Long-Term Performance Prediction for PE Pipes

International experience indicates that PE often exhibits the lowest failure rate of all materials in use. Many failures are due to third-party damage or poor joint preparation rather than failure under normal service loading conditions. While low failure rates should also be expected in the United States, there is insufficient historical data to extrapolate future failure rates. This project develops models to predict the long term performance prediction for PE pipes in the United States. The objectives of this study were to (1) review the current field performance for polyethylene (PE) water pipelines; (2) review U.S. and international standards for PE water pipes; (3) review previous and state-of-the-art test methods and modeling techniques for service lifetime prediction of PE pipelines; (4) identify and measure relevant pipe properties that govern long-term field performance; and (5) develop and benchmark models to predict long-term field performance of PE pipes. The experimental findings from this project demonstrate that the fracture performance of currently available PE materials is significantly improved from previous material grades. This indicates that the future performance of these current PE materials should not be assessed based on previous historical data held by water utilities. The simple equations provided from the physical probabilistic failure model in this study provide water utilities with a basis for estimating future failure rates. This information can be combined with knowledge of cost consequences of pipe failure and used to inform future asset management decisions, such as replacement planning and budget setting.