Practical experiences gathered and technical assessments carried out support that unplasticised (PVC-U), high impact polyvinyl chloride (PVC-Hi) and polyethylene (PE) buried pipes have an expected service lifetime of over 100 years, comfortably exceeding the predicted design point of the common extrapolation method for plastic pipes (ISO9080).
PVC pipes
The 50 year design basis and minimum service life for a PVC pressure water or gas pipe systems is secured through the established standards ISO 9080 and ISO 12162. The first large-scale installation of PVC-U pipes took place in 1936 in Germany, for drinking water distribution and gravity drainage systems in various residential areas, including the Berlin Olympic Village. Most of those pipes are still in service use today – representing 83 years of consistent performance. PVC-Hi has been the preferred material for low pressure gas distribution systems in some European countries for more than 60 years.
Many dig-up reports from Europe and worldwide have shown that PVC water and gas pipes can last for at least 100 years with no significant age-related degradation. The longer life expectancy based on real world results can be explained by the lower real pressure levels (stress) experienced by the pipes over their lifetime, the always positive wall thickness tolerances and the safety factors applied at the design stages.
PE pipes
The design basis for PE pressure buried pipe systems for water and gas has been secured through the established standards ISO 9080 and ISO 12162, with classifications for PE 80 and PE 100 material, designated by their minimum required strength (MRS). PE pipes were first installed in 1953 and many are still in successful operation 66 years later.
In studies from Japan, Europe, Russia, the Middle East, Africa and South America PE buried pipe have been investigated and proven to have a real expected service life in excess of 100 years, due to lower real pressure levels (stress) over the pipe’s lifetime, lower real temperatures in the ground, consistent zero-to-plus range tolerances for wall thicknesses and safety factors applied in the design stages.
All these cumulative studies have shown that PVC-u and PE pipes continue to provide a safe and long-lasting service life across the world.
TEPPFA position statements on PE and PVC pipes can be found online at: https://www.teppfa.eu/position-papers
Source: TEPPFA
