According to the design of explosion-proof equipment modification, we divide the explosion-proof equipment used in the explosive gas environment into two grades of Gb and Gc, and classify the explosion-proof equipment used in combustible dust environment into two grades: Db and Dc.
1) Gb explosion-proof equipment
For Gb-grade explosion-proof equipment used in explosive gas environments, explosion-proof design and modification consider the normal operating conditions of the equipment and safety under predictable failure conditions.
Gb-grade explosion-proof equipment can be used in Zone 1 and Zone 2 in explosive gas hazardous environments.
2) Gc explosion-proof equipment
For Gc class explosion-proof equipment used in explosive gas atmospheres, explosion-proof design and modification only consider the normal operating conditions of the equipment without considering the safety under any fault conditions.
Gc-grade explosion-proof equipment can be used in Zone 2 in explosive gas hazardous environments.
3) Db explosion-proof equipment
For Class Db explosion-proof equipment used in flammable dust environment, explosion-proof design and modification consider the normal operating conditions of the equipment and the safety in the foreseeable failure conditions.
Class Db explosion-proof equipment can be used in zones 21 and 22 in explosive gas hazardous environments.
4) Dc explosion-proof equipment
For Class Dc explosion-proof equipment used in flammable dust environments, explosion-proof design and modification only take into account the normal operating conditions of the equipment without regard to safety under any fault conditions.
Class Dc explosion-proof equipment can be used in zone 22 in explosive gas hazardous environments.
5) Correspondence between classification of explosion-proof vehicles and zoning of hazardous locations.
The correspondence between the classification of explosion-proof vehicles and the explosive gas/flammable dust hazardous area partitions is as follows: