Pentair Triton II Buttress Thread Closure O-ring

The Pentair Triton II Buttress Thread Closure O-Ring (part number 152516 or 152516Z) is a high-pressure, specialty structural gasket engineered exclusively for sealing the dome access port on side-mounted fiberglass sand filtration vessels. Specifically designed for the updated "new style" 6-inch buttress-threaded clear or black lid assemblies (part number 152519Z), this seal is standard hardware across the full footprint of Pentair Triton and Triton II models (TR40, TR50, TR60, TR100, and TR140), while cross-complying with modern Tagelus filter valve adapters.

Unlike traditional rounded rubber seals, this component is precision-extruded as a square-cord "quad seal" profile measuring approximately 6.5 inches in outer diameter with a heavy-duty $1/4" \times 1/4"$ square profile featuring micro-grooves molded onto all four sealing faces. Its primary operational role is to sit flush within the perimeter seat of the filter’s threaded neck opening. As the large buttress lid is manually screwed down onto the top dome, the quad seal undergoes uniform compression, forming an absolute watertight and airtight boundary. This optimized sealing layout ensures that the filtration hull can safely manage severe pump startup thrusts and securely contain the heavy hydraulic circulation forces required by large-format sand filters, maintaining system pressure integrity up to 50 PSI without weeping or air leakage.

Built from a high-density, weather-stabilized elastomer compound to withstand the most demanding outdoor equipment pad environments, its durable matrix completely resists compression fatigue, material flattening, and dry-rotting from intense seasonal thermal expansion. Furthermore, its advanced composition resists degradation from chemical vapors and continuous exposure to high-strength sanitizers like chlorine, bromine, and routine maintenance acid washes. Due to its solid-profile, heavy-duty structural geometry, this individual replacement closure O-ring carries a net product and shipping weight of approximately 0.15 to 0.20 pounds (about 2.4 to 3.2 ounces).