Hazardous areas are common place in many industries and while some are more obvious, such as where there is a build-up of flammable gases or vapours, it could also include areas where there are flammable dusts.
Indeed, a hazardous environment is defined as an area that poses a distinct risk of forming an explosive atmosphere when combined with air. It means special precautions need to be taken to operate within them safely.
In the UK, the Health and Safety Executive (HSE) specifies areas to be classified as hazardous, and once an area is identified as hazardous, it is then categorised a ‘zone’, depending on the severity of the hazard. Zones 0 to 2 include gases, vapours and mists, and zones 20 to 22 contain dusts.
ATEX rating
To protect against the risk of explosions, all equipment used in these zones must correspond to the relevant ATEX rating. ATEX ratings are required when a piece of equipment has its own source of ignition. In the oil and gas industry, it is obvious that it’s hazardous due to the petroleum vapours present. However, companies often fail to consider other materials, such as dust, which can be ignited by a single spark from a piece of industrial equipment.
To ensure that all PCs and peripheral equipment can be used in these areas, it is important to choose the right PC with the necessary ATEX rating. The ratings specify what equipment can be used in specific hazardous areas. Zones 0 and 20 require Category 1 marked equipment, Zones 1 and 21 require Category 2 marked equipment and Zones 2 and 22 require Category 3 marked equipment. Simply choosing a hazardous PC is not enough to comply with regulations.
As a rule, hazardous area PCs should be fully sealed to prevent any sparks getting out of the unit, and when choosing an industrial PC for a hazardous area, companies should also consider features such as sand or inert gas that can be placed inside the sealed equipment to prevent any sparks.
The longevity of the PC
Due to the high specifications demanded of industrial PCs in hazardous areas, the costs are often higher than a standard industrial PC. However, plant managers should choose the highest specification required from the start, as hazardous area PCs cannot be modified easily due to their sealed nature.
Author profile:
Adrian Swindells is director of industrial computing company Distec
