Glycol tracing is used for various pipe line and equipment heating applications. HAT (Heat Actuated Trap) or TV/HAT (Tube Valve Heat Actuated Trap) valves are placed at the end of trace lines to regulate glycol return temperature which helps to provide the correct flow of glycol for optimum use of energy.
To control temperatures in glycol heat tracing systems, HAT or TV/HAT valves will maintain the discharge temperature. When glycol temperature exceeds the set point, the valve will modulate closed. As heat loss occurs and glycol cools to below the set point, the valve will open to allow warmer glycol to circulate.