Introduction of anti-corrosion of inner wall of large diameter steel pipe

1. Before processing all steel pipes, the steel plate on the inner wall of the large-diameter steel pipe should be trusted, and it is required to reach the metal luster (whitening). It should reach the sa2.5 standard required in the "Surface Rust Grade and Derusting Grade of Steel Before Painting" GB8923-88.

2. The steel after rust removal should be processed immediately (to prevent secondary rust). After processing, use a clean rag to wipe off the residual rust powder on the inner wall of the tube (if secondary rust is found, perform a secondary rust removal to ensure painting), and use GZ-2 gray new polymer in time Two coats of anti corrosive paint (heavy build type) are used as primers, and two coats of sky blue paint are used for the topcoat, and the total thickness of the paint film reaches 250-300μm on both sides.

3. The primer should be finished before the pipe fittings leave the factory, and the topcoat should be painted before the pipe installation. All pipe ends (installation welds) should not be painted within 200mm. Paint after the pipe fittings are installed.

4. When applying the primer, only a brush is required. Spraying is not allowed, and the topcoat can be sprayed.

5. Ventilation conditions for the painted site to prevent wet metal surfaces, strong wind, dusty, hot sun, and other bad weather on the site, (such as high temperature> 70 ℃, or low temperature <+5 ℃ rainy days, etc.) Painting work is not allowed, the painting should be done at 10℃-25℃ and relative humidity below 70%.