Moreover, many safety explosion-proof lamp parts, such as lamp holder, interlock switch, also take flameproof structure. Electrical equipment with flameproof enclosure is called flameproof electrical equipment. If the explosive gas mixture enters the flameproof enclosure and ignites, the flameproof enclosure can suffer the explosive pressure of the internal explosive gas mixture and prevent the internal explosion from spreading to the explosive mixture around the enclosure. This is a gap explosion-proof principle, that is, the application of metal gap can block the spread of the explosion flame and cool the temperature of the explosion product, reach the flame extinguishing and cooling, the principle of restraining the expansion of the explosion design of a structure.