What happens when the pH level in steam exceeds 9.0?

When the pH level in steam exceeds 9.0, silica's solubility decreases significantly. In water chemistry, a higher pH indicates a more alkaline solution, which affects the behavior of silica.

At elevated pH levels, silica tends to polymerize and precipitate out of solution. This reduction in solubility is crucial in steam systems because it helps to reduce the risk of silica deposits forming on turbine blades or heat exchangers, which can hinder their efficiency and performance.

A pH above 9.0 typically leads to a favorable condition where the potential for silica-related scaling is minimized. Therefore, managing pH within this range is an essential part of water treatment programs in power plants to ensure the longevity and efficiency of equipment operating with steam.