ADVANCED MATERIALS & PROCESSES | OCTOBER 2025 21 Stress corrosion cracking (SCC) has emerged as a common cause of water loss in the insurance industry, particularly in plumbing systems with brass fittings. Following the passage of the Safe Drinking Water Act in 1974 and its subsequent amendments in 1986 and 1996—along with the 2011 Reduction of Lead in Drinking Water Act—the allowable lead content in water supply lines and related components was reduced to a weighted average of 0.25%[1]. To account for the reduced allowable lead content, at least in part, manufacturers have resorted to using higher levels of both copper and zinc, making brass fittings more susceptible to SCC[2]. As a result, courts have seen a rise in litigation involving stress corrosion cracking in plumbing supply lines, especially regarding brass fittings. See In re Zurn Pex Plumbing Products Liability Litigation, 267 F.R.D. 549 (2010); Waterfall Homeowners Ass’n v. Viega, Inc., 279 F.R.D. 586 (2012); Ortega v. Uponor, Inc. (In re Uponor, Inc.), 716 F.3d 1057 (2013); and Freeman v. NIBCO, Inc., 526 F. Supp. 3d 1112 (2020). CASE STUDY PRODUCT LIABILITY CASE STUDY: FAILURE OF BRASS PLUMBING FITTING DUE TO STRESS CORROSION CRACKING Learn how fault is determined in the case of a water leak caused by a cracked plumbing fitting. Dan Grice,* Materials Evaluation and Engineering Inc., Plymouth, Minnesota Ben Sorenson, Yost & Baill, Minneapolis, Minnesota *Member of ASM International how their work impacts the outcome of cases often remains open. WATER LEAK DETAILS In the following case study, the feedback loop was definitively closed— approximately two years after the failure occurred—by a private arbitration ruling. In 2018, a water leak originated from a bathroom on the upper floor When evaluating a plumbing loss potentially involving SCC, it is essential for insurance professionals to preserve the evidence in its original state and engage a qualified materials engineer. Proving both the occurrence and cause of such failures often requires in-depth materials analysis to be coordinated by expert witnesses, with the goal of assisting the triers of fact (i.e., the court) in resolving the dispute. Typically, each party retains their own expert witnesses. The opinions of these individual expert witnesses may align, partially align, or differ substantially. In many cases, insurance professionals and attorneys resolve a matter prior to a court ruling, or even prior to filing a formal lawsuit. The expert witness is rarely privy to settlement terms, so the feedback loop for witnesses regarding Fig. 1 — Photo of connections to shower mixing valve prior to removal from the home. Inset shows leak at the fitting during laboratory testing.
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