Pentair Fitting Injection with Check Valve | IntelliPH® Controller | 521510 FS2004 When these O-rings wear

When these O-rings wear

Even if the gasket appears intact

Length 19 1/8" Outer Diameter 7" Top Inner Diameter 3" Bottom Inner Diameter 3" Material 4 oz

In-Line (incl 2" inlet and outlet ports) CL2002S Hayward Automatic Chlorine Feeder

Pentair Fitting Injection with Check Valve | IntelliPH® Controller | 521510 FS2004 When these O-rings wearThe Pentair Fitting Injection with Check Valve (521510) is the OEM replacement injection fitting assembly for the Pentair IntelliPH pH controller system. This fitting serves as the chemical injection point where the IntelliPH controller delivers pH adjusting solution directly into the pool's return line. The integrated check valve prevents backflow of pool water into the chemical feed line, protecting the controller's dosing mechanism and maintaining