Both categories maintain a T4 temperature classification, thus the distinction arises between Zone A and Zone B. Explosion-proof rating BT4 exceeds that of AT4.
Condition Category | Gas Classification | Representative gases | Minimum Ignition Spark Energy |
---|---|---|---|
Under The Mine | I | Methane | 0.280mJ |
Factories Outside The Mine | IIA | Propane | 0.180mJ |
IIB | Ethylene | 0.060mJ | |
IIC | Hydrogen | 0.019mJ |
There is a substantial difference between Class ⅱa and Class ⅱb. Class ⅱb, the higher tier, is typically designated for fuels like gasoline, diesel, and crude oil; Class ⅱa, on the other hand, applies to standard explosion-proof areas, such as for propylene.
It primarily depends on whether a substance falls under Class ⅱa or Class ⅱb. Equipment rated for Class ⅱa can be utilized in Class ⅱa environments; however, Class ⅱb environments cannot employ Class ⅱa equipment.