The method and requirements of reinforced large-diameter anti-corrosion plastic-coated steel pipes

The method and requirements of reinforced large-diameter anti-corrosion plastic-coated steel pipes: The anti-corrosion treatment method of reinforced large-diameter anti-corrosion plastic-coated steel pipes is primer-primer-glass cloth-topcoat-topcoat-glass cloth-topcoat-topcoat-topcoat, and the paint film thickness is 0.60mm. The internal anti-corrosion of seamless steel pipes adopts H52-06-07 epoxy inner wall non-toxic anti-corrosion material (ratio A: B = 1:5), the method is primer-primer-primer-topcoat-topcoat-topcoat-topcoat, and the paint film thickness is 0.36mm. The inner and outer walls of large-diameter anti-corrosion plastic-coated steel pipes should be pre-treated before rust removal, and the grease, dirt, and debris on the outer surface should be cleaned to ensure the smooth surface of the inner and outer walls.

After the inner and outer walls of the large-diameter anti-corrosion plastic-coated steel pipe are cleaned, manual rust removal is carried out to remove the floating rust and iron oxide on the outer surface, and the rust removal treatment level of the metal surface must meet the specified requirements. After the rust removal is qualified after the joint inspection, the primer should be applied within 8 hours. If the atmospheric environment is bad (such as high humidity and salt mist in the air), the time should be further shortened.

Before applying the primer, it must be stirred, proportioned, and matured in strict accordance with the technical documents of the manufacturer.

When applying, the outer wall of the steel pipe should be dry and dust-free. The primer is applied manually, first axially and then circumferentially.

When applying, the paint film should be full, uniform, and free of bubbles, clots, flow, and leakage. The outer wall should be painted at one time, the primer thickness is 0.1~0.2mm, and 150mm of bare pipe is left at both ends of the steel pipe without painting, which is convenient for steel pipe assembly and welding. At room temperature, the interval between applying primer and the first coat of topcoat should not exceed 24 hours.