Temperature performance
HDPE handles cold service to 40°C. PPR-C (Type 3) handles 0°C to 95°C — designed for continuous hot water. This is the single biggest differentiator.
Jointing
Both use heat-fusion. HDPE uses butt/electrofusion; PPR uses socket-fusion with a heating iron. Both produce leak-proof, monolithic joints.
Pressure ratings
HDPE: PN 2.5–PN 16. PPR: PN 10, PN 16, PN 20, PN 25 — with PN 20 being standard for hot-water plumbing.
Applications
HDPE for underground water, gas, telecom, industrial cold-water. PPR for building plumbing, solar water heating, industrial hot-water, chilled-water.
