Which device helps ensure the boiler maintains the desired level of pressure?

The device that helps ensure the boiler maintains the desired level of pressure is the pressure switch. A pressure switch monitors the internal pressure of the boiler and activates or deactivates a pump or burner based on preset pressure levels. When the pressure drops below or exceeds the set threshold, the pressure switch will trigger an action to either add more heat or allow for cooling to restore the pressure to the desired range. This reliable mechanism is vital for the safe and efficient operation of a boiler, as it helps to prevent dangerous overpressurization and ensures that the boiler operates within ideal parameters.

In contrast, while an expansion tank may accommodate pressure fluctuations in a closed system, it does not directly control or regulate pressure levels. A pneumatic actuator is primarily used for controlling valves with compressed air, and a flow meter measures the flow rate of liquids or gases but does not influence pressure levels directly. Therefore, the pressure switch stands out as the key component in maintaining the appropriate boiler pressure.