13.4. ATEX-Zones

For the assessment of hazardous areas, these are subdivided into different zones. The subdivision is made according to the safety classification of the application and is evaluated according to the areas of application normatively as well as by the plant manufacturer depending on the project. A typical and everyday example of an ATEX application is a gas station. On the basis of which the ATEX zones can be described:

Figure 14.1.2: ATEX-zones

The diagram shows the various explosion hazard zones. The flammable medium is assigned the highest hazard level: Zone 0, since an explosive atmosphere is permanently present. Due to the escaping flammable gases, the directly adjacent area is assessed as the next highest level: Zone 1, since the explosive atmosphere is frequently present. In surrounding, more distant areas, the hazard is rated as the weakest zone: zone 2, due to a lower concentration and a lower frequency of occurrence in the air. This zone evaluation and classification for a plant or product must always be carried out by the plant operator.

ATEX areas can be divided into different groups and categories The following equipment groups are defined:

In addition, there are the following categories of equipment:

Since gas mixtures have different ignitability properties, they are divided into temperature classes. The surface temperature of the device must therefore not exceed the ignition temperature of the gas mixture. The temperature class division does not apply to dust-air mixtures. In this case, the glow temperature is specified in °C.