Standards and testing | process feature


Finding fault: identifying the reasons behind pipe failure


It is impossible to be certain that a lifetime prediction for a plastic pipe is accurate until the pipe fails. Problems arise if this failure happens ahead of the predicted time. In general, pipe life predictions are accurate – and much of this accuracy comes from the extensive amount of testing done on pipe samples. However, there is still plenty of room for improvement, as many piping systems are found to fail relatively soon after installation. Chlorinated polyvinylchloride (CPVC) is increasingly


used for piping systems. It is easy to install, and resistant to corrosion – but, as with any materials, can be subject to failure. “Our goal as forensic scientists is to determine the


root cause of failure of CPVC piping and provide data that will help clients select the most appropriate remediation option for their building,” said Duane Priddy, CEO of Plastic Failure Labs, at last year’s Antec conference in the USA. He highlighted a number of case studies that


www.pipeandprofile.com


Determining the likely lifetime of a plastic pipe is crucial if it is to be designed into systems such as hot water systems. Lou Reade reports


illustrate ways in which analysis can identify problems in CPVC pipe. The first step in analysing CPVC pipe failure is to


examine the fracture surfaces using microscopic methods, in order to determine the mode of failure. A variety of forensic tools can be used to evaluate a failing CPVC piping system failures, including: borescopy, microscopy, ultrasonic pulsed-echo (UPE) mapping, contaminant analysis, and statistical data analysis. In one example, a new CPVC hydronic heating/


cooling pipe system was experiencing multiple failures. Analysis revealed that this was due to environmental


April 2017 | PIPE & PROFILE EXTRUSION 39 Modelling and


testing helps to avoid cata-


strophic failure in plastic pipe


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