High-voltage switchgear and controlgear. Gas-filled welded composite enclosures of cast andwrought aluminium alloys|Repair, Pressure testing, Proof stress, Marking, Valves, Wrought alloys, Electric enclosures, Electrical components, Inspection, Switchgear, Certificates of conformity, Design, High-voltage equipment, Radiographic testing, Ultrasonic testing, Castings, Burst tests, Aluminium alloys, Designations, Bursting discs, Structures, Non-destructive testing, Welding, Switches, Electrical equipment