1. Eliminate the deposits of slag, burrs, grease and dirt on the surface of the polyethylene anti-corrosion tape. For the pipelines overhauled by the anti-corrosion layer, appropriate methods should be used to remove the original anti-corrosion layer and residue.
Second, the use of mechanical or sandblasting projectile derusting methods, the quality should reach the national standard rules St3 or Sa2.
3. After removing the rust from the polyethylene anti-corrosion tape, the defects exposed on the exterior of the pipeline should be stopped. The dust and abrasive attached to the exterior should be clean and clean. The appearance of the steel pipe should be boring. When the rust or appearance is present, the external appearance must be stopped. Dispose of.