Pictured units are for a blend application to maintain 5-grain hardness in treated water supply. The incoming hard water is blended with softened water to reduce overall hardness to 5 grains per gallon. Blend ratio is maintained throughout a wide range of flow. Two different size systems are shown. Each duplex is intended for installation at different areas with the same facility. Each system includes metered alternating operation with lead free brass multiport valves. Blending valve (not shown) is steel constructed. The valving automatically proportions the blend ratio to maintain a consistent blend stream regardless of flow. Left hand units are 42” FRP vessels with 30 ft3 of resin in each and 3” multiport top mount valve. Right hand units are 24” FRP vessels with 10 ft3 of resin in each and 3” multiport top mount valve.