Pentair Dyna-Jet™ O-Ring

The Pentair Dyna-Jet™ O-Ring (Product #: U9-374) is a factory-original OEM replacement sealing gasket engineered to establish an absolute, airtight hydraulic barrier within the internal assembly of high-performance pool, spa, and pressure-side booster pumps. Specifically designed to fit the premium Pentair Sta-Rite® Dyna-Jet™ series pumps, this specialized, large-diameter round-profile ring sits securely within the machined perimeter groove of the pump's diffuser or seal plate assembly. When the main pump housing bolts are tightened down, this gasket compresses uniformly to establish a positive pressure-side seal and block catastrophic suction-side air induction that would otherwise cause pump cavitation, loss of prime, or external water weeping. Molded from a high-grade, chemical-resistant nitrile rubber (Buna-N) compound, the component delivers exceptional structural elasticity, superior ozone resistance, and long-term compression memory, allowing it to withstand continuous exposure to high chlorine or bromine concentrations, heavy pool mineral scaling, and rapid thermal cycling without distorting, flattening, or dry-rotting. Built to comfortably manage continuous system operating line pressures and heavy water velocities, this flexible part ensures the entire circulation loop operates at peak hydraulic efficiency. The physical dry weight of this single Pentair Dyna-Jet™ O-Ring is approximately 0.02 pounds (roughly 0.32 ounces, with a nominal packaged shipping weight of 0.05 pounds), providing pool professionals and DIY homeowners with an essential, low-cost, and highly reliable hardware safeguard for flawless water management.