Areas where the explosion risk is high exists in almost every process engineering plant. Strict rules apply to mitigate these risks and electrical luminaires is a vital part of the risk management. The use of explosion-proof (Ex) luminaires is mandatory in these areas and their classifications are based on zones according to their hazard potential.
Hazardous areas are explosive atmospheres created by gases, vapours and ignitable dusts or fibres. Typically they are present in installations as oil/gas rigs, processing refineries, chemical production facilities, flammable liquids storage facilities, fuel transportation, petrol stations, paint production, paper production etc.
For hazardous areas, it is important that the lighting product is designed for use in the actual area, and that operation and maintenance is according to the requirements. Luminaire housings are often made of zinc-anodized aluminium or stainless steel, and they have extra batteries for emergency lighting and increased lifetime.
Classification of categories and zones
The new ATEX equipment directive 2014/34/EU Equipment and protective systems is intended for use in potentially explosive atmospheres. ATEX and IEC Ex define atmosphere groups depending on the type and presence of gases and dust. Site owners must classify areas where hazardous explosive atmospheres may occur into zones.
Areas classified into zones (0, 1, 2 for gas-vapour-mist and 20, 21, 22 for dust) must be protected from sources of ignition. Equipment intended to be used in Ex-classified areas must meet the requirements of the directive. Zone 0 and 20 require Category 1 marked equipment, zone 1 and 21 require at least Category 2 marked equipment and zone 2 and 22 require at least Category 3 marked equipment. Zone 0 and 20 are the zones with the highest risk of an explosive atmosphere being present.
Depending on the minimum ignition energy of the gas, gases are classified in maximum surface temperature groups ranging from T1 = 630 to T6 = 95 degrees Celsius.
Glamox has vast experience from the most extreme Ex-conditions in the North sea. We produce luminaires suited for Zone 1/21 and Zone 2/22 (Ex-n) and for maximum surface temperature groups T3 (200 deg) to T5 (100 deg).