpose of the serrated metal washer 1, and therefore cannot be determined in general. Therefore, it is preferred to appropriately determine them according to the purpose of the serrated metal washer 1. Figure 2 In the schematic cross-sectional view of the serrated metal gasket shown, the thickness t (thickness of the flange portion) of the serrated metal gasket 1 varies depending on the purpose of the serrated metal gasket 1, etc., and therefore cannot be determined in general. Therefore, it is preferably determined appropriately according to the purpose of the serrated metal gasket 1, and is usually around 1.5 mm to 15 mm.

[0037] Figure 1 The plane shape of the serrated metal gasket 1 is a circle. A circle is not only a perfect circle, but also a circle including a vertically elongated ellipse, a horizontally elongated ellipse, and an elliptical trajectory shape. The plane shape of the serrated metal gasket 1 can be appropriately determined according to the use of the serrated metal gasket 1.

[0038] like Figure 2 As shown, concentric serrated concave and convex portions 1a and 1b are formed on both surfaces of the serrated metal washer 1. A plurality of the serrated concave and convex portions 1a and 1b are concentrically arranged in the radial direction of the serrated metal washer 1.

[0039] like Figure 3 As shown, in Figure 2 The sawtooth metal washer 1 shown in FIG. 1 has a sawtooth-shaped concave-convex portion 1a formed on its upper surface. A flat portion L is formed in the diameter direction of the sawtooth metal washer 1 at the top T of the convex portion 3 constituting the sawtooth-shaped concave-convex portion 1a. Figure 3 As shown, the convex portion 3 has a trapezoidal cross-sectional shape. The flat portion L is a plane formed in a direction parallel to the diameter of the sawtooth metal washer 1, but it may not be formed in a direction parallel to the diameter of the sawtooth metal washer 1 and may have an inclination (slope) within the scope of not hindering the purpose of the present invention. Figure 2 The shape of the sawtooth-shaped concavo-convex portion 1 b formed on the lower surface of the sawtooth-shaped metal washer 1 is preferably the same as the shape of the sawtooth-shaped concavo-convex portion 1 a formed on the upper surface thereof.

[0040] Figure 3 The width W of the flat portion L formed at the top T of the protrusion 3 (the width in the diameter direction of the serrated metal gasket 1) depends on, for example, the tightening pressure when the metal toothed gasket having an elastic sheet (not shown) attached to the serrated concave-convex portions 1a and 1b of the serrated metal gasket 1 is clamped between two flanges and tightened. From the perspective of preventing the elastic sheet from breaking at the flat portion L formed at the top T of the protrusion 3 and improving the sealing performance of the serrated metal gasket 1, it is 50 μm to 180 μm, preferably 60 μm to 150 μm, and more preferably 80 μm to 120 μm. Figure 2 The width (not shown) of the flat portion L formed at the top of the sawtooth-shaped concavo-convex portion 1 b on the lower surface of the sawtooth-shaped metal washer 1 is preferably the same as the width W described above.

[0041] Figure 3 In the embodiment, the pitch P of the protrusions 3 of the serrated concave-convex portion 1a constituting the serrated metal gasket 1 is the distance between the center of the flat portion L formed at the top T of the protrusion 3 and the center of the flat portion L formed at the top T of other protrusions 3 adjacent to the protrusion 3. The pitch P between the protrusion 3 and other protrusions 3 adjacent to the protrusion 3 is usually fixed in a plurality of concave-convex portions 1a, but there may be non-fixed portions within the range not hindering the purpose of the present invention. From the perspective of improving the sealing performance brought by the serrated metal gasket 1, the pitch P is 1.2 mm to 1.8 mm. Figure 2 The pitch (not shown) of the convex portions 3 of the serrated concave-convex portion 1 b formed on the lower surface of the serrated metal gasket 1 is preferably the same as the pitch P described above.

[0042] Figure 3 In the embodiment, the depth D of the convex portion 3 of the sawtooth-shaped concave-convex portion 1a constituting the sawtooth-shaped metal gasket 1 is the height from the deepest position (bottommost position) B of the concave portion 4 constituting the sawtooth-shaped concave-convex portion 1a of the sawtooth-shaped metal gasket 1 to the top T of the convex portion 3. From the perspective of improving the sealing performance brought by the sawtooth-shaped metal gasket 1, the depth D is 0.3 mm to 0.8 mm, preferably 0.4 mm to 0.75 mm. Figure 2 The depth (not shown) of the protrusion on the lower surface of the serrated metal washer 1 is preferably the same as the depth D described above.

[0043] Figure 3 In the embodiment, at the bottom B of the concave portion 4 of the sawtooth-shaped concave-convex portion 1a constituting the sawtooth-shaped metal gasket 1, an arc is formed in the diameter direction of the sawtooth-shaped metal gasket 1. Therefore, the concave portion 4 has a cross-sectional shape similar to an inverted trapezoid having an arc at the bottom B. From the perspective of improving the sealing performance brought by the sawtooth-shaped metal gasket 1, the radius of the arc is 0.2 mm to 0.6 mm, preferably 0.3 mm to 0.5 mm. Figure 2The shape of the bottom (not shown) of the concave portion of the serrated concave-convex portion 1 b of the serrated metal washer 1 shown is preferably the same as the shape of the bottom B of the concave portion 4 described above.

[0044] Figure 3 In order to improve the sealing performance of the sawtooth metal gasket 1, the groove area in the cross section of the concave portion 4 constituting the sawtooth concave-convex portion 1a is preferably 0.25 mm 2 ~0.80mm 2 , more preferably 0.28 mm 2 ~0.72mm 2 . Figure 3 In the figure, the groove area is the cross-sectional area of ​​the space surrounded by the straight line connecting the flat portion L formed at the top T of the convex portion 3 and the flat portion L formed at the top T of other convex portions 3 adjacent to the convex portion 3, and the concave portion 4. The groove area in the cross section of the concave portion 4 constituting the sawtooth-shaped concave-convex portions 1a, 1b is a value obtained as follows: a test piece having a groove shape having the above-mentioned space portion is prepared, the volume of the test piece is obtained based on the mass and density of the test piece, and the volume of the test piece is divided by the thickness of the test piece. Figure 2 The groove area of ​​the concave portion (not shown) in the cross section of the serrated concave-convex portion 1 b of the serrated metal washer 1 shown is preferably the same as the groove area of ​​the concave portion 4 in the cross section.

[0045] Figure 3 The angle θ formed by the inclined surface adjacent to the concave portion 4 constituting the sawtooth-shaped concave-convex portion 1a is not particularly limited, but is preferably 60° to 120°, more preferably 80° to 100°, and further preferably 85° to 95° from the perspective of improving the sealing performance of the sawtooth-shaped metal gasket 1. Figure 2 The angle (not shown) formed by the adjacent inclined surfaces of the sawtooth-shaped concave-convex portion 1 b of the sawtooth-shaped metal washer 1 is preferably the same as the above-mentioned angle θ.

[0046] Figure 3 In order to improve the sealing performance of the serrated metal gasket 1, the convex portion 3 formed on the serrated concave-convex portion 1a protrudes from the flat flange portion 2 by a height H. From the perspective of improving the sealing performance of the serrated metal gasket 1, the height H of the convex portion 3 from the flat flange portion 2 is preferably 0.3 mm to 0.8 mm, and more preferably 0.4 mm to 0.75 mm. Figure 2 The height (not shown) of the sawtooth-shaped protrusion of the sawtooth metal washer 1 from the flat plate-shaped flange portion 2 is preferably the same as the height H described above.

[0047] Figure 3The number of protrusions 3 formed on the sawtooth-shaped concave-convex portion 1a varies depending on the purpose of the sawtooth metal gasket 1, and therefore cannot be determined in general. From the perspective of improving the sealing performance brought about by the sawtooth metal gasket 1, it is preferably at least 3, and more preferably at least 5. In addition, the upper limit of the number of protrusions 3 varies depending on the purpose of the sawtooth metal gasket 1, and therefore cannot be determined in general, and is generally about 10. Figure 2 The number of convex portions formed by the serrated concavo-convex portion 1 b of the serrated metal gasket 1 shown is preferably the same as the number of the convex portions 3 described above.

[0048] Figure 2 The serrated concavo-convex portions 1 a and 1 b of the serrated metal washer 1 shown can be formed by, for example, cutting the metal washer using a lathe or the like.

[0049] The serrated metal gasket 1 obtained as described above can improve the sealing performance with a flange or the like when used in a metal tooth-shaped gasket, and thus can be suitably used in the metal tooth-shaped gasket.

[0050] Hereinafter, the metal toothed pad of the present invention will be described in detail based on the drawings, but the present invention is not limited to the embodiments described in the drawings.

[0051] Figure 4 This is a schematic plan view showing one embodiment of the metal toothed pad of the present invention. Figure 5 yes Figure 4 A schematic cross-sectional view of the BB portion of the metal toothed pad is shown.

[0052] like Figure 4 As shown, the metal toothed gasket 5 of the present invention is characterized in that it has a sawtooth metal washer 1, and elastic sheets 6 are attached to sawtooth-shaped concave and convex parts (not shown) formed on both surfaces of the sawtooth metal washer 1.

[0053] Since the metal toothed pad 5 has the above-mentioned structure, for example, when the metal toothed pad 5 is clamped between two flanges and fastened, a part of the elastic sheet 6 enters the structure. Figure 2 and Figure 3 The sawtooth-shaped concave and convex parts 1a and 1b formed on both sides of the sawtooth metal gasket 1 increase the surface pressure of the elastic sheet 6 existing in the flat part L formed on the top T of the convex part 3, thereby improving the sealing performance.

[0054] From the viewpoint of improving the sealing property and mechanical strength of the elastic sheet 6 , the elastic sheet 6 is preferably an elastic sheet 6 containing an organic binder and an inorganic powder.

[0055] From the aspect of improving the sealing property and mechanical strength of the elastic sheet 6, the organic binder is preferably a rubber binder. As the rubber binder, for example, nitrile rubber, natural rubber, isoprene rubber, chloroprene rubber, acrylonitrile rubber, styrene-butadiene rubber, butyl rubber, fluororubber, silicone rubber, ethylene-propylene rubber, etc. can be cited, but the present invention is not limited to the above examples. These rubber binders can be used alone or in combination of two or more.

[0056] From the perspective of improving the sealing performance of the elastic sheet 6, the content of the organic binder in the elastic sheet 6 is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, and further preferably 20% by mass or more. From the perspective of improving the heat resistance of the elastic sheet 6, it is preferably 97% by mass or less, more preferably 95% by mass or less, and further preferably 90% by mass or less. Therefore, the content of the organic binder in the elastic sheet 6 is preferably 5% by mass to 97% by mass, more preferably 10% by mass to 95% by mass, further preferably 15% by mass to 90% by mass, and further preferably 20% by mass to 90% by mass.

[0057] The inorganic powder has the property of improving the flexibility of the elastic sheet 6 and the shape retention of the elastic sheet 6 at high temperatures. The inorganic powder is unlikely to disappear and remains even when the elastic sheet 6 is heated to high temperatures, thus improving the sealing performance of the metal toothed pad 5 of the present invention.

[0058] Examples of inorganic powders include talc, barium sulfate powder, clay, mica powder, titanium oxide powder, aluminum oxide powder, zinc oxide powder, magnesium oxide powder, silicic acid powder, silicon dioxide powder, calcium carbonate powder, sodium carbonate powder, calcium hydroxide powder, aluminum hydroxide powder, magnesium carbonate powder, graphite powder, metal powder, glass powder, etc., but the present invention is not limited to the above examples. These inorganic powders can be used alone or in combination of two or more.

[0059] From the perspective of improving the shape maintenance of the elastic sheet 6, the average particle size of the inorganic powder is preferably 2 μm or more, and from the perspective of improving the sealing performance, it is preferably 25 μm or less. It should be noted that the particle size of the inorganic powder is the value measured by a laser diffraction particle size distribution measuring device, and the average particle size of the inorganic powder is the value of the particle size when the cumulative number of particles of the inorganic powder in the particle size distribution measured by the laser diffraction particle size distribution measuring device is 50% (median particle size).

[0060] From the perspective of improving the heat resistance of the elastic sheet 6, the content of the inorganic powder in the elastic sheet 6 is preferably 3% by mass or more, more preferably 5% by mass or more, and further preferably 10% by mass or more. From the perspective of improving the sealing performance of the elastic sheet 6, it is preferably 95% by mass or less, more preferably 90% by mass or less, further preferably 85% by mass or less, and further preferably 80% by mass or less. Therefore, the content of the inorganic powder in the elastic sheet 6 is preferably 3% by mass to 95% by mass, more preferably 5% by mass to 90% by mass, further preferably 10% by mass to 85% by mass, and further preferably 10% by mass to 50% by mass.

[0061] The elastic sheet 6 may contain fibers from the viewpoint of improving the mechanical strength and flexibility of the elastic sheet 6. Examples of the fibers include inorganic fibers and organic fibers.

[0062] Examples of inorganic fibers include alumina fibers, glass fibers, zirconia fibers, asbestos, basalt fibers, biosoluble fibers, silica fibers, and ceramic fibers, but the present invention is not limited to the above examples. These inorganic fibers may be used alone or in combination of two or more.

[0063] Examples of organic fibers include synthetic fibers such as polyamide fibers, aramid fibers, polyester fibers, polyurethane fibers, polyethylene fibers, acrylic fibers, and polyvinyl alcohol fibers; plant fibers such as cotton, linen, and cellulose fibers; animal fibers such as wool; carbon fibers; and regenerated fibers such as rayon. However, the present invention is not limited to the above examples. These organic fibers may be used alone or in combination of two or more.

[0064] From the perspective of improving the mechanical strength of the elastic sheet 6, the average fiber diameter of the fibers is preferably 3 μm to 20 μm. From the perspective of improving the dispersibility in the elastic sheet 6 and improving the mechanical strength of the elastic sheet 6, the fiber length of the fibers is preferably 0.01 mm or more, more preferably 0.1 mm to 20 mm. It should be noted that the average fiber diameter of the fibers is a value obtained by measuring the fiber diameters of the fibers included in an image taken with a scanning electron microscope and finding the average value of the fiber diameters of the fibers.

[0065] From the perspective of improving the mechanical strength of the elastic sheet 6, the content of the fibers in the elastic sheet 6 is preferably 3% by mass or more, more preferably 5% by mass or more, and from the perspective of improving the sealing performance provided by the elastic sheet 6, it is preferably 30% by mass or less, more preferably 20% by mass or less, and further preferably 10% by mass or less. Therefore, the content of the fibers in the elastic sheet 6 is preferably 30% by mass or less, more preferably 3% to 30% by mass, further preferably 5% to 20% by mass, and further preferably 5% to 10% by mass.

[0066] The method for producing the elastic sheet 6 is not particularly limited. The elastic sheet 6 can be produced, for example, by mixing an organic binder, an inorganic powder, fibers as required, an organic solvent and other components into a uniform composition and molding the resulting mixture into a predetermined shape.

[0067] From the perspective of improving sealing properties and mechanical strength, the density of the elastic sheet 6 is preferably 0.8 g / cm 3 ~1.2g / cm 3 , more preferably 0.9 g / cm 3 ~1.1g / cm 3 .

[0068] The thickness of the elastic sheet 6 also depends on the tightening pressure when the metal toothed pad 5 is clamped between the two flanges and tightened. From the perspective of preventing the elastic sheet 6 from breaking at the flat portion L formed at the top T of the protrusion 3 and improving the sealing performance, it is preferably 0.6 mm to 1.5 mm, and more preferably 0.8 mm to 1.2 mm.

[0069] The elastic sheet 6 is usually attached to both sides of the serrated metal gasket 1 to cover the serrated concave-convex parts 1a and 1b formed on both sides of the serrated metal gasket 1. The elastic sheet 6 can be attached using, for example, an adhesive, a double-sided tape, etc. As the adhesive, for example, a rubber-based adhesive can be cited, but the present invention is not limited to the above examples.

[0070] Even when the metal toothed gasket 5 of the present invention configured as above is clamped between two flanges and adjusted to a high pressure of 80 MPa or more when the metal toothed gasket 5 is tightened, the elastic sheet 6 can be present in a thin layer state on the flat portion L formed by the top T of the convex portion 3 formed on both sides of the serrated metal gasket 1 used in the metal toothed gasket 5. For example, when the elastic sheet 6 having a thickness of about 0.6 mm to 1.5 mm is used, when the metal toothed gasket 5 is clamped between two flanges and tightened in such a manner that the surface pressure when the metal toothed gasket 5 is tightened is 80 MPa or more, the elastic sheet 6 existing in the flat portion L formed by the top T of the convex portion 3 has a thickness of about 0.05 mm to 0.1 mm, and the amount of fluid that permeates the thin layer of the elastic sheet 6 becomes very small, so that the sealing performance can be improved.

[0071] In addition, in order to impart heat resistance to the heat-resistant elastic sheet generally used for the metal toothed gasket, for example, a large amount of inorganic filler such as talc is used. When the content of the inorganic filler in the heat-resistant elastic sheet is high, the amount of fluid that permeates the heat-resistant elastic sheet increases compared to an elastic sheet that does not contain the inorganic filler, so it is necessary to increase the surface pressure when the gasket is tightened.

[0072] In contrast, when the metal toothed gasket 5 of the present invention is clamped between two flanges and the surface pressure when the metal toothed gasket 5 is tightened is adjusted to a high pressure of 80 MPa or more, the elastic sheet 6 remains in a thin layer state on the flat portion L formed by the top T of the protrusion 3 on both sides of the serrated metal gasket 1 used in the metal toothed gasket 5, so that the serrated metal gasket is not easily exposed due to the elastic sheet 6, thereby preventing damage to the flange caused by the exposure of the serrated metal gasket 1.

[0073] Therefore, even when the metal toothed gasket 5 of the present invention is installed between the flanges of the piping and is tightened in such a manner that the surface pressure of the metal toothed gasket 5 and the flange in contact when the flange is tightened is 80 MPa or more, the sealing performance between the convex portion 3 of the serrated gasket 1 and the flange can be fully ensured, so the metal toothed gasket 5 of the present invention has excellent durability under the surface pressure. Therefore, the metal toothed gasket 5 of the present invention is suitable for applications using fluids with high temperature and high pressure, and can be used, for example, as a high temperature / high pressure metal toothed gasket used in pipe flanges, towers, tanks, heat exchangers, autoclaves, valve covers, metal sealing mechanisms, etc., which use fluids such as water vapor with high temperature and high pressure.

[0074] As can be seen from the above, the metal toothed gasket 5 using the serrated metal gasket 1 of the present invention can be appropriately used when connecting pipes using fluids with high temperature and high pressure to each other in, for example, thermal power plants, nuclear power plants, steam mechanisms of steam turbine ships, oil refining lines, production lines in the petrochemical industry, semiconductor manufacturing lines, etc.

[0075] Example

[0076] Next, the present invention will be described in detail based on Examples, but the present invention is not limited to these Examples.

[0077] Examples 1 to 14 and Comparative Examples 1 to 6

[0078] A metal washer (outer diameter: 110 mm, inner diameter of the opening at the center: 75 mm) made of stainless steel (SUS316) was cut using a lathe to produce a Figures 1 to 3 The sawtooth metal gasket 1 has the shape shown (outer diameter of the concentric sawtooth convex and concave portions: 90 mm, inner diameter: 75 mm, flange thickness: 2 mm, angle between adjacent inclined surfaces of the concave portions: 90°). The details of the concave and convex portions formed in the sawtooth metal gasket 1 are shown in Table 1.

[0079] The ring-shaped elastic sheet 6 [outer diameter: 90 mm, inner diameter of the opening at the center: 75 mm, thickness: 0.9 mm, material: organic binder (nitrile rubber), inorganic powder (talc) and fiber (alumina fiber and cellulose fiber), density: 1 g / cm 3 ] is attached to the surface of the concentric serrated concave-convex portions formed on both sides of the serrated metal gasket 1 obtained above, thereby manufacturing the metal toothed gasket 5. It should be noted that the thickness of the elastic sheet 6 is changed to 0.8 mm in Example 13, and the thickness of the elastic sheet 6 is changed to 1.2 mm in Example 14.

[0080] Next, as an index of sealing performance and durability when high surface pressure fastening is performed using the metal toothed pad 5 obtained above, the adhesion of the elastic sheet 6 to the convex portion formed in the sawtooth-shaped concave-convex portion and the thickness of the elastic sheet 6 were investigated and evaluated based on the following method. The results are shown in Table 1.

[0081] [Sealing performance when tightening with high surface pressure]

[0082] The metal toothed gasket 5 was sandwiched between the flanges of the pipe, and the flanges were fastened while adjusting the fastening surface pressure to 100 MPa.

[0083] Next, nitrogen gas at 25°C was introduced into the pipe, and the internal pressure of the pipe was adjusted to 4 MPa. The leakage of nitrogen gas was measured by the submerged test method, and the sealing performance during high surface pressure tightening was evaluated based on the following evaluation criteria. The results are recorded in the "Sealing Performance" column of Table 1. It should be noted that the measurement limit when measuring the leakage of nitrogen gas is 1.7×10 -5 Pa·m 3 / s.

[0084] (Evaluation Criteria)

[0085] S: Nitrogen leakage is 1.7×10 -5 Pa·m 3 / s or less (qualified).

[0086] ◎: Nitrogen leakage exceeds 1.7×10 -5 Pa·m 3 / s and 1.7×10 -4 Pa·m 3 / s or less (qualified).

[0087] ○: Nitrogen leakage exceeds 1.7×10 -4 Pa·m 3 / s and 1.7×10 -3 Pa·m 3 / s or less (qualified).

[0088] △: Nitrogen leakage exceeds 1.7×10 -3 Pa·m 3 / s and 1.7×10 -2 Pa·m 3 / s or less (failed).

[0089] ×: Nitrogen leakage exceeds 1.7×10 -2 Pa·m 3 / s(Unqualified).

[0090] [Attachment of the elastic sheet to the convex portion]

[0091] After the sealing performance during high surface pressure tightening is evaluated as described above, the flange is removed from the metal toothed gasket 5 .

[0092] The elastic sheet attached to the metal toothed pad was visually observed, and the adhesion of the elastic sheet to the convex portion was evaluated based on the following evaluation criteria. The results are recorded in the column "Adhesion of the elastic sheet" in Table 1.

[0093] (Evaluation Criteria)

[0094] ○: No abnormality was observed in the elastic sheet.

[0095] ×: Tearing of the elastic sheet was observed.

[0096] [Thickness of elastic sheet in convex portion]

[0097] The thickness of the elastic sheet attached to the convex portion obtained in the adhesion of the elastic sheet to the convex portion was measured with a micrometer, and the thickness of the elastic sheet in the convex portion was evaluated based on the following evaluation criteria. The results are recorded in the column "Thickness of Elastic Sheet" in Table 1.

[0098] (Evaluation Criteria)

[0099] ⊚: The thickness of the elastic sheet attached to the convex portion is 150 μm or less (pass).

[0100] ◯: The thickness of the elastic sheet attached to the convex portion was more than 150 μm and 200 μm or less (acceptable).

[0101] ×: The thickness of the elastic sheet attached to the convex portion exceeded 200 μm (failure).

[0102]

[0103] It can be seen from the results shown in Table 1 that the serrated metal gasket 1 and the metal tooth-shaped pad obtained in each comparative example are poor in at least one of durability and sealing properties. In contrast, the serrated metal gasket 1 and the metal tooth-shaped pad 5 obtained in each embodiment are excellent in sealing properties. Moreover, no abnormality is confirmed in the elastic sheet under a surface pressure of 100 MPa, so the durability is also excellent.

[0104] Explanation of symbols

[0105] 1 Serrated metal washer

[0106] 1a Concavoconvex part

[0107] 1b Concave and convex part

[0108] 2 Flange

[0109] 3 convex part

[0110] 4 concavity

[0111] 5 Metal tooth pads

[0112] 6 Elastic sheet

[0113] B The bottom of the concave part

[0114] D Depth of the recess

[0115] L Flat part at the top of the convex part

[0116] Top of T convex part

Claims

1. A sawtooth metal gasket having concentric sawtooth-shaped concave-convex portions and a flat plate-shaped flange portion, wherein: The sawtooth-shaped concave-convex parts are formed on both sides, the pitch of the convex parts constituting the sawtooth-shaped concave-convex parts is 1.2mm-1.8mm, a flat part with a width of 50μm-180μm is formed on the top of the convex parts, the height of the convex parts constituting the sawtooth-shaped concave-convex parts from the flange part is 0.3mm-0.8mm, the depth of the concave parts constituting the sawtooth-shaped concave-convex parts is 0.3mm-0.8mm, a circular arc with a radius of 0.2mm-0.6mm is formed at the bottom of the concave parts, and the groove area in the cross section of the concave parts constituting the sawtooth-shaped concave-convex parts is 0.25mm 2 ~0.80mm 2 .

2. A metal toothed gasket comprising the sawtooth metal washer according to claim 1, wherein an elastic sheet having a thickness of 0.6 mm to 1.5 mm is attached to sawtooth-shaped concave and convex portions formed on both surfaces of the sawtooth metal washer.

3. The metal toothed pad according to claim 2, wherein: The elastic sheet contains an organic binder and inorganic powder, wherein the organic binder is a rubber binder.

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