Boiler Log Sheets and Shift Handover
A log sheet is the boiler’s memory. Recorded every hour, the same handful of readings show a problem days before it becomes a breakdown, show an inspector that the boiler has been run within its certificate, and give the next shift the full picture.
You'll learn
- Know what to record on a boiler log and how often
- Use trends to spot problems early
- Track the steam-to-fuel ratio
- Hand over a shift properly
Before this: Start-up: checks, warm-up, raising pressure, Chemical dosing and water tests
What to record
| Reading | Why |
|---|---|
| Steam pressure | Within certificate; stability of the load |
| Water level, both gauges | That they agree; that level control works |
| Feedwater temperature | Condensate return and deaerator performance |
| Flue gas temperature and O₂ | Fouling and combustion |
| Steam flow and fuel used (or meter readings) | Output and efficiency |
| Furnace draft | Fans and dampers, air leaks |
| Blowdowns done, and times | Water treatment |
| Water test results | Treatment and softener health |
| Alarms, trips and unusual events | Faults and their causes |
Under the Boilers Act the owner must not run the boiler above its certified pressure and must keep it in the charge of a certified person where required; a complete log is the plainest evidence of both.
Reading the trends
- Flue gas temperature creeping up at the same load: soot or scale building on the heating surfaces.
- Feedwater temperature dropping: less condensate coming back, or the deaerator short of steam.
- More blowdown needed for the same TDS: feedwater quality has worsened or condensate return has fallen.
- Draft falling: fan, damper or flue blockage; draft rising with high O₂: air leaks.
- Frequent short alarms or burner cycling: control tuning, or the boiler oversized for the current load.
One number summarizes a lot: steam generated per kilogram of fuel, from the daily totals. It moves when efficiency moves, whatever the cause.
- Last month the boiler made 3.2 kg of steam per kg of fuel; this month 3, with the same fuel and similar loads.
- Change: 3 ÷ 3.2 = 0.938.
Handing over a shift
- Walk the boiler together: level in both glasses, pressure, firing, feed, fuel stock.
- Hand over anything abnormal: alarms, faults, work in progress, permits open.
- Hand over what is planned: blowdowns due, a softener regeneration, a load change the process expects.
- Hand over the log, signed, with the readings up to the hour of handover.
- The incoming attendant accepts the boiler only once satisfied; until then the outgoing attendant is in charge.
Logs are increasingly kept by data loggers and plant control systems, which record more often and never forget. They help, but they do not replace the attendant’s walk round: a gauge glass that disagrees with the transmitter, a weeping gland or an unusual noise is only found by someone who goes and looks.
Key takeaways
- Log pressure, both levels, feed temperature, flue temperature and O₂, flow and fuel, draft, blowdowns, tests and events.
- Trends find problems early: rising stack temperature, falling feed temperature, more blowdown.
- Steam per kilogram of fuel is the single best efficiency trend.
- Hand over by walking the plant together; write the log as you go.