What device is used to reduce superheat of steam before it enters the system, protecting equipment?

• A. Attemperator
• B. Regulator
• C. Dampener
• D. Governor

Answer: (A)

Reducing the temperature of steam before it enters equipment helps prevent thermal stress and damage to turbines, boilers, and piping. The device used for this purpose is an attemperator, also known as a desuperheater. It injects a controlled amount of water into the superheated steam flow, and the water absorbs heat as it vaporizes and mixes with the steam. This cooling brings the steam down to or near its saturation temperature, protecting equipment from overheating and improving control of the process.

The amount of water sprayed is adjusted by a control system that monitors steam temperature (and sometimes pressure). Too little spray and the steam remains overly superheated; too much spray can reduce steam quality or affect pressure. The attemperator is specifically designed for this cooling task, making it the most appropriate choice for protecting equipment.

Regulators, dampeners, and governors serve different roles—regulators control pressure, dampeners smooth out flow or dampen fluctuations, and governors control speed—so they don’t directly address lowering steam superheat.