A pressurized-gas storage assembly has a liner defining a gas storage chamber and an end portion with a planar surface, with an access opening on the planar surface that is in fluid communication with the gas storage chamber. A raised circular ring extends from the planar surface and surrounds the access opening. The assembly also includes a polar boss having a longitudinally extending part that has a top surface with a recessed opening, and a planar bottom surface, with a channel extending through the polar boss to serve as a passageway through the polar boss. A circular groove is provided on the bottom flat surface of the polar boss, with the raised ring received inside the circular groove. An outer shell is provided around the entirety of the liner, with the outer shell having an edge-defining aperture that receives the polar boss.

A storage container includes a wall structure defining an interior, where the interior is configured to contain a fluid. A portion of the wall structure is formed by a composite material. The composite material includes frozen water and a fibrous additive.

A toroid pressure vessel includes a toroid body having an inner shell and an outer shell. The toroid body includes a toroid outer perimeter. The outer shell extends along the toroid outer perimeter. A planar exterior face extends along at least a portion of the outer shell and the toroid outer perimeter. A support belt circumscribes the toroid outer perimeter and is coupled along the planar exterior face. The support belt braces and supports the pressure vessel along the toroid outer perimeter against bulging force (and hoop stress) generated by pressurized fluids within the vessel. The support belt facilitates the use of thinner pressure vessel shells and thereby decreases the weight of the pressure vessel while providing a support to the outer shell that substantially prevents deformation of the planar exterior face.

A method of forming a thick wall section on a specific region of a thin wall spinformed metallic tank shell includes forming a thin wall metallic tank shell blank by spinforming a metal sheet over a mandrel and removing the tank shell blank from the mandrel. The method further includes mounting the blank in an additive manufacturing system and adding metallic structural features to the tank shell according to a 3D model stored in memory in the additive manufacturing system.

A heat exchanger comprises an inlet, an outlet, a heat exchanging channel, and an opening. The heat exchanging channel surrounds a cavity. The opening provides access to the cavity. The inlet is coupled to one end of the heat exchanging channel and the outlet is coupled to another end of the heat exchanging channel. The heat exchanging channel is isolated from the cavity. No access or passage is present between the heat exchanging channel and the cavity. During operation, heat exchanging fluid flows through the heat exchanging channel thereby cooling fluid within the cavity. The heat exchanging fluid never contacts the fluid within the cavity. In various embodiments, the heat exchanging channel has a single or stacked layer when viewed along a cross section. The heat exchanging channel has a spherical, cylindrical, or rectangular shape. In one embodiment, an insulative layer is disposed between layers of the heat exchanging channel.