AI Vision Boiler & Turbine Blade Inspection

By Josh Brook on October 9, 2026

ai-vision-boiler-turbine-blade-inspection

Outages are short, and the inspection list is long. In a few days, crews have to borescope turbine stages, walk boiler walls, check pressure-vessel welds and decide what gets fixed now and what can wait. Most of that work is visual, done by tired people looking at thousands of images. AI vision reviews every frame, flags cracks, erosion, coating loss and corrosion, and tracks each blade and tube from one outage to the next, while NDT confirms what matters. To try it on your next outage, book an outage inspection call.

Power Plant · Vision Defect Detection

AI Vision Boiler and Turbine Blade Inspection

Deep learning on borescope, camera and drone images finds surface damage on turbine blades, boiler tubes and pressure-vessel welds, gives every finding a location and a size, and compares it with the last outage.

  • What vision can and cannot see, next to NDT
  • What it really takes to see a very small crack
  • How findings are trended blade by blade, outage to outage
Unit 2 · spring outageday 3 of 9
Borescope frames reviewed by AI18,400 212 flaggedHP and IP stages done, LP in progress
Stage 1 blade 17 · crack indicationNDT
Stage 1 blades 3–5 · edge erosionTrend
Furnace wall · tube thinning zoneUT
Drum nozzle weld · no indicationsClear
NextSend blade 17 for penetrant testing before deciding on repair.
One unit, illustrative.
One blade row, blade by bladestage 1 · 24 blades shown · illustrative
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2
3
4
5
6
7
8
9
10
11
12
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14
15
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17
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24
  • No finding
  • Edge erosion
  • Coating loss
  • Crack indication, send to NDT
Blades 3–5Leading-edge erosion grew since the last outage, still inside limits. Trend and re-check next outage.
Blades 11–12New coating loss on the pressure side. Engineer to review against the repair criteria.
Blade 17Linear indication near the root. Not on last outage's images. Confirm by NDT before any decision.
~3%average availability loss from boiler tube failures at coal-fired units above 200 MW, Inspectioneering reports
No. 1availability problem for fossil and combined-cycle plants is boiler and HRSG tube failure, the same article says
97 bladesin one compressor row were tracked frame by frame in a published deep learning borescope study
2–3 pxacross a crack is a common rule of thumb for seeing it at all, which sets the camera and optics needed

Three Assets, Three Inspection Problems

Blades, tubes and welds fail in different ways and are inspected in different ways.

Turbine blades suffer erosion, coating loss, foreign object damage and fatigue cracks, and are mostly seen through a borescope. Boiler tubes thin, corrode, bulge and crack across thousands of square metres of wall. Pressure-vessel welds can crack at the toe or in the heat-affected zone. Each needs its own images and its own models. Our power plant support team can help you plan which to start with.

Turbine blades

Small, many, hard to reach

Hundreds of blades per stage, seen through a borescope in tight, dark spaces.

Boiler tubes

Huge surface area

Furnace walls, superheaters and economisers, often reached by scaffold, rope access or drone.

Welds

Small zones, high stakes

Nozzle, seam and attachment welds on drums, headers and vessels under pressure.

The bottleneck is review, not capture

A single outage can produce tens of thousands of borescope frames and wall photos. Capturing them is quick. Looking at every one carefully, at the end of a long shift, is where things get missed. That is the part AI vision takes on.

What Vision Can and Cannot See

AI vision is a visual inspection. It finds surface indications, and NDT confirms them.

Cameras see surfaces. They can find erosion, coating loss, visible cracks, pitting, bulging and discolouration very well, on every image. They cannot see wall thickness, internal corrosion or cracks below the surface. Those need ultrasonic, eddy current, magnetic particle, penetrant or radiographic testing. The value of AI is in looking everywhere and pointing NDT to the right spots. To match methods to your assets, book an inspection plan review.

Method
What it finds
Limits
Where AI helps
Visual and borescope
Surface cracks, erosion, coating loss, impact damage
Surface only, depends on light and optics
Reviews every frame, sizes and tracks findings
Penetrant testing
Surface-breaking cracks on non-porous parts
Surface must be clean and reachable
Points it at AI-flagged spots
Magnetic particle
Surface and near-surface cracks in steel
Ferromagnetic parts only
Prioritises welds to test
Ultrasonic testing
Wall thickness, internal flaws
Point by point, slow over large areas
Targets thinning zones seen on camera
Eddy current
Surface cracks, tube wall loss
Needs calibration, sensitive to set-up
Combines with images for one record
Radiography
Internal weld flaws
Safety controls, time
Shares the same finding record
"Indication" is the honest word

When AI flags a possible crack on an image, it is an indication, not a confirmed defect. The plant's inspection procedure and a qualified inspector decide what it is. Good systems are built around that hand-off, not around replacing it.

What It Takes to See a 50-Micron Crack

Small cracks can be found by vision, but only if the image is good enough. Here is the simple arithmetic that decides it, before any AI is involved.

Resolving a 50 µm crackillustrative
Crack width to see50 µm
Pixels needed across it · 2–3≤ 20 µm/px
Camera sensor width4,000 px
Field of view · 4,000 × 20 µm80 mm
Images along a 300 mm blade face4 or more
Most borescopes see a much wider view per frame, so very fine cracks need close-up or higher-resolution imaging. We confirm the smallest reliable size on your own equipment during the pilot.

Boiler Tubes: Erosion, Corrosion and Overheating

Most tube failures give visible warnings, if someone looks at the right tube.

Boiler and HRSG tube failures are the leading availability problem for fossil and combined-cycle plants, and they tend to repeat in the same areas. Many mechanisms leave marks on the outside of the tube long before a leak: thinning near soot blowers, bulges from overheating, cracking at attachments. Others start inside the tube, show nothing on the outside, and need NDT to find. If you want help mapping mechanisms to your boiler, our engineers can help.

Mechanism
Typical area
Visual sign
Confirm with
Fly ash erosion
Economiser, convection pass
Polished, thinned tube faces
Ultrasonic thickness
Soot blower erosion
Near blower lanes
Flattened, shiny areas
Ultrasonic thickness
Fireside corrosion
Furnace walls, superheater
Scale, pitting, wastage
Thickness mapping
Long-term overheating
Superheater, reheater
Bulging, swelling, oxide cracking
Diameter checks, oxide scale tests
Fatigue at attachments
Supports, welds, bends
Cracks at weld toes
Magnetic particle, penetrant
Waterside damage
Inside the tube
Usually none outside
Ultrasonic, tube samples
Label past outages first

Most plants already hold years of wall photos and borescope video. Labelling a few hundred known findings from those archives gives the models a strong start, and gives your team a baseline to measure the next outage against.

Map, then measure

Use images of the whole wall to map where erosion, bulging or corrosion is visible, then send thickness measurements to those zones first. The same number of UT readings covers far more risk when they are aimed by a full visual map.

Turbine Blades: Finding Damage at Outage Speed

Every blade, every frame, with an ID that follows it to the next outage.

Borescope video of a rotating stage shows each blade many times. AI follows each blade through the frames, gives it an ID, and flags erosion, coating loss, nicks, dents and crack indications, with a size and position. The result is a blade-by-blade record that can be compared with the last outage, which is where small changes become visible. To see it on your own borescope video, book a blade review session.

1

Capture

Borescope video or stills, stage by stage.

2

Track

Each blade identified and followed across frames.

3

Detect

Erosion, coating loss, impact and crack indications.

4

Size

Area and length estimated, with position on the blade.

5

Compare

Same blade checked against the last outage.

6

Decide

Engineer reviews and sends items to NDT or repair.

What makes borescope images usable

1

Steady speed

Turn the rotor slowly and evenly so each blade is seen clearly in several frames.

2

Same angle

Use the same port and probe angle each outage so images can be compared.

3

Even light

Avoid glare and dark corners, which hide fine cracks and coating edges.

4

Close-ups

Take still close-ups of roots and edges, where cracks usually start.

Example exchange · illustrative
Outage managerWhich stage 1 findings need action before we close the casing?
iFactory AIOne. Blade 17 shows a linear indication about 3 mm long near the root, which was not visible on last outage's images. Blades 3 to 5 show edge erosion that has grown but is still inside your limits. Blades 11 and 12 show new coating loss.
Outage managerWhat do you suggest for blade 17?
iFactory AIPenetrant or eddy current testing to confirm it, then a decision by your turbine engineer against the OEM repair criteria. The images and position are attached to the work order.

Pressure-Vessel Welds

Small zones, but the consequences of a miss are large.

Welds on drums, headers and other pressure vessels are inspected under strict codes and by qualified inspectors. AI vision supports that work by reviewing weld images for visible cracks, undercut, porosity, corrosion and coating breakdown, so the inspector's time goes to the welds that need it. The inspector and the applicable code still decide what is fit to run.

What vision can flag on welds

  • Visible cracks at the toe or across the weld
  • Undercut, porosity and spatter
  • Corrosion and coating breakdown
  • Changes since the last inspection

What still needs NDT and an inspector

  • Cracks below the surface
  • Internal lack of fusion or slag
  • Wall thickness and remaining life
  • Code decisions and sign-off
Weld zone
What to look for on camera
Usual follow-up
Drum and header nozzles
Toe cracks, corrosion at the fillet
Magnetic particle or penetrant
Longitudinal and girth seams
Surface cracks, undercut, coating breakdown
Ultrasonic testing
Support and lug attachments
Cracks from thermal and mechanical cycling
Magnetic particle
Dissimilar metal welds
Cracking or oxide notching at the fusion line
Ultrasonic, replica testing
Same record for every method

Keep images, AI findings and NDT results against the same weld ID. Over a few outages, that single history shows which welds are changing and which are not, which is exactly what a risk-based inspection plan needs.

How iFactory Vision Defect Detection Works in Power Plants

Every image reviewed, every finding located, every change tracked.

iFactory's Vision Defect Detection runs deep learning models on an edge server at the plant. It reviews borescope video, camera stills and drone images, flags surface damage on blades, tubes and welds, sizes and locates each finding, compares it with past outages, and sends confirmed items to your maintenance system as work orders. Questions on fit go to our support desk.

Input

Your images

Existing borescopes, cameras and drones, no new probes needed to start.

Detect

Surface damage

Cracks, erosion, coating loss, corrosion and impact damage.

Trend

Outage to outage

Each blade, tube zone and weld compared over time.

Act

Work orders

Confirmed findings sent with images and location.

What inspectors see

  • Flagged frames, sorted by severity
  • Position and size of each finding
  • Last outage's image beside this one

What engineers see

  • Findings by stage, wall zone and weld
  • Growth trends across outages
  • Items waiting for NDT or repair

The smallest reliable crack size depends on your borescope, lighting, access and surface condition. We measure it on your own images during the pilot, against your inspectors' findings, rather than promising a general figure.

Turnkey AI: Delivered, Connected and Live in 6–12 Weeks

You do not build this. It arrives ready.

iFactory ships as a pre-configured NVIDIA AI server, racked and ready, with the software pre-loaded. Rack it, plug in power and Ethernet, and the AI is live on your network.

Our team handles cabling, network setup, PLC and SCADA integration, operator training and 24×7 remote monitoring. The server sits inside your own network, so inspection images and plant data stay on site. For a scope matched to your units, request a turnkey quote.

Weeks 1–4

Ship, network and data

Server installed. Past outage images and inspection records loaded. Maintenance system connected.

Weeks 5–8

Model training and pilot

Models trained on your own images and checked against your inspectors' findings, stage by stage.

Weeks 9–12

Go-live and training

Ready for the next outage. Inspectors and engineers trained. 24×7 remote monitoring begins.

Live in 6–12 weeksfrom delivery to outage-ready
1000+ clientsacross industrial operations
99.9% uptimewith 24×7 remote monitoring

Frequently Asked Questions

Can AI vision find 50-micron cracks on turbine blades?

Only if the images can resolve them, which usually means close-up, high-resolution imaging rather than a wide borescope view. The smallest reliable size is measured on your own equipment during the pilot, and every crack indication is confirmed by NDT.

Does it work with our existing borescopes?

Yes. It reviews video and stills from the borescopes, cameras and drones you already use. Better images give better results, so we review image quality early in the pilot.

Does it replace NDT?

No. Vision finds surface indications on every image. Ultrasonic, eddy current, penetrant, magnetic particle and radiographic testing confirm them and find what cameras cannot see.

Can it inspect boiler tubes?

Yes, from wall images taken by camera, rope access or drone. It maps visible erosion, corrosion, bulging and cracking, so thickness testing can be aimed at the right zones.

How does outage-to-outage trending work?

Each blade, tube zone and weld gets an ID. Findings are stored against that ID, so this outage's images can be compared with the last ones and growth can be measured.

Who makes the final call on a finding?

Your qualified inspectors and engineers, under your plant's procedures and the applicable codes. AI flags and sorts. People decide.

How do we start?

With images from a past outage on one turbine or boiler area, so models can be trained and checked against known findings before your next outage. To plan it, contact our team.

Review Every Frame Before the Casing Closes

In thirty minutes we look at your outage scope, the images you already capture and your inspection backlog, and pick the area most likely to pay back first. You keep the plan whether or not you go further with iFactory.

Five things worth bringingif you have them
  • 1Borescope video from a past outage
  • 2Boiler wall photos or drone footage
  • 3Recent inspection reports and findings
  • 4Your next outage dates and scope
  • 5Repair criteria from your OEMs

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