The abbreviation ATEX (Atmospheres Explosives) refers to two new EU directives on the risk of explosion within different areas. The first ATEX Directive (94/9 / EC) covers the requirements for the equipment used in areas at risk of explosion. The manufacturer must satisfy the requirements and mark its products with certain categories. The second ATEX Directive (99/92 / EC) is related to minimum health and safety requirements that you must meet when working in areas at risk of explosion.
According to the new guidelines, now the powder is considered an explosive atmosphere too. An explosive atmosphere is an atmosphere that develops explosively because of changing surroundings or as a consequence of use. An explosive atmosphere consists of air and combustible materials such as gases, vapors, mist or powder material, in which the explosion propagates after ignition.
Typical examples of productions in which the combustible powder generates alarm is related to the handling of cereals, animal feed, paper, wood, chemicals, plastics and coal.
Security equipment and systems exposed to gas or powder explosions.
Safety, control and regulation devices which ensure safe operation of the means of production and control equipment.
Electrical, mechanical, hydraulic and pneumatic equipment including pumps and electric motors.
After 1 July 2003:
The Companies that produce, use or distribute this type of equipment must comply with the basic safety and health requirements contained in the ATEX directive.
Despite not having retroactive effect, however, the ATEX Directive existing products will have to be examined.
In the presence of defects, (wear etc.), the old products will have to be replaced with equipment that complies with the ATEX Directive.
In addition, the products specially designed for use in high-risk areas of explosion should be marked only if fully ATEX compliant.
To avoid explosion, the equipment user is required to:
Take all necessary technical and organizational precautions.
Run a full estimate of the risk of explosion.
Zoning potential areas at risk of explosion.
Clearly indicate the areas at risk.
The ATEX directive provides two types of explosive atmospheres: gas and powder.
Areas within these two types of explosive atmospheres are divided into three zones.
The characteristics of each zone are identical for the gas and for the powder, but their numbering is different. The zones 0, 1 and 2 refer to the gas while the areas 20, 21 and 22 refer to the powder.
Zone 0/20: Constant Danger
Permanent explosive gas or combustible powder. Equipment of minimum category 1.
Zone 1/21: Potential danger
Occasional presence of explosive gases or combustible powder during normal operation. Minimum of Class 2.
Zone 2/22: Danger minor
Improbable presence of explosive gases or combustible powder, or only for a short period of time. Equipment of minimum category 3.
For each of the three zones, only a certain category of equipment - in this case, motors and pumps - can be used in view of the danger of explosion. It is entirely up to the user to define whether an area should be considered dangerous according to the requirements of the ATEX directive. If in doubt about the definition of hazardous areas, the user must contact the Inspectorate of competence.
Equipment and parts must be ATEX compliant. The CE mark is evidence that the equipment in question is built in compliance with all the basic requirements and assessment procedures for each EU Member State.
The Directive requires specific safety requirements that must be met by the equipment manufacturer, user or maintainer.
As a manufacturer, it has the exclusive responsibility to produce equipment that meets the requirements stated in the EU Directive
The equipment user must notify the manufacturer the type of equipment required, with reference to:
Category, for example. 2G
Temperature, for example 125 ° C
Motor protection 2G / 3G, for example EExe II T3.
In addition, the equipment user must use the product according to the areas, taking into account any possible risk. Similarly, the equipment user is required to ensure safe device operation, through a continuous maintenance.
By 2003, the installations must meet the requirements stated in the ATEX directive. If the user of the equipment is also its producer, the user must fulfill the requirements for both.
The maintenance technicians are not covered by Directive 94/9 / EC. Maintainers must still make sure that the work performed meets the safety requirements for products and equipment, to avoid putting at risk the safety. Institutions notified as KEMA and PTB have the authority to issue quality certificates for Maintainers as proof of qualification.
The requirements of the ATEX Directive are not entirely new for the electric motors. In the past they were formerly grouped in the IEC60079 standard and local regulations in different countries. The ATEX Directive contains references to EC standards containing the same requirements of the IEC60079 standard. The IEC60079 standard remains in force for the electric motors in other parts of the world.