Brass plumbing fittings for Pex plumbing systems sold by Zurn Pex, Inc. are allegedly fail prematurely. Reports of failing fittings appear to be escalating. And that's where the concern lies—the brass fittings that join two pieces of flexible PEX pipe together are failing with the potential to cause water and mold damage.
Zurn Pex Plumbing Failures cause Damage

PEX (a generic term for cross-linked polyethylene) plumbing systems use flexible plastic tubes which are attached to brass fittings, instead of the traditional copper piping. Brass fittings are subject to "dezincification" which leaves the fittings subject to corrosion and failure.
Zurn has used also used the following names to describe its brass crimp fittings: "QestPEX Crimp System","Qicksert fittings" and"Qick/Sert Insert".
Zurn Pex Inc. has sold more than a million of the brass Pex fittings. While originally honoring its warranty, since receiving hundreds of claims from homeowners for damages resulting from the faulty fittings, Zurn Pex has stopped paying claims, and homeowners must for the damages themselves.