In boiler operation, which device regulates draft?

In boiler operation, which device regulates draft?

• A. Pressure relief valve
• B. Draft control
• C. Circulator pump
• D. Mixing valve

Answer: (B)

Controlling the air entering the burner is essential for proper combustion in a boiler. The device that tunes this air flow to keep the flame stable and efficient is the draft control. It adjusts the air supply—often via a damper or a controlled fan—to either increase or decrease the draft as needed. If the draft is too strong, heat is wasted and the flame may become unstable; if too weak, combustion can be incomplete, producing smoke or carbon monoxide. The other devices don’t manage combustion air: a pressure relief valve vents excess pressure to protect the system; a circulator pump moves hot water through the heating loop; a mixing valve blends hot and cold water to control outlet temperature. So the draft control is the one that regulates draft.

Controlling the air entering the burner is essential for proper combustion in a boiler. The device that tunes this air flow to keep the flame stable and efficient is the draft control. It adjusts the air supply—often via a damper or a controlled fan—to either increase or decrease the draft as needed. If the draft is too strong, heat is wasted and the flame may become unstable; if too weak, combustion can be incomplete, producing smoke or carbon monoxide. The other devices don’t manage combustion air: a pressure relief valve vents excess pressure to protect the system; a circulator pump moves hot water through the heating loop; a mixing valve blends hot and cold water to control outlet temperature. So the draft control is the one that regulates draft.