🔍 Key Concepts

• Flame safeguard control system purpose on an automatic boiler • Relationship between combustion fuel supply and boiler pressure • Typical safety shutdown conditions on an auxiliary boiler (e.g., low water, high pressure, flame failure)

💭 Think About

• Which of the listed items, if it becomes too high, would most quickly create an overpressure or unsafe firing condition in the boiler? • Think about what conditions are normally controlled by separate protective devices (like low-water cutouts or safety valves) versus what the flame safeguard is designed to stop by cutting off fuel. • Which option has the most direct link between continued fuel firing and a dangerous rise in boiler operating conditions?

✅ Before You Answer

• Verify which condition is directly managed by fuel cut‑off to prevent overfiring, not by a mechanical relief device. • Eliminate any choice that is not normally a boiler operating parameter (something the boiler does not routinely measure as a control point). • Consider which parameter, when excessive, would standardly trigger a high‑limit shutdown on an automatic auxiliary boiler.