EN ISO 13971:2025

This International standard describes requirements, design and installation of flexible pipeelements (e.g.,metallic flexible pipe, metallic flexible tube, vibration isolator, expansion joint) and non-metallictube used in the refrigerant circuits of refrigerating systems and heat pumps.It 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 heatpumps.This International standard does not apply to flexible pipes that are only occasionally stressedbeyond theelastic limit (e.g., during repair work), or to joints that are free to rotate or hinge.