Specifies the requirements relating to the safety of persons and property for the design, construction, installation and operation of refrigerating systems. Gives a classification of the refrigerating systems. Applies to all types of refrigerating systems in which the refrigerant is evaporated and condensed in a closed circuit, including heat pumps and absorption systems, except for systems using water or air as the refrigerant. Is applicable to new refrigerating systems, extensions and modifications of already existing systems, and for used systems.