🔍 Key Concepts

• Flash point and why it matters for fuel oil safety • Layout of a main boiler fuel oil service system from settling tank to burner • Where fuel is under pressure in enclosed piping versus stored with air space above it

💭 Think About

• Think about what happens if fuel above its flash point is in a tank or suction line that has an air space or potential for vapor release. • Ask yourself: in which segment is the fuel closest to controlled combustion (the burner) and fully contained in a tight, pressurized system? • Which sections of the system would present the greatest fire/explosion risk if the fuel temperature exceeded the flash point?

✅ Before You Answer

• Identify which choices include any tanks, vents, or suction lines that might have air/vapor space. • Note where the service heater sits in relation to the pump and the burners and what the heater’s purpose is. • Verify in your mental diagram which segment is short, enclosed, and immediately upstream of the burner atomizers.