PPR (Polypropylene Random Copolymer) pipes can be used for compressed air distribution only if the specific grade is rated, certified, and approved by the manufacturer for compressed air service (typically PN20 or PN25 classes). [1, 2]
Key Requirements & Safety Rules
- Avoid Direct Hot Discharge: Never connect standard PPR pipes directly to the hot air discharge point of a compressor. Use a metal (steel or aluminum) section near the compressor to allow the air to cool down first. [1, 2]
- Pressure & Temperature Limits: Certified PPR can handle working pressures up to 25 bar at low-to-medium temperatures, but its pressure resistance drops as the operating temperature increases. [1, 2]
- Compressor Oil Compatibility: If using a lubricated rotary screw compressor, synthetic or ester-based compressor oils can degrade standard PPR over time, making it brittle and prone to sudden shattering. Check the manufacturer's chemical resistance chart first. [1]
- Thermal Expansion & Support: PPR expands significantly more than metal pipes when heated. Long runs require proper support
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