Digital Radiology for Application „on stream“ - SiteGenndt.sitegen.no/customers/ndt/files/7....
-
Upload
hoangkhuong -
Category
Documents
-
view
221 -
download
2
Transcript of Digital Radiology for Application „on stream“ - SiteGenndt.sitegen.no/customers/ndt/files/7....
1
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway1
Application „on stream“
Content: - basic principles of TRT- software for evaluationand documentation
- corrosion depth evaluation- validation of methods- development of standards
Digital Radiology forCorrosion Inspectionand Wall ThicknessMeasurement ofInsulated Pipes
AGFA, GE S&IT, HOIS,IAEA
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway2
Corrosion ErosionCorrosion and Seads
Projection Radiography Examples on Corrosion and Erosion
2
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway3
History: radiographic wall thickness evaluation
BASF drawing from 1954• applied since ca.
1950
• nearly no literatureuntil 1980
• growing importancein chemical industrycaused by on-stream application
• since 1996 projectsBASF und BAM forphysical studies
• Never standardized(first CEN draft2010 by S. Burch, HOIS)
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway4
classical tangential set-up of TRT: film,imagingplate,orflatpanel
pipeline
radiation source, Ir 192
insulationtypical exposure:
profile line
3
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway5
Projection Radiography
on-site exposure, Ir 192 radiograph
sourcefilm
Example : distribution station
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway6
visual evaluation of wall thickness
error sources:
- wrong density range - inaccurate edge detection (unsharpness)- wrong magnification factor
w
Projection Radiography
4
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway7
Principle of projection radiography (TRT)
w` measured on film
tangential penetration of pipe wall
pipe
insulation
f - film focus distancer - outer pipe radiusR - outer radius of insulationw‘ - wall thickness projection
on detector plane
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway8
digitized film imaging plate
D7 + Pb,50 µm pixel size
25 % exposure time,145 µm pixel size
AGFA BAM projectin 1995 ff(Peter Willems)
special NDT IP readerprototype(28 µm pixel)
5
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway9
film digitization (FD) flat panel (DDA)imaging plate (CR)
PC based wall thickness measurement
• single program for evalution of all digital images, no size limitation• support for all detectors by external 16 bit LUT tables for lineari-
sation (gray value proportional to radiation intensity)• easy documentation by protocol generation in PDF format
Projection Radiography
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway10
16 bit software platform
image processing know-how on Windows PC:(since 2006 ISee!, see http://www.kb.bam.de/ic.html)
- fully 16 bit data depth for evaluation and display- unlimited image sizes, limited only by main memory (>1 GByte)- all detectors (digitized film, imaging plates, flat panel detectors)via external 16 bit Lookup Tables (LUT) linearizable, ASCII text
- fast rekursive moving average filtering for arbitrary sizes of high andlow pass filters, convolution with variable kernels, FFT-Filters
- sub-sampling for image display with true averaging- error estimation for measured values and geometric correction- quick documentation of measurements by protocol generation and
transfer to Word (wtScope for BASF, wtModule in Rhythm, GE S&IT)- protection of application by individual encrypted license keys
wtScope
6
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway11
tangential wall thicknessalgorithm
wall thickness result
table with mea-surement regions
wall thickness deviation in mea-surement region
input exposure parameters
Projection Radiography PC based wall thickness measurement
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway12
synchronous display of positions in profile and image !
position correction by hand, if algorithm fails !
7
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway13
PC generated measurement protocolProjection Radiography
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway14
PC based wall thickness measurementProjection Radiography
Algorithms : problem: correct detection of wall positionscharacteristic points, curve fitting, CT reconstruction
inner wall of pipe
outer wall of pipemax.
projectedwall thickness w‘
8
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway15
Limits of Tangential Radiography (TRT):
Energy: Lmax
100 kV : 10 mm200 kV : 30 mm300 kV : 40 mm400 kV : 50 mmSe-75 : 60 mmIr-192 : 75 mmCo-60 : 120 mm
L max
W
Lmax = 2W sqrt(Da/W –1)
200 kV
300 kV
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway16
2003 2004 2005
Algeria Hungary Romania Iran Pakistan Germany Uruguay Syria India Turkey Malaysia Canada
Radiographic Evaluation of Corrosion and Deposits in Pipelines:
Results of an IAEA Co-ordinated Research Programme
Steel pipes up to 20” with NDT film and X-ray, Ir-192, Co-60
9
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway17
Fabricated Reference Blocks with Steps and Holes:
Iran
Idea:explore inspection methods with known wall thicknesses
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway18
10
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway19
Ir 192, DN200:
6 11 mm
Co 60, DN300:
14 24 mm
algorithm detects edges, visual not seeable in image :
extension ofapplicationrange in com-parison tovisual evalu-ation
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway20
2006: Validation of wtScope, CR-Tower and Ir-192
BAMBASFGE S&IT
11
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway21
Validation as measurement method according to ISO 17025:
Steel pipes 50 – 300 mm dia, empty, water filled, w/o insulation
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway22
Second inspection technique possible :
2. Corrosion assessment from local film density changes (Double Wall Technique, DWT)
Radiographic Corrosion Inspection
12
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway23
erosionw-w
intensity change, I
detector
pipesource
attenuation law: µeff - effective attenuation coefficientIw = I0 e -µeff w
local corrosion : wall thickness differences in penetration direction (DWT)
relative measurement: 2 step algorithm
1. Calibration:
2. Measurement:
µeff = ln ( DREF / DIQI ) / wIQI
w = ln ( DREF / DMEAS ) / µeff
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway24
1. Calculation of effective attenuation coefficient µeff
signal atreference point
signal atmeasurement point
known pipe wall thicknessw at reference point
known hole depth
DWT for localcorrosion
Result: µeff = f(w)dep. on radiation energy andwall thickness differences
13
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway25
Double wall technique 6" and 8", 100 kV, with and without insulation
y = 0,6689x-0,3385
R2 = 0,7316
y = 0,5039x-0,3927
R2 = 0,3817
0,00
0,05
0,10
0,15
0,20
0,25
0,30
0,35
0,40
0,45
0,50
0 2 4 6 8 10 12 14 16 18
Penetrated steel wall thickness (mm)
Cal
cula
ted
att
enu
atio
n c
oef
fici
ent
(1/m
m)
insulation
decreasing µeff with penetrated wall and insulation
Iran, UruguayIAEA CRP, film
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway26
Double wall technique, Ir 192
0,00
0,01
0,02
0,03
0,04
0,05
0,06
0,07
0,08
0,09
0,10
0 10 20 30 40 50 60
Penetrated steel wall thickness (mm)
Ca
lcu
late
d a
tte
nu
ati
on
co
eff
icie
nt
(1/m
m)
Uruguay Iran
Uruguay with Insulation Iran with Insulation
80 % of all measurements: µeff = 0.046 +/- 0.005 mm-1
IAEA CRP, film Ir-192
14
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway27
Computer based evaluationwith wtScope/ISee! software:accuracy 10% wt, µeff=0.028/mm
Co-60
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway28
Practical application: profile plot in wall thickness loss
15
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway29
- 0 mm
+ 10 mm
- 5 mm
real pipe, innercorrosion, insulated
corrosion mappingafter median high pass(gray value prop. penetratedwall thickness, 1x300 points) :
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway30
corroded pipewith weld
+ 5 mm
- 0 mm
- 5 mm
corrosion mappingafter median high pass(gray value prop. topenetrated wall thickness1x200 points) :
16
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway31
Comparison Film / CR
DWT with Ir-192:
reason: scatter sensitivity!0
0,01
0,02
0,03
0,04
0,05
0,06
0 2 4 6 8 10 12 14
pipe wall thickness [mm]
eff
ec
tiv
e a
tte
nu
ati
on
co
eff
icie
nt
[1/m
m]
CR
Film
Result of wtScope validation for CR Tower byBAM / BASF / GE S&IT
µeff
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway32
Parameter Ir-192 Co-60
DWT: µeff 0.046 +/- 0.005 mm-1 0.028 +/- 0.004 mm-1
TRT: Lmax forDcenter = 2 and Dmax = 4
80 mm 130 mm
TRT: Lmax forDmax = 8
95 mm 155 mm
Determined Lmax limits for TRT and µeff-values for DWT (T3 film systems):
agreed results of IAEA CRP:Limits of film application!
Accuracy for TRT wall measurement: < 0.3 mm
Accuracy for DWT depth measurement: 0.5 mm or 10%wt
17
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway33
BAM certification of GE S&IT Rhythm WTM versus wtScope:
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway34
SummaryProjection Radiography
inspection technique not yet standardised, written practice necessary !
• program for PC based routine measurements on images from all radiographic detectors, tangential wall thickness measurement and local corrosion, simple documentation
• wall thickness range enlarged compared with visual evaluation in projection radiography
• measurement of corrosion depth (in centre of pipe)• validation as measurement methods acc. to ISO 17025• programs transfered to GE S&IT for worldwide marketing
(Rhythm Version 3 all methods implemented)• differences in sensitivity to scattered radiation between
film and imaging plates
standard development at CEN started in 2010
18
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway35
See NDT informasjon fra Norsk Forening for Ikke-devstruktiv Proving, April 2011
Digital Radiology for Corrosion Inspection
Uwe Zscherpel, Uwe Ewert, BAM Berlin
Peter Rost, BASF SE, Ludwigshafen; Steve F. Burch, ESR Technology, UK
May 2011, Bodo, Norway36
The End