Many challenges exist with turbine blade inspections -- Cracks and crack initiation in the blade attachment serrations need to be reliably detected. Complex geometry of the component is a very challenging factor for inspection design. In-situ inspection without blade removal is required, thus limiting blade access. This application presentation highlights a recommended solution with techniques to overcome the challenges.

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Turbine Blade Inspection
Application Solution

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• Inspection Challenge
• Recommended PA UT Solution
• Results
• Benefits of Zetec Solution
Overview
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• Cracks and crack initiation in the blade
attachment serrations (“hooks”) need to
be reliably detected
• Complex geometry of the component is
very challenging factor for inspection
design
• In-situ inspection without blade removal
is required, thus limiting blade access
• Inspection speed and reproducibility are
key factors for reducing outage time
Inspection Challenge
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Encoded phased array UT improves efficiency and reliability of
this challenging inspection, compared to manual UT and PA UT:
• 1D linear and/or 2D matrix array probes and wedges
• Customized scanner, allowing for in-situ inspection of blades
• or PA UT systems, with
embedded UltraVision Touch for on-site data recording
• UltraVision Classic 3D, complete package for PA UT probe and
inspection technique design, and analysis in 3D environment
Recommended PA UT Solution
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Inspection Technique – Legacy
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• Scanning sequences from:
Extrados Intrados Platform
• 1D linear array, 5 MHz, with custom wedges to generate
acoustic beams 40° to 75°SW, from extrados and intrados
• Additionnal scans from platform using LW beams, depending
on blade geometry
• Data analysis on 2D views with blade overlay

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Inspection Technique – Legacy
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UT coverage maps generated in UltraVision Classic 3D show
important limitation, especially for extrados configuration
Extrados hooks coverage:
from 40 to 70%
(depending on blade geometry)
Intrados hooks coverage:
from 85 to 95%
(depending on blade geometry)

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• Recording extra data from extrados and intrados, using skewed
beams, to increase coverage and detection probability:
– From extrados : adding skews -15° and +15°
– From intrados : adding skews -15° and +15°
• Options :
1. Using same 1D linear array probe, with roof angle wedges, requires
2 extra scanning sequences for both extrados and intrados
2. Using 2D matrix array probe allows to record data from the 3 skews
in the same scanning sequence
Inspection Technique – Improved Coverage
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Inspection Technique – Improved Coverage
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UT coverage maps generated in UltraVision Classic 3D
Extrados hooks coverage:
from 50 to 80%
(depending on blade geometry)
Intrados hooks coverage:
nearly 100%
(depending on blade geometry)

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• Custom design based on blade shape (CAD model required)
• Easy probe insertion/removal
• Easy positioning on the blade
• Encoded scanning, motorized or manually driven
• Interchangeable probe-head allowing for all required inspection sequences
Custom Scanner for Axial Entry Blade Type
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• Fully integrated, portable, battery operated unit
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• PA UT 32/128PR for driving
1D linear array probes
• Rugged, battery operated
• Driven by UltraVision Touch
for setup, recording and
on-site flaw detection
• 2GByte data files on-board

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• Fully integrated, portable, battery operated unit
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• PA UT 64/128PR for driving
2D matrix array probes
(more than 32 elements)
• 12” Hi-Res touch display
• Bipolar pulser, 150 Vpp
• Live high-resolution TFM
• Driven by UltraVision Touch
for setup, recording and
on-site flaw detection

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2D & 3D Visualization of Inspection Results
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• PA UT probes and inspection techniques, using skewed beams
for improved coverage and detection probability in all hooks
• Feasibility study to optimize inspection technique on specific
blade geometry, and for actual coverage evaluation
• , , fully integrated portable PA
UT systems, with on-board UltraVision Touch include all
required tools for data acquisition and on-site flaw detection
• Fast and reliable data acquisition in-situ, using custom scanner
adapted to blade geometry
• UltraVision Classic 3D software, for flaw characterization and
sizing in 3D geometry
Benefits of Zetec Solution
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