Heat transfer pump

A heat transfer pump is a pump used for circulating heat transfer fluids, e.g. for maintaining the heat transfer fluid circulation in a heating system. 

Since the temperature of thermal oils can reach up to 350 °C, a cooling section (usually with air) must be used between the pump casing and the shaft seal to reduce high temperatures so that normal product-lubricated plain bearings (e.g. carbon bush) and standard mechanical seals can be employed. See Fig. 1 Heat transfer pump