Inspection, Maintenance, and Recordkeeping
What this domain tests
This domain covers preparing a boiler for internal and external inspection, what an inspector looks for, how maintenance is scheduled, and what must be written down. Items often present a condition - pitted tubes, a leaking gasket, an overdue safety valve test - and ask for the correct response.
Preparing for internal inspection
- Shut down, cool slowly, and drain only after the boiler is below about 200°F to avoid thermal shock.
- Lock out and tag out all energy sources: fuel, electrical, steam, feedwater, and blowdown.
- Open all manholes and handholes, remove the covers, and ventilate before entry. Test the atmosphere for oxygen and combustible gas; use a second person as an attendant.
- Wash the waterside so scale, sludge, and corrosion are visible, and clean the fireside so tube failures, cracks, and refractory damage can be seen.
- Never enter a boiler that has not been proven safe by atmosphere testing.
Waterside and fireside findings worth knowing
- Scale and blisters indicate treatment or blowdown failures; pitting indicates oxygen.
- Cracking near tube ends and in stayed areas is a rejection item; the jurisdiction's inspector decides, not the operator.
- Safety valves are repaired and set only by qualified personnel with the proper test facilities, and their nameplates must not be painted over or removed.
- A hydrostatic test is normally run at 1.5 times MAWP for new construction and is performed under the jurisdiction's witness.
Worked example: preparing for a required internal inspection
A boiler is scheduled for its periodic internal inspection. Sequence with reasoning: notify the operating group and the authority having jurisdiction; shut the burner down from low fire and purge; close and lock the fuel valves; cool and drain; open all openings and ventilate; lock out feedwater and steam; wash and clean both sides; then notify the inspector. Reasoning: each step protects either the equipment from thermal shock or the people who must enter, and the inspector cannot assess surfaces that are still coated or hot.
Traps that cost marks
- Draining a hot boiler and cracking tube seats.
- Entering without atmosphere testing or an attendant.
- Adjusting or repairing a safety valve in the field without the proper facility.
- Keeping no written record of water tests, blowdowns, and cutoff tests - the log is your evidence.