| 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? |
| A) Introduce the heavy fuel oil and steam simultaneously establishing full flow of both fluids immediately to avoid thermal shock. |
| B) Introduce both the heavy fuel oil and steam simultaneously and gradually to avoid thermal shock. |
| C) Introduce the steam first, then gradually introduce the heavy fuel oil until full flow is established to avoid thermal shock. |
| D) Introduce the heavy fuel oil first, then gradually introduce the steam until full flow is established to avoid thermal shock. |
