Which material is best for anti-corrosion repair of underground pipelines? ?
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The anti-corrosion form of the ground pipe in our project adopts 3PE anti-corrosion structure (DN100 to 2600), and epoxy asphalt glass fiber cloth is used for anti-corrosion below DN100 and above DN2600. The pipe fittings were wrapped with liquid epoxy powder + heat shrink tape, but very difficult problems were encountered during the construction process. The on-site patching with heat shrink tape could not be completed in the pull-out test. The final conclusion was that it was affected by temperature (regardless of construction proficiency). The lower the temperature, the lower the pass rate. In the end, it was forced to use cold-wrapped tape patching. The disadvantage of cold-wound tape patching is that it is impact-resistant and does not allow heat-shrinkable tape, and it is easy to hollow out due to the high temperature during summer construction. I would like to ask all the anti-corrosion experts, which material is better matched with 3PE for on-site repair of ground pipes? ? ?
In addition, what is the most reasonable material for patching 3PE pipes and glass fiber cloth pipes? ? ?
Please ask the moderator to answer the question @王伟2
We also have this phenomenon during the construction process of buried pipes. We use heat shrink tape or cold-wrapped tape for bent pipes. The requirements during the construction process are relatively strict, and such problems are prone to occur after construction. This is one reason. Although after the construction is qualified, it will be easy to open the glue in the elbow during the future construction process, and the service life will be short. Therefore, it is best to use epoxy coal pitch as the fiberglass layer, so that there will be no adhesive joints at the elbow. During construction, attention must be paid to the overlap between epoxy coal pitch patching and 3PE.
We also construct the interface between epoxy coal pitch and 3PE in this way, but they are two structures after all. Although the peeling test can be passed, we can't find relevant specifications to support it, and I still feel uneasy. Moreover, the special reinforcement grade of epoxy is only 1mm, and 3PE is often 3 or 4mm, so the overlap thickness is not uniform. Although these methods have their own advantages, the disadvantages are also relatively obvious. The quality of the production process of the heat shrinkable pipe can be basically controlled, but problems do occur during the installation process. However, tees with pipe diameters above 1000mm often have hollows at the neck, which is too difficult to handle.
The patching area is made of our light-cured sheet.