Routine Operation, Startup, and Shutdown Procedures
Getting up to pressure
A cold start is a controlled warm-up: verify water level, confirm vents and drains are set, start feedwater and then the burner on low fire, and warm the boiler slowly - thermal stress, not pressure, causes most damage. Open the main steam stop slowly and warm the header and piping; trap and drain condensate before steam reaches it.
Watching level
Drum level moves with load. On a load increase, swell makes the glass read high; on a load drop, shrink reads low. Confirm with the glass before adding feedwater. Priming and foaming carry water over and show as erratic level, low steam temperature and water hammer.
Blowdown
Surface (continuous) blowdown controls dissolved solids; bottom blowdown removes sludge. Do it in short bursts with the level clearly visible, never on a low-water condition and never with the burner on high fire.
Shutdown, layup and records
Cool down slowly. Keep the boiler full and hot for a short outage; drain and dry it for a long one; use wet or dry layup with the correct chemicals. Log levels, pressures, tests and blowdowns.
Traps
- Opening the steam stop wide to a cold, undrained line.
- Adding feedwater on the strength of a swelling glass.
- Long, lazy blowdowns.
Rule of thumb
Warm a large boiler over hours, not minutes - treat roughly 100 °F per hour as an upper comfort limit for most drums.