Question 104Steam Plants - Assistant Engineer

The correct answer is A) to a depth greater than the thickness of the drum tube sheet. The correct method of expanding a generating tube at the boiler drum tube sheet is to roll the tube to a depth greater than the thickness of the drum tube sheet. This ensures a tight, secure fit between the tube and the tube sheet, preventing leaks and improving the overall integrity of the boiler system. Rolling the tube to a depth less than the thickness of the drum tube sheet (option C) would not provide a sufficient seal, while rolling it heavily or slightly at the tube end prior to welding (options D and B) are not the recommended techniques.