Regulation published on 27 February 1980, Federal Law Gazette I, Page 173, governing the building and operation of pressure vessels, pressure gas vessels and filling facilities. Pressure vessels are classified in test groups I to VII on the basis of their operating pressure p in bar, their capacity I in litres, and the product of pressure and capacity p · I in bar/I. The regulation also describes the tests to be carried out before starting up the pressure vessel and those tests to be conducted at regular intervals.

It is not allowed to start up a pressure vessel in groups III, IV, VI and VII until the expert subjects it to an original test and an acceptance test, and certifies the pressure vessel to be in proper condition. The original test and the acceptance test can be waived provided a prototype test has been carried out and the manufacturer certifies that the pressure vessel conforms with the tested prototype, that it has been subjected to a pressure test and that, on the basis of the results of this pressure test, it satisfies the intended requirements.