Zurn PEX® CR Polymer Male Adapter. The QQPMC55FX adapter is used to transition from female pipe thread to PEX tubing. Molded from Acudel®. These fittings, as a system with Zurn PEX® tube, are pressure rated at 160 PSI at 73 deg F, 130 PSI at 120 deg F (fire protection rating),100 PSI at 180 deg F, and 80 PSI at 200 deg F. These fittings are listed by NSF as complying with the following standards: NSF/ANSI Standard 14, NSF/ANSI Standard 61, ASTM F877, CSA B137.5, ASTM F2159, and UL 1821.