Question 25Steam Plants - QMED

The correct answer is A) The furnace must first be purged of combustible vapors with the forced draft blower while the air register doors are open. Explanation: Before initially lighting off an idle boiler, it is critical to purge the furnace of any combustible vapors to prevent a dangerous flare-back or explosion. This is typically done by running the forced draft blower with the air register doors open, which allows the blower to effectively clear the furnace of any flammable gases or vapors. Keeping the air register doors open ensures proper airflow and ventilation during the purge process. The other answer choices are incorrect as they either call for purging inert vapors instead of combustible ones, or they specify closing the air register doors, which would inhibit the purging process.