Refractory linings decide how long a furnace, converter, ladle or tundish can stay in service. Wear, cracking, spalling and hotspots develop slowly, then accelerate once slag penetrates joints or the shell begins to heat up. A missed early sign can turn a planned patch into an emergency shutdown, or worse, a breakout. This checklist gives steel plant maintenance teams a consistent way to inspect linings, record measurements and decide on repairs, using maintenance management software to keep every reading tied to the asset and its lining history.
Refractory Management
Steel Plant Refractory Inspection Checklist for Steel Plant Maintenance
A digital inspection routine covering cracks, hotspots, wear, spalling, thermal damage and repair requirements across furnace and ladle linings.
Hot face and working lining: wear, slag attack, spalling
Backup and safety lining: cracks, joint opening
Insulation and gaps: hotspots, gas leakage paths
Steel shell: temperature, discolouration, deformation
Where to Apply
Lining Types This Checklist Covers
| Equipment | Main inspection focus | Typical timing |
|---|---|---|
| Blast furnace and hot blast stoves | Hearth and stave condition, checker bricks, shell temperature | Continuous monitoring plus outage checks |
| Converter or BOF | Working lining thickness, slag line, trunnion area, tap hole | Between heats and at each campaign stage |
| Electric arc furnace | Sidewall, slag line, bottom and tap hole | Between heats and at scheduled stops |
| Ladles and tundishes | Slag line, impact pad, nozzles, joints | Every cycle before reuse |
| Reheating furnaces | Roof, walls, burner blocks, skid areas | Weekly walk-down and shutdown survey |
Inspection frequency key
CEvery cycle or heat
WWeekly
MMonthly
OOutage or reline
Section 01
Preparation and Safe Access
Accurate inspection starts with safe conditions. Rushing a hot inspection leads to poor readings and unnecessary exposure.
Equipment isolated, cooled to the site permitted temperature and locked out. Confirm gas, power, tilt and charging systems are secured before anyone enters or approaches.
Confined space, hot work and working-at-height permits confirmed where required. Refractory work often combines all three.
Previous inspection, lining design and campaign history reviewed. Knowing installed thickness, brick grade and earlier repairs makes measurements meaningful.
Inspection tools ready and calibrated: thermal camera, pyrometer, thickness gauge or laser scanner, and photo capture.
Section 02
Cracks, Joints and Structural Condition
Cracks are not always failures, but they show where stress, thermal cycling or mechanical load is concentrating.
Cracks located, measured for length and width, and photographed. Note whether they run along joints or cut across bricks, since through-brick cracks are more serious.
Joint condition checked for opening, mortar loss or metal and slag penetration. Open joints give molten material a path behind the hot face.
Bricks checked for displacement, loosening or lifting. Movement suggests expansion problems or lost support.
Monolithic and gunned areas inspected for delamination or hollow sound when tapped. Poor bonding often hides behind a sound-looking surface.
Section 03
Wear, Erosion and Remaining Thickness
Remaining thickness measured at defined reference points using the same method each time, so readings can be trended against previous heats.
Slag line, impact zone, tap hole and nozzle areas compared with expected wear pattern. Local wear that runs ahead of the rest of the lining sets the campaign life.
Wear rate calculated from successive readings and compared with the plan. A change in rate is often the first signal of a process or material problem.
Minimum allowable thickness confirmed for each zone and flagged when reached. Use your own site limits and supplier guidance, not generic figures.
Wear severity guide
NormalWear on trend. Continue routine inspection.
WatchFaster than planned. Increase inspection frequency.
RepairNear limit. Schedule patch or gunning.
StopAt or below limit. Remove from service.
Keep Lining Records Where Maintenance Can Use Them
Oxmaint stores inspection results, photos and wear readings on each asset, and raises work orders when a lining zone reaches its repair trigger.
Section 04
Hotspots and Thermal Damage
A hot shell means the lining behind the surface is thinner or damaged than it appears from inside.
Shell scanned with a thermal camera and compared against a baseline image. Record location, temperature and time so patterns can be trended.
Paint discolouration, glowing spots, warping or cracking on the shell noted. These are visible signs of overheating and are escalated at once.
Thermocouple and cooling system readings reviewed where fitted. Confirm sensors are working, since a failed sensor can hide a real hotspot.
Hotspot response defined: increased monitoring, cooling, reduced load or shutdown, each with an approver named in advance.
Section 05
Spalling, Slag Attack and Chemical Wear
Spalled areas mapped by size and depth. Repeated spalling in one zone often points to thermal shock from heating, cooling or tapping practice.
Slag attack checked at the slag line for penetration, softening or glazing. Compare with slag chemistry and basicity records.
Build-up, skulls and accretions removed only as procedure allows, then the surface below inspected for damage.
Process changes noted against wear: steel grade, oxygen practice, temperatures and heat times. Wear correlation guides material choice.
Section 06
Repair Decision and Records
1
Finding recorded with photo and location
2
Severity assigned using site limits
3
Repair chosen: monitor, gunning, patch, partial or full reline
4
Work order raised with materials and crew
5
Post-repair check and campaign record updated
Repair materials, cure or dry-out requirements and hold times confirmed before work begins.
Heat-up curve followed after repair and readings logged. Fast heating can cause new cracks in fresh lining.
Campaign life, repair history and lessons recorded on the asset for the next lining design and purchase decision.
Measure It
Refractory KPIs
| KPI | How to measure | Direction |
|---|---|---|
| Inspection completion | Checklists done against schedule | Aim for complete |
| Wear rate per zone | Thickness change per heat or period | Within plan |
| Campaign life | Heats or days per lining | Stable or rising |
| Hotspot events | Shell temperature alarms logged | Trending down |
| Unplanned relines | Emergency stops for lining failure | Trending down |
Frequently Asked Questions
How often should refractory linings be inspected?
It depends on equipment. Ladles and converters are checked every cycle, and furnaces weekly with outage surveys.
What does a shell hotspot mean?
It usually means the lining behind the hot face is thin or damaged. Escalate it and check thickness.
Can refractory wear be tracked in a CMMS?
Yes. Store thickness readings and photos on the asset. Try Oxmaint to set it up.
How do we decide between patching and relining?
Compare wear against site limits, remaining campaign and outage time. Keep the decision and reason on record.
Can inspections run on mobile devices?
Yes. Book a demo to see mobile checklists with photo capture.
Inspect Every Lining. Record Every Reading.
Use Oxmaint to schedule refractory inspections, capture wear and hotspot findings, and turn repair decisions into tracked work orders.
