At what point will the Low Water Cut-Off (LWCO) trip?

The Low Water Cut-Off (LWCO) is a critical safety device in steam boilers designed to prevent the boiler from operating without sufficient water. This is essential because low water levels can lead to overheating and potentially catastrophic failure of the boiler, as the heating surfaces would be exposed.

The correct answer, which indicates that the LWCO will trip at 1/4" below the lowest permissible water level, is accurate because this threshold is specifically designed to provide a safety margin. The LWCO is set to detect when the water level falls below a certain point, which is defined as the minimum level necessary to ensure safe operation. By tripping at this level, the LWCO prevents further operation of the boiler, thereby protecting equipment and personnel from the dangers associated with low water conditions.

In contrast, the other options do not reflect the operational design of the LWCO. For instance, the highest water level is not a trip point because the LWCO is intended to monitor low water levels, not high levels. The normal operating level is where the boiler is expected to function efficiently, but it is not the point at which the LWCO activates. Finally, the LWCO does not trip when the boiler is shut off; it is activated specifically to prevent operation under