Plastic Pipe Failure Analysis

The Gas Technology Institute is currently addressing the risks and threats to plastic pipes through research sponsored by the United States Department of Transportation, Pipeline and Hazardous Materials Safety Administration. With the upcoming proposed rulemaking, the United States distribution companies will be required to implement a distribution integrity management plan. In developing an integrity management plan, it is key to understand system risks and threats and with 39.6 million plastic services and nearly 620,000 miles of plastic gas main, the threats to plastic pipe need to be addressed. The research discussed in this paper identifies the types of failures that affect plastic piping, excluding third party damage. The paper also describes the most common cause of leaks, slow crack growth, as well as root cause analysis of a pipe removed from service due to leaking. The cause of leaks for five other pipe segments is also discussed. The final topic of this paper is rapid crack propagation and small-scale steady state testing.