Pentair 3-1/2" Union Nut Black

Pentair 3.5" Black Union Nut Replacement (98212200Z / 98212200)

The Pentair 3-1/2" Black Union Nut (Product #: 98212200Z / 98212200) is a factory-original OEM replacement hardware component designed to maintain rigid, leak-free plumbing connections across a broad selection of Pentair cartridge and diatomaceous earth (D.E.) filtration systems. This critical coupling collar is engineered for seamless compatibility with standard Clean & Clear®, Predator®, Warrior®, and EasyClean® aboveground filter lines, serving as the primary mechanical interface that locks external plumbing adapters tightly against the filter vessel's bulkhead. Injection-molded from a high-strength engineering thermoplastic polymer, this heavy-duty nut provides complete immunity to aggressive pool chemicals, high salt concentrations, and continuous mineral scaling, while its deeply saturated black composite formula features built-in UV stabilizers to prevent structural brittleness, warping, or cracking under intense outdoor weathering and high-temperature pump pad environments. The collar features thick, molded external ridges that allow service technicians or pool owners to easily generate maximum manual hand-tightening torque during seasonal assembly, securely compressing internal sealing gaskets and locking down union C-clips without stripping threads or requiring specialized wrenches. By continuously absorbing high-frequency system vibrations, hydraulic pressure spikes, and backpressure surges up to a standard rating of 50 PSI, this retaining nut effectively isolates fluid lines to prevent suction-side air induction or pressure-side water weeping. The physical weight of this standalone Pentair 3-1/2" Black Union Nut is approximately 0.25 pounds (with a boxed shipping weight of roughly 0.35 pounds), delivering a lightweight yet exceptionally robust, durable, and vital plumbing safeguard for pristine pool circulation networks.