Pentair Chemical Resistant 1-1/2" x 2" Check Valve

The Pentair Rainbow R172288 is a spring loaded check valve made for the one job most check valves fail at: sitting downstream of a chlorine feeder. Its spring and seal are chosen for corrosive service, so chlorinated water does not eat the valve that is supposed to protect the rest of the equipment.

Why it belongs after the chlorinator

When the pump shuts off, the concentrated solution in a tablet feeder can flow backwards into the heater, filter and pump. That is how heat exchangers get pitted and how pump seals fail early. Installed between the feeder and the equipment, this valve lets water pass only toward the pool and holds everything else back. Pentair shows it in the installation drawings for the Rainbow 300 series and 320 feeders as well as the 302, 300-19, 300-29, 322, HC-3315, HC-3330 and 3340.

Fit and installation

One end is a 1-1/2 in. slip socket and the other is a 2 in. spigot, so it solvent welds straight into either pipe size. The 2 lb spring is fully enclosed and closes the valve in any orientation, which means it can go in a vertical or horizontal run wherever there is room. The full free flow design keeps the pressure drop low.