New York Low Pressure Boiler COF Practice

At what pressure does an 800 psi safety valve typically lift?

1. 800 psi

2. 824 psi

3. 850 psi

4. 900 psi

The correct answer is: 824 psi

Safety valves are designed to lift at a specific pressure, which is known as the set pressure. Generally, an 800 psi safety valve is calibrated to lift at a pressure that exceeds the set point slightly, allowing for a margin of safety. This is important to ensure that the system is protected against overpressure conditions. When an 800 psi safety valve lifts at 824 psi, this represents the operational pressure at which the valve activates to relieve excess pressure, providing a safeguard against potentially dangerous conditions that could occur if the pressure were to continue to rise. This lifting pressure is determined based on industry standards and is calibrated accordingly to ensure that the valve reacts properly without unnecessary lifting in normal operating conditions. In this context, 824 psi represents a typical lift pressure for an 800 psi safety valve, striking a balance between operational safety and functional reliability. The additional pressure above the set point allows for variations in system pressure and ensures that the safety valve activates only when truly necessary.