Abstract: A high pressure tank includes: a resin liner for containing a fluid; and a cap including a supply/discharge hole. A cylindrical portion formed with the liner in a protruding manner is inserted in the supply/discharge hole. In a seal groove formed in an inner circumferential surface of the supply/discharge hole, a seal member and a back-up member disposed on an upstream side of the seal member in the supply direction are provided. A tapered groove surface of the seal groove facing toward the back-up member is apart from the outer circumferential surface of the cylindrical portion along the supply direction. A tapered member surface of the back-up member facing toward the tapered groove surface has a diameter expanding along the supply direction.

Abstract: A high pressure tank includes: a resin liner for containing a fluid; a reinforced layer covering an outer surface of the liner; and a cap including a supply/discharge hole for supplying and discharging the fluid to and from the liner. Gas vent passages formed in the cap each including at one end a first opening open toward the cap-facing surface of the liner and at the other end a second opening open toward at least one of an inside of the supply/discharge hole and an outside of the reinforced layer. A cross-sectional area of the gas vent passage at the one end perpendicular to a longitudinal direction and the first opening are smaller than other cross-sectional areas of the gas vent passage perpendicular to the longitudinal direction.

Abstract: A high pressure tank includes a resin liner, a cap, a seal member, and a collar. The liner contains fluid. The cap has a supply/discharge hole for supplying/discharging the fluid to/from the liner. The collar has a passage hole connected to the supply/discharge hole. A tubular portion of the liner is inserted into the supply/discharge hole, and held between an outer circumferential surface of the collar and an inner circumferential surface of the supply/discharge hole. The seal member is provided in a seal groove formed in the inner circumferential surface of the supply/discharge hole. A fluid inlet channel is formed at least in one of the cap and the collar, for guiding the fluid from a protruding end of the tubular portion into the seal groove through space between the inner circumferential surface of the supply/discharge hole and the outer circumferential surface of the tubular portion.

Abstract: A hydrogen storage container has an inner side resin layer that comes into contact with hydrogen gas that is introduced into the container, a barrier layer which is disposed on the outside of the inner side resin layer and which prevents permeation of hydrogen gas, and an outer side resin layer comprising a resin. Among these layers, the inner side resin layer comprises a polyethylene-based resin, and if the thickness of the barrier layer is denoted by Y and the thickness of the inner side resin layer is denoted by X, the thickness X satisfies formula (1). Moreover, D in formula (1) is the diffusion coefficient of the polyethylene-based resin, as determined by means of a differential pressure method at 50° C.

Abstract: A pressure tank includes a resin liner, a base, a seal, and a collar. The resin liner contains fluid therein. The resin liner has a tubular portion via which an inside of the resin liner communicates with an outside of the resin liner. The base includes a supply/discharge hole in which the tubular portion is inserted. The seal is provided between the tubular portion and the base in the supply/discharge hole. The collar has a through-hole and inserted into the tubular portion.

Abstract: A pressure gas container includes a liner to store a gas, a reinforcing layer provided on an outer side of the liner, a boss attached to the liner, and an attachment attached to an outer surface of the liner. The boss has an opening through which the gas is introduced into the liner and through which the gas inside the liner is released. The attachment is to support the liner rotatably when the reinforcing layer is provided. At least one of the boss and the attachment has a gas release channel that allows communication between a gap formed between the outer side and an inner side of the reinforcing layer and a space outside the pressure gas container to release the gas having permeated through the liner and present in the gap between the liner and the reinforcing layer to the space.

Abstract: A pressure gas container includes a liner to store a gas, a reinforcing layer provided on an outer side of the liner, a boss attached to the liner, and an attachment attached to an outer surface of the liner. The boss has an opening through which the gas is introduced into the liner and through which the gas inside the liner is released. The attachment is to support the liner rotatably when the reinforcing layer is provided. At least one of the boss and the attachment has a gas release channel that allows communication between a gap formed between the outer side and an inner side of the reinforcing layer and a space outside the pressure gas container to release the gas having permeated through the liner and present in the gap between the liner and the reinforcing layer to the space.

Abstract: A remaining lifetime of a pressure vessel mounted on a fuel cell vehicle or the like and comprises a liner at its inner side and a reinforcing layer at its outer side can be predicted with high precision and in short time. An artificial imperfect structure is formed at an outer surface of the liner in a size capable of being maintained by a weakest part of a hydrogen gas tank throughout the total period of use of the hydrogen gas tank. A detector is, for example, comprised of a crack gauge intervening between the liner and the reinforcing layer, and is fixed to the outer surface of the liner close to the artificial imperfect structure. A crack length increases accompanying the increase of a pressure cycle of an internal pressure caused by usage of the hydrogen gas tank. The detector increases a resistance value accompanying a crack growth.

Abstract: A remaining lifetime of a pressure vessel mounted on a fuel cell vehicle or the like and comprises a liner at its inner side and a reinforcing layer at its outer side can be predicted with high precision and in short time. An artificial imperfect structure is formed at an outer surface of the liner in a size capable of being maintained by a weakest part of a hydrogen gas tank throughout the total period of use of the hydrogen gas tank. A detector is, for example, comprised of a crack gauge intervening between the liner and the reinforcing layer, and is fixed to the outer surface of the liner close to the artificial imperfect structure. A crack length increases accompanying the increase of a pressure cycle of an internal pressure caused by usage of the hydrogen gas tank. The detector increases a resistance value accompanying a crack growth.

Abstract: Disclosed are an austenitic stainless steel, and a hydrogenation method thereof, in which occurrence of fatigue cracks and growth of fatigue cracks are suppressed by charging the austenitic stainless steel with hydrogen. In particular, focusing on the amount of diffusible hydrogen and non-diffusible hydrogen, which cause hydrogen embrittlement in austenitic stainless steel, the fatigue strength characteristics of austenitic stainless steel are improved by bringing the amount of diffusible hydrogen and non-diffusible hydrogen contained in the austenitic stainless steel to 0.0030 wt % (30 wt ppm) or higher. The austenitic stainless steel is subjected to a thermal treatment at a heating temperature of 200 to 500° C. for up to 460 hours in a hydrogen environment. The hydrogen (H) contained in the austenitic stainless steel is brought thereby to 0.0030 wt % (30 wt ppm) or higher.

Abstract: The present invention focuses on diffusible hydrogen and non-diffusible hydrogen that cause hydrogen embrittlement in an austenitic stainless steel, and provides the austenitic stainless steel having diffusible hydrogen and non-diffusible hydrogen removed therefrom, and a method for removing hydrogen therefrom. In order to remove diffusible hydrogen and non-diffusible hydrogen, which cause hydrogen embrittlement in the austenitic stainless steel, an aging treatment is performed to the austenitic stainless steel at a temperature ranging from 200 to 1100° C. while being kept in an air atmosphere. As a result, the hydrogen (H) content in the austenitic steel is removed to 0.001 wt % (1 wt ppm) or less.

Abstract: There is provided a fatigue test method with which the crack growth can be checked for a plurality of cycle rates in a single test. At a first cycle rate f1 of 0.01 Hz, hydrogen has a greater effect on crack growth than at a second cycle rate f2 of 1 Hz. As a result, an area of large hydrogen effect (an area developed at the cycle rate f1) and an area of small hydrogen effect (an area developed at the cycle rate f2) appear alternately on the fatigue fracture surface, and since these two areas have different fracture surface morphologies, it is possible to see the boundary lines. Consequently, the lengths of the cracks developed under each set of conditions can be specified, and a fatigue crack growth curve can be acquired for each set of conditions.

Abstract: By focusing on the non-diffusible hydrogen that causes hydrogen embrittlement of austenitic stainless steel, the present invention provides an austenitic stainless steel in which the non-diffusible hydrogen is removed by maintaining the austenitic stainless steel in a vacuum of 0.2 Pa or less and heating at a heating temperature of 200° C. to 500° C. for 460 hours or less to remove the hydrogen (H) contained therein to a level of 0.00007 mass % (0.7 mass ppm) or less.

Abstract: By focusing on the non-diffusible hydrogen that causes hydrogen embrittlement of austenitic stainless steel, the present invention provides an austenitic stainless steel in which the non-diffusible hydrogen is removed by maintaining the austenitic stainless steel in a vacuum of 0.2 Pa or less and heating at a heating temperature of 200° C. to 500° C. for 460 hours or less to remove the hydrogen (H) contained therein to a level of 0.00007 mass % (0.7 mass ppm) or less.