If the deaerator is not functioning, what happens to feedwater dissolved gas content?

• A. It increases
• B. It decreases
• C. It remains the same
• D. It becomes pure water

Answer: (A)

Deaeration removes dissolved gases from feedwater by heating and venting noncondensable gases. If the deaerator isn’t functioning, those gases aren’t removed, so the feedwater ends up with more dissolved gases, especially oxygen. This higher gas content promotes corrosion in the boiler and piping. The water won’t become pure; it will simply carry an increased amount of dissolved gases.