Shenhai Explosion-Proof
The “Ex” at the beginning of a complete explosion-proof marking signifies that it belongs to a specific type of explosion-proof equipment, yet it does not detail its particular explosion-proof features.
Markings of Explosion-Proof Electrical Equipment
| Type | Explosion Proof Type | Increased Safety Type | Intrinsic Safety Type | Positive Pressure Type | Oil Filled Type | Sand Filled Mold | Spark Free Type | Exm | Airtight Type |
|---|---|---|---|---|---|---|---|---|---|
| Sign | d | e | ia and ib | p | o | q | n | m | h |
These markings methodically display the explosion-proof type, level, and category. For instance:
Ex d ii refers to a Class II, Level B, Group T3 flameproof electrical device;
Ex ia II AT5 indicates a Class II, Level A, Group T5 ia level intrinsically safe electrical device;
Ex ep II BT4 designates an increased safety type electrical device with pressurized components for explosion protection;
Exd II (NH3) or Ex d II ammonia identifies a flameproof electrical device designed for helium gas environments;
Ex d I represents a mining-specified Class I flameproof electrical device;
Ex d/II BT4 signifies a flameproof electrical device applicable for both Class I and Class II, Level B, Group T4.
Dust explosion-proof electrical devices are marked with the DIP (Dust Ignition Proof) symbol. Examples include:
DIP A20 and DIP A21, for Type A dust explosion-proof devices in Zones 20 and 21, respectively;
DIP A22 for a Type A dust explosion-proof device in Zone 22;
DIP B22 for a Type B dust explosion-proof device in Zone 22, among others.