GULF TECHNICAL
INSPECTION SERVICES
Conventional and Advanced Inspection services
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Company Introduction
 Gulf Technical Inspection Services LLC, herein after referred as GTIS, was founded in 2010 with the objective
of developing its business and progress in Non-Destructive Testing (NDT) and Post Weld Heat Treatment
(PWHT) industry. The company started its activities with the execution of NDT and PWHT services to several
Oil & Gas industries in the Sultanate of Oman.
 Our aim is to provide the highest quality of service and attain the leader in Local Industry and beyond through
Excellence in Safety, Quality of Service, & Total Customer Satisfaction. At GTIS, We want to inspire our
customer’s sense of confidence that their quality needs are being met by the best in the business.
 All our workforce is highly trained and strives to provide an excellent service with exceptional integrity, a
superior work ethic, extensive knowledge, and professional character.
 GTIS have obtained Management System Certifications for ISO9001: 2015, 14001:2015(EMS) and ISO 45001:
2018 (Occupational Safety and Health).
 Our Head office in Muscat, Sultanate of Oman and having branch offices at Sohar, Salalah and Duqm.
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What we do?
Company Activities: We provide high quality services in the following disciplines.
Conventional Non Destructive Testing:
 Gamma Radiography Testing
 X-Ray Radiography Testing Using
Directional X-Ray Unit
 X-Ray Radiography Pipeline Crawlers
From 6” To 60” Diameter
 Ultrasonic Testing (Thickness Gauging &
Manual Weld Scan )
 Liquid Penetrant Testing & Magnetic
Particle Testing
 Hardness Testing
 Ferrite Measurement
 Positive material identification (PMI)
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Post Weld Heat Treatment:
 Electrical Induction Using Coils
 Pre Heating Services
Advanced NDT Inspections:
 Time Of Flight Diffraction (TOFD)
 Phased Array Ultrasonic Testing (PAUT)
 Eddy Current Inspection (ET)
 Internal Rotating Inspections Services
(IRIS)
 Corrosion Mapping Using AUT and MFL
 Boroscope / videoscope
 Vacuum box testing (Leak testing)
 ECT/MFL/IRIS Tube inspection
 Magnetic flux leakage for tank floor bottom
plate
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Why this presentation?
To propose PAUT & ToFD inspection in lieu of radiography for pipeline as per project requirement
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What code says?
 ASME Sec V article 4 mandatory appendix III, IV, V, IX and ASME Sec VIII, div 2 section 7
clearly mandates the requirement for PAUT and ToFD inspection in Pressure vessels
 ASME Sec V article 4 mandatory appendix III, IV, V, IX and ASTM B 31.3 Appendix R Clearly
mandates the requirement for PAUT and ToFD inspection in Pressure piping.
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Why PAUT & ToFD over Radiography?
 No Radiation hazard
 No chemical handling
 No legal permits requirements to handle radioactive material
 Real time results
 Digital storage of results
 High volume inspection
 No limitation in size and thickness
 Un interrupted construction progress (Other works can be done in close proximity)
 High probability of detection (POD) for planar flaws.
 Accuracy in results
 Ability to assess through-wall depth attributes to accurately determine the defect location
 Calculation of defect height measurements as an indicator of flaw severity
 Ability to discriminate among defects stacked throughout the material thickness in a proximate
circumferential location
 Equipment compact and portable
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Extent of examination for the given scope
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Reference: Project Specification Volume 2,
Book 4
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Project Scope
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CLIENT
CONSULTANT
CONTRACTOR
PROJECT- REINFORCEMENT OF AD DHAKHILIYAH WATER TRANSMISSION SYSTEM PHASE-II
PUBLIC AUTHORITY FOR WATER
ENERGOPROJEKT ENTEL LLC
L&T CONSTRUCTION
BOQ FOR RADIOGRAPHY
SR.NO.
Alignment
1
2
3
4
5
AL-1
AL-2
AL-3
AL-4
AL-5
6
AL-6
7
8
9
10
11
12
13
AL-7
AL-8
AL-9
AL-10
AL-11
AL-12
AL-13
SR.NO.
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Pipe Thk.
Total
INCH
68
64
64
60
60
11.91
9.53
9.53
9.53
9.53
INCH DIA.
17,507.28
37,467.52
10,537.28
21,928.20
5,376.30
" Length
71,779.85
153,616.83
43,202.85
89,905.62
22,042.83
56
9.53
26,134.92
107,153.17
56
9.53
56
9.53
56
9.53
56
9.53
48
8.74
36
6.35
32
6.35
TOTAL
MANUAL UT
DISCIPLINE
QTY.
UT TECHNICIAN Level II
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MAGNETIC PARTICLE TESTING
445.48
464.80
8,462.44
27,217.12
30,025.92
2,595.24
6,238.72
194,401
1,826.47
1,905.68
34,696.00
111,590.19
123,106.27
10,640.48
25,578.75
797,045.00
Description
1.MPS-Rusail(R)
2.Rusail(R)-BPS1
3.BPS1-BID ESR
4.BID ESR - BPS2
5.BPS2-SAMAIL ESR
6.BPS2SAMAIL ESRExisting
7. Existing CONNECTION BPS3
8. BPS-3 - Existing PH-1
9. BPS3-Existing PH-1 - SR
10. SR-Future ESR
11. SR-Future ESR
12. SR-Future ESR
13. SR-Future ESR
Pipe Dia
Pipe Dia
M
1.7
1.6
1.6
1.5
1.5
1.4
1.4
1.4
1.4
1.4
1.2
0.9
0.8
DURATION
6 MONTH
Total
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Phased array Ultrasonic testing
 Principle : Same as conventional Pulse-Echo A-scan i.e..,
“reflection/refraction of sound energy”.
 It differs with Pulse-Echo A scan UT in generation and
receiving of ultrasound.
 A conventional pulse-echo UT probe consists of a single
piezoelectric element, while that for phased-array UT has
multiple piezoelectric elements i.e., one PA probe is a
combination of several conventional probes in a single
casing.
 Finally a PA Probe is nothing but an array of transducer
elements in which the timing of the elements' excitation can
be individually controlled to produce certain desired effects,
such as steering the beam axis or focusing the beam.
Beam Forming
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Phased array Ultrasonic testing
 To focus the ultrasonic beam, time delays are applied to the
elements to create constructive interference of the wave
fronts, allowing the energy to be focused at any depth in the
test specimen undergoing inspection.
 This principle is illustrated in the right picture, where delay
laws have been computed to focus the acoustic beam at a
specified depth and angle. As shown in the figure, each
element radiates a spherical wave at a specified time. The
super position of these wavelets results in an almost planar
wave front at the specified location.
Beam focusing principle for (a) Normal and (b) angle incidences
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Phased array Ultrasonic testing
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 Linear scan
 Sectorial scan
Linear Focal Law beyond First Leg and Sectorial Scan Display
Typical Scan plan
Typical scan and its respective image
-30° to 30° Sectorial Scan using L wave Wedges
Typical PAUT display (A-scan, S-scan, C scan)
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Time of flight diffraction (ToFD)
 Based on diffraction, so relatively indifferent to
weld bevel angles and flaw orientation
 Uses time of arrival of signals received from
crack tips for accurate defect positioning and
sizing
 Precise sizing capability makes it an ideal flaw
monitoring method
 Quick to set up and perform an inspection, as a
single beam offers a large area of coverage
 Rapid scanning with imaging and full data
recording
 Highly sensitive to all weld flaw types
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ToFD Working principle
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Transmitter
Back wall
Receiver
Upper tip
Lateral wave
Upper tip
Lateral wave
Lower tip
Lower tip
Back-wall reflection
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Advantages
 Ability to sweep sound beam through a range of angles without moving the probe, normally 40 to 70
degrees.
 Ability of interrogating defect with different angles increases the probability of detection
(POD) of defects regardless of their orientation.
 High inspection speeds over conventional UT employing raster scanning.
 Accuracy in defect plotting, gives precise readings for depth, defect orientation.
 Multiple view formats like S- Scan, C- Scan, B-Scan possible.
 Inspection of coarse-grained welds like DSS, Inconel, SS are possible with Dual Matric Array probes.
 Sensitive to virtually all types of defects regardless of orientation.
 Provides high speed inspection of heavy walled vessels even up to 250 mm thickness unlike radiography
which would require longer exposure times and slower films for sensitivity.
 The tip diffraction technique used in TOFD is so far the most accurate height sizing technique available.
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Limitations
 Cost Impact.
 Requirement of interpretation skill is relatively higher compared to radiography
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Scanners
 Holds up to 12 probes
 Probes independently loaded with spring
 Independent suspension on all 4 magnetic wheels for uneven
surfaces
 Compact (350mm x 325mm) and lightweight aluminium
frame (3kg)
 Accurate tracking via guide chain or laser
 Operates in any orientation and from 4.5” OD through to flat
plate
 Splash-proof, spring-loaded wheel encoder
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Weld Coverage
• Since our max thickness is 12 mm PAUT shall act as a main technique. Even though PAUT
covers complete weld volume, we prefer to use ToFD to have double confirmation.
• Both are compliment technique to each other.
PAUT Coverage
ToFD Coverage
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Typical scanning in pipeline
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Sample validation block design
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No of Blocks required (as per scope)
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No of Blocks required (as per scope)
Total PAUT Reference blocks required – 3 no.s
Total TOFD reference blocks required - 4 no.s
Total Validation blocks required – 7 no's (each joint requires 1 no.)
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Sample record
Weld Length
Defect
Weld Thickness
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RT Productivity
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DWSI where SWSI is not feasible
SWSI
Joint Details
With 25 Ci. Time
required for each
joint with D7 film
using SWSI
technique
No. of joints can be
done in 10 Hrs. shift
per RT crew (Set up
time considered)
Joint Details
No.
exposures
Required
With 25 Ci.
Time
required for
each
exposure
with D7 film
using DWSI
technique
With 25 Ci.
Time
required
for each
joint with
D7 film
using
DWSI
technique
No. of joints
can be done
in 10 Hrs.
shift per RT
crew (Set
up time
considered)
68’’x11.91 mm
18 min.
3
64’’x9.53 mm
14 min.
3
60’’x9.53 mm
11 min.
5
56’’x9.53 mm
68’’x11.91mm
4
1.6 Hr.
6.4 Hr.
1 or 2
9 min.
7
48’’x8.74 mm
64’’x9.53 mm
4
1.1 Hr.
4.4 Hr.
2
6 min.
9
36’’x6.35 mm
60’’x9.53 mm
4
1 Hr.
4 Hr.
2
4 min.
14
32’’x6.35 mm
56’’x9.53 mm
3
54 Min.
2.7 Hr.
3
4 min.
14
48’’x8.74 mm
3
36 Min.
1.8 Hr.
3
36’’x6.35 mm
3
12 Min.
36 Min.
6
32’’x6.35 mm
3
12 Min.
36 Min.
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AUT Productivity
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Joint Details
No. of joints can be done in 10
Hrs. shift per PAUT-TOFD crew
68’’x11.91 mm
3
64’’x9.53 mm
3
60’’x9.53 mm
4
56’’x9.53 mm
4
48’’x8.74 mm
10
36’’x6.35 mm
12
32’’x6.35 mm
12
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Procedure
Procedure shall minimum cover the following as per the requirement given in ASME sec V article 4 Table III – 421 & Table IV 421
 Procedure qualification requirement
 Personnel qualification
 Equipment qualification
 Calibration/validation block design details
 Scan plan
 Examination coverage
 Scanning technique
 Flaw sizing technique
 Acceptance criteria
 Validation process
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Resource
 Topaz 32 portable equipment – 2 Nos
 Magman Scanner – 2 Nos
 PCN / CSWIP PAUT & TOFD Level 3 – 2 Nos
 PCN Level II Operators- 2 Nos
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Projects
 BP Khazaan CPF Phase II
 Yibal Khuff Project
 Duqm Refinery project
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Client Approvals
 Petroleum development of Oman (PDO)
 British Petroleum (BP)
 Oman Gas Company (OGC)
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Our Clients
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Questions???
Thank you everyone for your attention
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