In order to ensure that the surfaces of all parts are smooth and free from flash or burr, it is necessary to check the cutting and welding conditions of parts, degrease them before painting, derust the steel surface and take rust-proof measures, sandblast the structural parts and take rust-proof measures before painting, and all parts should be painted with primer and secondary paint, and dramatic topcoat according to the equipment instructions. The damaged part of the coating should be repaired in time, and the corroded part should be cleaned, and the paint can not be painted correctly until the metal is bright. After all welding is completed, it should be cleaned and painted correctly. When the inner surfaces of pipes and similar parts cannot be painted, the ends should be completely sealed to prevent internal rust.