What can cause overheating of tubes on a boiler?

The overheating of tubes in a boiler is significantly influenced by the presence of scale on the tubes. When scale accumulates on the surfaces of the tubes, it creates a layer of insulation that hinders the effective transfer of heat. This insulation effect prevents the water in contact with the tubes from absorbing sufficient heat, causing the metal of the tubes to reach higher temperatures than intended. As the temperature of the tube metal increases, it can lead to damage such as tube rupture or failure due to thermal stresses.

In conjunction with other factors like low water levels or excessive feed water temperatures, scale accumulation can exacerbate overheating issues within a boiler system, making it essential to regularly inspect and clean boiler tubes to prevent scale buildup. This maintenance helps ensure proper heat transfer and safe operation of the boiler.