Quality control valves for softeners and other filtration systems are available from well known manufacturers like Fleck and Autotrol.

Evoqua sanitary sampling valves are designed for the sterile sampling of high-purity water in many applications including laboratory, beverage, semiconductor and biopharmaceutical water systems. The products allow for mid-stream sample collection in water lines, resulting in truly representative sampling. The unique design eliminates bacterial and particle build-up that could interfere with bacteriological test results. Valves are operational up to 100 PSIg (7 bar) at 25°C and are available in 1/4" (for use with 1-1/2" or larger diameter lines) and 1/8" (for use with 3/4" or larger lines) NPT or weldable configurations.

Bacteriological analysis monitors can be directly attached to the Luer slip outlet on the valve, or flow can be directed into any type of container. Evoqua sanitary valves are complete with two 18-gauge blunt-end syringe needles (for sanitization), a spare set of seals, and two sealing caps (covers the Luer slip outlet to maintain sanitary conditions).