Which Explosion-Proof Area Is DII BT4

The designation dIIBT4 refers to a Class II, Category B explosion-proof rating.

II	B	T4	Gb	IP64
Mine I	Methane	T1 450°C	Ma Extremely high level of protection	IP64
		T2 300°C
			Mb High level protection
		T3 200°C
I Surface Materials	Propane		Ga Extremely high level of protection
		T4 135°C
	Ethylene		Gb High level protection
		T5 100°C
	Hydrogen, Acetylene		Gc General level protection
		T6 85°C

The prefix ‘d’ denotes a flameproof type of enclosure, designed so that any internal explosion is contained without damaging the enclosure and preventing the spread of explosion outside;

IIB specifies the category of gas utilized;

T4 signifies that the product’s maximum surface temperature remains below 130°C.