Featuring a distinctive corrugated structural design and outstanding material properties, HDPE double-wall corrugated pipes serve as the primary piping solution for buried municipal sewage and rainwater collection systems. The engineering performance heavily relies on ring stiffness, hydraulic characteristics and proper installation procedures. All technical applications comply strictly with GB/T 19472.1-2019.
In terms of structural design, HDPE double-wall corrugated pipes adopt a smooth inner wall + corrugated outer wall structure. The outer corrugated profile greatly enhances ring stiffness. Common ring stiffness classes include SN4, SN8 and SN16, representing 4kN/m², 8kN/m² and 16kN/m² respectively. Selection is based on burial depth and traffic load: SN4 for burial depth ≤1.5m, SN8 for 1.5–3.0m, SN16 for ≥3.0m. The pipes can effectively withstand earth pressure and vehicle loads to prevent deformation and breakage.
For core technical parameters, these pipes are manufactured from PE80 / PE100 raw material with density ranging from 0.930–0.965g/cm³. They deliver tensile strength ≥14MPa and elongation at break ≥300%. Excellent acid and alkali resistance enables long-term service in sewage environments with pH 4–10 without aging or damage. Hydraulically, the smooth inner wall achieves a friction coefficient ≤0.010. Under the same nominal diameter, flow capacity is 10%–15% higher than concrete and cast iron pipes, reducing blockage risks and cutting maintenance costs.
Installation must follow professional specifications. Socket joints with nitrile rubber gaskets resistant to aging and sewage corrosion are used to guarantee tight, leak-free connections. Medium-coarse sand is applied for layered backfilling with compaction ≥95% to avoid pipe damage caused by sharp debris. During buried installation, thermal expansion allowance should be reserved to accommodate soil settlement and prevent joint cracking.
Widely adopted in municipal sewage networks, residential rainwater-sewage separation systems and farmland drainage projects, HDPE double-wall corrugated pipes are the preferred buried drainage pipe thanks to lightweight construction, high external pressure resistance and convenient installation.
