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 Bell & Gossett Circuit Setter® Balance Valve Calculator, curve booklet G10091, or the System Syzer application for iPhone, iPad, or PC,Circuit Setter®s 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 P measurement. Additionally, All brass Circuit Setter®s are CSA certified to be in compliance with the low lead requirements of California, Vermont, Maryland, Louisiana, and NSF//ANSI 372.For larger sized systems, Circuit Setter®s are available in ball style (2-1/2 to 4 in) and globe style (4 to 12 in). Our globe style valves include a multi-turn stem, calibrated nameplate, memory button for easy re-setting of the valve position after shut-off/isolation, and integrated pressure/temperature ports.