Scope of this guide
This senior guide covers the hard cases: combined variables, boundary conditions and the judgement calls that separate consistent lines from lucky ones.
Process: Equipment Maintenance. Figures in this guide are industry-standard starting ranges; confirm against your supplier TDS before locking settings.
Working ranges and control points
The table below is the daily reference for a line maintenance. Set by the card, verify by the control point column.
| Item | Check frequency | Healthy reading | Watch out |
|---|---|---|---|
| Rectifier ripple | Monthly scope check | < 5% ripple at load | Ripple dulls deposits |
| Filter pump ΔP | Daily log | Within card band | Rising ΔP starves bath flow |
| Heat exchanger ΔT | Weekly | Within design ΔT | Scale kills cooling slowly |
| Anode bag condition | Weekly visual | No sludge bleed | Burst bags dump sludge |
| Bus bar joints | Quarterly IR scan | Uniform temp | Hot joint drops current |
Push The Boundary: the senior view
Beyond the basic card, this is the layer that matters at your level:
| Hard case | Why it is hard | Method | Data to keep |
|---|---|---|---|
| Mixed-alloy loads | Different windows collide | Split by family or map positions | Per-family thickness trend |
| Seasonal humidity swings | Flash and dry times move | Season-set viscosities | Monthly setting log |
| Recesses at spec limit | Throwing power ceiling | Auxiliary anode trials | Before/after thickness maps |
| Repeat claim from one customer | Use conditions differ | Reproduce their test | Claim-vs-lab correlation |
Standard routine
- Walk the line with the log book at shift start
- Trend ΔP and ΔT, act on the slope not the point
- IR-scan bus joints under load quarterly
- Record every intervention with part numbers
- Keep critical spares counted, not estimated
Engineer notes
- Rising filter ΔP with steady flow means media loading, not pump failure
- Rectifier ripple shows in the deposit before it shows on gauges
- Scale in exchangers follows water hardness — log conductivity
- Anode bag checks prevent the classic sludge rain on racks
- Spare-parts stock-outs cost more than the parts
Safety: Electrical panels stay live behind doors. Only authorised staff open panels; lock-out before work, verify zero voltage.
FAQ
How often should rectifier ripple be checked?
Monthly under real load, and immediately after any deposit-quality drift.
What does rising filter pressure mean?
Media loading or clogging — service before flow drops starves the bath.
Why IR-scan bus joints?
A hot joint steals current from positions downstream and burns its neighbours.
How do I train juniors on this judgement?
Have them log the variable they changed and the measured result; review the log weekly against line outcomes.