A fixed orifice plate is generally installed in the live steam supply to a flash evaporator. One of the functions of this orifice is to control the quantity of the supplied steam. A second function is to __________.

Correct Answer: Option D — reduce pressure fluctuations of the steam supply in the salt water feed heater

A fixed orifice plate in the steam supply line acts as a flow restrictor. Beyond controlling steam quantity, it creates a pressure drop that dampens downstream fluctuations. This stabilization ensures a steady heat input to the saltwater feed heater, preventing erratic flashing and maintaining consistent evaporator performance despite boiler pressure variations.