Because corrosion is an irreversible spontaneous process, even high-quality spray paint coating to maintain the layer, it is difficult to protect the steel plate from corrosion, especially when the steel plate surface spray paint coating layer combined with poor, damaged, or pinholes, bulging, cracking, peeling and other defects, the protective effect of spray paint coating will be greatly reduced, and even cause increased corrosion of steel plate. Effective means of prevention is the industrial plate heat exchanger clamping plate painting process, including roughly primer + topcoat + varnish. The clamping plate is first shot blasted (to enhance the adhesion of the paint), after which it is ready for painting.