1. Sanitary Butterfly Valve Except for rubber, copper, and stainless steel, all castings, including the valve body and disc, must be completely derusted, dehumidified, and free of moisture and air. Both internal and external surfaces must be coated with a sanitary, non-toxic epoxy resin powder that meets Chinese national standards (electrostatic spray sintering method).
2. The coating must be smooth, uniform, and free of defects. After drying, the coating must be insoluble in water, not affect water quality, and not decompose due to changes in air temperature.
3. After curing, the coating must not be soluble in water, not affect water quality. Except for mating surfaces, the coating thickness on internal surfaces must be no less than 250μm, and on external surfaces no less than 150μm.