Hazardous Information
Â
The ATEX directive defines the mandatory requirements for manufacturers and users of all hazardous area equipment sold in the European Union. Each must have applicable ATEX certiïŽcates. Other countries accept the IECEx standard, which is derived from similar principles.
In addition to the technical requirements demanded by the appropriate standards for each type of protection concept, the Atex Directive imposes additional requirements on the certiïŽcate holder in terms of quality system, product documentation, installation information, possible limitations of use in the relation to its intended environment, labelling information etc.
Equipment Marking
Marking of equipment shall include the following typical data:
Ex II 2 G, Ex II 3 D
Where II is the equipment group; 2 is the category for use (see table for equivalent zone); G (or D) is the type of explosive atmosphere – G = gas, vapour or mist; and D = Dust
IIC T4 Ta = -20°C to + SS°C
IIC refers to the gas group, and where the T class will vary against ambient
IIC TS Ta = -20°C to + 2S°C
The T class marking for dust may also be shown if different to gas
Each type of protection achieves its safety from ignition in a different way. It is essential that those who specify and or select products, ensure that they are suitable for the ZONE in which they are to be installed and are appropriate for the Gas Groups and the Temperature Class required by referencing BS EN 60079-14. All equipment installed in hazardous areas is inspected and maintained at regular intervals so as to ensure the continued integrity of the protection concepts used on the equipment design. Such inspections and maintenance should be carried out in accordance with BS EN 60079-17 and, where applicable, the manufacturer’s instructions. Specific records should be kept on site locally of all maintenance carried our on such equipment. these shall allow the unique identification of each item of equipment system.
Categories and Zone definitions for gas and dust
Dust
Zone 20 –Â 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 –Â Â 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 –Â Â 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.
Gas
Zone 0 –Â 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 –Â Â 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 –Â Â 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.