High-voltage switchgear and controlgear. Gas-filled wrought aluminium and aluminium alloy enclosures|Welded joints, Electrical equipment, Switchgear, Electric enclosures, Flanges, Assembling, Acceptance inspection, Form tolerances, Non-destructive testing, Holes, Welding, Insulating enclosures, Aluminium, Wrought alloys, Pressure testing, Gases, Electrical insulation devices, Dimensional tolerances, Certification (approval), High-voltage equipment, Elastic design, Stress analysis, Design calculations, Protected electrical equipment, Design, Marking, Rated voltage, Electric control equipment, Thickness, Approval testing, Shell structures, Enclosures, Aluminium alloys