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 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 high-pressure composite container having a gastight nozzle structure includes a metal nozzle formed at a side of an inlet of a plastic liner layer that defines an inner layer of the high-pressure composite container; a nozzle insert which is inserted into and attached to the metal nozzle in a direction from an inner side of the plastic liner layer to an outer side of the plastic liner layer; and a nut member fixed to an upper end portion of the nozzle insert.

A high-pressure composite container having a gastight nozzle structure includes a metal nozzle formed at a side of an inlet of a plastic liner layer that defines an inner layer of the high-pressure composite container; a nozzle insert which is inserted into and attached to the metal nozzle in a direction from an inner side of the plastic liner layer to an outer side of the plastic liner layer; and a nut member fixed to an upper end portion of the nozzle insert.

A reinforced plastic air storage cylinder, including an upper shell comprising a first inner volume, a first inner wall defining the first inner volume, and a first outer frame comprising reinforcing ribs connected to an exterior surface of the first inner wall to provide structural support thereto, wherein the first inner wall comprises a plurality of arc segments connected together to form petal-like structures wherein the plurality of arc segments of the first inner wall forms a plurality of peaks projecting into the first inner volume at locations where adjacent arc segments of the plurality of arc segments of the first inner wall connect to one another; a first center column positioned in the first inner volume; a first set of tensile ribs; and a lower shell comprising a second inner volume.

A reinforced plastic air storage cylinder, including an upper shell comprising a first inner volume, a first inner wall defining the first inner volume, and a first outer frame comprising reinforcing ribs connected to an exterior surface of the first inner wall to provide structural support thereto, wherein the first inner wall comprises a plurality of arc segments connected together to form petal-like structures wherein the plurality of arc segments of the first inner wall forms a plurality of peaks projecting into the first inner volume at locations where adjacent arc segments of the plurality of arc segments of the first inner wall connect to one another; a first center column positioned in the first inner volume; a first set of tensile ribs; and a lower shell comprising a second inner volume.

A bladder-type pressure tank includes an outer shell, a bladder, a nozzle, and an elbow pipe. The outer shell includes a liner and a glass-fiber layer covering the outer surface of the liner. The liner includes polyethylene (PE). The liner further includes a chamber, a first opening, and a second opening. The bladder is disposed in the chamber. In an inflated state of the bladder, a gap is formed between the inflated bladder and the inner surface of the liner. The bladder includes polyurethane (PU). The nozzle is integrated with the bladder, and is disposed in the first opening and seals the first opening. The elbow pipe includes a first end and a second end. The first end of the elbow pipe is disposed in the second opening and communicates with the chamber; and the second end of the elbow pipe is configured to connect to a pipeline.

A bladder-type pressure tank includes an outer shell, a bladder, a nozzle, and an elbow pipe. The outer shell includes a liner and a glass-fiber layer covering the outer surface of the liner. The liner includes polyethylene (PE). The liner further includes a chamber, a first opening, and a second opening. The bladder is disposed in the chamber. In an inflated state of the bladder, a gap is formed between the inflated bladder and the inner surface of the liner. The bladder includes polyurethane (PU). The nozzle is integrated with the bladder, and is disposed in the first opening and seals the first opening. The elbow pipe includes a first end and a second end. The first end of the elbow pipe is disposed in the second opening and communicates with the chamber; and the second end of the elbow pipe is configured to connect to a pipeline.

A pressure vessel for storing fluid is disclosed. The pressure vessel includes a metallic liner comprising a cylindrical portion and a pair of ellipsoidal domes positioned at opposite ends of the cylindrical portion. Further, the pressure vessel includes a composite material wrapped over the cylindrical portion and the pair of ellipsoidal domes. The composite material is formed of a polymeric matrix reinforced with fibers, the composite material comprises of a combination of hoop layers and helical layers which are positioned in predetermined order with respect to each other. A hoop layer is wrapped over a cylindrical portion of the metallic liner of the pressure vessel and a helical layer is wrapped over both the cylindrical portion and the pair of ellipsoidal domes. The helical layer is wrapped on each of the pair of ellipsoidal domes in a manner that a helical angle is defined at an intersection between the cylindrical portion and the pair of ellipsoidal domes.

A pressure vessel for storing fluid is disclosed. The pressure vessel includes a metallic liner comprising a cylindrical portion and a pair of ellipsoidal domes positioned at opposite ends of the cylindrical portion. Further, the pressure vessel includes a composite material wrapped over the cylindrical portion and the pair of ellipsoidal domes. The composite material is formed of a polymeric matrix reinforced with fibers, the composite material comprises of a combination of hoop layers and helical layers which are positioned in predetermined order with respect to each other. A hoop layer is wrapped over a cylindrical portion of the metallic liner of the pressure vessel and a helical layer is wrapped over both the cylindrical portion and the pair of ellipsoidal domes. The helical layer is wrapped on each of the pair of ellipsoidal domes in a manner that a helical angle is defined at an intersection between the cylindrical portion and the pair of ellipsoidal domes.