Pentair Piston Assembly with O-Ring

The Pentair Piston Assembly with O-Rings (Product #: 273111) is a factory-original OEM replacement internal fluid-routing module engineered to regulate dynamic water shifting within high-capacity pool and spa backwash loops. Specifically designed as the central mechanical core for Pentair and PacFab 2-inch side-mounted PVC push-pull slide valves—which are routinely paired with premium Triton® II sand systems, FNS® Plus, and Quad D.E.® vertical grid separation tanks—this complete piston shaft serves as the primary water diversion axis. Injection-molded from a thick-walled, ultra-high-impact engineering polymer composite, the structural rod features pre-seated, dual heavy-duty compression o-rings made from a premium elastomeric rubber compound that establishes an absolute hydraulic barrier against the internal valve walls. When an operator pulls or pushes the manual exterior handle, this central piston translates that physical energy smoothly inside the valve casing to re-route pressurized water columns up to 50 PSI between standard filtration, high-velocity backwashing, and rinse modes without causing internal fluid cross-contamination or pressure-side waste line weeping. The rugged polymer matrix offers permanent resistance to chemical degradation from high chlorine shock, salt-chlorine generation, and hard water mineral scaling without warping, sticking, or dry-rotting over time. The physical dry weight of this complete Pentair Piston Assembly with O-Rings is approximately 1.55 pounds (with a nominal boxed retail shipping weight of 2.00 pounds), providing pool service professionals and DIY homeowners with a durable, low-friction replacement standard for flawless filter pad water management.