92 This document applies to pressurized compartments (gas-filled compartments with maximum allowable 93 pressure above 50 kPa relative) of AC switchgear and controlgear with rated voltages above 1 kV up to and 94 including 52 kV for indoor or outdoor installations. All gases stable and non-corrosive in the conditions that 95 prevail inside the compartment are covered e.g. gases such as SF6, compressed air, natural-origin gases, 96 alternative fluorinated compounds used alone or in gas mixtures with natural origin gases. The gas or gas 97 mixture being used principally for its dielectric and/or arc-quenching properties.