Precautions and process of valve plate spraying

       The following are the precautions for valves in automatic electrostatic spraying equipment:







1. Pre-treatment process: After casting, sandblasting is used to treat the oxide scale and molding sand on the surface. Try not to use shot blasting. Because the valve requires high accuracy, there will be some local points that cannot be cleaned by shot blasting. Sandblasting can better control surface roughness and finish. But its relatively slow efficiency is its disadvantage.











2. Surface treatment: If the surface of the valve contains oil before entering the powder spraying chamber, the first thing to appear is that the oil-containing surface coating is obviously thinner. The second is the poor adhesion of the coating film, which is easy to fall off. Finally, the color difference of the coating film is obvious.











3. Preheating time: Valve castings are generally thicker and require sufficient preheating time. This is generally easy to ignore.











The overall design of the powder coating line must be reasonable to ensure that the valve has enough time to preheat and run in the oven.











4. Anti-corrosion: For large-scale outdoor valves, it requires heavy anti-corrosion. The selection of thermosetting powder should not be used for the sake of cheapness. Pure epoxy powder should be used, and the manufacturer should be required to issue an authoritative inspection report.











In addition, there is the problem of valve coating. Many manufacturers only pay attention to the appearance color, and do not really pay attention to the quality of the coating film. In fact, the color is mainly related to the powder, but also has an important relationship with the spraying method. When the automatic electrostatic spraying equipment is operating, it should be matched with coatings with good anti-corrosion performance and strong environmental protection, and strictly follow the process standards to produce good products.