ISO 13971:2012 describes requirements, design and installation of flexible pipe elements (e.g. metallic flexible pipe, metallic flexible tube, vibration isolator, expansion joint) and non-metallic tube used in the refrigerant circuits of refrigerating systems and heat pumps.
ISO 13971:2012 also describes the requirements to qualify the tightness and permeability of non-metallic tubes (e.g. plastic) used in evaporating and/or condensing sides of refrigerating systems and heat pumps.
ISO 13971:2012 does not apply to flexible pipes that are only occasionally stressed beyond the elastic limit (e.g. during repair work), or to joints that are free to rotate or hinge.