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.

A pressure vessel can include a liner having a cylindrical section and a pair of dome sections; and a reinforcement layer constituted by a fiber-reinforced resin material and formed on the outside of the liner. The pressure vessel's reinforcement layer can include protruding sections formed so as to protrude at the dome sections by high-angle helical winding; and a central section formed by hoop winding which spans the area between each peak of the pair of protruding sections, or by approximate hoop winding in which winding is carried out at a higher angle than the high-angle helical winding.

A high-pressure container includes a liner and a fiber layer formed of reinforcing fibers wound around an outer periphery of the liner. The fiber layer has a plurality of hoop layers in which reinforcing fibers are wound in the circumferential direction of the liner to reinforce the body portion. The reinforcing fibers used for a first hoop layer from an inner peripheral side of the fiber layer or the first hoop layer and one or more hoop layers subsequent to the first hoop layer, among the plurality of hoop layers, have a structure in which a plurality of filaments are twisted so as to be inclined with respect to a fiber bundle direction, and have a property of more easily elongating than the reinforcing fibers used for the hoop layer that is located on an outer peripheral side of the fiber layer.

A pressure vessel is disclosed comprising an inner vessel with a rotationally symmetrical middle part with an axis of symmetry along the middle part and two dome-shaped polar caps which close off the middle part, and an outer layer, wound on the inner vessel to reinforce it, made of fiber composite material made of a plurality of plies of fibers embedded in a matrix material which are arranged one above another, which run as a fiber band made of a number of fibers with a location-dependent and position-dependent fiber orientation across the inner vessel, wherein the fiber band at least in some of the plies enters from the middle part at a respective entry fiber angle relative to the axis of symmetry into the region of the dome-shaped polar caps.

A high-pressure tank includes a liner for storing a fluid, and a reinforcing layer covering an outer surface of the liner and including a fiber wound around the liner and a resin. The reinforcing layer includes a helical layer group including laminated helical layers, and a large-angle layer provided adjacent to the helical layer group and on the liner-side. The helical layer group includes an innermost layer that is closest to the liner and that is one of first and second helical layers respectively having the largest and second largest fiber winding angles, an outermost layer that is closest to an outer surface of the high-pressure tank and that is the other one of the first and second helical layers, and an intermediate layer disposed between the innermost and outermost layers and including a helical layer that is smaller in winding angle than the innermost and outermost layers.

A pressurized-gas storage vessel includes a liner defining a chamber therein, the chamber being configured to receive a gas; a first wrapping surrounding the liner; and a second wrapping surrounding the liner. Methods of manufacturing and using the storage vessel are also disclosed.

A manufacturing method of a tank comprises winding a fiber on a liner by hoop winding. The winding comprises: forming an (N+1)-th layer such that a position closer to a center of the liner by a first predetermined distance along an axis line direction of the liner from an end in the axis line direction of an N-th layer is set to position of an end in the axis line direction of the (N+1)-th layer with respect to a direction perpendicular to the axis line direction; and winding the fiber on the N-th layer to provide one winding turn of the fiber, such that a pressing force of pressing the N-th layer in the axis line direction by the fiber is equal to or smaller than a total frictional force in an area in the N-th layer on an edge side in the axis line direction of a fiber winding position.

A FRP tubular body includes a tubular fiber structure formed by winding a reinforced fiber sheet made of fabric. The reinforced fiber sheet includes first reinforced fiber bundles arranged such that a yarn main axis direction extends in a circumferential direction of the fiber structure and second reinforced fiber bundles arranged such that a yarn main axis direction extends in an axial direction of the fiber structure. The reinforced fiber sheet includes a starting end, a finishing end, and a general portion located between the starting end and the finishing end. The general portion includes the first reinforced fiber bundles and the second reinforced fiber bundles. At least one of the starting end or the finishing end is a decreased portion that is smaller than the general portion in an amount of reinforced fibers per unit length in the circumferential direction of the fiber structure.

A tank production method for preventing generation of non-uniform stacked portions in a sheet layer while securing the strength of the tank, the method including a winding step of winding resin-impregnated fiber sheets to form a sheet layer with a predetermined thickness. The winding step includes divided winding steps of winding divided fiber sheets obtained by dividing a fiber sheet into a plurality of divided fiber sheets having a length shorter than the length required to form the sheet layer with the predetermined thickness. The second divided winding step or each of the second and following divided winding step satisfies an Inequality: X>(σ.Math.t.Math.L)/(A.Math.W), where an overlapped length of the start end of a new divided fiber sheet stacked on the terminal end of the divided fiber sheet wound in the preceding divided winding step is X, the tensile stress applied to the tank in the circumferential direction thereof is σ, the thickness and width of each divided fiber sheet are t and W, respectively, the length of a cylindrical portion of the tank is L, and the shearing strength of the resin is A.

A high-pressure tank in a method of manufacturing a high-pressure tank includes a liner and a fiber. The manufacturing method includes: preparing a dome and a pipe each having a general portion and a joining end portion formed to be thicker than the general portion such that an outer diameter at least at an end face is larger than an outer diameter of the general portion by an estimated level difference amount; joining the joining end portion of the dome and the joining end portion of the pipe together in an axial direction; cutting off portions on the further outer side in a radial direction than a reference plane, with an outer peripheral surface of the general portion of the dome having a large outer diameter at the joined surface as the reference plane; and winding a carbon fiber around the outer peripheral surface of the liner in helical winding.