What can low-water cutoffs help prevent in a boiler system?

Low-water cutoffs play a crucial role in preventing boiler explosions by ensuring that the water level within the boiler remains within safe operational limits. When the water level in a boiler becomes too low, it can lead to overheating of the boiler metal, which in turn may cause catastrophic failures, including explosions. The cutoff device is designed to automatically shut down the boiler if the water level drops below a certain point. This safeguard is essential because when there's insufficient water to absorb the heat produced during combustion, the risk of damage to the boiler and a potential explosion significantly increases.

The other options relate to different aspects of boiler operation. For instance, excessive pressure can be mitigated through pressure relief valves and not specifically by low-water cutoffs. Increased energy consumption is more related to inefficiencies in combustion and heat transfer rather than water levels. Lastly, while flue gas emissions are affected by combustion processes, low-water conditions do not directly control or reduce emissions. Therefore, the primary function of low-water cutoffs is about maintaining safe water levels to avert hazardous situations like boiler explosions.