HDPE Pipe vs DI Pipe — Comparison Guide

High-Density Polyethylene (HDPE) pipes and Ductile Iron (DI) pipes are both excellent choices for water distribution infrastructure. The selection depends on the operating pressure, diameter requirements, soil conditions, installation method, and economic analysis of capital versus lifecycle costs.

HDPE vs DI — Key Factors

• Corrosion: HDPE is completely corrosion-free; DI requires zinc and bituminous coating
• Jointing: HDPE uses heat fusion (no gaskets); DI uses push-in rubber ring joints
• Flexibility: HDPE is flexible and resistant to seismic movement; DI is rigid
• Pressure rating: DI K9 is suitable for 900m head; HDPE SDR 11 suitable for ~16 bar
• Diameter range: DI available to 1200mm; HDPE typically up to 630mm OD