Tennessee Wastewater Operator Practice Exam

Fusible plugs used in safety systems are designed to melt at what temperature range?

1. 120-130 F

2. 158-165 F

3. 140-150 F

4. 175-185 F

The correct answer is: 158-165 F

Fusible plugs play a crucial role in safety systems, particularly in pressure vessels and storage tanks. These devices are designed to provide a fail-safe mechanism in the event of a fire or extreme temperature. The correct answer indicates that fusible plugs are engineered to melt within the temperature range of 158 to 165 degrees Fahrenheit. This melting point is critical because it allows the plug to effectively relieve pressure by creating a venting pathway when temperatures reach levels that could threaten the integrity of the vessel. In essence, this temperature range strikes a balance between providing sufficient safety against high temperatures while ensuring that the system can function properly under normal conditions. When the fusible plug melts, it prevents potentially dangerous buildups of pressure by allowing contents to escape, thereby minimizing the risk of explosions or structural failures. The other options propose temperature ranges that are either too low or too high for effective operation of fusible plugs. Ranges below the correct answer may not activate in time to avert danger, while ranges above can lead to an increased risk of failure in addressing overheating issues.