Pentair Black Manual Air Relief Assembly

The Pentair Black Manual Air Relief Assembly (most commonly referenced under part number 273550Z or the High Flow™ equivalent 98209800) is a critical external safety and venting control valve engineered for the upper tank crowns of a wide array of Pentair pool and spa filtration systems. This heavy-duty component is extensively used across premium filtration equipment lines, including the Pentair FNS, FNS Plus, Nautilus Plus, and SM/SMBW 4000 Series Diatomaceous Earth (D.E.) filters, as well as the Clean & Clear and Clean & Clear Plus cartridge series. Injection-molded from thick-walled, high-impact, and UV-stabilized black polymer composites, this manual valve features integrated fine threaded or quick-connect integration ports. Its primary operational role is to allow pool technicians and homeowners to safely vent accumulated pocketed air out of the absolute peak of the filter dome during pump start-up cycles.

By manually turning the ergonomic lever or cap, trapped air is cleanly expelled from the core, preventing internal pressure-lock, establishing an optimized completely flooded hydraulic state, and protecting the filter body from dangerous air-bound structural shock waves up to standard system operating parameters of 50 PSI. Built to endure relentless outdoor environment weathering, intense direct sunlight exposure, and continuous contact with harsh sanitizers like chlorine, bromine, and winterizing acid flushes, its robust engineering completely resists structural warping, leaking, and thread degradation. Due to its ultra-compact, high-strength plastic geometry and lightweight internal O-ring seal, this individual manual air relief assembly carries a net product and shipping weight of approximately 0.30 to 0.85 pounds (about 4.8 to 13.6 ounces).