The normal medium temperature range for HDPE (High-Density Polyethylene) water supply pipes is:
Standard Operating Temperature Range
Recommended continuous working temperature:
0°C to 40°C (32°F to 104°F)
This range applies to most municipal and industrial cold water supply systems.
Extended Temperature Capability
HDPE pipes can technically tolerate:
Maximum short-term temperature: up to 60°C (140°F)
However, at temperatures above 40°C, the pipe's:
Pressure rating (PN value) decreases
Long-term strength is reduced
Service life may shorten
Manufacturers provide temperature derating coefficients to adjust allowable working pressure at elevated temperatures.
Why HDPE Is Limited to Cold Water
HDPE is a thermoplastic material. As temperature increases:
Tensile strength decreases; Creep deformation increases; Internal pressure resistance drops
Therefore, HDPE is not recommended for hot water supply systems. For hot water applications, materials like:
PPR (Polypropylene Random);PEX (Cross-linked Polyethylene);CPVC are more suitable.
