Home › Case briefs › Civil Procedure

In re Zurn Pex Plumbing Products Liability Litigation

United States Court of Appeals for the Eighth Circuit · 2011 · Civil Procedure

Civil ProcedureClass certificationExpert evidenceStandingRule 23(b)(3)predominanceRule 23(f)Daubert

Facts

Minnesota homeowners alleged that Zurn's brass crimp fittings in PEX plumbing systems are inherently defective because stress corrosion cracking begins once the fittings are exposed to domestic water and eventually causes leaks. Zurn disputed that theory, arguing leaks result from individualized factors such as improper installation and corrosive water, and some systems had leaked while others had not. On bifurcated class-certification discovery, the homeowners relied on Dr. Staehle's metallurgy opinions that SCC begins upon use and on Dr. Blischke's statistical opinions projecting high system failure rates. The district court used a tailored Daubert review, denied exclusion of those experts, and certified warranty and limited negligence classes.

Issue

Whether the district court erred by refusing to conduct a full and conclusive Daubert inquiry before class certification, by declining to strike the homeowners' experts, by including homeowners whose systems had not yet leaked in the warranty class, and by finding predominance for the warranty and negligence classes under Rule 23(b)(3).

Rule

At the class-certification stage, a district court must conduct a rigorous Rule 23 analysis, but it need not conclusively decide ultimate trial admissibility of expert evidence. It may instead perform a focused Daubert inquiry examining the reliability of expert opinions in light of the available evidence and the purpose for which they are offered. For predominance under Rule 23(b)(3), common questions predominate when, if plaintiffs' general allegations are true, a prima facie case can be established through common evidence rather than member-by-member proof. A class cannot include members lacking standing, but warranty plaintiffs who allege that their products presently contain a universal inherent defect may have cognizable claims even if leakage has not yet occurred.

🔒

See the holding & full analysis

Create a free KwikCourt account to unlock the rest of this brief — and practice the case.

The court's holding and reasoning
Doctrine tests, pitfalls & exam hypotheticals
10 practice questions + 4 AI-graded essays on this case

Free sample · practice this case

Test yourself

One of 10 multiple-choice questions for this case. Pick an answer to see why.

Homeowners in St. Paul sue North Valley Heater Systems, alleging that a brass valve used in its residential boilers begins corroding as soon as ordinary tap water enters the system. The court allowed only class-certification discovery, and plaintiffs rely on a metallurgy expert who used accepted corrosion-testing methods. North Valley demands a final ruling now on whether the expert will be admissible at trial before any Rule 23 ruling may issue.

How should the court rule on North Valley's request?

Explanation. At class certification, the court must conduct a rigorous Rule 23 analysis, but it need not conclusively determine ultimate trial admissibility of expert testimony. The majority approved a tailored or focused Daubert inquiry aimed at reliability in light of the existing record and the purpose for which the opinion is offered. A full and conclusive trial ruling is not required at that preliminary stage, especially when merits discovery is incomplete.