New York Low Pressure Boiler COF Practice

At what pressure must safety valves reseat?

1. 98% of set pressure

2. 92% of set pressure

3. 96% of set pressure

4. 90% of set pressure

The correct answer is: 96% of set pressure

The correct answer is based on the standards and regulations that dictate the performance of safety valves in low-pressure boiler systems. Safety valves are designed to protect the boiler from overpressure by opening to release steam when the pressure exceeds a predetermined set point. Upon releasing the pressure, these valves must reseat—meaning they close again and prevent steam from escaping—at a specific pressure to ensure safety and efficiency. The standard for safety valves is that they must reseat at no less than 96% of the set pressure. This ensures that the valve functions properly within a margin that allows for some variation in pressure while maintaining a safe operational environment. The reseating at this pressure level helps to prevent both nuisance blow-off and excessive pressure buildup in the system, contributing to the safety and reliability of the boiler. The other percentages listed do not meet the standard required for reseating, which is why they are not correct options. By establishing that 96% is the minimum for effective reseating, it provides adequate assurance that the safety mechanism will function correctly to prevent dangerous pressure levels within the boiler.