Corrosion in the flue pipe may occur if the flue gas temperature is:

Corrosion in the flue pipe is primarily influenced by the temperature of the flue gases in relation to the dew point. When the flue gas temperature is below the dew point, the water vapor in the flue gases condenses into liquid water. This condensation can lead to the formation of acidic products, particularly when the flue gases contain sulfur dioxide or other corrosive compounds. The presence of these acidic condensates can significantly accelerate the corrosion process in the flue pipe.

Maintaining flue gas temperatures above the dew point is crucial to preventing condensation and the subsequent corrosion it causes. This is why understanding the relationship between flue gas temperatures and the dew point is essential for the maintenance and longevity of oil burner systems.