🔍 Key Concepts

• Boiler heat-up and expansion: why certain parts must be open to allow drainage and venting when lighting off • Purpose of superheater and economizer drains and vents during startup • What can happen if water or air is trapped in heated components (water hammer, tube damage)

💭 Think About

• Think about which components need to be free to drain or vent when you first apply heat to a boiler and its attached systems • Ask yourself: which valve, if left OPEN, could allow unwanted flow or loss of fluid that is not desirable during initial firing? • Consider which devices (superheater, economizer, drum) are most vulnerable to damage if condensate or air is not properly removed at light-off

✅ Before You Answer

• Identify which valves are normally kept open during boiler warm-up to allow safe drainage and venting • Consider which valve, if left open, would defeat its own safety/operating purpose at the moment of lighting off • Verify which component (superheater, economizer, drum) should already be full and not draining when you first light off the boiler