A FRP tubular body includes a tubular fiber structure formed by winding a reinforced fiber sheet made of fabric. The reinforced fiber sheet includes first reinforced fiber bundles arranged such that a yarn main axis direction extends in a circumferential direction of the fiber structure and second reinforced fiber bundles arranged such that a yarn main axis direction extends in an axial direction of the fiber structure. The reinforced fiber sheet includes a starting end, a finishing end, and a general portion located between the starting end and the finishing end. The general portion includes the first reinforced fiber bundles and the second reinforced fiber bundles. At least one of the starting end or the finishing end is a decreased portion that is smaller than the general portion in an amount of reinforced fibers per unit length in the circumferential direction of the fiber structure.

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 cap of a high-pressure gas tank includes a first member and a second member. The first member is located on the inner side of a liner. The second member is located on the outer side of the liner and is connected to the first member. A rotation restricting structure includes a first rotation restricting portion and a second rotation restricting portion. The first rotation restricting portion is provided on an inner surface of the liner. The second rotation restricting portion is provided on the first member so as to be fitted into the first rotation restricting portion.

A storage vessel can include a shell that is formed by fibers wound about an axis and infused with a resin matrix. The resin matrix can include metal nanoparticles coated with a polymer and distributed within a resin. The nanoparticles provide low coefficients of thermal expansion, and the polymer coatings enhance their bonding with the resin The shells of such storage vessels provide increased tensile strength and modulus at both room and cryogenic temperatures. Such improvements stem from the higher interfacial residual thermal stress at cryogenic temperature due to their low thermal expansion properties, which in turn promotes crack branching that increases the energy dissipation of the matrix.

A manufacturing method for manufacturing a reinforced layer constituting a high-pressure tank includes: a first forming step of forming a cylindrical pipe portion and extending in an axial direction of the high-pressure tank, the pipe portion including a first end portion including a first end and a second end portion including a second end, the pipe portion being formed to have a first stepped portion such that the first stepped portion projects outwardly at a position distanced from the first end in the axial direction by a first distance; a first placing step of placing the first end inside a first dome portion by moving at least either of the first dome portion and the pipe portion until a first bottom end portion of the first dome portion abuts with the first stepped portion; and a first joining step of joining the pipe portion to the first dome portion.

A high-pressure tank includes a cylindrical portion including a fiber-reinforced resin and a dome portion including a fiber-reinforced resin. The cylindrical portion includes an axial fiber layer including a fiber oriented in a center axis direction of the high-pressure tank, and a circumferential fiber layer including a fiber oriented in a circumferential direction of the high-pressure tank. An end portion of the axial fiber layer and an end portion of the dome portion are joined to each other.

A high-pressure tank includes a container main body (10) constituted of a body (11) and dome portions (12) disposed on both ends of the body, and a reinforcing layer (20) formed such that a fiber member is wound around an outer periphery of the container main body. The reinforcing layer includes a hoop winding layer (40) formed by hoop winding that winds the fiber member such that a winding angle is approximately perpendicular to a central axis of the body, and a high helical winding layer (30) formed by high helical winding that winds the fiber member such that a winding angle is inclined with respect to the central axis compared with the hoop winding, and the high helical winding layer extends to the dome portion. The high helical winding layer includes a thick portion having a thickness at an outer side part of a boundary position between the body and the dome portion, which thickness is thicker than a thickness at a part positioned on the body. The hoop winding layer is formed from the body to the dome portion where the thick portion is formed, as a layer at an outer diameter side of the high helical winding layer.

The present invention is directed to a reinforcement method for a cylindrical high-pressure tank reinforced by FRP prepreg bandage, totally. For that purpose, this invention developed the manufacturing process for the internal metallic tank assembly where its diameter is comparatively large. It is effective for lightening weight of a high-pressure tank.

An assembly includes a pressure vessel for containing a fluid, the vessel including a domed end portion having an outer surface; and a component positioned at the domed end portion, wherein the component is attached to the outer surface by a plurality of filament bands wound upon the domed end portion and over at least a part of the component. In another aspect, an apparatus is described for preventing damage to a vessel. The apparatus includes a component configured to be positioned at the domed end portion, wherein the component is configured to be attached to the outer surface by a plurality of filament bands wound upon the domed end portion and over at least a part of the component. A method for attaching a component to a vessel is described that includes positioning the component at the domed end portion and winding a plurality of filament bands.

Embodiments are directed to fiber-reinforced compressed gas storage tanks or vessels comprising one or more shells that are made by metal forming, plastic molding, braiding, filament-winding, or fiber placement. Particular embodiments employ one or more discrete pre-formed fiber-reinforced endcaps with fibers oriented in preferential angles that are integrated to the vessel end-domes to reinforce the polar openings and the dome-cylinder transition areas of the load carrying shells.