Which control mechanism regulates the amount of fire in the burner?

The modulating pressure control serves as a vital component in regulating the burner flame by adjusting the amount of fuel and airflow to the burner. This mechanism continuously monitors the pressure within the boiler and modulates the fuel supply accordingly to maintain the desired pressure set point. When the pressure drops below the set point, the modulating pressure control increases the fuel and air supply to create a larger flame, which raises the pressure back to the desired level. Conversely, if the pressure exceeds the set point, this control decreases the fuel flow, thereby reducing the size of the flame.

This dynamic adjustment is crucial for ensuring efficient and safe operation, as it helps maintain the boiler's performance while preventing the risks associated with overpressure. Other control mechanisms, though important for safety and operational efficiency, do not specifically regulate the burner flame size in the same continuous and responsive manner. For instance, the low water cutoff protects against boiler operation with insufficient water, high limit control prevents excessive temperatures, and feedwater control manages the water supplied to the boiler, but none of these directly modulate the fire in the burner itself.