AS EN 50069 pdf download – Welded composite enclosures of cast and wrought aluminium alloys for gas- filled high-voltage switchgear and controlgear This document applies to welded composite enclosures of cast and wrought aluminium alloy pressurizedwith dry air, inert gases (e.g. sulphur hexafluoride or nitrogen or a mixture of such gases), used in indoor andoutdoor installations of high-voltage switchgear and...