Class 5 Boiler Practice Exam

Is it permissible to install a safety valve below the lowest permissible water level?

1. Yes

2. No

3. Only in certain conditions

4. It depends on the manufacturer

The correct answer is: No

Safety valves are critical components in boiler systems, designed to prevent overpressure conditions that can lead to catastrophic failures. Installing a safety valve below the lowest permissible water level is not permitted because it would expose the valve to conditions that could hinder its proper operation. When the water level in a boiler drops below the specified level, there may be insufficient water to absorb the steam pressure, leading to the risk of overheating the boiler metal, weakening its structure, and eventually causing failure. If a safety valve is positioned below this level, it may not function correctly when needed, potentially allowing dangerous pressure levels to accumulate. In essence, the safe and effective operation of a boiler requires that all components, particularly safety devices, are installed in accordance with safety regulations and best practices. Placing the safety valve at or above the lowest permissible water level ensures that it will operate correctly when it is needed to relieve excess pressure and protect the boiler system.