1. Visual Inspection: After repair, inspect the surface of the anti-corrosion coating of each pipe to ensure there are no wrinkles, bulges, or bubbles. The fiberglass mesh should be completely filled with the topcoat.
2. Thickness Inspection: Use an anti-corrosion coating thickness gauge to measure the thickness. Randomly check one pipe out of every 20 pipes, measuring three cross-sections (top, bottom, left, and right). A thickness less than 85% of the design thickness is considered unacceptable.
3. Pinhole Inspection: Use an electric spark leak detector (2000V for ordinary grade, 3000V for reinforced grade, and 5000V for extra-reinforced grade). No sparks are considered acceptable.
4. Adhesion Test: Cross-cut test: Drill a V-shaped cut through the anti-corrosion coating, apply tape, and observe the peeling. If it is difficult to peel off and the pipe surface is still covered by the paint film, it is acceptable. 5. Joint Repair and Damage Inspection
Joint Repair: Material is the same as the pipe body; overlap width > 100mm; inspection method is the same as the pipe body.
Damage Repair: Damaged areas are treated according to the joint repair standard; overlap width ≥ 50mm.
6. Records and Labeling
Qualified pipes must be labeled with the anti-corrosion manufacturer's name, length, grade, batch number, and date (for diameters < 400mm, the outer wall can be labeled).
