A multilayer structure for storing hydrogen, including, from the inside, at least one sealing layer and at least one composite reinforcement layer, an innermost composite reinforcement layer being welded to an outermost adjacent sealing layer, the sealing layers being a composition predominantly of: at least one semi-crystalline polyamide thermoplastic polymer P1i, i=1 to n, n being the number of sealing layers, excluding an amide polyether block (PEBA), up to 50% by weight of impact modifier relative to the total weight of the composition, up to 1.5% by weight of plasticizer relative to the total weight of the composition, and at least one of the composite reinforcement layers of a fibrous material in the form of continuous fibers, which is impregnated with a composition predominantly of at least one semi-crystalline polyamide polymer P2j, j=1 to m, m being the number of reinforcement layers.

A pressure vessel includes a liner including a cylindrical body and a dorm portion continuous with at least one end of the body in an axial direction and includes a reinforced fiber sheet covering an outer side of the liner and made of fabric. The reinforced fiber sheet includes first yarns arranged on the body and the dorm portion such that yarn main axes of the first yarns extend in the circumferential direction of the liner and second yarns arranged on the body and the dorm portion such that yarn main axes of the second yarns extend in the axial direction of the liner. A total number of the first yarns or the second yarns that exist per unit length in the axial direction of the liner is smaller in the dorm portion than in the body.

In a hydrogen or helium container and method for containing the gas, a double-walled housing is provided, which defines an inter-space between the inner and the outer walls, the inter-space being filled with a fluid at a higher pressure than the pressure of the hydrogen or helium contained within the inner wall.

A hollow molded article having a joining site where two or more split objects are welded by plastic welding and comes into contact with pressurized hydrogen, wherein an average spherulite size in a portion which is 500 μm deep inside from a surface of the hollow molded article is 20 μm or less, and a tensile strength of a test piece containing the joining site of the hollow molded article is 80% or more based on a tensile strength of a test piece not containing the joining site of the hollow molded article.

Method for preparing a hydrogen tank including at least one sealing layer of a composition including at least one polyamide P1, and at least one base in order to provide the tank with at least one opening, wherein the method includes: providing of at least one base, the at least one base being covered by at least one layer of a composition including at least one adhesion primer; preparing the at least one sealing layer; fastening the at least one base to the at least one sealing layer.

The method for producing a filled container of the present invention includes: providing a metal storage container, at least an inner surface of which is formed of a manganese steel and in which the inner surface has a surface roughness R.sub.max of 10 μm or less; performing fluorination by bringing the inner surface of the storage container into contact with a gas containing at least one first fluorine-containing gas selected from the group consisting of ClF.sub.3, IF.sub.7, BrF.sub.5, F.sub.2, and WF.sub.6 at 50° C. or lower; purging the inside of the storage container with an inert gas; and filling the inside of the storage container with at least one second fluorine-containing gas selected from the group consisting of ClF.sub.3, IF.sub.7, BrF.sub.5, F.sub.2, and WF.sub.6.

A cryogenic storage system basically includes a first cryogenic storage tank, a second cryogenic storage tank, a fluid transfer line and a cryogenic containment structure. The first cryogenic storage tank has a first predetermined capacity of liquefied gas. The second cryogenic storage tank has a penetration free bottom and a second predetermined capacity of the liquefied gas that is larger than the first predetermined capacity of the first cryogenic storage tank. The fluid transfer line is fluidly connected between the first cryogenic storage tank and the second cryogenic storage tank. The heat exchanger converts liquid exiting the first cryogenic storage tank to a higher pressure gas that is used as a motive force to move liquidized gas out of the second cryogenic storage.

A multilayer structure for transporting, distributing and storing hydrogen including, from the inside to the outside, a sealing layer and at least one composite reinforcement layer, the sealing layer including from the inside to the outside: a layer of a composition including: a short-chain polyamide thermoplastic polymer, more than 15% and up to 50% by weight of impact modifier, or including: a semi-crystalline long-chain polyamide thermoplastic polymer, up to 50% by weight of impact modifier, up to 3% by weight of plasticizer; a hydrogen barrier layer; a layer of a composition including: a short-chain polyamide thermoplastic polymer, more than 15% and up to 50% by weight of impact modifier, or including: a semi-crystalline long-chain polyamide thermoplastic polymer, up to 50% by weight of impact modifier, up to 3% of weight of plasticizer, the innermost composite reinforcement layer being wound around the sealing layer.

A type IV conformable pressure vessel is provided comprising an elongated folded tank and a valve assembly configured to pass fluid into and out of an interior of the tank through first and second filling couplers directly connected to a respective first and second end of the tank. The tank has at least two chambers for the storage of fluid. The valve assembly receives fluid from an external source, selectively provides the external fluid through a Venturi nozzle into a mixing chamber, recirculates fluid from the second end of the tank into the mixing chamber, and delivers the mixture of the recirculated fluid and the external fluid to the first end of the tank.

A high-pressure tank comprising: a resin liner for a high-pressure tank including at least one opening portion; an aluminum mouth portion attached to the opening portion; and a reinforcement layer formed on an outer surface of the liner, wherein an aluminum oxide coating is formed on a surface of the aluminum mouth portion, the aluminum oxide coating includes a porous surface layer in which columns with an average height of 10 to 100 nm are arranged in a dispersed state, an average value of a percentages of the protruding portion area of the columns in randomly sampled 400 nm square visual fields of the porous surface layer is 5.0 to 26.0%, and an average value of the numbers of the columns in randomly sampled 400 nm square visual fields of the porous surface layer is 500 to 2000.