Photo courtesy of NREL
Liquid hydrogen is usually stored in horizontal or vertical cylindrical tanks. Spherical tanks are sometimes used for larger volumes. Tanks are vacuum-insulated and contain redundant pressure-relief devices as a safety precaution to prevent over pressurization.
Permanent storage vessels for liquid hydrogen should be designed, constructed, and tested in accordance with the ASME BPVC or API Standard 620 (Design and Construction of Large, Welded, Low-Pressure Storage Tanks).
Permanent vessels should have substantial noncombustible supports securely anchored to firm noncombustible foundations. Steel supports > 18 inches high should be protected with a coating with a two-hour fire resistance rating.
Mobile containers for liquid hydrogen (i.e., tankers) should be designed, constructed, and tested per DOT specifications and regulations. Liquid hydrogen tankers are equipped with automatic shutoff valves.
Liquid hydrogen vessel designs should include adequate thermal insulation systems to minimize evaporation losses. Pressure relief is required for both the inner vessel and the vacuum jacket.
The large temperature difference between ambient and cryogenic conditions (temperature difference of 300° F or more) results in significant thermal contraction of most materials, which must be accommodated for in designs for cryogenic service.