The SW‑26‑855 3/4″ stainless steel air vent strainer is a direct replacement for OEM part 172855, designed for FNS, Nautilus, and Nautilus Plus DE filters. It allows trapped air to escape while preventing debris from entering the air relief system—ensuring safe, efficient, and long-lasting filtration performance.

Key Features:

• Direct OEM Replacement (Part 172855): Precisely matches specifications of Pentair 172855—guaranteeing compatibility with FNS, Nautilus, and Nautilus Plus DE filters. 

• Stainless Steel Construction: 3/4″ body resists corrosion and pool chemicals for reliable long‑term use.

• Two‑Function Design: Allows air to escape freely while blocking debris from entering the vent system, supporting consistent filter operation. 

• Precision Fit: Engineered for easy, secure installation and a snug fit within compatible filter tanks. 

• Compact & Lightweight: Weighs approximately 0.05 lb for convenient handling and storage.

• Essential for System Balance: Keeps internal tank pressure regulated and ensures efficient water circulation. 

Product Overview:
The SW‑26‑855 air vent strainer serves a critical function in DE-style pool filters by enabling trapped air to escape while preventing contaminants from entering the air relief pathway. Crafted from high-quality stainless steel, this 3/4″ strainer offers outstanding corrosion resistance and durability. It’s a reliable, OEM-spec replacement for Pentair part 172855, perfectly suited for FNS, Nautilus, and Nautilus Plus filter models.

Whether you're replacing a worn-out component or stocking spare parts, the SW‑26‑855 ensures your filtration system maintains proper pressure balance and uninterrupted flow. Its precise fit and robust design make it a simple yet invaluable addition to your pool maintenance essentials.