Inspection, Maintenance, and Testing
This domain tests how you verify that the boiler and its safety devices remain fit for service. Know the difference between routine operator checks and formal inspections. Operators check water level, gauge glass condition, safety valve freedom, flame scanner operation, and low-water cutout function. Formal internal inspection requires the boiler to be cooled, drained, isolated, and cleaned so surfaces and stays can be examined for corrosion, cracking, and scale.
Understand common tests: hydrostatic test to check the pressure boundary; safety valve pop test to confirm set pressure and reseat; low-water cutout test by blowdown or simulated low water; flame scanner and fuel train leak tests; and gauge glass blowdown. Know that a safety valve must be tested at the required interval and that a valve that fails to reseat is a serious defect. Maintenance includes tube cleaning, refractory repair, gasket and packing replacement, and lubrication.
Traps: assuming a hydrostatic test replaces a safety valve test (it does not); thinking a low-water cutout can be tested only by draining the boiler (blowdown is the usual method); and forgetting that lockout/tagout and isolation are required before internal work. Questions may ask what to do if a safety valve leaks-secure the boiler and have it repaired by qualified personnel, not adjusted under load.
Rule of thumb: test protective devices often, inspect the pressure boundary thoroughly, and never defeat a safety device to keep the boiler running.