The reason why explosion -proof electric gourds can be used in the flammable and explosive environment is because the components of explosion -proof electric gourds are based on explosion -proof performance, not just shell explosion -proof. The explosion -proof level of explosion -proof electric gourds is divided into three -level explosion -proof and fourth -level explosion -proof. The environment for explosion -proof adaptation to the four levels is more complicated than the third level. All electrical components of the electrical thought are then installed in the explosion -proof shell. The parts of the explosion -proof shell include several, end cover, bearing inner lid, shaft, wiring box and cover, wiring terminal, wiring screw, sealing ring, threaded terminal sleeve, pressing nut, etc. Lack, a spring cushion ring is equipped on each bolt to prevent itself from loosening by itself, otherwise the explosion -proof function will be lost.