The problem of forming the anticorrosive layer of the three-layer polyethylene adhesive tape for large-caliber hot simmering elbows

For the current stage, the difficulty of long-distance pipeline anti-corrosion is not the choice of anti-corrosion layer, but the overall anti-corrosion patch and the consistency of the performance of the anti-corrosion coating of the curved pipe and the anti-corrosion coating material of the straight pipe. Due to the special shape of the steel elbow, it is difficult to perform anti-corrosion operations on the production line, so the anti-corrosion of the elbow has become the weak link of the entire pipeline.

The main methods of external anti-corrosion for hot-snuggling elbows at home and abroad:

1. Prefabricated on the anti-corrosion line of elbows: single-layer fusion-bonded epoxy powder (single layer FBE), double-layer fusion-bonded epoxy powder (double FBE) coating;

2. On-site construction manual operation: liquid epoxy coating, three-layer radiation cross-linked polyethylene heat shrinkable sleeve (belt), polyethylene (propylene) ene anticorrosive tape, etc.;

The molding of the three-layer polyethylene adhesive tape on the elbow is a problem to be solved in the field of anti-corrosion.

Many domestic and foreign documents have proposed the idea of u200bu200busing three-layer polyethylene adhesive tape for bent pipes: the three-layer polyethylene adhesive tape prefabricated by factory corrosion science and protection technology covers the anticorrosive layer formed by cold bending of the bent pipe, Refer to the straight pipe rotating three-layer structure polyethylene adhesive tape forming technology, and adopt the anti-corrosion coating machine for the elbow pipe. However, these ideas are often not feasible in practical applications, or are rejected because of the easy damage to the anti-corrosion layer, or completely impossible to implement due to the complexity of the tooling. Tianhua Institute has developed the three-layer polyethylene adhesive tape molding technology of cold-belt hot-melt to complete the elbow, which is a brand-new technology that successfully solves the worldwide problem of forming the anticorrosive layer of the three-layer polyethylene adhesive tape for the elbow.