How can caustic corrosion be prevented in lower pressure boilers?

Maintaining caustic corrosion at bay in lower pressure boilers is effectively achieved by implementing a scale prevention program using substances like phosphates or chelates. This approach helps to control the formation of scale deposits on the boiler surfaces and ensures a uniform distribution of alkalinity throughout the water.

In the context of lower pressure boilers, caustic corrosion occurs primarily due to high concentrations of sodium hydroxide, which can concentrate in areas of low water flow or in the presence of scale. By utilizing a program that incorporates phosphates or chelates, the risk of concentrated caustic environments is minimized. These agents aid in maintaining proper water chemistry, facilitating the removal of scale, and preventing the localized pH increase that leads to caustic corrosion.

While maintaining high pH levels can be related to preventing corrosion, it is not the sole measure and can lead to issues if not managed correctly. Increasing boiler temperature does not directly prevent caustic corrosion and can potentially exacerbate it under certain conditions. Avoiding the use of sodium hydroxide is beneficial but does not address the root cause of scale formation effectively, which is why a comprehensive scale prevention program is the best preventive measure in this scenario.