What is the classification of dust?
A scheme for classification of dusts is illustrated which classifies dust into: oxidizers, explosives, and pyrophoric materials; noncombustible dusts; and combustible dusts with various ignition sensitivities that have either conductive or nonconductive resistivity.
What is Gas Group IIC?
– Group IIA—Atmospheres containing propane, or gases and vapors of equivalent hazard. – Group IIC—Atmospheres containing acetylene or hydrogen, or gases and vapors of equivalent hazard. n Group III—Equipment intended for use in places. with an explosive dust atmosphere.
How many group of classification is dust fire?
Combustible dusts are divided into three groups, depending on the nature of the dust: Group E, Group F, and Group G.
How do you classify combustible dust?
If the material will burn and contains a sufficient concentration of particles 420 microns or smaller to create a fire or deflagration hazard, it should be classified as a combustible dust.
What is a Zone 1 area?
Zone 1 is an area in which an explosive atmosphere is likely to occur occasionally in normal operation. It may exist because of repair, maintenance operations, or leakage.
What is Zone 21 ATEX?
A Zone 21 area is classified as a place in which an explosive atmosphere consisting of a mixture with air or flammable substances in the form of powder or dust is likely to occur in normal operation occasionally. These are typically process areas where dusts and powders are more likely to be present.
What is an Ex zone?
Explosion Hazardous Areas are divided into zones according to risk probabilities. Within the European Union, these are defined by IEC/EN standards (IEC/EN 60079-10-1 or 2) as directed by ATEX. Put simply, the 0-zones (0 and 20) are highest risk probability, and 2-zones lowest (2 and 22). …
What is the zone for dust in a building?
In most plants and facilities handling dusts the inside of the dust equipment will be Zone 20 or Zone 21. Rooms within the building, if they need to be zoned, should only be the less onerous Zone 22 hazardous area classification. A few very small areas where explosive dust escapes in quantity in normal operation might need to be Zone 21.
What is a zone 21 or 22 hazardous area?
Parts of buildings or process plant may be described as Zone 21 or 22 hazardous areas, depending on the amount of time that an explosive dust cloud may be present. Equipment installed in a zoned area should then be built and certified to an appropriate standard, such as the ATEX Directive.
What is zone 22?
Secondary grade of release gives rise to 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. For example, leaks from incorrectly fitted lids or spillages.
What hazardous area classification do I need for my rooms?
Rooms within the building, if they need to be zoned, should only be the less onerous Zone 22 hazardous area classification. A few very small areas where explosive dust escapes in quantity in normal operation might need to be Zone 21.