Forensic Engineering Analysis of Toilet Connector Failures in a Class-Action Lawsuit

Abstract

A major manufacturer of water supply lines that connect flushable toilets to house water piping was the object of a class-action lawsuit. The author examined a large number of failed and exemplar connectors, complete fill lines, and similar injection-molded products as well as visited failure sites with the goal of ascertaining the root cause of the failures. Forensic work included strength tests and finite element analyses to determine the expected life of the nuts, including single overload failure strength and creep analysis to predict life. Tightening tests using random subjects were conducted. A statistical analysis of the failures was also performed. The products of competing manufacturers were evaluated for comparison of similar designs. After much investigation and analysis, it was concluded that the design of the connector was not defective and met relevant industry standards.