Anti-corrosion Steel Pipe Supplier-GNEE
1. Technical requirements and testing for pipeline anti-corrosion. According to the requirements, the anti-corrosion coatings for all steel pipes and steel accessories in this project are non-toxic epoxy zinc-rich paint and epoxy coal pitch.
(1) The internal anti-corrosion is non-toxic epoxy zinc-rich paint. Notes: When applying the primer, it is required to apply it evenly without any leakage; the topcoat can be applied after the primer is dry. Painted pipes or steel Omissions, hollows, wrinkles, and scratches on painted parts should be repaired. Pay attention to avoid damaging the anti-corrosion layer during transportation and hoisting. If there is any damage, it should be recoated in time, otherwise the installation will not be allowed. When anti-corrosion painting of pipe joints is carried out in the pipe trench, the soil and water traces on the anti-corrosion parts must be removed; when backfilling soil, care should be taken to avoid damaging the outer anti-corrosion layer. When constructing in areas with poor ventilation conditions, artificial ventilation equipment should be used. Open-air construction is not allowed in rain, snow, or foggy weather.
(2) Construction quality and inspection standards: Appearance inspection: Anti-corrosion pipes should be inspected one by one. The surface should be smooth, showing a bright paint film, the coating should be uniform, without wrinkles, hollows and clots. The fiberglass cloth mesh of the anti-corrosion layer should be filled with water. Full face paint. Thickness inspection: Randomly check 1 pipe out of every 20 pipes, and use a computerized film thickness gauge (MCH-2004J) to test it. Measure a total of 3 sections at both ends and in the middle of each pipe, 4 on the upper, lower, left, and right sides of each pipe. The thickness of thin spots and thin spots should meet the requirements of anti-corrosion grade. Inspection of paint film breakdown strength: Use JG-3 type DC electric spark detector to inspect each root. No sparks. The dry paint film applied is 450μm, and the voltage test is 2500-2800V.
(3) Pipeline anti-corrosion construction technology Pipeline pre-treatment: use manual and electric tools to remove rust. Clean off the oil, dust, welding slag, oxide scale and loose rust on the surface of the anti-corrosion parts. The surface should be kept dry, free of water marks, and have a metallic luster. Manual rust removal to meet Sa2.5 level requirements:
① Internal anti-corrosion: Use non-toxic epoxy zinc-rich paint on the two bases and two sides. The specific construction steps are: first apply two layers of primer, then apply two layers of paint. After each layer is dry, apply the next layer. Thickness Not less than 2.5μm.
②Exterior anti-corrosion: Epoxy coal pitch uses four oils and three cloths. Specific construction steps: first apply a primer (colorless), wait for it to dry, then apply a primer, wrap three layers of glass cloth, and apply two surface layers Paint. The total thickness of the paint is not less than 200μm.
③Packing and repairing of anti-corrosion coatings. The coating structure and materials used for repairing and repairing parts should be the same as those of the pipe body coating. The repairing work should be carried out after butt welding and the pipe surface temperature is cooled to below 50 degree .
