What Is The Explosion-Proof Sign? How Is The Explosion-Proof Grade Divided?

Writer：Jane Time：2021-06-26 Browse：177

Q: What is the explosion-proof sign? How is the explosion-proof grade divided?

A: Definition of explosion-proof signs in explosion-proof lights:

The explosion-proof mark in the nameplate of explosion-proof lights refers to the mark used to describe the explosion-proof grade, temperature definition, explosion-proof type and the limited area of explosion-proof lights.

To avoid the maintenance of LED explosion-proof lights as an example, explosion-proof signs explanation:

Maintenance-free LED explosion-proof lights and lanterns are recommended in accordance with GB 3836 standard. The explosion-proof signs of explosion-proof lights and lanterns include:

Explosion-proof type, equipment class and (gas group) temperature definition

1.Maintenance-free LED explosion-proof light explosion-proof type

According to the explosion-proof measures implemented, explosion-proof lights can be divided into flameproof type, increased safety type, intrinsically safe type, pressing type, oil-immersed type, sand filling type, pouring sealing type, N type, specific type, dust explosion-proof type, etc. : Flameproof Ex D, sand filled Ex Q, increased safety Ex E, pouring type Ex M, positive pressure Ex Pn /Ex N, intrinsically safe Ex IA, dust explosion-proof DIP A, intrinsically safe Ex IB, dust explosion-proof DIP B, oil-immersed Ex O, special type Ex S 

2. Maintenance-free LED explosion-proof lights

Lighting lamps used in explosive gas environment are divided into:

Class I: Explosion-proof lighting equipment under coal mines;

Class II: Explosion-proof lighting equipment used in explosive gas environment other than coal mine;

Class II flameproof type "D" and intrinsically safe type "I" explosion-proof lighting equipment are also divided into IIA, IIB, and IIC.

Explosion-proof lighting equipment in combustible dust environment is divided into:

Type A dust dense equipment; B-type dust dense equipment; Type A dustproof equipment; B type dust proof equipment.

3. Maintenance-free LED explosion-proof light gas sector

The detonation transmission ability of explosive gas mixture symbolizes the level of its explosion risk. The smaller the detonation transmission ability of explosive mixture is, the lower its risk is. The ability of explosive mixtures to transmit detonation can be indicated with the smallest test safety gap. In addition, the difficulty of extinguishing explosive gas, liquid vapor and mist is also a symbol of the extent of the risk of explosion. The maximum ignition current is higher than that indicated. Class II flameproof explosion-proof lighting equipment or intrinsically safe explosion-proof lighting equipment, according to its limited in the explosive gas mixture of the smallest test safety gap or the largest ignition current ratio, further divided into IIA, IIB and IIC class.

4. Temperature definition of maintenance-free LED explosion-proof light

The ignition temperature of explosive gas mixtures is the temperature limit that can be extinguished.

Explosion-proof lighting equipment is divided into T1 ~ T6 groups according to its minimum surface temperature, so that the minimum surface temperature of the matching T1 ~ T6 groups of explosion-proof lighting equipment must not be less than the allowable value of the matching temperature boundary. The relationship between temperature definition, equipment surface temperature and ignition temperature of combustible gas or vapor is shown in Table 3.

Temperature definition, the relationship between the surface temperature of the equipment and the ignition temperature of flammable gases or vapors

Temperature levels IEC/EN /GB 3836 Minimum surface temperature of equipment T[℃] Ignition temperature of combustible substances [℃]

T1 450 T≥450
     T2 300 450≥T>300
     T3 200 300≥T>200
     T4 135 200≥T>135
     T5 100 135≥T>100
     T6 85 100≥T>85