An Investigation Of Durability And Reliability Of HDPE Pipe For Large Diameter Water Transmission Applications

Abstract

The drinking water infrastructure in the North America requires a durable and reliable water transmission pipe material. Thus, it is important to study pipe performance, so that water utilities can benefit from cost-effective and efficient pipe installations and longer design life. All pipe materials deteriorate overtime and every pipe has unique properties with advantages and limitations. During a pipe's life cycle, failures occur due to numerous factors such as age, loading conditions, environmental conditions, installation quality, manufacturing procedures, operation and maintenance strategies and so on. The fatigue performance under cyclic loading in conducted, since very limited information is available on high density polyethylene (HDPE) large diameter pipe. The main purpose of this thesis is to investigate durability and reliability of large diameter (16 in. and larger) HDPE pipe in water transmission applications. To conduct this research, in addition to a comprehensive literature search, a national survey of water utilities in the North America was performed. Additionally a testing concept was developed to determine the performance of a HDPE high density pipe sample with recurring surges for two million cycles. This specimen was subjected to a pressure of 1.5 times Pressure Class (PC) for a 16-in., 15-ft long, DR 17, 4710 HDPE pipe. The results of this investigation showed that at this time, few water utilities use large diameter HDPE pipe. Those that use large diameter HDPE, majority are satisfied with the pipe performance; however, they had some concerns regarding joints and fittings as described in this thesis. Also, some utilities did not differentiate between 4710 HDPE pipe tested in this research, and older product's such as 3408 and 3608. The results of testing showed that the 16-in., 15-ft, DR 17 sample with one butt-fused joint in the middle, was able to withstand the 2 M cyclic loadings between 125 psi and 188 psi (1.5 times its pressure class).