Different requirements for explosion-proof classifications of cranes arise from varying flammable and explosive environments. These requirements fall into three main categories:
| Usage Area | Gas Classification | Representative Gas | 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 |
1. Class I explosion-proof cranes, designated as Exd I;
2. Class II industrial explosion-proof cranes, designated as Exd IIB T4 or Exd IIC T4;
3. Dust explosion-proof cranes, designated as DIP A21 TA T4;
Within Class II, explosion-proof cranes categorized as flameproof “d” and intrinsically safe “i” are classified into IIA, IIB, and IIC levels. Cranes with an IIB rating are appropriate for IIA environments, whereas cranes rated IIC are suitable for both IIA and IIB environments.
