What is the identifying feature of a float-operated level control?

The identifying feature of a float-operated level control is that the float is submerged in the boiler drum. This design allows the float to rise or fall with the water level, thereby directly measuring the level of water in the boiler. As the water level changes, the float moves accordingly, which then communicates this movement to a control mechanism that can adjust water input or alert operators when the water level reaches set thresholds.

This method of level control is widely used because it provides a reliable and straightforward means of monitoring water levels, essential for safe boiler operation. The float's ability to physically respond to water level changes makes it a practical solution for continuous level management in various applications.

In contrast, relying solely on the size of the boiler may not accurately represent the functionality of float-operated controls, while monitoring the chemical composition of the water pertains to water quality management rather than level control. Additionally, recognizing swell and shrinkage is more about understanding changes in water volume due to temperature and pressure variations rather than the level control mechanism itself.