With its unique corrugated structure design and excellent material performance, HDPE double-wall corrugated pipes have become the core pipes for municipal buried sewage discharge and rainwater collection systems. The professional adaptation of their ring stiffness, hydraulic performance and installation process directly determines the engineering operation effect, and the related technical applications must strictly follow the GB/T 19472.1-2019 standard.
In terms of structural design, HDPE double-wall corrugated pipes adopt an “inner flat wall + outer corrugated” structure. The outer corrugated design greatly improves the ring stiffness of the pipe. The commonly used ring stiffness grades in the industry are SN4, SN8 and SN16, corresponding to 4kN/m², 8kN/m² and 16kN/m² respectively. They can be flexibly selected according to the buried depth (SN4 for ≤1.5m, SN8 for 1.5-3.0m, SN16 for ≥3.0m) and traffic load, which can effectively resist soil pressure and vehicle load and avoid pipe deformation and damage.
In terms of core technical parameters, the pipe is made of PE80/PE100 grade raw material, with a density of 0.930-0.965g/cm³, a tensile strength of ≥14MPa, an elongation at break of ≥300%, excellent acid and alkali corrosion resistance, which can adapt to the long-term erosion of sewage medium with pH value of 4-10 without aging and damage. In terms of hydraulic performance, the inner wall is smooth, the friction coefficient is ≤0.010, and under the same pipe diameter, the flow rate is 10%-15% higher than that of traditional concrete pipes and cast iron pipes, which can effectively reduce pipe network blockage and lower operation and maintenance costs.
The installation process must follow professional specifications: adopt socket-type rubber ring connection, the rubber ring must be nitrile rubber resistant to aging and sewage corrosion, and ensure that the interface is tightly sealed without leakage during connection; use medium-coarse sand for layered backfilling during backfilling, with layered compaction degree ≥95% to avoid sharp debris squeezing the pipe; during buried construction, reserve the pipe expansion amount to adapt to soil settlement and prevent pipe interface cracking. At present, this pipe has been widely used in municipal sewage pipe networks, community rainwater and sewage diversion, farmland drainage and other projects. With its advantages of light weight, external pressure resistance and easy construction, it has become the preferred pipe for buried sewage discharge projects.
