PE piping can withstand certain pressure, usually requiring PE resins with high molecular weight and good mechanical properties, such as HDPE resins. LDPE resins have poor rigidity, poor dimensional stability during molding and processing, and are difficult to connect, making them unsuitable for pressure piping materials. LDPE, especially LLDPE resins, have become common materials for producing drinking water pipes. LDPE and LLDPE resins have low melt viscosity and good fluidity, making them easy to process, thus offering a wide range of melt index options, typically between 0.3-3g/10min.
Compared to traditional pipe materials, HDPE pipe systems possess the following range of features:
1. Polyethylene pipe systems are connected using electric heat-fusion methods.
2. Polyethylene has a low-temperature brittleness temperature, making it usable within a temperature range of -60 to 60°C. During winter construction, it is less prone to pipe cracking.
3. HDPE pipes can be corroded by various chemical media. Chemical substances present in the soil do not cause degradation to the pipes. Therefore, they are not prone to rotting, rusting, or electrochemical corrosion. Additionally, they are also not conducive to the growth of algae, bacteria, or fungi.
4. Excellent Flexibility: The flexibility of HDPE pipes allows for easy bending, which enables engineers to navigate around obstacles by altering the pipeline direction. In many cases, this flexibility can reduce the need for fittings and lower installation costs.
5. Low Flow Resistance: HDPE pipes feature a smooth inner surface with a Manning coefficient of 0.009. The smooth surface and non-adhesive characteristics ensure HDPE pipes have higher conveying capacity than traditional piping materials, while also reducing pressure loss in the pipeline and water conveyance energy consumption.
6. Easy to Handle: HDPE pipes are lighter than concrete pipes, galvanized pipes, and steel pipes, making them easy to transport and install. This reduces the need for excessive labor and equipment, meaning lower installation costs for the project.
