What additional control is required by ASME when using a combination LWCO/water level control device?

The requirement for a second dedicated low water cutoff (LWCO) when using a combination LWCO/water level control device adheres to safety protocols mandated by the American Society of Mechanical Engineers (ASME). This is to ensure that there is a reliable backup system in place to prevent potential boiler failure or hazards due to low water conditions.

The primary function of an LWCO is to shut off the boiler burner if the water level falls below a certain point, thereby preventing the boiler from running dry. However, when a combination device is used, the redundancy provided by having a separate, dedicated LWCO serves several important purposes. It acts as an independent safety measure that can respond to water level changes without relying on a single device that could potentially fail or malfunction. This layered approach to safety is crucial in maintaining operational integrity and safeguarding against catastrophic failures.

Other options might include safety measures that are important in their own right, but do not specifically address the critical requirement for redundancy in low water level monitoring.