The Bell & Gossett Circuit Setter Plus is a calibrated balance valve designed for pre-set proportional system balance. Since its introduction to the HVAC industry in 1968, the Bell & Gossett Circuit Setter has set the standard for proportionally balancing hydronic HVAC systems. This system balance method, developed by Bell & Gossett, assures optimum system flow balance at minimum pump operating horsepower. Valves can simply be pre-set using the B&G circuit setter balance valve calculator, curve booklet G10091, or the system syzer application for iPhone, iPad, or PC. Circuit Setters are available in a wide range of sizes and styles to meet all your system demands. Brass valves, in sizes 1/2 in through 3 in, utilize a full port ball valve with calibrated nameplate and feature a memory stop and two integrated pressure/temperature ports for easy Differential Pressure measurement.