When placing a shell-and-tube heat exchanger with a removable tube bundle such as a bayonet-tube heavy fuel oil service heater into service, to avoid thermal shock what statement represents the correct operating procedure?

Correct Answer: Option D — Introduce the heavy fuel oil first, then gradually introduce the steam until full flow is established to avoid thermal shock.

Under USCG National Maritime Center examination standards, the accepted correct answer is: Introduce the heavy fuel oil first, then gradually introduce the steam until full flow is established to avoid thermal shock..