This document applies to wrought aluminium and aluminium alloy enclosures and their welding. These
enclosures are pressurized with dry air, inert gases, for example sulphur hexafluoride or nitrogen or a
mixture of such gases, used in indoor and outdoor installations of high-voltage switchgear and controlgear
with rated voltages above 1 kV, where the gas is used principally for its dielectric and/or arc-quenching
properties with rated voltages.
— above 1 kV and up to and including 52 kV concerning gas-filled compartments with design pressure
higher than 300 kPa relative pressure (gauge);
— above 52 kV concerning all gas-filled compartments.