First, according to different types of explosion-proof classification:

1, explosive gas environment:

(1) Flameproof type d

(2) Increased safety type e

(3) Intrinsic safety type i

(4) Positive pressure type p

(5) Liquid immersion type o

(6) Sand filling type q

(7) Casting type m

(8) Type n

2, flammable dust environment:

(1) Positive pressure protection pD

(2) Shell protection type tD

(3) Intrinsic safety type iD

(4) Cast and sealed mD

3, non-electrical equipment:

(1) Current limiting shell type fr

(2) flameproof housing type d

(3) Structural safety type c

(4) Control ignition source type b

(5) Liquid immersion type k

4, compound (two or more explosion-proof type combination)

Second, according to the applicable environment of the medium category classification

1, Class I explosion-proof certificate, suitable for mine

2, Class II explosion-proof certificate, suitable for non-mine explosive gas environment

3, Class III explosion-proof certificate, that is, dust explosion-proof certificate, suitable for explosive dust environment