Question 352Steam Plants - Assistant Engineer

The correct answer is B) those tubes to overheat. Oil or scale deposits on boiler tube walls act as an insulator, preventing efficient heat transfer from the fire to the water. This causes the tube walls to overheat, which can lead to tube failure and potentially dangerous consequences. The other answer choices are incorrect: A) Decreased boiler steam pressure - Overheating tubes would actually cause increased steam pressure, not decreased pressure. C) Increased boiler steam pressure - Overheating tubes can increase steam pressure, but this is not the primary effect. D) An explosion in the boiler - Overheating tubes is more likely to cause tube failure and leaks, rather than a full-scale boiler explosion.