What is the function of caustic soda in boiler systems?

Caustic soda, or sodium hydroxide, plays a critical role in boiler systems primarily by controlling alkalinity in boiler feedwater. Maintaining proper alkalinity is essential to prevent acidic conditions which can lead to corrosion of the boiler's components. When caustic soda is added to the feedwater, it increases the pH level, which helps in forming a protective layer on the metal surfaces. This protection is crucial in minimizing the risk of pitting and corrosion, ensuring the longevity and efficiency of the boiler.

The controlled alkalinity also aids in preventing scale formation, which can interfere with heat transfer and ultimately affect the system's efficiency. By managing these chemical properties, caustic soda ensures that the boiler operates safely and efficiently, directly contributing to the overall health of the system.