ISO 14903:2017提供了ISO 5149相关部分所述的制冷系统和热泵中使用的密封和封闭部件、接头和零件的密封性型式认证的认证程序。相关的密封和封闭部件、接头和零件尤其是配件、爆破片、法兰或装配组件。ISO 13971规定了非金属材料制成的挠性管道的密封性。本文件涵盖金属挠性管道。 本文件中包含的要求适用于最大DN 50的接头和最大内部体积为5 l、最大重量为50 kg的组件。 ISO 14903:2017旨在根据制造商规定的装配程序描述其在操作过程中遇到的密封应力，并规定部件供应商向负责执行该程序的人员提供的必要信息的最小列表。 它规定了整个组件及其制造商规定的组件的密封程度。 它适用于制冷装置中使用的密封和封闭部件、接头和零件，包括带有密封件的部件，无论其材料和设计如何。 ISO 14903:2017规定了可识别为气密接头的机械接头的附加要求。

ISO 14903:2017 provides 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 ISO 5149. The sealed and closed components, joints and parts concerned are, in particular, fittings, bursting discs, flanged or fitted assemblies. The tightness of flexible piping made from non-metallic materials is dealt with in ISO 13971. Metal flexible piping are covered by this document. The requirements contained in this document are applicable to joints of maximum DN 50 and components of internal volume of maximum 5 l and maximum weight of 50 kg. ISO 14903:2017 is intended to characterize their tightness stresses met during their operations, following the fitting procedure specified by the manufacturer, and to specify the minimal list of necessary information to be provided by the supplier of a component to the person in charge of carrying out this procedure. It specifies the level of tightness of the component, as a whole, and its assembly as specified by its manufacturer. It applies to the hermetically sealed and closed components, joints and parts used in the refrigerating installations, including those with seals, whatever their material and their design are. ISO 14903:2017 specifies additional requirements for mechanical joints that can be recognized as hermetically sealed joints.