Close to the junction box cover: no more than 0.2 mm round cover: no more than 0.5 mm button shaft and hole: no more than 0.3 mm reversing handle and hole: no more than 3.3 mm explosion-proof surface is accurately defined as explosion-proof joint surface, which refers to the part where the corresponding surfaces of different parts of the explosion-proof housing are fitted together (or the joint of the housing), and flame or combustion products may be transmitted from the inside of the housing to the outside (the joint between the base and the end cover, the joint between the bearing cover and the rotating shaft, etc.). ). Explosion-proof lamp refers to the lamp used in dangerous places where combustible gas and dust exist, which can prevent the arc, spark and high temperature that may be generated inside the lamp from igniting the combustible gas and dust in the surrounding environment to meet the explosion-proof requirements. There are four main types, namely explosion-proof lighting, explosion-proof emergency lighting, explosion-proof signal lighting and explosion-proof anticorrosion lighting, among which explosion-proof lighting can be divided into explosion-proof fluorescent lamp, explosion-proof floodlight, explosion-proof projection lamp, explosion-proof electrodeless lamp, explosion-proof fire-proof lamp, explosion-proof LED lamp, explosion-proof station lamp and explosion-proof street lamp.