Is PE resistant to the chemicals commonly used for disinfection, e.g. chlorine?
PE pipe is resistant to the chemicals commonly used for water treatment and disinfection.
Disinfection of water mains is a frequent operation. Disinfection takes place when commissioning newly constructed potable water mains; mains that have
been removed from service for planned repairs or for maintenance that exposes them to contamination; mains that have undergone emergency repairs due to physical failure; and mains that, under normal operation, continue to show the presence of coliform organisms. The chlorine disinfection process puts pipe in contact with a strong oxidising agent.
Several studies have been conducted to verify the effects of chlorine disinfection on the performance of PE pipes. A study by the US Plastic Pipe Institute included pre- and post-exposure testing of several characteristics of PE pipes, including resistance to slow crack growth. The testing performed in this study indicated that chlorine disinfection, when conducted within the guidelines of AWWA-C651, did not have a significant adverse affect on the subsequent performance of PE pipe.
This is supported by many years of extensive trouble free use in potable water applications. However due to the variety of chemicals, concentrations and practices in various countries if there is any doubt, advice can be sought from the polymer or pipe manufacturer.
For pipe applications where chlorinated water is to be carried over a long term period, rather than the short term disinfection process, further advice should be sought.
Chemicals commonly used in the disinfection and water treatment process include; chlorine, chlorine dioxide, monochloramine and ozone.