What are the requirements for the explosion-proof enclosure design of level switches?

　　Explosion-proof level switches are widely used in coal, petroleum, chemical and other environments with explosive gases or dust. The quality of their explosion-proof housing structure is directly related to the safety of the equipment.

　　So what are the requirements for the design of explosion-proof housing for level switches?

　　According to the requirements of GB3836.1, GB3836.2, GB12476.1 and GB12476.5, the explosion-proof enclosure of the level switch has the following design requirements:

1. IP protection requirements
　　For flameproof enclosures, the enclosures of dust-proof explosion-proof electrical equipment must meet two types of requirements:
　　Dust-tight enclosure: The structure of the enclosure is designed to be dust-tight, dust cannot enter, and the enclosure's foreign object protection capability is level 6.
　　Dust-proof enclosure: It cannot completely prevent dust from entering, but the amount of dust entering is not enough to affect the normal operation of the electrical equipment, and the enclosure's foreign object protection capability is level 5.
　　For gas flameproof enclosures, the enclosure's protection capability must reach IP54 or above.
　　For intrinsically safe explosion-proof enclosures, the requirements for the enclosure are relatively low, and only IP20 or above is required.

2. Material selection requirements
　　For flameproof enclosures, the enclosure material should have good thermal stability and sufficient strength to withstand explosion pressure without damage or deformation, and its flameproof joint surface should be able to withstand explosion without explosion transmission.
　　For intrinsically safe enclosures, the insulation resistance of the enclosure material should be no less than 20 MΩ.

3. Requirements for non-metallic parts
　　The non-metallic parts of explosion-proof enclosures should meet the heat and cold resistance requirements of relevant standards.

4. Appearance requirements of the shell
　　The surface coating of the explosion-proof shell should be smooth, intact, free of rust and mildew, and the nameplate should be complete and clear.