This European Standard specifies requirements for using a combination of appropriate in situ (without dismantling), Non-Destructive Examination (NDE) techniques [e.g. visual examination, Acoustic Emission Testing (AT) and Ultrasonic Testing (UT)] when periodically inspecting and testing of seamless steel tubes with a water capacity between 150 l and 3000 l, used for compressed gases for a further period of service. This European Standard is applicable only to tubes installed in locations where attempting any removal from their containing superstructure would be hazardous or difficult (e.g. submarines, offshore installations), or where the downtime required to remove the tube would hinder safe operation of a plant or service (e.g. power generation, hospitals, advanced research applications and marine installations such as heave compensation systems on semi-submersible drilling rigs). Battery vehicles e.g. designed to EN 13807 can be tested according to EN ISO 16148. This Standard only applies to tube assemblies whose designs permit all necessary inspections stipulated herein.