Zone atex pdf

Group III - is related to electrical equipment intended for used in places with an explosive dust atmosphere other than mines. Zone 0 - A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is present continuously or for long periods or frequently.

Zone 1 - A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is likely to occur in normal operation occasionally. Zone 2 - A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is not likely to occur in normal operation but, if it does occur, will persist for a short period only. For hazardous areas involving dusts then the above classifications are prefixed with a "2", so zone 1 for dusts becomes zone 21, as below Zone 20 - A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is present continuously, or for long periods or frequently.

Zone 21 - A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally. Zone 21 - A place in which an explosive atmosphere in the form or a cloud of combustible dust in air is not likely to occur in normal operation but, if it does occur, will persist for a short period only.

ATEX categories are categories which are used to define equipment to be used in the various zones as detailed on the previous page. From this we can see that if an oven is to be used in a zone 1 application then equipment suitable for use in category 2 will need to be used. Another important aspect of correct classification is the determination of a correct "T Rating".

The "T Rating" determines the maximum allowable surface temperature of any item within the potentially explosive area. The determination of the "T Rating" is related to the flammable or potentially explosive material being processed and is often related to the auto ignition temperature of the material in question.

The protection concepts are as follows:. Airflow has vast experience of supplying bespoke systems for use within hazardous and potentially explosive atmospheres. The protection concepts employed are usually a combination of Ex d equipment such as flameproof fan motors etc and intrinsically safe equipment.

The Ex i concept includes for devices mounted in the main control panel in the safe area. These devices called barriers are used to limit the electrical energy supplied to devices in the hazardous area such as pressure switches, thermocouples, etc.

A hazardous area classification is mandatory and written down in the Explosion Protection Document. Shaded areas on the map of the industrial site see the figures, below indicate the size and shape of the hazardous areas. To reduce explosion risks, there are several available solutions. These are both technical and organizational measures. Also important to note is that the lower the ATEX zone, the less expensive the explosion-proof equipment. And the cost of such equipment is considerable — all the more reason to make limiting the occurrence of an explosive atmosphere a number 1 priority.

A measure, like specific ventilation, is often an effective and relatively inexpensive solution for zone reduction. Figure 1: Situation before implementation of safety measures. Figure 2: Situation after implementing measures. When the ATEX zone is clear, the table helps you to find the accessory equipment.

ATEX equipment is classified into equipment-groups. Equipment groups are divided into categories. We are almost there. Equipment category 1 Equipment in this category is intended for use in Zone 0 areas gases or Zone 20 dusts , and must ensure a very high level of protection i.

The design of the equipment must ensure protection, even in the event of rare incidents relating to the equipment. And safety must be guaranteed in the case of two faults occurring independently of each other. Equipment category 2 This equipment is intended for use in Zone 1 gases or Zone 21 dusts. A high level of protection is ensured.

You will find these zones at the manifold of a tank truck or the interior of a silo. Safety is ensured in the event of frequently occurring disturbances or equipment faults which normally have to be taken into account. Equipment category 3 Is intended for us in Zone 2 gases or Zone 22 dusts.

Explosion protection must be ensured during normal operation.