Mechanical Spray Desuperheater (MSD) – This is the simplest type of Desuperheater, consisting of a fixed area nozzle arranged to face downstream at or near the Desuperheating pipe. The MSD relies on the pressure differential available across the nozzle to achieve the conditions for rapid absorption of the water into the steam.
Variable Spray Desuperheater (VSD) – Variable nozzle spray Desuperheaters are recommended for low load conditions as their design allows for the spray nozzle area to be reduced.