Multilayer structure for transporting hydrogen, including, from the inside, at least one sealing layer and at least one composite reinforcing layer, an innermost composite reinforcing layer being wound around an outermost adjacent sealing layer, the sealing layers of a composition predominantly of at least one semi-crystalline, long-chain polyamide thermoplastic polymer P1i (i=1 to n, n being the number of sealing layers), the Tf of which, as measured according to ISO 11357-3: 2013, is greater than 160° C., with the exception of one polyether block amide (PEBA), up to 50% by weight of impact modifier relative to the total weight of the composition and up to 1.5% by weight of plasticiser relative to the total weight of the composition, the composition being free of nucleating agent, and at least one of the composite reinforcing layers being of a fibrous material.

A composite pressure vessel assembly includes a plurality of lobes, each of the lobes having at least one interior wall and at least one curved wall, the plurality of lobes being positioned in a side by side arrangement and extending in a longitudinal direction from a first end to a second end. Also included is a plurality of end caps disposed at the ends of the lobes, wherein the plurality of lobes and end caps are formed of at least one fiber-reinforced polymer. A method of manufacturing a composite pressure vessel assembly is provided. The method includes forming a plurality of lobes consisting of at least one fiber-reinforced polymer. The method also includes forming a main body with the plurality of lobes, the lobes disposed in a side by side arrangement.

A pressure vessel and a method for producing a pressure vessel are provided. The pressure vessel has a liner and a fiber-reinforced laminate, which surrounds the liner and has a first fiber layer and a second fiber layer, which are incorporated in a matrix material. The method includes: a) providing the liner for storing a fluid, having a cylindrical region and two cap regions at opposite ends of the cylindrical region, b) wrapping a fibrous material impregnated with matrix material around the liner at the cap regions and the cylindrical region to produce the first fiber layer, which is already permeated with matrix material, c) arranging the second fiber layer around the first fiber layer, wherein the second fiber layer is formed by at least one braided sleeve of dry fibers, and d) curing or consolidating the matrix material without supplying additional matrix material to produce the fiber-reinforced laminate.

A high pressure tank is provided with a reinforcement layer. The reinforcement layer is provided with an inner laminated section, an outer laminated section, and an intermediate laminated section. The inner laminated section includes a winding start of an impregnated fiber and is disposed radially inward. The outer laminated section includes a winding end of the impregnated fiber and is disposed radially outward. The intermediate laminated section is formed between the inner laminated section and the outer laminated section. First and second dome portions of a liner are respectively provided with first and second core materials between the inner laminated section and the outer laminated section.

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.

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 step of forming a low-angle helical layer on an outer surface of at least part of each liner dome portion and an outer surface of a liner cylindrical portion, a step of forming an inner hoop layer on an outer surface of the low-angle helical layer on the liner cylindrical portion, and a step of forming a mixed layer by alternately laminating a low-angle helical layer and an outer hoop layer on an outer surface of the inner hoop layer and low-angle helical layer on each liner dome portion. Then, on the liner cylindrical portion, 90% or more of the sum of the thickness of the inner hoop layer and the thickness of the outer hoop layer in the mixed layer is arranged within the range of 75% of the fiber reinforced plastics layer adjacent to the liner in a thickness direction of the fiber reinforced plastics layer.

A high-pressure tank comprises a liner, a strengthening layer including a first helical layer and a first hoop layer each including a carbon fiber, and a protective layer including a second helical layer and a second hoop layer each including a glass fiber, in this order. The high-pressure tank is provided with a stress-generating portion, a reinforcement layer includes a first area α overlapping the stress-generating portion in a stacking direction and a second area β that is an area except for the first area, and a one-round portion including a final crossing portion at an end of winding of the glass fiber constituting the second hoop layer overlaps the second area in the stacking direction.