Why is deaeration of boiler feedwater important?

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Removing dissolved gases, especially oxygen, from boiler feedwater is essential to prevent corrosion in the boiler and its piping. Oxygen in hot water accelerates rusting and pitting of metal surfaces, which can lead to leaks, failures, and costly maintenance. A deaerator heats the feedwater and uses steam to strip out these gases, so the water entering the boiler is much less aggressive toward the metal. This protection helps extend the life of boiler components, improves reliability, and supports efficient operation. Removing CO2 also reduces carbonic acid formation, further reducing corrosion tendencies.

Increasing oxygen content would make corrosion worse, not better. Adding minerals is not the purpose of deaeration, since minerals are addressed by water treatment downstream. Decreasing the water’s pH is not a goal of deaeration; removing dissolved gases, especially CO2, can actually raise pH slightly, which is still favorable for reducing corrosion.