🔍 Key Concepts

• Boiler flareback: what it is and why it happens (ignition of unburned fuel in the furnace or burner register) • Normal emergency actions when there is fire or explosion risk in fuel-fired equipment • Relationship between fuel flow, air (forced draft), and safe combustion in a boiler

💭 Think About

• In a flareback, is the immediate danger more related to fuel, air, or steam pressure? Which one do you address first to prevent escalation? • Think about which action most directly and quickly removes the source feeding the flareback. • Which option could actually make the flareback worse by providing more energy (either fuel or air) to the furnace?

✅ Before You Answer

• Identify which choice immediately stops or isolates fuel to the burner, not just reduces load. • Check if any option would increase combustion intensity (more fuel or more draft) and therefore is unsafe during a flareback. • Consider standard boiler emergency shutdown procedures: what is the first protective step when you suspect fire or explosion at the burner?