Pentair 36 SqFt FNS Plus Tie Rod

The Pentair 36 SqFt FNS Plus Tie Rod (part number 59021200 or 59021200Z) is a critical internal structural fastening component engineered exclusively for the vertical core assembly of the mid-capacity Pentair FNS Plus 36-square-foot Diatomaceous Earth (D.E.) pool and spa filtration system. Fabricated from heavy-gauge, corrosion-resistant marine-grade stainless steel, this elongated tension rod measures approximately 23 inches in length and features precision threads on both ends. Its primary structural role is to span the entire vertical height of the internal grid nest, passing directly through the center of the top manifold down to the lower grid locator template.

When tightened down with its corresponding brass or nylon locknuts, the rod acts as the central structural anchor that exerts continuous, heavy compressive force to bind the upper manifold, vertical D.E. grid elements, and lower locator into a single rigid, unified core assembly. This high-tensile stabilization prevents the grids from lifting, shifting, or vibrating out of alignment when hit by massive water distribution velocities and ensures the filter core safely sustains continuous internal operating pressures up to 50 PSI without hydraulic bypass or structural warping. Designed to remain permanently submerged in a highly dynamic, chemical-laden environment, its stainless steel architecture completely resists rust, pitting, and material fatigue from concentrated pool sanitizers like chlorine, bromine, and routine acid washes. Due to its slender, solid metal rod geometry, this individual 36-square-foot tie rod carries a net product and shipping weight of approximately 0.60 to 0.75 pounds (about 9.6 to 12.0 ounces).