The Fleck 9100SXT valve incorporates the time-tested design of the 9000 in a rugged, glass-reinforced Noryl, twin-tank control valve. Perfect for light commercial/heavy residential systems that require twin-tank conditioning capabilities. Six-cycle control regenerates with soft water immediately when needed keeping the system clean for optimum operating efficiency.Regenerates as often as every 90 minutes if required. Continuous flow rates up to 18 gpm on " valves. Handles up to 16" softeners. Bypass sold seperately