This standard describes the specifications and general principles recommended for piping systems for gaseous (Type I) or liquid (Type II) hydrogen. The standard addresses both low and high pressure hydrogen piping systems onsite from the point where hydrogen enters the distribution piping (the battery limits of the hydrogen storage system) to the point of use. For the purposes of this standard, high pressure is defined as gaseous hydrogen at service pressures equal to or greater than 3000 psig (20 680 kPa). The information in this standard is general in nature and is intended for designers, fabricators, installers, users, and maintainers of hydrogen piping systems as well as for safety personnel, fire departments, building inspectors, and emergency personnel. [Superseded material in CGA G-5.8]