Correctly understanding explosion-proof zones and equipment categories

What is an ATEX zone? A clear explanation using practical examples.

There is always a risk of explosion in areas where flammable gases, vapors, mists, or dust may be present. Examples include the chemical industry, energy supply, biogas plants, solvent processing facilities, hydrogen infrastructure, and gas distribution systems. An important point to understand about explosion protection is the location of the measurement point within the zones. A common misconception is that if flammable gas is used, the highest hazard classification automatically applies; however, the frequency of explosive atmospheres can vary significantly from one industrial plant to another. For instance, explosive mixtures may always be present inside a tank, while they rarely occur in well-ventilated piping areas, usually only during abnormal situations. This is precisely why ATEX systems categorize zones into 0, 1, and 2. The related links below provide a detailed explanation of the basic principles of ATEX zones, real-life examples from hydrogen filling stations, a comparison of protection concepts (why safety barriers or isolation amplifiers are necessary), and what types of pressure sensors we at KELLER can offer for each zone.

PressurePressure Sensor