How does a feedwater regulator maintain water level in a boiler?

The feedwater regulator maintains the water level in a boiler primarily by controlling the flow of water into the boiler. This regulation is crucial because a consistent water level is essential for safe and efficient operation. If the water level drops too low, it risks damaging the boiler and can lead to unsafe operating conditions, while too high a water level can cause water carryover into the steam system, leading to operational issues.

The feedwater regulator achieves this by monitoring the water level and automatically adjusting the incoming water flow to either increase or decrease the amount of feedwater based on the current level in the boiler. This dynamic response ensures that the boiler maintains the appropriate water level for optimal functioning.

Other methods listed, such as releasing excess steam or adjusting fuel supply, do not directly contribute to maintaining the water level. While steam release is important for pressure management and fuel supply adjustments are necessary for temperature control, they do not address the specific function of maintaining water levels like the feedwater flow control does. Similarly, changing the feedwater temperature, although important for efficiency, does not equate to controlling the actual water level in the boiler.