... , Weld the suction, Tube assembly, Leakage test, Drying, Surface cleaning, Coating, Inspection, PackagePerformance1) Al plate or (and) pipe with powder painting, ... tube powder painting: 30 100umHardness of coating≥2HImpact of coating50cmkg/cm impact, no crackAdhesion of coating≥two gradeFlexibility of coatingAround R=3D ...