Pressure vessels having a grooved liner and methods of forming the same are described. The pressure vessel includes a liner surrounding a cavity therein, an outer surface of the liner disposed opposite the cavity, a boss disposed at a first end of the liner, a composite layer surrounding the liner, an inner surface of the composite layer disposed proximate the liner, and a plurality of longitudinal grooves configured to release gas present between the inner surface of the composite layer and the outer surface of the liner. The liner defines a longitudinal axis therethrough. The boss and the outer surface of the liner define the plurality of longitudinal grooves therein. The plurality of longitudinal grooves extends along the longitudinal axis from the boss toward a second end of the liner. The composite layer spans each of the plurality of longitudinal grooves.

A liner of a high-pressure tank is made of a material having a shrinkage amount that is calculated by an equation below being 0 or less, the equation being shrinkage amount=−1.533538e−03*x1−3.82355406*x2−7.81992308*x3+1.89342646e−01*x4−7.84558163e−03*x5+1.15956871e−03*x1x2+6.29564353e−04*x1x3−9.34550213e−06*x1x4−6.59253799e−04*x1x5−1.52692282e+00*x2{circumflex over ( )}2+1.67290964e+00*x2x3−1.85202252e−02*x2x4−1.79615713e+00*x2x5+2.37163664e+00*x3{circumflex over ( )}2−1.17467786e−02*x3x4−9.04442817e−01*x3x5−1.86321584e−03*x4{circumflex over ( )}2+6.62631756e−03*x4x5+1.27572698e*x5{circumflex over ( )}2.

Disclosed herein is a structure that comprises a tank including an outer cylindrical surface and a domed end. The structure also comprises a tank skirt positioned circumferentially around the tank. A wall of the tank and a wall of the tank skirt form two sides of a y-joint between the tank and the tank skirt. The y-joint includes a wedge structure positioned between the tank and the tank skirt. Additionally, a thickness of at least one of the wall of the tank or the wall of the tank skirt forming the y-joint tapers such that the thickness of the at least one of the wall of the tank or the wall of the tank skirt that tapers has a greater thickness at the y-joint than away from the y-joint.

A Liquid Natural Storage (LNG) tank comprising an outer mechanical support structure (20) providing a closed space housing a membrane wall of the cryogenic tank is disclosed. Spacer elements (21) is supporting a membrane wall constituted by a mixture of steel plates, steel rods, wooden beams and plywood plates.

A hydrogen tank body includes a base layer formed of a synthetic resin selected from the group consisting of silicon resin, polyphenylene sulfide, polybutylene terephthalate, polyvinyl chloride, polypropylene, polyethylene, and polycarbonate, and a liner layer formed of hydrogen impermeable resin, on an inside wall surface of the base layer.

A restraining structure for a structural body includes: a restrained portion that is a tubular body or a stacked body; a pair of holding portions provided at the restrained portion; a first CFRP belt wrapped around the restrained portion in an axial direction of the restrained portion so as to extend between the pair of holding portions and having carbon fibers of a 0° direction along the axial direction; and a second CFRP belt stacked adjacent to an outermost layer near an end of the first CFRP belt and having carbon fibers of 45° to 90° directions with respect to the axial direction. One of the holding portions is provided at an end of the restrained portion. The other of the holding portions is provided at the other end of the restrained portion.

A precast, prestressed concrete tank and method that facilitates construction of a primary inner tank within a secondary outer tank, and which permits for the construction of the primary inner tank after the secondary outer tank has been erected, but without requiring insertion through a top of the secondary outer tank, or by tunneling underneath the secondary outer tank, is disclosed. The primary inner tank has an inner wall and the secondary outer tank has an outer wall (precast, prestressed concrete) and wire windings. The primary inner tank is disposed inside of the secondary outer tank. The secondary outer tank has a plurality of first precast outer wall panels, and a temporary construction opening frame. The temporary construction opening frame defines an access doorway during construction of the tank. The temporary construction opening frame is disposed on a foundation base slab.

A high-pressure tank includes: a cylindrical hollow container; an outer shell that is formed of a fiber-reinforced plastic band which is wound on an outer circumference of the hollow container to cover the outer circumference; and a cap that is attached to an inner side of at least one of one axial end and the other axial end of the outer shell. The hollow container is formed of a material which has airtightness and which is able to expand and contract in an axial direction and a radial direction inside the outer shell, and a frictional portion that is used to set a frictional resistance to an inner circumferential surface of the outer shell to be greater than that in the other area is provided in an axial intermediate portion on an outer circumferential surface of the hollow container.

A hydrogen gas storage tank includes a body including a steel bulk region and a passivating metal oxide layer adjacent to the steel bulk region, the oxide layer comprising a number of metal oxide molecules, all having a morphology, wherein at least about 51 wt. % of the number of metal oxide molecules are Fe.sub.2O.sub.3 molecules having morphologies of (012), (001), and/or (110) surface facets such that the oxide layer is configured to lower hydrogen adsorption into the steel bulk region by at least 25% compared to a steel bulk region free from the passivating metal oxide layer.

A method of storing hydrogen involves forming an excavation in the earth and constructing a storage tank therein comprised of integrated primary and secondary containment structures. The primary containment structure composed of a plurality of joinable cylindrical segments, or pre-fabricated sections joined to form a cylinder within the excavation. The secondary containment structure formed by pumping a curable, flowable composition into the cylinder, allowing it to flow out the bottom and up the second annulus to the earth's surface, and then hardening; thereby encasing the primary containment structure. The bottom of the cylinder is sealed with the bottom assembly. The top assembly is attached to the cylinder and tubing and packer are run into the cylinder creating a first annulus between the cylinder and tubing. Top assembly is sealed, fluids circulated out, and the tank dried. Thereafter, the tank is capable of safely storing hydrogen gas.