Minnesota Boiler License Practice Exam

In addition to the A.S.M.E. safety valve, what other safety device should be installed on hot water boilers?

1. A low water fuel cut off

2. Steam safety valves

3. Purge valve

4. Automatic blowdown controls

The correct answer is: A low water fuel cut off

The inclusion of a low water fuel cut off is essential for the safe operation of hot water boilers. This device plays a critical role in monitoring the water level within the boiler. If the water level drops below a certain threshold, the low water fuel cut off automatically shuts down the fuel supply to the burner. This prevents the boiler from operating in a potentially hazardous condition where insufficient water could lead to overheating or damage to the boiler components. A.S.M.E. safety valves focus on relieving excess pressure to prevent explosions, but they do not address the risk associated with low water levels. The combination of both the A.S.M.E. safety valve and the low water fuel cut off creates a more comprehensive safety system, protecting against different types of failure modes that could compromise the boiler's integrity and safety. The other options, while relevant to boiler operations, do not provide a direct safety mechanism that serves the same purpose as the low water fuel cut off. Steam safety valves primarily concern steam systems rather than water boilers, purge valves assist in the removal of air or contaminants but do not protect against low water levels, and automatic blowdown controls focus on maintaining water quality rather than safety related to low water conditions.