Provided is a high-pressure tank including: a helical layer containing first fibers that are wound in a helical pattern and a first resin that fixes the first fibers; a hoop layer located outward of the helical layer in the high-pressure tank and containing second fibers that are wound in a hoop pattern and a second resin that fixes the second fibers; and an intermediate layer located between the helical layer and the hoop layer and containing third fibers that are thinner than at least either the first fibers or the second fibers and a third resin that fixes the third fibers, the first fibers of the helical layer, and the second fibers of the hoop layer.

A method for manufacturing a high pressure tank includes a step of forming a reinforcing pipe portion including a straight pipe portion and reduced-diameter portions, a step of forming reinforcing dome portions, a step of forming a joined body by joining the reinforcing pipe portion and the reinforcing dome portions, and a step of forming an outer helical layer on an outer face of the joined body. The reinforcing dome portions are disposed with opening ends of the reinforcing dome portions positioned on outer faces of the reduced-diameter portions of the reinforcing pipe portion.

A method for producing a high-pressure tank that can reduce the positional deviation of a wound fiber bundle. In the method for producing the high-pressure tank, the fiber bundle impregnated with an uncured thermosetting resin is wound around a liner for housing gas so as to form, on the liner, a reinforcing layer with a plurality of fiber-reinforced resin layers. The method for producing the high-pressure tank includes pressing an edge portion on at least one side along the longitudinal direction of the fiber bundle in the width direction of the fiber bundle to deform the edge portion so as to protrude in the thickness direction of the fiber bundle and thermally curing the thermosetting resin in the edge portion deformed so as to form a protruding portion in the edge portion, and forming the fiber-reinforced resin layers with the fiber bundle with the edge portion deformed.

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.

An organic composite gas storage tank 300 comprises a hollow central portion 306 which is substantially cylindrical and formed integrally with first and second end portions 302, 304, and which defines a longitudinal tank axis 301. The first end portion comprises a hollow truncated conical region which meets the hollow central portion at a first end thereof. The hollow central portion comprises first and second hollow truncated conical portions 306A, 306B, the external radius of a given hollow truncated conical portion decreasing in a direction towards a corresponding end portion. The tank comprises an organic composite fibre winding extending between first and second positions along the length of the tank which coincide with the first and second hollow truncated conical portions of the hollow central portion respectively, biassing these portions together and increasing the axial strength of the central portion.

An organic composite gas storage tank 100 comprises a hollow central portion 106 which is substantially cylindrical and formed integrally with first and second end portions 102, 104, and which defines a longitudinal tank axis 101. The first end portion 102 comprises a hollow truncated conical region 102A which meets the hollow central portion at a first end thereof, and a cylindrical region 102B which meets an end of the hollow truncated conical portion remote from the hollow central portion. An organic fibre winding 107 extends at least between axial positions which coincide with the hollow truncated conical region of the first end portion and the hollow central portion respectively. A hollow metal end-fitting 120 has a hollow truncated conical portion 124 embedded within the wall of the hollow truncated conical region of the first end portion, providing a long leakage path around the metal end-fitting.

In the vicinity of an opening end of a first liner constituent member and a second liner constituent member made of a resin material, a flange portion is formed. After end surfaces of the opening end are abutted and joined to each other, the flange portion is removed in such a way that a part of a bottom portion remains. The remaining amount of protrusion is set such that the joint strength of a joint portion is not less than the tensile strength of the resin material or not less than the cohesion failure strength of the joint portion.

A method for manufacturing a high pressure tank includes a step of forming a reinforcing pipe portion including a straight pipe portion and reduced-diameter portions, a step of forming reinforcing dome portions, a step of forming a joined body by joining the reinforcing pipe portion and the reinforcing dome portions, and a step of forming an outer helical layer on an outer face of the joined body. The reinforcing dome portions are disposed with opening ends of the reinforcing dome portions positioned on outer faces of the reduced-diameter portions of the reinforcing pipe portion.

Provided is a high-pressure tank wound with a hoop layer and a helical layer. According to the present invention, the high-pressure tank includes: a liner which includes a cylinder portion and two dome portions respectively formed at both ends of the cylinder portion; and a composite material layer which includes a hoop layer and a helical layer, wound on an outer circumferential surface of the liner, wherein the helical layer includes a twist portion wound on a junction portion of the cylinder portion and the dome portion, and the twist portion is twisted and wound while wrapping on an end portion of the hoop layer when the helical layer passes by the hoop layer and is then wound toward the dome portion.

A polar end ring mechanism for use with composite pressure vessels. The end ring is designed to support a pressure vessel during its formation via filament winding. The end ring helps define an opening at one of the polar ends of a tank. Spikes positioned along a portion of the end ring help prevent rotation or translation of the tank during formation and provide an improved mechanical lock with the tank body. A cap may then be secured to the polar end ring after formation in order to close the pressure vessel.