What equipment is used to expand tubes inside mud and steam drums?

• A. Rolling motors and espanders
• B. Hydraulic press and mandrel
• C. Belt sander
• D. Pipe cutter

Answer: (A)

Expanding tubes in mud and steam drums is done with a controlled swaging action that tightens the tube against the tube sheet. Rolling motors drive an expander with a set of dies that roll around the tube as it advances, plastically enlarging the tube’s outer wall so it bears firmly on the tube sheet. This method spreads the expansion force evenly around the circumference, creating a secure, leak‑tight joint that can withstand boiler pressure and thermal cycling. Other tools listed aren’t suited for this task: a hydraulic press and mandrel are used for different forming operations and can crush or misalign tubes; a belt sander is just for surface finishing; a pipe cutter only trims tubes and doesn’t form the joint.