Zurn PEX® XL-Low Lead Brass Barb x Female Thread Swivel Adapter. The QQSFC__GX adapter is used to transition from PEX to 1 in male pipe threads, such as on QickPort® manifold inlets and outlets. Manufactured from EcoBrass®,C69300. These fittings, as a system with Zurn PEX® tube, are pressure rated at 160 psi at 73 deg F, 100 psi at 180 deg F and 80 psi at 200 deg F.