Steel & Metals
Heat, water, scale and high hydraulic loads demand disciplined cleanliness, water control and varnish surveillance.
Steel & Metals programmes should connect equipment criticality, credible failure modes, representative samples, routine and triggered tests, response ownership and maintenance feedback.
Design the programme around how the assets fail.
Steel plants expose hydraulic, circulation, gear and grease systems to high temperatures, rolling debris and water. The test programme should distinguish mill hydraulics, rolling oils, gear drives, turbine systems and fire-resistant fluids.
Use this guide to scope an oil-analysis programme; then confirm equipment-specific limits, methods and safety controls with the laboratory, OEM and site engineering team.
What to test—and why.
Routine panels create comparable history. Triggered tests answer a focused question after a trend change, inspection finding or operating event.
| Equipment | Fluids | Primary risks | Routine tests | Triggered / advanced tests | Sampling approach |
|---|---|---|---|---|---|
| Rolling-mill hydraulics | Mineral hydraulic oil or fire-resistant fluid | Water, scale, servo sticking, pump wear | particle count, karl fischer water, kinematic viscosity, acid number | elemental analysis icp oes, analytical ferrography, ftir oil condition monitoring | Sample upstream of return filtration from a flushed live-system port. |
| Mill gearboxes and pinion stands | EP gear oil | Shock wear, water ingress, oxidation, large ferrous debris | kinematic viscosity, elemental analysis icp oes, pq index, karl fischer water | analytical ferrography, particle count | Sample from active return flow and examine magnetic plugs or filter debris. |
| Continuous-caster and furnace systems | Grease, circulating oil, thermic fluid | Heat degradation, water washout, thickener failure, deposits | kinematic viscosity, acid number, ftir oil condition monitoring | pq index, analytical ferrography, karl fischer water | Capture oil at operating temperature; obtain grease from the loaded bearing purge path. |
Controls that make the data useful.
- 01Keep water and scale out of precision hydraulics
- 02Use chemistry-specific limits for water-glycol and fire-resistant fluids
- 03Correlate varnish indicators with servo behaviour
- 04Link oil results with roll changes, cooling-water leaks and production campaigns
Decisions the programme should improve.
- 01Fewer servo and valve incidents
- 02Targeted dehydration and filtration
- 03Planned gearbox inspection
- 04Reduced heat-related lubricant degradation
Build a closed evidence-to-action loop.
A test panel becomes a reliability programme only when the sample, interpretation, response and field outcome remain connected to the same asset and compartment.
| Stage | Control | Evidence created | Decision |
|---|---|---|---|
| 1 · Baseline | Confirm asset, compartment, fluid, method, point and operating state | Comparable new or stable in-service reference | Define normal variability and initial interval |
| 2 · Routine surveillance | Collect at a fixed risk-based interval from the documented point | Trend of fluid condition, contamination and wear | Continue, monitor or request focused confirmation |
| 3 · Exception diagnosis | Use mechanism-specific tests, secondary points, filters and companion technologies | Independent evidence for or against the failure hypothesis | Protect, inspect, correct or revise the hypothesis |
| 4 · Verification | Repeat comparable evidence after maintenance | Post-action condition and rate of change | Close the work order or escalate |
| 5 · Programme learning | Record inspection findings, false positives and missed detections | Asset-specific failure signatures and improved rules | Change point, panel, interval, limit or procedure |
Translate severity into a defined response.
These are workflow classes—not universal pass/fail limits. Asset consequence, rate of change and site safety procedures control the urgency.
| Class | Typical evidence pattern | Minimum review | Possible response |
|---|---|---|---|
| Stable / Normal | Comparable results remain within the justified baseline and no corroborating distress is present | Confirm route and context are complete | Continue the planned interval |
| Monitor | A small deviation, unusual rate of change or incomplete contextual explanation | Check sample, top-up, maintenance and companion indicators | Clarify data, add one focused test or shorten the interval |
| Abnormal / Investigate | Unsatisfactory fluid, contamination or wear evidence with a credible developing mechanism | Confirm promptly using independent evidence | Inspect, control the source and plan corrective work |
| Critical / Urgent review | Rapid, severe or corroborated change with material equipment or safety consequence | Immediate qualified operational and engineering review | Apply site procedures; protect people and equipment before diagnosis continues |