Plant Operation Practice Test

Before lighting off a boiler during a cold startup, what must an operator do regardless of the fuel type?

1. Open all vents

2. Close all boiler main steam stop valves

3. Check the fuel level

4. Start the feedwater pump

The correct answer is: Close all boiler main steam stop valves

The correct action before lighting off a boiler during a cold startup is to close all boiler main steam stop valves. This step is critical for safety and operational integrity. Closing the steam stop valves ensures that steam does not escape from the boiler during the startup process, which could lead to pressure imbalances and potentially unsafe conditions. Additionally, it helps to establish the necessary pressure within the boiler once it begins to heat up. It's also important to note that while checking the fuel level, opening vents, and starting the feedwater pump are integral tasks in the broader startup procedure, they do not specifically address the immediate safety concerns associated with boiler pressurization and steam containment at the beginning of the lighting-off sequence. Therefore, closing all main steam stop valves is the fundamental step that must be taken first to ensure a safe and controlled environment for the lighting off process.