According to a new joint position paper by PVC4Pipes and TEPPFA, underground PVC-U and PVC-Hi pressure pipe systems for water and natural gas supply have been shown to have an expected service life of at least 100 years.
PVC4Pipes believes durability is crucial for underground piping systems due to the high cost of installing and replacing pipes buried in the ground.
The position paper explains the difference between the predicted design point at 20C/50 years and the expected lifetime of PVC-U and PVC-Hi pressure pipe systems.
The paper highlights how the 50-year design basis, which estimates the stress that a thermostatic pipe is able to withstand for 50 years at 20C, must not be confused with the actual lifespan of a plastic pipe system.
The service life is expected to be more than 100 years due to a number of reasons; mainly the lower real pressure levels experienced by the pipe over its lifetime, the lower real average ground temperatures, the always positive wall thickness tolerances and the safety factors applied at the design stages.
Vincent Stone, PVC4Pipes Project Manager, said: “There is ample evidence that underground PVC-U and PVC-Hi pressure pipes for water and natural gas supply are fit for service for 100 years or more. The utility companies critically depend on highly durable and reliable piping systems and the position paper clearly demonstrates that PVC piping systems can deliver outstanding performance in various operation conditions.”