The principle function of any desuperheaters is to accelerate the phenomena of absorption of the spray water by the steam so that steady conditions of steam temperature are reached within a short distance from the outlet at all loads. This ensures that poor quality of steam or water droplets are not carried downstream in the steam pipeline. The purpose therefore, is to develop methods by which heat transfer between steam and water can be hastened. The main purpose is to break spray water droplets into very fine particles at all loads to ensure increased surface area for water to come in contact with the steam is available, thereby increasing the rate of evaporation. It is very clear that size of the water droplets should be smallest, utmost surface area available, absorption will be almost instantaneous and true temperature will be measured within shortest distance.

In all instances of desuperheating, the nature of the downstream steam and the avoidance of large spray water droplets that can be propelled at high speed to damage elbows, valve seats, heat exchanger tubes, or process material are very important factors while designing desuperheating system and equipment selection