The requirements contained in this International Standard are applicable to joints of maximum DN 50 and components of maximum 5 l and maximum mass of 50 kg. This International Standard is intended to describe the qualification procedure for type approval of the tightness of components, joints and parts used in refrigerating systems and heat pumps as described in ISO 5149. It characterizes the joint tightness and stresses met when operating, following the fitting procedure specified by the manufacturer, and specifies 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. This International Standard specifies the level of tightness of the component, as a whole, and its assembly as specified by the manufacturer. This International Standard applies to the hermetically sealed and closed components, joints and parts used in refrigerating installations, including those with seals, whatever their material and their design are. This International Standard specifies additional requirements for mechanical joints that can be recognized as hermetically sealed joints.