What is a boiler trip and what actions follow?

• A. A manual shutdown initiated by operator when conditions are abnormal.
• B. An automatic shutdown triggered by abnormal conditions; safety interlocks isolate fuel and water, depressurize, and initiate restart procedures after fault clearance.
• C. A planned shutdown for maintenance.
• D. A momentary trip that resets automatically after a minute.

Answer: (B)

A boiler trip is an automatic protective shutdown that occurs when abnormal conditions are detected, to prevent damage or danger. When it trips, safety interlocks immediately cut off the fuel supply and isolate the water/steam system, stopping heat input and steam generation. The system is depressurized to a safe level to reduce the risk of overpressure and equipment damage. After the fault is cleared and conditions are safe, restart procedures are initiated to bring the boiler back to service in a controlled sequence, which typically involves verifying water level and pressure, re-establishing feedwater, and re-igniting the burner if needed. This differs from a manual shutdown, which is operator-initiated, and from a planned maintenance shutdown. A momentary trip that resets automatically isn’t the normal mode of operation, since protective systems aim to ensure the fault is resolved and the boiler is safely restarted.