When taking a shell-and-tube heat exchanger with a removable tube bundle such as a bayonet-tube heavy fuel oil service heater out of service, to prevent water hammer what statement represents the correct operating procedure?

Correct Answer: Option C — Crack open the condensate drains first. Gradually close down and secure the steam, then close the condensate drains when no longer draining condensate. Finally, secure the heavy fuel oil.

Under USCG National Maritime Center examination standards, the accepted correct answer is: Crack open the condensate drains first. Gradually close down and secure the steam, then close the condensate drains when no longer draining condensate. Finally, secure the heavy fuel oil..