How does a float-operated low water cut off work?

A float-operated low water cut-off functions by detecting the water level in a boiler and using a float mechanism to ensure safe operation. When the water level in the boiler drops to a certain point, the float descends and activates a switch. This switch is critical because it signals the boiler control system to shut off the fuel supply or deactivate the boiler to prevent it from running dry, which could lead to overheating and potential damage to the boiler components.

The operation of the low water cut-off is essential in maintaining safe boiler operation, as it prevents situations where low water levels could compromise the boiler's integrity. When water levels drop beyond a safe limit, the float mechanism will trigger the shutdown sequence, providing an automatic safeguard.

In contrast, some of the other options present functions unrelated to the specific operation of a float-operated low water cut-off. For instance, manually adjusting the fuel valve does not involve automatic controls; activating an alarm when water levels are high is not the primary function of a low water cut-off, as it is designed to react to low levels; and controlling the steam output of the boiler pertains more to operational management rather than the protective mechanism of monitoring water levels. Thus, the correct functioning of the float-operated low water cut-off hinges on the