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 pressure vessel includes a polymeric liner defining a fluid containment cavity and having an opening defining a port aperture extending between an inner surface and an outer surface of the polymeric liner and a rigid ring element is embedded within the polymeric liner and surrounding the port aperture. A metallic port element is disposed on the outer surface of the polymeric liner and fixed to the rigid ring element. A fiber composite material is disposed about the outer surface of the polymeric liner.

A method for constructing a double-shell-structured cylindrical tank having an inner tank and an outer tank includes: a step of, inside the outer tank, assembling a first structure of the inner tank excluding a lowermost level of the inner tank by alternately and repeatedly performing raising of an inner tank lateral plate using a jack-up unit and attaching of a next inner tank lateral plate below the raised inner tank lateral plate; a step of assembling a second structure serving as the lowermost level of the inner tank on an annular portion provided on a base portion of the outer tank and configured to support the inner tank; and a step of assembling the inner tank by joining the first structure and the second structure.

A method for constructing a double-shell-structured cylindrical tank having an inner tank and an outer tank includes: a step of, inside the outer tank, assembling a first structure of the inner tank excluding a lowermost level of the inner tank by alternately and repeatedly performing raising of an inner tank lateral plate using a jack-up unit and attaching of a next inner tank lateral plate below the raised inner tank lateral plate; a step of assembling a second structure serving as the lowermost level of the inner tank on an annular portion provided on a base portion of the outer tank and configured to support the inner tank; and a step of assembling the inner tank by joining the first structure and the second structure.

A locking mechanism for a tank body and a tank cover of a pressure tank. The locking mechanism includes: a tank body, a tank chamber, a tank cover, a hydraulic cylinder, a locking ring, a spring cylinder, a fixing supporting mechanism, a fixing plate, a barb, a notch, and a pulling cylinder.

A locking mechanism for a tank body and a tank cover of a pressure tank. The locking mechanism includes: a tank body, a tank chamber, a tank cover, a hydraulic cylinder, a locking ring, a spring cylinder, a fixing supporting mechanism, a fixing plate, a barb, a notch, and a pulling cylinder.

A composite material comprises of at least first and second layers, each comprising a polymeric matrix material and wound tows for reinforcement. The tows are wound in opposite directions in each of the first and second layers such that overlapping tows form crossover regions. The wound tows in the second layer are arranged such that the crossover regions are formed to be laterally offset from the crossover regions in the first layer.

A composite material comprises of at least first and second layers, each comprising a polymeric matrix material and wound tows for reinforcement. The tows are wound in opposite directions in each of the first and second layers such that overlapping tows form crossover regions. The wound tows in the second layer are arranged such that the crossover regions are formed to be laterally offset from the crossover regions in the first layer.

A gas storage structure includes: a container and a continuous coiled pipe supported by the container, the continuous coiled pipe including a major portion formed of thin walled pipe and a thick walled pipe defining an end of the continuous coiled pipe, the thick walled pipe having a wall thickness thicker than the thin walled pipe, the thick walled pipe being welded at a welded joint to the major portion to place an inner diameter of the thick walled pipe into communication with an inner diameter of the major portion and the thick walled pipe being connected to the container, while the major portion is free of any rigid, such as welded, connections to the container.

A gas storage structure includes: a container and a continuous coiled pipe supported by the container, the continuous coiled pipe including a major portion formed of thin walled pipe and a thick walled pipe defining an end of the continuous coiled pipe, the thick walled pipe having a wall thickness thicker than the thin walled pipe, the thick walled pipe being welded at a welded joint to the major portion to place an inner diameter of the thick walled pipe into communication with an inner diameter of the major portion and the thick walled pipe being connected to the container, while the major portion is free of any rigid, such as welded, connections to the container.