🔍 Key Concepts

• Boiler cooldown behavior and risk of vacuum forming in the steam drum • How water level changes as steam condenses during initial cooling • Why maintaining a safe margin above low-water level is critical for boiler integrity

💭 Think About

• As the boiler cools and steam condenses, what happens to the volume of steam space and the indicated water level in the gauge glass? • What are the potential dangers if the water level is allowed to become too low or go out of sight during cooldown? • Would you want the drum level during initial cooling to be lower than normal, at normal, or higher than normal for safest metal coverage?

✅ Before You Answer

• Check which choices could allow water level to go out of sight at any point during cooling and eliminate them for safety. • Consider which option best keeps all critical heating surfaces covered with water as long as possible. • Think about standard operating practice: during securing and cooldown, operators aim for a level that provides a safe reserve, not the bare minimum.