This part of ISO 8835 specifies requirements for anaesthetic breathing systems that are supplied either assembled by the manufacturer or for assembly by the user in accordance with the manufacturer's instructions. It also covers circle absorber assemblies, exhaust valves, inspiratory and expiratory valves and, in some designs, those parts of an anaesthetic breathing system that are incorporated within an inhalation anaesthetic system, including the expiratory gas pathway of an anaesthetic ventil