Failure Analysis of a Large Diameter Heat-Fusible PVC Pipe in a Horizontal Directional Drilling Installation

摘要

Many times it is assumed that the material is at fault when there is a large-scale failure in a piping system. In this case, a 30-inch fusible PVC pipe, approximately 1100 feet in length failed during a pressure test. A careful analysis of the failed pipe and an assessment of the pipe properties revealed that the material was not at fault and that improper test procedures were to blame. The analysis includes fracture toughness measurements and calculations that show that the propagation of the crack was directly related to the pressure test procedures that were used including the attachment of end-caps and entrapment of air in the system.