A Rada "R" Series Thermostatic Mixing Valve from Armstrong gives you everything you need for consistent, total control of your central recirculating hot water system, like low seepage and larger capacity. Rada "R" Series valves have a flow-modulating internal design, which means that while it can deliver 100 gpm, it will also control temperature I2?F at flows as low as 2 gpm. Rada "R" series valves feature a unique thermostatic return-limiting valve that monitors returning water temperatures and eliminates dangerous overnight temperature creep.Armstrong International, Inc.