Atex Valve and ATEX standard on fire control

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Atex Valve and ATEX standard on fire control

Atex Valve

In the field of valves, surely you have heard of ATEX standards and valves, is there a relationship between float control valves (Ex-Atex certified) and ATEX standards? Let’s take a look at some of the issues associated with the Atex valve.

  1. Atex Valve

CENELEC is the European Commission for Standardization for Electrical Engineering. It has been formally recognized as the European Organization in its field by the European Commission in Directive 83/189 EEC. CENELEC uses the IEC standard (International Electrotechnical Commission) for their reference and harmonization with all European Union countries (see below).

ATEX- Atmosphere Explosif is the name given to the framework for fire control and the standards of the equipment and systems used in it. ATEX includes the Directive and is an extension of CENELEC standards. It issues not addressed by the original EN standards such as dust hazards. That brings with it general standards for the complete elimination of trade barriers in the European Union.

ATEX requires the user to remove or control the risk of hazardous substances. Field operations must ensure that plant, equipment, protection systems and associated connection equipment are in service when explosion proof materials indicate that they can be used. Use safely in explosive atmospheres, including gas meters of all kinds. ATEX is based on the requirements of Europe.

Directive 99/92 / EC (also known as ‘ATEX 137’ or ‘ATEX Workplace Directive’) on minimum requirements for the improvement of the protection of the health and safety of workers risk of explosion.

Directive 94/9 / EC (also known as ‘ATEX 95’ or ‘the ATEX Equipment Directive’) on the Estimates of Member States relating to equipment and protective systems for use in the environment Flammable.

Directive 94/9 / EC divides the protective equipment and systems which it covers into categories of equipment; This directive gives a classification by the employer in the places where fire and explosion may occur in the particular condition of the area, defining the equipment group and the protection system should be used in each zone.

  1. Classification of hazardous areas

Hazardous places are classified based on location conditions on the basis of the frequency and duration of the occurrence of an explosive atmosphere.

Name areas with flammable gas hazards classified as Zone 0, Zone 1 or Zone 2.

Flammable dust hazard areas are classified as Zone 20, Zone 21 or Zone 22.

Note: Layers, scaling and flammable heaps must be considered as any other source that could form an explosive atmosphere. A description of each zone is displayed on the page pane below.

  1. Classification of equipment in conjunction with the ATEX Directive

The Atex Valve Directive defines two groups of equipment

Group 1 equipment is designed for use in mining applications, divided into M1 and M2 categories. M1 determines that the equipment must continue to operate when potentially explosive is present. M2 determines that the device is not working when an explosive capability is present. Portable gas detectors will be listed in this classification.

Group 2 is for all other Surface Industries. Class 1 devices are designed for use in Zone 0 environments. Class 2 devices are designed for use in Zone 1. Class 3 devices are designed for use in Zone 1 environments. Designed for use in Zone 2 environments.

This condition is mandatory for manufacturers if they manufacture appliances of type 1, 2, M1 and M2.


DIVISION 1: An area where an explosive atmosphere consists of a mixture with air or flammable substances in the form of vapors, fogs or dusts is present continuously or for long or frequent periods. Gas: Zone 0; Dust: Zone 20.

DIVISION 2: An area where there is an explosive atmosphere consisting of a mixture with air or flammable substances in the form of vapor, mist or dust that may be present in normal operation occasionally; Gas: Zone 1, Dust: Zone 21.

DIVISION 3: An area where there is an explosive atmosphere consisting of a mixture with air or flammable substances in the form of vapors, fogs or dust is unlikely to occur in normal operation, but if it occurs , will only last for a short time; Gas: Zone 2; Dust: Zone 22.

  1. Explosion prevention: In the design of equipment, various protective techniques are used to prevent explosion.
  2. Temperature classification

To ensure that there is no risk of fire due to heated surfaces, the device is classified in relation to the maximum surface temperature of any part of the device during work or due to a fault that when the temperature ambient temperature around 40oC. This is known as the “T” value. The equipment must be selected with the appropriate temperature classification when the maximum surface temperature does not exceed the flash point of gases and vapors where the equipment will be installed.

Group gas, equipment group and temperature range; Gas is grouped together based on the total amount of energy required to burn a mixture of gaseous and explosive atmospheres. Equipment is classified into groups according to the gases and vapors that are suitable.

Marking mark

The Atex Valve requires that the certified product be marked with a CE marking (mandatory compliance with the EMC and Low Voltage Directive requirements for the voltage source device), the ‘EX’ mark (indicating that equipment designed for use in hazardous areas) and device code (group identification, gas grouping and temperature classification for which the product is certified).

We can see an example on the back of any handheld gas detector.

ATEX Group and Category

Explosion Proof according to ATEX standard

The explosion condition consists of five factors:

  • Heat source or ignition sources: hot surfaces, bare flames or hot air, spark plugs or mechanical friction, electrostatic, lightning, electromagnetic…
  • Material: gas, solvent vapor, dust, fiber…
  • Catalysts for fuel: oxygen gas…
  • Enclosed space.
  • The density of the material is appropriate.

Methods to prevent fire and explosion:

In order to prevent fire and explosion, the production area should follow at least the following steps:

  • Step 1: Prevent the formation of environment with fire risk.
  • Step 2: Prevent ignition, ignition in potentially explosive environment.
  • Step 3: Limit the effect of the fire incident if it occurs at the allowed level.

So, based on these important things above, when we choose the valve to use, we try to check the Atex valve standard also.