These requirements cover hose in sizes up to and including a nominal internal diameter of 4 in (102 mm) for conducting liquefied petroleum gas intended to be installed in closed systems in compliance with the Standard of the National Fire Protection Association for the Storage and Handling of Liquefied Petroleum Gasses, NFPA 58. The hose is made for a maximum working pressure of 350 pounds per square inch gague (psig) (2400 kPa). Hose in sizes larger than 2 in (50.8 mm) is not intended for use on reels.