Question 480Steam Plants - Assistant Engineer

The correct answer is B) Smoke periscope. When adjusting the firing rate or forced draft pressure on a vessel, the smoke periscope should be checked to ensure proper combustion and smoke emissions. The smoke periscope allows the operator to visually inspect the exhaust and make necessary adjustments to maintain efficient and clean burning. The other options are not directly related to the firing rate or forced draft pressure adjustment. Atomizing steam pressure, fuel oil suction pressure, and fuel oil heater inlet temperature are important parameters to monitor, but they do not need to be checked when specifically adjusting the firing rate or forced draft pressure.