Safety, Emergency Procedures, and Environmental Protection
Core concepts
Know emergency procedures: low water, high water, flame failure, furnace explosion, and tube rupture. Understand lockout/tagout, confined space entry, and hot work permits. Learn environmental controls: NOx, SOx, particulate, and CO emissions; stack testing; and continuous emission monitoring (CEM). Grasp the role of scrubbers, low-NOx burners, and selective catalytic reduction.
Traps
Questions often treat low water as "add water immediately" - if the crownsheet or tubes are overheated, adding water can cause catastrophic failure. Watch for items that ignore permit requirements for hot work or confined space entry. Also distinguish NOx formation mechanisms (thermal vs fuel-bound).
Worked example
On a low-water condition with the burner on and no water visible, secure the burner and do not add water until the boiler cools and is inspected. Rule of thumb: when in doubt, trip and investigate - never rush to restore operation.