HDPE Pipe – Enhanced Disinfectant Resistance
Qenos Alkadyne’s Market Segment Manager – Jeroen Wassenaar recently presented a paper on the suitability of PE Pipe Systems for Conveying Disinfected Drinking Water under Pressure, at the OzPipe Conference’19.
Suitability of PE Pipe Systems for Conveying Disinfected Drinking Water under Pressure
In moderate to warm climates drinking water requires disinfection to avoid growth of micro-organisms and prevent disease during distribution in drinking water networks. Typically chlorine is used for disinfection and the quantity required depends on water temperature and source quality.
Piping materials, including HDPE pipe also known as Poly Pipe, have been designed for transport of disinfected water containing chlorine at typical concentrations and water temperatures. In selected regions of the world, average annual drinking water temperature may be significantly above these typical values, which requires elevated levels of disinfectants to control growth of micro-organisms. For example, whilst average annual soil temperature in major Australian capitals such as Sydney, Brisbane, and Perth are below 21°C, over 30°C is measured in Northern parts of Western Australia. Under these extreme conditions pipe materials may be prone to oxidative degradation induced by the chlorine based disinfectants present, which will limit their expected service life.
In recent years, new techniques have been developed to measure the resistance of HDPE pipe materials to disinfectants that allow to predict the design life at elevated temperatures and disinfectant concentrations. This has enabled the development of improved materials such as Hostalen CRP100 RCD Black that is now commercially available in Australia. The paper presented by Qenos during the OzPipe conference shows that this material still meets design life expectations in accordance with Australian standards and guidelines at high disinfectant concentrations.