This British Standard specifies requirements for using a combination of appropriate in situ, Non-Destructive Examination (NDE) techniques [e.g. visual examination, Acoustic emission Testing (AT) and Ultrasonic Examination (UE)] when periodically inspecting and testing tubes of seamless steel construction and water capacity between 150 L and 3000 L, used for compressed gases for a further period of service.

This British Standard is applicable only to tubes installed in locations where attempting any removal from their containing superstructure would be hazardous or impossible (e.g. offshore oil 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).

Indication of any anomaly in the tube(s) under test that are revealed at the time of in situ inspection have to be evaluated using a different technique to be able to quantify (location and frequency) and size any possible imperfection.