What is the advantage of the 'bent tube' method of installing tubes in a boiler?

• A. A comparatively greater amount of holes can be placed in a given area of the tube sheet.
• B. It reduces corrosion risk.
• C. It shortens construction time.
• D. It improves water flow.

Answer: (A)

The main idea is that the bent-tube method allows a higher density of tube holes on the tube sheet. By bending the tubes near the sheet, adjacent tubes can be arranged more closely without interference, so more tubes (and thus more holes) can fit into the same area. This increases the total heat-transfer area and the boiler’s potential capacity without needing a larger tube sheet. The other options aren’t the primary benefit of this method—corrosion risk, construction time, or water flow aren’t the main reasons bent tubes are used.