Pentair Fitting Injection with Check Valve | IntelliPH® Controller | 521510 FS2004 and TR140C-3 sand filters manufactured

and TR140C-3 sand filters manufactured before November 1999 only

inspect the air tube screen any time the tank is open

When these O-rings wear

Operates smoothly at wide salinity ranges of 2000-6000 ppm

O-rings on heater manifolds are subjected to repeated thermal cycling that degrades the seal over time

Pentair Fitting Injection with Check Valve | IntelliPH® Controller | 521510 FS2004 and TR140C-3 sand filters manufacturedThe 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