A high-pressure tank includes a reinforcing layer and a liner having a gas-barrier property and disposed on an inner surface of the reinforcing layer. The reinforcing layer includes a cylindrical reinforcing pipe having a plurality of cylindrical pipe forming portions coupled together, and a pair of semispherical reinforcing domes, one of the pair of semispherical reinforcing domes being disposed at a first end of the reinforcing pipe, and the other one of the pair of semispherical reinforcing domes being disposed at a second end of the reinforcing pipe.

A pressure vessel includes: a liner made of a resin and configured to store a pressurized fluid; and a reinforcing layer made of a fiber-reinforced resin provided around an outer peripheral surface of the liner. The liner includes a body portion having a tubular shape and a pair of side-end portions each having a domical shape. One of the side-end portions extends continuously from one of two ends of the body portion, and the other one of the side-end portions extends continuously from the other one of the two ends of the body portion. The liner includes a restriction portion provided at a center of the liner in an axial direction of the body portion. The restriction portion is configured to restrict displacement of the reinforcing layer in the axial direction.

Provided are a prepreg in which reinforcing fibers are impregnated with an epoxy resin composition containing an epoxy resin (A) and an epoxy resin curing agent (B) containing a reaction product (X) of a component (x1) and a component (x2) described below, a fiber-reinforced composite material that is a cured product of the prepreg, a method for producing the prepreg, and a method for producing a high-pressure gas storage tank.

(x1) At least one selected from the group consisting of meta-xylylenediamine and para-xylylenediamine

(x2) At least one selected from the group consisting of unsaturated carboxylic acids represented by General Formula (1) below and derivatives thereof.

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(In Formula (1), R.sup.1 and R.sup.2 each independently represent a hydrogen atom, an alkyl group having from 1 to 8 carbons, an aryl group having from 6 to 12 carbons, or an aralkyl group having from 7 to 13 carbons.)

A fuel cylinder, such as a high-pressure fluid storage tank, is provided with dual-inlet refilling capabilities. The storage tank may include a main body section with a first domed end portion and a second domed end portion disposed at opposite portions of the main body section. A first inlet assembly and a second inlet assembly are provided at the respective first domed end portion and the second domed end portion. Each inlet assembly is configured to provide fluid communication between a supply of a high-pressure fluid and an interior of the storage tank. Each inlet assembly may include a boss and a tank valve, with each tank valve being in fluid communication with the compressed fluid receptacle. During filling of the storage tank, the high-pressure fluid travels through a compressed fluid receptacle and enters the interior of the storage tank simultaneously through each of the first and second inlet assemblies.

A tank includes a liner including an inner shell; and a reinforcing layer covering an outer surface of the liner; wherein the reinforcing layer is formed by continuously winding resin-impregnated fiber bundles around the liner, the reinforcing layer includes a hoop layer placed in a side of the liner, and a helical layer, gaps are formed between adjacent bundles of the resin-impregnated fiber bundles wound in the hoop layer, there is at least one site where the resin-impregnated fiber bundles are wound without forming a gap between adjacent bundles in the helical layer, and resin in the resin-impregnated fiber bundles has a resin toughness value of not less than 1.0 MPa.Math.m.sup.0.5.

A reinforcement element, suitable for composite pressure vessel, may be configured to be inserted and to fill in a hollow shaft of a plastic liner of the composite pressure vessel, the hollow shaft connecting opposite walls of the liner. The reinforcement element may include a central part and two external parts constituted by a plurality of continuous fibres impregnated with a first resin. The central part of the reinforcement element may have a dimension substantially equal to the dimension of the hollow shaft and being a full part. The two external parts may be able to be unfolded and fixed on the external surface of opposite walls of the liner. A composite pressure vessel may include such a reinforcement element.

A method for manufacturing a high-pressure tank including a reinforcing layer in which rims of both ends of a tubular member and rims of a pair of dome members are joined to overlap each other in a radial direction includes producing the dome members and producing the tubular member. The producing of the dome members includes producing a wound body on a mandrel, curing a resin contained in the wound body, shaving the wound body after the resin is cured to reduce, toward a split line, thicknesses of the rims of the dome members to be obtained by splitting the wound body, splitting the shaved wound body into the dome members by cutting the wound body along the split line, and demolding the dome members from the mandrel.

Storage tank comprising—an outer container (2) having a first closable opening (23), and—an inner bladder container (3) disposed within said outer container (2) and having a second closable opening (30), said outer container (2) and inner container (3) being sealed with respect to each other, said inner container (3) being adapted to be filled and or emptied with a liquid through said second closable opening (30), a space (8) between the outer container (2) and the inner container (3) being adapted to be filled with liquid through the first closable opening (23). The outer container (2) is rigid with at least one flexible portion incorporated in the rigid outer container and configured to flex so as to expand and contract to compensate volume variations caused by pressure and or temperature variations to which the storage tank (1) is subjected.

Provided is a pressure vessel having an outer layer with an improved gas barrier property, a lightweight liner with an excellent gas barrier property, and a novel method for manufacturing a pressure vessel. The pressure vessel contains a liner and an outer layer of the liner, wherein the outer layer is configured by a composite material that contains a continuous fiber and a polyamide resin impregnated into the continuous fiber; the polyamide resin contains a structural unit derived from diamine and a structural unit derived from dicarboxylic acid; and 50 mol % or more of the structural unit derived from diamine is derived from xylylenediamine.

An internal casing for a pressurized fluid storage tank for a motor vehicle includes: a hollow body includes a layer made of a first polymer material; and a neck arranged on the hollow body and delimiting an opening of the hollow body, the neck receiving an interface part mounted on the neck in a sealed manner by a gasket arranged between the neck and the interface part. The neck is made of a composite material composed of a second polymer material loaded with reinforcing fibers, the composite material having a deformation resistance than that of the first polymer material. The neck is joined to the hollow body by molecular entanglement of polymer chains of the first polymer material and polymer chains of the second polymer material. Methods for manufacturing such an internal casing, and a storage tank including such an internal casing are disclosed.