Pentair 25" Upper Half Tank Lid Kit

The Pentair 25" Upper Half Tank Lid Kit (part number 24851-9001) is a critical, heavy-duty replacement pressure vessel component engineered exclusively for the dual-shell housing of Sta-Rite System:3 modular pool and spa filtration systems, encompassing the S8M150 and S8M500 cartridge series, S8D110 D.E. configurations, and S8S70 sand filters. Injection-molded from a thick-walled, fiberglass-reinforced thermoplastic composite, this expansive dome lid serves as the entire top half of the filter tank chassis. Its primary structural and operational role is to align precisely with the matching lower tank shell, establishing an absolute airtight and watertight containment boundary when locked down by the main perimeter clamp ring. This allows the high-capacity filter to safely manage massive water distribution velocities and sustain continuous internal hydraulic operating pressures up to 50 PSI without weeping, flexing, or risking sudden structural blowout. The kit typically comes complete with the factory warning decals and pre-molded top ports configured to accommodate the manual air relief valve and pressure gauge assembly. Engineered to endure decades of relentless outdoor UV exposure, intense seasonal temperature shifts, and corrosive chemical environments containing concentrated chlorine, bromine, or acid washes, this robust upper shell prevents hairline stress fractures and structural warping. Due to its rigid, thick-gauge composite construction and wide, 25-inch diameter profile built to withstand intense internal forces, this individual upper tank half carries a net product weight of approximately 29 pounds (with a dimensional shipping weight that can range higher depending on packaging configurations).