SMC (6940090) 694 Series PVC NSF Check Valve ; 1/4"FNPT x 1/4"FNPT Buna Activated Alumina1459 This dual-media design significantly extends

This dual-media design significantly extends filter life compared to carbon-only cartridges while addressing chlorine

Keep a spare on hand as these wear components typically last 5-7 years in normal residential service

Works in both RO systems and whole-house filter configurations

ensuring reliable brine draw and regeneration cycles

SMC (6940090) 694 Series PVC NSF Check Valve ; 1/4"FNPT x 1/4"FNPT Buna Activated Alumina1459 This dual-media design significantly extendsThe SMC 6940090 is a 1 4" FNPT threaded PVC check valve from the 694 Series, NSF certified with a Buna N seal for reliable one way flow protection in residential and commercial water systems. This compact valve prevents backflow and protects pumps, filters, and RO membranes from reverse pressure damage. SPECIFICATIONS SMC 694 Series Check Valve Technical Details Model Number SMC 6940090 Series 694 Series Connection Type 1 4" FNPT x 1 4" FNPT Body