Training and qualification inspectors for advanced GWT inspections

David Alleyne

7MENDT, Bahrain

14 September 2015

1

Presentation Outline

2

Biography

History of GWT and inspector training

GULT training scheme and recommendations

Certification and Qualification process

Challenge educate and support inspectors at all levels

ISO 17024, 9712 compliant certification

Conclusions

Biography Summary of GUL

3

GUL: Primary function development, design and manufacture of GWT equipment.

Guided Ultrasonics Ltd. was set up in 1998/9 to commercialize guided

wave inspection systems and train field inspectors.

World experts in Guided wave testing of plates and pipe from Imperial

College of Science, Technology and Medicine (London, UK). Patent

holder for GWT methods.

Over 200 man years experience in the guided wave field within GUL,

including outstanding academic contributors with widest range of

application specific knowledge and expertise.

Driver and major contributors for the development of GWT standards,

qualification and certification.

Long range GWT concept

4

If the guided wave encounters a defect then part of the signal is reflected

A single measurement inspects all the material in a long length of the structure

Transducer

Structure

Time, distance

Defect

End of structure

Results when you just try….

5

Problem (understanding of the physics) involving:- Multiple modes- Multiple directions- Dispersion- Sensitivity to defects varies with modes

Milestones of GWT Method• Plate, tubes and spot weld testing application1980’s Research –Lamb Waves

• Understanding, Simulation Software

• Initial prototype equipment

Research and Development

Imperial College

• Transduction

• Electronics

Development

GUL

• Applications

• Limitations definition

Technology demonstration

GUL and oil and gas companies

• Training

• Support

Technology transfer

GUL and service companies

• Definition of standards, recommended practices and specifications, certification

Technology transfer

GW community

Dispersion curves for 6” pipe

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T(0,1)

F(1,2)

F(2,3)

F(1,3)

L(0,2)

Square Cut End

8

• FR = 3.7 • BW=0• 8 inch Sch. 40

GWT

9

Wavemaker® system.

Used for range of pipe testing applications

Pipe sizes from 1“ to 96“

Typical test time 10-20 minutes

Internal battery (8 hour life)

Automatic testing sequencing and equipment diagnostics

Operator recognition (iButton)

Wavemaker® result

10

-24dB

0.0 5.0 10.00

90

180

270

360

Angle

(deg)

0.0 5.0 10.00.0

0.5

1.0

1.5

2.0

Distance (m)

Am

p (

Lin

ear)

+F5

+F4

+F3

+F2

+F1

-F1

-F2

Distance

Rectangular Defect

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• FR = 3.7 • BW=0• 8 inch Sch. 40• Weld (3mm Cap height, 12mm length)

Defect172 x 21 x 4mm

Height x Axial Length x Depth

Welded Support

12

• FR = 8.8 • BW=0

• 8 inch Sch. 40

Support 100x250x10mm

Height x Axial Length x Thickness

90 degrees Bend

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• FR = 3.8 • BW=0• 4 inch Sch. 40• Weld (2mm Cap height,

12mm length )

Multiple Features

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• FR = 3.7 • BW=0• 8 inch Sch. 40• Weld (3mm Cap height, 16mm Length,

2mm Root Height, 3mm Root Length)

Series of Pits 18 nos x 14mm

Diameter x 4mm Depth

Application Specific Training

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Many applications are complex and require additional equipment specific training and qualifications

Testing of buried pipe

Testing of road crossings

Process pipwork including bends and pipe fittings

Monitoring (gPIMS) applications

Certification

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GUL has pioneered electronic certification using the iButton system since 2005

Can be remotely updated and revalidated

Allows automatic logging of inspector for QA purposes

Log of tests is used as proof of experience for advanced qualifications

Conclusions

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Improving fundamental understanding through training Properties of waves, interaction with damage and features Environmentally induced affects Historical review of results used to improve accuracy and reduce false calls Monitoring and regular data collection improves understanding of

environmental effects

Optimisation of inspection (POD) Minimisation of false calls Signal-to-noise ratio (different sources) Variability of sensitivity with frequency and mode

New capabilities and technologies Tomography, sizing and monitoring