Safety, Codes, and Regulations
What this domain tests
This domain covers the legal and safety framework that governs power plant operation: codes and standards, inspection requirements, permit-to-work systems, confined space entry, and the responsibilities of the engineer in charge.
Core rules to have at your fingertips
- Codes: ASME Boiler and Pressure Vessel Code (BPVC) Section I (power boilers) and Section IV (heating boilers); ASME B31.1 for power piping; National Board Inspection Code (NBIC) for repairs and alterations.
- Jurisdiction: the local authority having jurisdiction (AHJ) sets operating certificates, inspection intervals, and operator qualification requirements.
- Inspection: internal inspection typically every 1–2 years depending on jurisdiction; external inspection annually. Hydrostatic test at 1.5 × MAWP for new construction.
- Permit-to-work: isolation, lockout/tagout, gas testing, and authorised sign-off before entry or hot work.
- Confined space: test for oxygen (19.5–23.5 %), flammable gas, and toxic gas before entry; continuous monitoring and a standby person.
- Incident reporting: report overpressure events, failures, and near misses to the AHJ.
Worked example
A boiler has MAWP of 1 500 kPa. A hydrostatic test is required after major repair.
Test pressure = 1.5 × 1 500 = 2 250 kPa at the boiler. If the gauge is at the drum and the test is done cold, the pressure must be held for the duration specified by the code and all joints examined.
If the safety valve is set at 1 500 kPa and the operating pressure is 1 200 kPa, the valve must be set at or below MAWP and the operating margin must be sufficient to prevent nuisance lifting - typically the set pressure is at or below MAWP and the operating pressure is at least 5 % below set pressure.
Traps that cost marks
- Confusing ASME Section I (power boilers) with Section IV (heating boilers).
- Assuming the hydrostatic test pressure is the same as the operating pressure.
- Entering a confined space without gas testing or a standby person.
- Forgetting that lockout/tagout must be applied before any maintenance on rotating or pressurised equipment.
- Ignoring the AHJ's specific intervals - they override general guidance.
Exam strategy
For code questions, name the code, section, and the requirement. For safety scenarios, state the hazard, the control, and the person responsible.