In order to improve surface quality of automatic internal pipeline welding machine, following measures are taken:

①Pre-treatment of workpiece is strengthened (Degreasing+pickling+phosphating)

②Keep ambient temperature, humidity and dust within the specified range

③Spray the primer once to dry out, then add the topcoat twice to dry out.

In order to avoid too much dust on the rough surface of the workpiece, we added a coat varnish process to improve the smoothness and make the workpiece surface more delicate and lubricated. In this way, the pipeline automatic internal welding machine is made with full appearance and beautiful color.

In order for our pipeline automatic internal welding machine to work normally in harsh weather conditions in the field, the protective layer of machine needs to avoid being falling off and changing color in the sunshine and rain for long time, we adopt powder coating process. Several plastics powder manufacturers have been surveyed. Finally, two large enterprises is selected and both of them passed IS9001 certification. The selected plastic powders are all high-gloss powders, baked at 200 degrees, which are known as "color won’t change for more than three years".