Which of the following is primarily vulnerable to oxygen pitting in a boiler?

Oxygen pitting in a boiler is primarily associated with superheaters due to their exposure to high temperatures and pressures, where the presence of oxygen in the water can lead to localized corrosion. Superheaters operate by transferring heat to steam, and any dissolved oxygen in the water can cause pits to form in the metal when it comes into contact with the superheater surfaces.

This localized attack occurs because oxygen can be particularly aggressive in high-temperature environments, stripping away protective oxide layers from the metal, leading to pitting corrosion. The unique conditions that prevail in superheaters—such as elevated temperatures and pressures—make them especially susceptible to this type of corrosion.

In contrast, while other components like feed water pumps, condensate return lines, and blow-off valves are also subject to corrosion, they typically do not experience the same level of localized pitting due to oxygen exposure as found in superheaters. These components are often designed to handle different operational conditions which do not favor the occurrence of oxygen pitting in the same way.