What must never be adjusted during a white smoke casualty to the boiler?

During a white smoke casualty, it is crucial not to adjust the fuel oil header pressure. White smoke typically indicates that there is an issue with the combustion process in the boiler, often related to the fuel-to-air mixture being too rich, which implies incomplete combustion. Adjusting the fuel oil header pressure could exacerbate the situation by either increasing or decreasing the amount of fuel oil being injected into the combustion process, potentially leading to further inefficiencies or even hazardous conditions.

Maintaining stability in the fuel oil header pressure is essential to ensure that the fuel and air mixture can be corrected properly with other adjustments, such as air flow rate or water level, rather than introducing a change that could destabilize the combustion. By avoiding adjustments to the fuel oil header pressure during this type of casualty, it allows for troubleshooting and addressing the underlying issues without creating additional variables that could complicate the situation further.