The present invention discloses a knob cap for a high-pressure tank including a first knob cap portion having a coupling groove coupled to a knob of a liner of the high-pressure tank in a lower surface, including a peripheral wing portion extending outward to be in contact with a surface of the liner to outside of a lower portion, and having a column portion in the shape of a column extending upward in a center; and a second knob cap portion integrally coupled with the first knob cap portion, having the column portion of the first knob cap portion inserted into a hollow, and including a plurality of inner grooves in the shape of a column having an upper end opened outside of the hollow and extending downward.

The present invention discloses a knob cap for a high-pressure tank including a first knob cap portion having a coupling groove coupled to a knob of a liner of the high-pressure tank in a lower surface, including a peripheral wing portion extending outward to be in contact with a surface of the liner to outside of a lower portion, and having a column portion in the shape of a column extending upward in a center; and a second knob cap portion integrally coupled with the first knob cap portion, having the column portion of the first knob cap portion inserted into a hollow, and including a plurality of inner grooves in the shape of a column having an upper end opened outside of the hollow and extending downward.

Method for preparing a hydrogen tank including at least one sealing layer of a composition including at least one polyamide P1, and at least one base in order to provide the tank with at least one opening, wherein the method includes: providing of at least one base, the at least one base being covered by at least one layer of a composition including at least one adhesion primer; preparing the at least one sealing layer; fastening the at least one base to the at least one sealing layer.

This high-pressure tank includes a resin liner constituting a hollow fluid filling part, a ferrule including a supply/discharge port which communicates with an internal space of the liner and a flange part which protrudes outward in a radial direction from a circumferential region of the supply/discharge port and abuts on the liner, and a reinforcing layer made of a fiber reinforced resin attached to cover across the liner and an outer circumferential surface of the flange part, in which a discharge hole allowing a gap between abutting surfaces of the flange part and the liner to communicate with an inside of the supply/discharge port and discharging a fluid accumulated between the liner and the reinforcing layer to the supply/discharge port is provided in the ferrule, and a trap groove surrounding a circumferential region of the discharge hole is provided on at least any one of the abutting surface on the flange part side and the abutting surface on the liner side.

The presently-disclosed subject matter includes valve covers. The valve covers can protect valves from exposure as well as from tampering. In some embodiments the valve cover comprises a cap that includes a top end and a side wall that is substantially cylindrical. Embodiments of valve covers also include a plug on an interior side of the top end of the cap that projects toward the opening of the cap. When the valve cover is installed, the plug can extend beyond an opening of the valve.

The presently-disclosed subject matter includes valve covers. The valve covers can protect valves from exposure as well as from tampering. In some embodiments the valve cover comprises a cap that includes a top end and a side wall that is substantially cylindrical. Embodiments of valve covers also include a plug on an interior side of the top end of the cap that projects toward the opening of the cap. When the valve cover is installed, the plug can extend beyond an opening of the valve.

A closing element for selectively blocking an opening of a cryogenic storage container is disclosed. The closing element has a head assembly and a bottom member, at least one layer of insulating material disposed between the head assembly and the bottom member, at least one hole extending through the insulating material, and at least one member disposed in the at least one hole and extending through the insulating material. A diameter of the at least one hole is substantially equal to a diameter of the at least one member.

A closing element for selectively blocking an opening of a cryogenic storage container is disclosed. The closing element has a head assembly and a bottom member, at least one layer of insulating material disposed between the head assembly and the bottom member, at least one hole extending through the insulating material, and at least one member disposed in the at least one hole and extending through the insulating material. A diameter of the at least one hole is substantially equal to a diameter of the at least one member.

Provided is a portable cylinder including a tank having an upper portion having a valve port, a mounting collar coupled to the upper portion of the tank, and a handle attached to the mounting collar. The mounting collar has an upwardly extending portion surrounding the valve port and a plurality of circumferentially spaced tabs extending radially outwardly from the upwardly extending portion, wherein a respective gap is formed between adjacent ones of the plurality of circumferentially spaced tabs. The handle includes a shroud portion including a plurality of circumferentially spaced ledges for abutting an underside of a respective one of the plurality of circumferentially spaced tabs, and at least one tab for engaging the mounting collar in one of the gaps, and a handle portion extending from the shroud portion and having one or more areas for grasping the handle.

A compressed gas energy storage system may include an accumulator for containing a layer of compressed gas atop a layer of liquid. A gas conduit may have an upper end in communication with a gas compressor/expander subsystem and a lower end in communication with accumulator interior for conveying compressed gas into the compressed gas layer of the accumulator when in use. A shaft may have an interior for containing a quantity of a liquid and may be fluidly connectable to a liquid source/sink via a liquid supply conduit. A partition may cover may separate the accumulator interior from the shaft interior. An internal accumulator force may act on the inner surface of the partition and the liquid within the shaft may exert an external counter force on the outer surface of the partition, whereby a net force acting on the partition is less than the accumulator force.