Why is boiler water chemically treated?

Boiler water is chemically treated primarily to prevent scale from forming on the boiler heating surfaces. Scale is a hard, mineral buildup that forms when certain dissolved solids precipitate out of solution as the water is heated. This scale acts as an insulating layer, reducing thermal conductivity, which can lead to inefficient heat transfer and can even cause overheating and damage to boiler components.

By treating the water chemically, various agents are added to control pH levels, precipitate hardness, and manage dissolved solids, which helps maintain the water quality within appropriate limits. Preventing scale buildup is crucial for ensuring the boiler operates efficiently and safely, prolonging its lifespan and reducing maintenance costs. Other treatments can also target corrosion and improve overall water chemistry, but the prevention of scale is one of the most critical aspects of maintaining boiler efficiency.