Pentair 170022 – Replacement Tank Lid for FNS Plus 60 sq ft DE Filter

The Pentair 170022 is the OEM replacement tank lid assembly designed for the FNS Plus 60 sq ft diatomaceous-earth (DE) pool filter. This lid closes and seals the filter tank, ensuring the internal pressure and flow–through during filtration and backwash cycles are maintained properly.

Key Features

• Tank lid assembly sized for 60 sq ft FNS Plus DE filters (model FNSP60).
  
• Manufactured from pool-rated, corrosion-resistant materials compatible with DE filtration systems.
• OEM-spec part — designed to match the original FNS Plus tank geometry and clamp assembly for a correct, leak-free fit.

Specifications

• Brand: Pentair
• Part Number: 170022
• Intended Filter Model: FNS Plus 60 sq ft DE filter (FNSP60 and compatible variants)
  
• Material: Pool / DE filter-rated thermoplastic / molded plastic suitable for pressurized filter tanks

When to Use / Replace

Replace the 170022 lid if the original is cracked, warped, leaking. Replacement is also necessary if the lid can no longer form a reliable seal — common causes include freeze damage, impact damage, or chemical degradation. A proper tank lid is critical to maintain safe, efficient filtration performance in DE filters.

Installation & Maintenance Tips

• Turn off the pump and relieve all pressure before removing the old lid — always ensure the system is depressurized before maintenance.
• Inspect the sealing surface on top of the filter tank and the gasket / O-ring (if present) — clean or replace as needed to ensure a tight seal.
• Transfer the pressure gauge and air-relief valve from the old lid to the new one, ensuring components are properly seated and tightened.
• Re-install the clamp band (or clamp ring) evenly around the tank, gradually tightening to avoid deforming the lid or tank.
• After installation, refill and prime the system — check for leaks at the lid seam, clamps, and around the air-relief before running the pump under full pressure.
• Periodically inspect the lid for cracks, UV degradation, or chemical damage — replace immediately if the integrity is compromised.