Fatigue of Plastic Water Pipe: A Technical Review with Recommendations for PE4710 Pipe Design Fatigue

The PE design practices for preventing pressure surge fatigue failures in water pipe have a long and very successful history. These practices were developed based on the older generation PE materials. Since this time there has been considerable evolution in the performance of PE pipe and the introduction of a new classification of high performance PE4710 materials. This study conducted an assessment of the current design approaches to determine their continued suitability with the introduction PE4710 materials. Comparison was also made with the current US fatigue design approaches for PVC along with an examination of other international design practices. The fatigue resistance of PE4710 materials is seen to be excellent, and shows these materials are capable of providing for essentially unlimited fatigue resistance under the operating conditions of water transmission and distribution systems. The current design approaches for both occasional (short-term) surge resistance and repetitive (long-term) fatigue resistance for PE4710 materials are conservative and appear justified based on available data. The US design approach for PE4710 materials is also seen to more conservative than that of the UK for both occasional and repetitive surge events.