The heat expansion and contraction phenomenon of pipe fittings during construction in winter or summer can easily damage PE pipe fittings. Therefore, it is necessary to prevent longitudinal expansion and contraction of PE pipe fittings. Large-caliber water supply pipe

The pipe fittings should be laid in a serpentine shape in the pipe trench, with a slight curved arc, leaving a margin for expansion, and when installing PE pipes, as far as possible, no expanders or double coil short pipes should be used to replace the expanders. When making PE pipe fittings buttresses and town piers, both sides should be simultaneously poured with concrete at one time. The bottom foundation of PE pipe fittings must be cushioned with fine sand and not less than 100 mm. After the PE pipe fittings are installed, the 500mm backfill work on both sides and the top of the pipe must be backfilled and compacted, and the backfill compaction coefficient is not less than 95%.

When pipe fittings are installed in hot weather, they should be constructed as far as possible from night to 8:00 in the morning. The atmospheric temperature is low, and the pipes are properly contracted and then backfilled and the final joints meet. They must be compacted in layers to prevent thermal expansion and contraction of the pipes. Large internal stress failure.