What is the life expectancy of PVC pipe?
PVC has an impressive record of long-term durability. When water utility managers and engineering firms were surveyed in a study sponsored by the American Water Works Association Research Foundation (AWWARF), they cited corrosion resistance, longevity and durability as their top reasons for choosing PVC. When these same water supply professionals were asked to rank PVC against the other common types of pressure pipes for life expectancy, PVC ranked first. [Source: Moser, A.P., and Kellogg, Kenneth G., “Evaluation of Polyvinyl Chloride (PVC) Pipe Performance,” AWWA Research Foundation, Denver, Colorado, 1994.] Uni-Bell has an extensive collection of technical papers and experience articles that cover the subject of water and sewer pipe longevity in detail. These items are available, free of charge, by contacting Uni-Bell.
The durability of PVC pipes is related, as it is for all other thermoplastics materials, to the chemical degradation of the polymer used in the pipes. However unlike other thermoplastic pipes PVC pipes do not oxidise. Stabilisers are used in PVC pipes to prevent degradation of the polymer during the extrusion process and storage of the pipes before they are buried in the ground. However, when the pipes are buried in the ground, no chemical degradation is expected to take place. For this reason the durability of the PVC material in buried pipes is expected to be very good (maybe even be more than 1000 years¹). In standardised pipes for potable water (EN 1452) the expected lifetime of PVC pipes under pressure is extrapolated based on hoop stress testing of pipes for up to 20000 hours. This allows an estimation of the durability by extrapolation to a life expectancy under pressure of 50 to100 years² . Real experience in Germany³ has shown that buried PVC pressure pipes dug up after 60 years of active use were proven to be fit for purpose when analysed and likely to have a further life expectancy of 50 years. "Studies in the Netherlands have examined several potential degradation processes for PVC pipes and carried out tests on pipes up to 45 years old. These studies also concluded that the life of PVC drinking water systems could exceed 100 years."
4 References 1 Janson, Lars Eric 1996 "Plastics Pipes – How long can they last? KP Council Nov. 1996 2 EN-ISO 9080. 3 60 Jahre Erfahrungen mit Rohrleitungen aus Weichmachfreiem PVC, 1995, KRV 4 ‘Long Term Performance of Existing PVC Water Distribution Systems’ by A. Boersma and J Breen, 9th International PVC Conference, Brighton, 26-28th April 2005, pp 307-315.