The new Series 7000 SmartValve is a flow proportional control valve for use wherever chlorine or sulfur dioxide is needed to treat varying water flow rates. The unit can be factory configured to operate in either flow proportional or step rate control mode. It can be operated in the field four ways: fully automatic, electric/manual and two methods of manual. The valve is always linear when dosage is set at a 1-to-1 ratio because the unique linearization program in the microcontroller compensates for tolerance differences in valve plugs, rotometers and component parts. The unit also has an adjustable low-flow alarm circuit, consisting of an LED, and a relay alerts operators to flow transmitter problems.