Reference: 20/WM/03/22 ISBN: 978-1-84057-893-5 Published Date: 13/09/2020 Polyethylene (PE) potable water mains have been in widespread use for several decades. Over 30 years ago, Severn Trent Water took a far-sighted approach of laying testbeds of plastic pipe mains, which provided a unique opportunity for sections to be exhumed and studied to establish long term deterioration in typical service conditions.
Chemical and mechanical testing was backed by statistical analysis to show that PE pipes will remain in very good condition, and significantly greater than the commonly quoted 50 year lifespan, with useful information for a number of material cohorts. Focus was also given to joints and useful information provided on creep and its effect. Although butt fusion joints performed well, pipe lifetime is likely to be limited by electrofusion joints. Causes of deterioration are explained and validated through the analysis with a view given of “end of life”. A simple risk assessment tool for PE pipe has been developed to assist with the targeting of samples needed when assessing a particular network for asset management decisions on pipe repair and replacement. |