Maintenance, Inspection, and Testing
Inspection types
Know the difference between an external inspection (fired surfaces, fittings, gauge glasses, safety valves, piping, insulation, settings, and records with the boiler operating), an internal inspection (fireside and waterside condition, drum internals, tubes, stays, refractory, corrosion and cracking with the boiler opened and cleaned), and a hydrostatic test (typically 1.5 times MAWP for new construction or repairs, with the safety valve removed or isolated). Ultrasonic thickness testing, magnetic particle and dye penetrant methods, and tube sampling supplement visual inspection. Radiographic or other examination is used on welds.
The operator's routine
Day-to-day work: blow down gauge glasses and verify level, test low-water cutoffs, test flame safeguards, check safety-valve try levers where permitted, inspect burners and refractory, clean firesides and watersides, maintain water treatment logs, lubricate and align pumps and fans, check belts and couplings, and record stack temperature and draft. Keep a maintenance and inspection file - it is part of the operating record and will be reviewed.
Regulation and testing
New Jersey requires periodic inspection of boilers and pressure vessels by authorized inspectors, with a certificate to operate issued after a satisfactory inspection. The exact intervals and the conditions for internal versus external inspection are set in the rules; know that the current text of N.J.A.C. 12:90 governs, and that an operator may not alter, weld, or repair pressure parts without proper authorization and code compliance.
Traps
Thinking a hydrostatic test substitutes for an internal inspection; assuming the safety valve can be gagged for a test; recording a test that was not actually performed; and confusing "cleaned for inspection" with "inspected."
Worked example
A boiler with a 150 psig MAWP is hydrostatically tested after a tube replacement at 1.5 × 150 = 225 psig. The safety valve must be removed or isolated, all air vented, and water temperature kept above ambient to avoid brittle behavior; the test pressure is held only long enough for examination.