Aquatherm Australia issues cautionary note on Combined Copper with PP-R heated water circulatory systems
The Victorian Building Authority (VBA) is encouraging all plumbing practitioners to review a cautionary note on mixed (Polypropylene – Random (PP-R/Copper) hot water recirculation systems published by Aquatherm Australia.
Aquatherm Australia is a producer of PP-R pipe systems. Aquatherm has found that PP-R, like any other polyolefin, can fail in the main ring of a mixed (PP-R/Copper) hot water recirculation system due to "Oxidative Stress Cracking".
The cautionary note recommends, in a mixed PP-R/Copper hot water recirculation pipe system, to bring the hot water velocity in the copper pipe system down to 0.7 m/s (absolute max. 0.9 m/s) to avoid excessive copper (erosion-) corrosion.
Practitioners are encouraged to review the cautionary note prior to carrying out work on a mixed (PP-R/Copper) hot water recirculation system.