A safety valve opens automatically at a set pressure to protect equipment from overpressure. When does it operate?

A safety valve opens automatically at a set pressure to protect equipment from overpressure. When does it operate?

• A. When a timer elapses
• B. In response to temperature rise
• C. Only during manual testing
• D. At a predetermined pressure

Answer: (D)

Safety valves protect equipment by venting automatically when system pressure reaches a specific threshold. They are designed to respond to pressure, not to a timer or to temperature, and they operate without any manual action. The valve is spring-loaded and held closed until the system pressure pushes against the spring to the set point; at that predetermined pressure the valve opens to release excess pressure and then reseats once the pressure drops. This automatic opening at the chosen set point is what prevents overpressure and protects the system.

Safety valves protect equipment by venting automatically when system pressure reaches a specific threshold. They are designed to respond to pressure, not to a timer or to temperature, and they operate without any manual action. The valve is spring-loaded and held closed until the system pressure pushes against the spring to the set point; at that predetermined pressure the valve opens to release excess pressure and then reseats once the pressure drops. This automatic opening at the chosen set point is what prevents overpressure and protects the system.