Minnesota Special Engineer Boiler License Practice Exam

What is the maximum BTU input that requires two low water fuel cut-outs on a burner?

1. 500,000

2. 750,000

3. 1,000,000

4. 1,250,000

The correct answer is: 750,000

Two low water fuel cut-outs are required for burners with a maximum BTU input exceeding a certain threshold to ensure safety and reliability in boiler operations. In this context, the specific threshold where the installation of dual cut-outs becomes mandatory is set at 750,000 BTUs. This requirement is established due to the heightened risk associated with higher BTU inputs, as a failure in water levels can lead to catastrophic failures. By having two cut-outs, a redundant safety mechanism is put in place that acts to prevent the burner from operating if the water level drops below a safe threshold. This approach significantly reduces the likelihood of overheating and potential damage to the boiler and associated systems. For BTU inputs below this level, a single low water fuel cut-out is deemed sufficient to manage the safety risks effectively, which is why the options reflecting lower BTU inputs do not necessitate the use of two cut-outs. Thus, the option indicating a requirement for two low water fuel cut-outs becomes very clear at the specified input level of 750,000 BTUs.