ISO 14903:2025

This document specifies the qualification procedure for type approval of the tightness of hermetically sealed and closed components, joints and parts used in refrigerating systems and heat pumps as described in relevant parts of the ISO 5149 series, including metal flexible piping. It specifies the level of tightness of the component as a whole and its assembly as specified by the manufacturer. It specifies additional requirements for mechanical joints that can be recognized as hermetically sealed joints. This document is applicable to joints of maximum DN 50 and components of internal volume of maximum 5 l and maximum weight of 50 kg. It is applicable to the hermetically sealed and closed components, joints and parts (e.g. fittings, bursting discs, flanged or fitted assemblies) used in the refrigerating installations, including those with seals, whatever their material and design are. This document does not apply to the tightness of flexible piping made from non-metallic material. This is covered in ISO 13971. Components tested before the date of publication of this document and found to comply with ISO 14903:2017 are considered to comply with this document.