🔍 Key Concepts

• Relief valve function in any pressurized liquid system • Difference between pressure protection and pressure regulation/control • Where a relief valve is usually installed in a fuel oil service system (suction side vs discharge side of pump)

💭 Think About

• Ask yourself: What happens to the fuel oil system if the discharge line or downstream valves become restricted or closed while the pump keeps running? • Which component in a fuel oil system is specifically designed to open only when pressure gets too high, and where does the excess oil go? • Which options describe a normal continuous control function, and which describe an emergency or safety‑type function?

✅ Before You Answer

• Identify which choice describes overpressure protection rather than normal pressure control. • Think about what would be damaged first if discharge pressure became too high: what is the valve trying to protect? • Eliminate any options that sound like they provide continuous regulation of burner or atomizer pressure instead of acting only when pressure is excessive.