Which type of exchanger requires only one end for plugging tubes?

• A. Plate
• B. Hairpin
• C. U-tube
• D. Shell-and-tube

Answer: (B)

Isolating a damaged tube by plugging depends on how the tubes are laid out. In a hairpin heat exchanger, each tube is bent into a U shape and both ends of that tube exit on the same side of the shell. That means a plug can be inserted from that single access point to seal the tube, so you don’t need to reach the opposite end. In other designs, like shell-and-tube or U-tube configurations, the two ends of a tube sit on opposite tube sheets, making it necessary to plug both ends to fully isolate a leaking tube. Plate exchangers have no tubes to plug. So the hairpin design uniquely allows plugging from just one end.