Pentair 48 SqFt FNS Plus Tie Rod

The Pentair 48 SqFt FNS Plus Tie Rod (part number 59002100 or 59002100Z) is a critical internal structural fastener machined from corrosion-resistant, high-tensile stainless steel, engineered exclusively for the grid matrix configuration of Pentair FNS Plus 48-square-foot Diatomaceous Earth (D.E.) pool and spa filtration systems (model FNSP48). Measuring exactly 27.5 inches ($27-1/2"$) in length and featuring a slim 1/4-inch structural diameter with threaded ends, this specialized rod serves as the primary high-tension vertical spine that locks the entire filtration core together. It threads down through the exact center of the internal top manifold, extending through the core of the eight-piece vertical D.E. grid nest to anchor firmly into the lower collector hub. When the upper brass wing nut assembly is tightened down onto its top threads, the rod generates substantial axial compression that tightly clamps the manifold and bottom hub together, maintaining an unyielding structural alignment. This mechanical clamping prevents the 24-inch tall individual grid elements from shifting, tilting, or warping under the heavy, turbulent back-pressures of water circulation. By establishing a flawless structural seal against the internal alignment seats, it prevents unfiltered pool water or loose D.E. powder from bypassing the media core and blowing back into the pool while safely sustaining continuous internal operating pressures up to 50 PSI. Built to remain permanently submerged at the absolute center of the pressurized vessel, its commercial-grade stainless steel construction completely resists advanced oxidation, rusting, and material deformation from continuous exposure to sanitizers like chlorine, bromine, or routine scale-remover chemical acid baths. Due to its slender, solid steel rod geometry, this genuine replacement tie rod carries a nominal product and net shipping weight of approximately 0.28 to 0.35 pounds (about 4.5 to 5.6 ounces).