Abstract: To obtain a gasket holding device which is unlikely to slip out of a bolt and facilitates mounting of the bolt thereon, a bolt mounting hole made in a metal plate constituting the gasket holding device is provided with an engaging portion which engages the bolt. This engaging portion is formed by processing part of the metal plate on the bolt mounting hole thinly such that it is elastically deformed and projected in between a crest and a root of the bolt.

Abstract: In order to provide a gasket which can be repeatedly used over a temperature range in which a rubber gasket cannot be used, which does not have any risk of damaging a flange, and which can follow the change of the distance between flanges, a gasket is constructed in such a way that two metallic coned disc springs each of which has a circulation opening for a fluid in a central portion and each of which is formed into a seal surface in which an outer peripheral portion with respect to the circulation opening rises having an arc-like curved surface are combined while being oppositely directed and have outer diameter peripheral edge portions which are welded and fixed so that by tightening flanges, repulsive force of the two coned disc springs concentratedly affects the seal surfaces consisting of the arc-like curved surfaces, and a tight fluid seal is formed between the flange surfaces.

Abstract: An annular-shaped metal gasket, which can reduce a tightening force necessary to a seal and easily manage the manufacturability and the characteristics thereof, the metal gasket, in an annular-shaped metal gasket having a cross section provided with an outer circumferential opening and formed in one of a laterally U-shape, voids are formed to the innermost circumferential portions on the two confronting flat sealing surfaces of the metal gasket that are in contact with opponent surfaces, each void having a width equal to or more than 40% of the central wall thickness t0 of a bight section and a height equal to or more than 5% of the height H of the gasket, wherein the cross section of the gasket is formed in a tuning-fork shape. A tightening force necessary to the seal can be reduced by forming the cross section of the metal gasket in the tuning-fork shape and providing the voids with the surfaces of the metal gasket in contact with the opponent surfaces.

Abstract: To provide an annular-shaped metal gasket, which can reduce a tightening force necessary to a seal and easily manage the manufacturability and the characteristics thereof, the metal gasket, in an annular-shaped metal gasket having a cross section provided with an outer circumferential opening and formed in one of a laterally U-shape, voids are formed to the innermost circumferential portions on the two confronting flat sealing surfaces of the metal gasket that are in contact with opponent surfaces, each void having a width equal to or more than 40% of the central wall thickness t0 of the gasket and a height equal to or more than 5% of the height H of the gasket, wherein the cross section of the gasket is formed in a tuning-fork shape. A tightening force necessary to the seal can be reduced by forming the cross section of the metal gasket in the tuning-fork shape and providing the voids with the surfaces of the metal gasket in contact with the opponent surfaces.

Abstract: In order to provide a gasket which can be repeatedly used over a temperature range in which a rubber gasket cannot be used, which does not have any risk of damaging a flange, and which can follow the change of the distance between flanges, a gasket is constructed in such a way that two metallic coned disc springs each of which has a circulation opening for a fluid in a central portion and each of which is formed into a seal surface in which an outer peripheral portion with respect to the circulation opening rises having an arc-like curved surface are combined while being oppositely directed and have outer diameter peripheral edge portions which are welded and fixed so that by tightening flanges, repulsive force of the two coned disc springs concentratedly affects the seal surfaces consisting of the arc-like curved surfaces, and a tight fluid seal is formed between the flange surfaces.

Abstract: To obtain a gasket holding device which is unlikely to slip out of a bolt and facilitates mounting of the bolt thereon, a bolt mounting hole made in a metal plate constituting the gasket holding device is provided with an engaging portion which engages the bolt. This engaging portion is formed by processing part of the metal plate on the bolt mounting hole thinly such that it is elastically deformed and projected in between a crest and a root of the bolt.

Abstract: A metal C-shaped ring gasket is constructed so that a satisfactory sealing property can be obtained even with a low clamping pressure. The metal C-shaped ring gasket is made of an austenite stainless steel and constructed so as to have a superficial roughness below 0.2 &mgr;m Ra and a superficial hardness below 230 Hv by electrolytic polishing.