Operation, Startup, and Shutdown Procedures
Operators must know the correct sequence for safe operation. Before startup, verify water level, open vents and drains as required, confirm the boiler is filled to the proper level, check that safety valves are free, and confirm the fuel train and draft system are ready. Purge the furnace to clear combustible gases, establish airflow, then light the burner and prove flame. Warm the boiler slowly to avoid thermal stress and uneven expansion; bring pressure up gradually and open the main steam stop slowly after warming the line.
During normal operation, maintain water level, monitor pressure and temperature, watch flame stability, and record readings. Know when to blow down: bottom blowdown removes sludge, continuous blowdown controls solids. On shutdown, reduce firing gradually, stop fuel, purge the furnace, and allow controlled cooling. Do not dump pressure suddenly; keep the boiler under proper water level and, where required, under a protective atmosphere or dry layup.
Traps: lighting off without purging; filling a hot boiler too quickly; opening the main steam stop too fast and causing water hammer; and forgetting that a low-water condition means secure the fuel first, then investigate. Questions may ask the order of steps-purge always precedes ignition, and fuel is secured before any corrective action on the water side.
Rule of thumb: purge, prove airflow, ignite, prove flame, warm slowly, and on any unsafe condition secure the fuel first.