The standardisation of inert welding gases is uniform throughout the world under the international DIN EN ISO 14175 standard. Previously, inert welding gases were standardised under the European DIN EN 439 standard. Messer, the gases specialist, provides comparison tables on the Internet at www.messergroup.com showing at a glance the allocation of products from the Messer range of inert welding gases and providing comprehensive information about the new designations. The new standardisation is of particular interest to companies with international operations who work in areas requiring licenses.

In addition to the classification of gases and gas mixtures into main groups, changes have also been made to the mix accuracy, the permissible moisture content and the names of the main groups. In the main groups, the changes only affect the forming gases and special gases. The groups have been renamed “N” and “Z”. The group Oxygen “O” has also been added. The maximum permitted moisture content of the gas groups “O” and “C” has been altered as the purities used in practice have far exceeded the standard for a number of years. With regard to the mix accuracy, no definition has been made for additions of less than one per cent. Nothing has changed as far as additions of more than one per cent are concerned.