A thermostatic balancing valve has a sealed thermostatic "motor" in the flowstream of the valve body, which responds to temperature to open and close the valve to control water flow. The thermostat expands when heated which drives the valve seat toward closed, and contracts on falling temperature to open the valve seat. The linear action of the motor is calibrated with an opposing spring to control the stroke of the valve stem. Thermostatic balancing valve seats do not close completely; they must allow some water to flow across the thermostat so it can respond to changing inlet temperatures.
Caleffi's 116 Series ThermoSetter is a brand new, technologically advanced adjustable thermostatic balancing valve; the setpoint knob changes the spring tension for the thermostat which in turn changes the open/close setting of the thermostatic and valve seat. The ThermoSetter also has an optional temperature gauge and a choice of integral second cartridges for systems that implement thermal disinfection cycles for Legionella control. Check out all the 116 Series information on Caleffi's website!
Thermostatic balancing valves are relatively new choice for hot water recirculation circuits, compared to manual (a.k.a. pressure dependent or static) balancing valves and automatic (a.k.a. pressure independent or dynamic) balancing valves. Each type have their place, with varieties of features & benefits, and price point. Caleffi manufactures all types, such as our 142 Series and 130 Series Manual Balancing Valves, our 127 Series and 121 Series Automatic Balancing Valves, and our totally unique 132 Series QuickSetter. Contact us for more details on these too; we'll be glad to help.