Generally speaking, after the PE pipe is installed and welded, it will be backfilled, and then the composite pipe will be buried in the ground. Therefore, at this time, it is necessary to pay attention to the backfill soil and soil layer. If there are problems in the soil layer of the backfill, it will cause some undesirable hazards to the composite pipe, and even destroy the composite pipe. Therefore, the backfill soil layer must meet the following requirements:
1. The buried depth of the PE pipe should not be less than 0.8 meters. If there is a pavement above the pipe, a complete set of steel pipe backfills should be added when paving.
2. When paving in mountainous areas, the stones should be arranged in a trench beforehand. For large rocks, sand should be used for backfilling. The thickness is not less than 30cm, and the density should be compacted, not less than 80%.
3. When working on low-water level pipelines, drain the water in the trenches before working. During the whole welding process, water in the pipeline must not enter to prevent damage to the welding of the welded pipe fittings.
4. It is necessary to maintain the level of the geological soil layer when paving PE pipes. If there are dents or low-lying areas, they must be filled with sand and gravel to achieve the design elevation scale.
5. The soil layer should not be soft. In an environment where the geological soil layer is loose, the soil layer must be compacted, and then a layer of sand not less than 10cm thick is laid to make the density not less than 80%.