Instrumentation, Testing, Inspection and Recordkeeping
Indication
Gauge glass is the primary water level indication; blow it down and verify it each shift, and treat try cocks and remote level as backups. A glass showing a steady level that does not move on blowdown has plugged connections. Pressure gauges should be ranged so that normal operating pressure sits near mid-scale - roughly twice the working pressure - and should have a siphon and a marked operating range. Calibrate against a test gauge and record the result.
Testing and inspection
Routine tests include low-water cutoff, high limit, flame safeguard, safety valve try lever, burner shutdown and fuel train leak test. Formal inspections include internal and external visual inspection, hydrostatic testing and ultrasonic thickness measurement where wastage is suspected. Repairs and alterations follow the National Board Inspection Code with an R stamp, and records of the repair stay with the boiler.
Records
Maintain a boiler log: water level, pressure or temperature, blowdowns, water tests, burner and control tests, repairs, and operator names. Inspection certificates must be current and posted. Records are what an inspector or accident investigator reads first, so incomplete logs become a liability.
Traps and rule of thumb
Do not hold a safety valve open with the lifting lever for an extended period - it can damage the seat. Rule of thumb: the pressure gauge range is about double the operating pressure, so normal operation reads near the middle of the dial.