🔍 Key Concepts

• Function of the steam drum during normal operation and during cooldown • What happens to pressure and volume of steam as a boiler cools (basic gas laws) • How boilers are protected from damage when pressure and temperature change

💭 Think About

• Think about what happens inside the steam drum as the boiler cools and steam condenses. Does pressure increase, decrease, or stay the same? • If the steam condenses and the space is sealed, what could happen to the pressure inside relative to outside atmospheric pressure? • Which of the choices describes something that would protect the boiler structure (drum and connected parts) during this cooling and pressure change?

✅ Before You Answer

• Identify whether the main concern during cooldown is excess positive pressure or excess negative pressure (vacuum) • Consider which components (drum, superheater, etc.) are directly affected by changes in pressure inside the steam space • Verify which option best matches a standard safety practice when taking a boiler out of service and letting it cool