Pentair 21" and 25" Air Bleed Assembly

The Pentair Air Bleed Assembly (part number 154593) is a critical internal air-relief safety and operational component engineered exclusively for the upper dome section of medium-to-high capacity sand filtration systems. This specialized, high-flexibility venting hardware is designed specifically for Pentair Triton and Triton II side-mount high-rate sand filter models—most notably the 21-inch diameter TR40 and 25-inch diameter TR60 vessels.

Injection-molded from a durable, high-impact, and chemically inert polymer composite material, the assembly consists of a long, flexible internal air-bleed tube integrated with a fine mesh, non-clogging collector strainer screen cap at its upper terminal apex. Its primary operational role is to establish a continuous, low-resistance venting conduit that floats at the very peak of the filter's pressurized water chamber, just underneath the top access dome.

During active filtration cycles, dissolved air bubbles and pocketed gases naturally separate from the incoming pool water and rise to collect at the top of the tank. The air bleed assembly captures this trapped air and channels it cleanly downward through the internal plumbing framework and out through the manual air relief valve on the tank exterior. By continuously evacuating these gaseous pockets, it prevents the filter from becoming air-bound, maintains optimal internal hydraulic balance, and ensures that the entire sand bed surface area remains fully utilized for filtration. Furthermore, this automated venting mitigates the risk of severe pressure spikes or localized water-hammer effects, allowing the filter system to safely sustain continuous operating pressures up to 50 PSI without experiencing structural lid stress or joint weeping under sudden pump startup surges.

Built to remain permanently submerged at the highest and most volatile pressure point of the filter core, its rugged polymer matrix and fine fabric mesh screen completely resist structural warping, material brittleness, and advanced chemical degradation from prolonged exposure to high-velocity water currents, intense heat shifts, and concentrated sanitizers like chlorine, bromine, and winterizing acid washes. Due to its slender, elongated tube profile and lightweight plastic strainer hardware, this individual air bleed replacement assembly carries a nominal net product and shipping weight of approximately 0.15 to 0.30 pounds (about 2.4 to 4.8 ounces).