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Microscopic Characterization of CPVC Failure Modes


November 16, 2009

Dr. Jennfer Hoffman, Manager in Exponent’s Mechanical Engineering and Materials Science practice, is presenting a talk entitled "Microscopic Characterization of CPVC Failure Modes", at the Golden Gate Section of the Society of Plastics Engineers on Thursday, November 19th. 

Abstract:  This talk will demonstrate the utility of fractography (i.e., the study of fracture surfaces) in failure analysis investigations. CPVC fire sprinkler pipe sections were subjected to controlled loading conditions typifying hydrostatic burst, impact loading, and environmental stress cracking (ESC) to induce cracks. Hydrostatic burst is an overload failure mode (e.g. water hammer), which may occur during pipeline operation, while pipe crush is a failure mode that may occur during installation or maintenance of the pipeline. ESC, a time-dependent failure mode involving physical embrittlement of plastic materials, may occur when stressed pipes are exposed to certain chemicals such as solvent cements, solder fluxes, fitting lubricants, and transported fluids. A pipe recovered from a field failure was also examined and compared to a pipe that failed under simulated service conditions involving a combination of chemical and thermal insult and hydrostatic load. In addition, the effect of chemical concentration on ESC behavior is evaluated using common phthalate ester plasticizers, which are known ESC agents for CPVC.

Registration: For location and registration information, please click here.