Work in Explosive Atmosphere

Purpose

An explosive atmosphere is defined as a mixture of dangerous substances with air, under atmospheric conditions, in the form of gases, vapours, mist or dust in which, after ignition has occurred, combustion spreads to the entire unburned mixture. To mitigate the risk of explosion, all equipment used in such atmosphere is classed explosion proof. To maintain the explosion proof integrity of the equipment, we need trained people to work in explosive atmosphere.  

This 5-day course provides delegate’s with an understanding of the terminology and protection concepts for electrical instrument / equipment utilized in explosive atmospheres. Course contains IEC Standards and ATEX European Directives, including the preparation, installation, inspection and maintenance of electrical instrument / equipment used in explosive atmospheres.

Target Audience

This course is for the electricians, instrument engineers who have the responsibility to fit such equipment in explosive atmosphere such as oil and gas installations, paint work shops, petrochemical plants etc.   

Course Content

Hazardous zones and ATEX directives

This course covers the IEC Standard 60079 Parts 14 & 17, NEC 500/505 & ATEX 95 & 137 European Directives, including the preparation, installation, inspection and maintenance of electrical/instrument equipment used in explosive atmospheres. The course utilizes both practical and theoretical assessments, covering protection concepts to validate a candidate’s core competency to work safely in explosive atmospheres in a series of specific modules.

• The preparation & installation of Ex ‘d’, ‘n’, ‘e’ and ‘p’ electrical equipment in explosive atmospheres
• The inspection and maintenance of Ex ‘d’, ‘n’, ‘e’ and ‘p’ electrical equipment in explosive atmosphere
• The preparation & installation of Ex ‘i’ equipment and systems in explosive atmospheres
• The inspection and maintenance of Ex ‘i’ equipment and systems in explosive atmospheres

Within industries, all potential to work in explosive atmosphere are required to have area classifications called zones. It is the employer’s responsibility to ensure that the classification of their site is performed before suitable products can be selected and installed at the location. Globally, a zone system is used to classify potentially explosive areas. The Worker Protection Directive 1999/EC and the international standards IEC 60079-10-x, EN 60079- 10-x define these zones. In all cases, zone classification is the responsibility of the owner of the site where the potentially explosive atmosphere exists.

The 6 zones:

Hazard – Gas / vapor / mist

Zone 0 – A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapor 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, vapor 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, vapor or mist is not likely to occur in normal operation but, if it does occur, will persist for a short period only.

Hazard – dust / fibers

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 22 – A place in which an explosive atmosphere in the form of 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.

To work in explosive atmosphere, equipment categories are used in ATEX. The category indicates which safety level of product must be used in each zone. In Zone 0/20, category 1 devices must be used; in Zone 1/21, category 2 devices; and in zone 2/22, category 3 devices. Classification into categories is of particular importance, because all the inspection, maintenance and repair duties of the end user will depend on the category of the product/equipment and not on the zone where it is installed.