For example, IP55 stands for dust and water spray
IPX4 stands for splash proof
防爆等级：Ex p IIB T4
1. "Ex" means that the equipment is explosion-proof equipment
2. "P" indicates that the equipment is a positive pressure explosion-proof type
The specific explosion-proof forms can be divided into:
“d”隔爆型，包含“da”“db”“dc”（GB_T 3836.2-2021）
“e”增安型，包含“eb”“ec”（GB_T 3836.3-2021）
"i"y"" (GB_T 3836.4-2021)
“m”浇封型，包含“ma”“mb”“mc”（GB_T 3836.9-2021）
"n" type protection, including "nA" non-sparking type, "nC" spark protection, "nR" restricted breathing
（GB_T 3836.8-2021）
"O"液浸型,包含"OB""OC"(GB_T 3836.6-2017)
“p”正压型，包含“pv”“pxb”“pyb”“pzc”（GB_T 3836.5-2021）
“q”充砂型（GB_T 3836.7-2017）
"S" Special Type (GB_T 3836.24-2017)
3. "IIB" indicates the explosion-proof gas environment used by the equipment
The specific environment has
"I" Coal Mine Gas Atmosphere
"II" Explosive gas atmospheres other than coal mine gas atmospheres
It can be further divided into "IIA", and the representative gas is methane
"IIB"代表性气体是乙烯
The representative gases of "IIC" are hydrogen and acetylene
Increased explosiveness from top to bottom.
"III" Explosive Dust Atmosphere
It can be further divided into "IIIA" to stand for flammable fly floc
"IIIB"代表非导电性粉尘
“IIIC”代表导电性粉尘
Increased explosiveness from top to bottom.
4. "T4" represents the maximum surface temperature of the equipment (°C) (GB/T3836.1)
具体为：T1 （450）、T2（300）、T3（200）、T4（135）、T5（100）、T6（85）
5. "Gb" is the protection level of the equipment (refer to GB 50058 for the specific explosion-proof area division)
Selection of Explosive Gas Atmospheres (GB 50058)