NFPA 51

Abstract

This standard applies to the following: (1) Design and installation of oxygen–fuel gas welding and cutting systems and allied processes (see 3.3.2), except for systems meeting the criteria in 1.1.5 (2) Utilization of gaseous fuels generated from flammable liquids under pressure where such fuels are used with oxygen (3) Storage on the site of a welding and cutting system installation of the following: (a) Gases to be used with such systems where more than one cylinder each of oxygen and fuel gas are stored in any single storage area [includes storage of more than one cylinder each in any single storage area even though all such stored cylinders may be intended for use in systems of the kind described in 1.1.1(1)] (b) Calcium carbide Unless specifically indicated otherwise, the term welding and cutting systems shall be considered to include allied processes in this standard. Where only a portion of a fuel gas system is to be used for welding, cutting, or allied processes, only that portion of the system need comply with this standard. Where only a portion of an oxygen system is to be used with fuel gas for welding, cutting, or allied processes, only that portion of the system need comply with this standard. This standard shall not apply to the following: (1)* Systems consisting of a single cylinder not exceeding 120 ft3 (3.4 m3) of oxygen and a single cylinder not exceeding 120 ft3 (3.4 m3) of fuel gas used for welding and cutting (2) Systems in which fuel gases are not to be used with oxygen, as described in NFPA 54 and NFPA 58 (3) The manufacture of gases and the filling of cylinders (4) Storage of empty cylinders (5) Compressed air–fuel gas systems Purpose. The purpose of this standard is to reduce the risk of fires and explosions in oxygen–fuel gas cutting and welding systems