Explosion-proof electric gourds are mainly divided into three protection grades: ⅡA, ⅡB, and Ⅱc. The flammable gases of T1-T4 groups of the temperature group are places for explosive gases composed of steam and air. Explosion -proof electric gourds can be divided into level B and C. Explosion -proof electric gourds are generally applied to area 1 and 2. Explosion-proof electric gourds are suitable for the highest temperature limit from T1-T6 to reach the level of T6. For example, the DIICT4 represents: D represents the explosion type. II represents explosion -proof, that is, explosion -proof. C means that it can be used in the C -level explosion -proof area, that is, the most dangerous area. T4 represents the temperature group. At present, there are many DIICT4 levels of explosion -proof electric gourds.

Dangerous gas species EX IIBT4, propane, cytane, heptane, ethylene, carbon dioxide, gasoline, acetone, pyrene, toluene, benzene, methanol, ethylene, acetaldehyde, etc. EX IICT4 hydrogen, water and gas, and gas other than EX IIBT4.