Minnesota Boiler License Practice Exam

In a high pressure boiler plant exceeding 750,000 Btu, what must be included for safety?

1. A flow sensing device to cut off fuel in case of loss of circulating flow

2. A manual shut-off valve

3. A pressure relief valve

4. A temperature gauge

The correct answer is: A flow sensing device to cut off fuel in case of loss of circulating flow

In a high pressure boiler plant exceeding 750,000 Btu, the inclusion of a flow sensing device to cut off fuel in case of loss of circulating flow is essential for safety. The primary function of this device is to monitor the flow of water through the system. If a drop in flow is detected, which could indicate a potential failure in the circulating system, the flow sensing device automatically shuts off the fuel supply. This prevents the boiler from overheating or experiencing damage due to insufficient water circulation, which is critical in maintaining safe operating conditions and preventing catastrophic failures. While manual shut-off valves, pressure relief valves, and temperature gauges are also important components in boiler safety, they do not specifically address the immediate risk posed by a loss of circulation. The manual shut-off valve is used for operational control, pressure relief valves are designed to prevent overpressure situations, and temperature gauges monitor thermal conditions. However, in high pressure systems, ensuring continuous flow is crucial, hence why the flow sensing device is prioritized for safety in this context.