Which of the following provisions for thermal expansion for shell-and-tube heat exchangers only requires a single tube sheet located at one end?

Correct Answer: Option B — A shell-and-tube heat exchanger featuring U-tube type tubes.

U-tube heat exchangers utilize a single tube sheet where both ends of the U-shaped tubes are secured. This design allows the entire tube bundle to expand and contract freely within the shell without mechanical stress, eliminating the need for a floating head or complex expansion joints in marine machinery.