Oxygen pitting mostly occurs in boiler tube down comers, steam ends of generating tubes, along with where else?

Oxygen pitting mostly occurs in boiler tube down comers, steam ends of generating tubes, along with where else?

• A. Economizers
• B. Water walls
• C. Superheaters
• D. Condenser tubes

Answer: (C)

Oxygen pitting is a corrosion process that occurs when dissolved oxygen in water leads to localized areas of corrosion, particularly in boiler systems. This phenomenon is most notably observed in high-temperature and high-pressure environments where water and heat interact closely. The superheaters in a boiler are critical components where steam is heated beyond the boiling point to increase efficiency and output. Due to the high temperatures and pressures present in superheaters, any dissolved oxygen in the water can aggressively attack the metal surfaces, leading to pitting. This makes superheaters particularly susceptible to oxygen pitting, especially because they often operate at temperatures where aggressive corrosive processes can thrive. In contrast, while economizers, water walls, and condenser tubes can also be affected by corrosion, they operate under different conditions that might mitigate the severity of oxygen pitting. For instance, economizers typically handle lower temperature water returning from the condenser, and water walls may have different exposure levels to corrosive agents. Therefore, the conditions in superheaters align perfectly with the characteristics that promote oxygen pitting, solidifying their place as a primary concern in the maintenance and operation of boiler systems.

Oxygen pitting is a corrosion process that occurs when dissolved oxygen in water leads to localized areas of corrosion, particularly in boiler systems. This phenomenon is most notably observed in high-temperature and high-pressure environments where water and heat interact closely.

The superheaters in a boiler are critical components where steam is heated beyond the boiling point to increase efficiency and output. Due to the high temperatures and pressures present in superheaters, any dissolved oxygen in the water can aggressively attack the metal surfaces, leading to pitting. This makes superheaters particularly susceptible to oxygen pitting, especially because they often operate at temperatures where aggressive corrosive processes can thrive.

In contrast, while economizers, water walls, and condenser tubes can also be affected by corrosion, they operate under different conditions that might mitigate the severity of oxygen pitting. For instance, economizers typically handle lower temperature water returning from the condenser, and water walls may have different exposure levels to corrosive agents. Therefore, the conditions in superheaters align perfectly with the characteristics that promote oxygen pitting, solidifying their place as a primary concern in the maintenance and operation of boiler systems.