Minnesota Boiler License Practice Exam

What must be ensured when using multiple safety valves?

1. All valves should be identical

2. The smaller valve must have a certain relieving capacity

3. All must be operated manually

4. They should be maintained at the same pressure

The correct answer is: The smaller valve must have a certain relieving capacity

When using multiple safety valves, it is crucial to ensure that the smaller valve has a certain relieving capacity. This requirement stems from the need to maintain effective pressure control and ensure that the entire system can adequately handle the pressure that may build up. Each safety valve is designed to relieve a specific amount of pressure, and if the smaller valve does not have the appropriate relieving capacity, it could fail to release enough pressure, leading to potentially hazardous conditions. Properly sizing the safety valves ensures that in a scenario where pressure exceeds safe limits, all valves can work together efficiently to prevent overpressure. This is particularly important in systems where different valves may be serving various parts of the operation or equipment, as a lack of sufficient capacity in one of the valves could compromise the entire safety mechanism. In contrast, while having identical valves might seem ideal for uniformity, it is not a strict requirement as long as each valve's capacity and design meet the safety needs of the system. Similarly, although regular maintenance is important, safety valves are generally designed to operate automatically in response to pressure increases, rather than requiring manual operation. Finally, while maintaining the same pressure setting for all valves can be beneficial, the primary concern is ensuring that the relieving capacities are adequate to handle potential pressure