Details of epoxy coal tar anti-corrosion steel pipes in common industrial projects

First, the production process of epoxy coal tar anti-corrosion steel pipes

Step 1: 1. Steel pipe → Shot blasting (or sandblasting) to remove rust → 2. Steel pipe sandblasting, gray surface cleaning → 3. Pre-coating of welds with epoxy zinc-rich primer → 4. Spraying epoxy zinc-rich primer by airless spraying → 5. Spraying epoxy coal tar paint → 6. Wrapping glass cloth → 7. Spraying epoxy coal tar paint → 8. Wrapping glass cloth → 9. Spraying 2 coats of epoxy asphalt paint → 10. Coating curing → 11. Quality inspection → 12. Correction → 13. Submission

Step 2: Pipeline patching lining: 1. Welding of steel pipes → 2. Cooling → 3. Grinding of the weld patch at the end of the pipe to ST3 level → 4. Applying epoxy zinc-rich primer → 5. Applying epoxy asphalt paint and pipe body (overlap 100mm) → 6. Wrapping glass cloth → 7. Spraying epoxy asphalt paint → 8. Wrapping glass cloth → 9. Spraying 2 coats of epoxy asphalt paint → 10. Coating curing → 11. Quality inspection → 12. Correction → 13. Submission.

Second, the defects of epoxy coal tar paint coating anti-corrosion

1) During on-site construction, the curing of epoxy resin is affected by temperature, the curing is slow, and the construction period is long.

2) Due to the addition of a large number of solvents during construction, it is easy to provide some construction units with opportunities to cut corners (add more solvents, dilute the paint, and increase the cost).

3) Because it is a two-component, the curing agent ratio will be inaccurate or unevenly stirred during on-site construction, which is easy to causes poor curing or uneven quality after curing.

4) The anti-corrosion layer is reinforced with glass cloth, which contains wax, affecting the adhesion between the layers. Glass fibers are generated during the construction process, which can easily damage the skin of construction workers. Most workers are unwilling and unable to do their job well.