In which state should the burner be started and shut down?

The burner should be started and shut down in the low fire state to ensure safety and efficiency during these critical phases. Starting a burner at low fire minimizes the risk of creating a hazardous condition, such as an explosion or excessive emissions, by allowing for controlled ignition and gradual ramp-up of heat. It provides sufficient time for the combustion process to stabilize before moving to higher firing rates.

Similarly, shutting down the burner in the low fire position allows for a controlled and safe decrease in combustion activity. This gradual reduction helps to prevent abrupt changes in pressure or temperature, which can lead to equipment stress or damage. By managing the transition in and out of operation at a lower intensity, operators can maintain better control and ensure the integrity of the system throughout the operational process. This practice is a standard operating procedure in many types of burner systems.