Improvements in Image Quality and Productivity of Digital Radiography on Pipeline Girth Welds

Presented by:

Charles Bollinger, 3ENDT

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Paper Outline

• Basic Comparison: Conventional versus Digital RT

• Quality Improvements

• RT Digital System Design

• Detector (DDA) features

• Image Quality and Processing

• Code Compliance

• Data Review & Retention

• Productivity Improvements

• Mechanized system design features

• Set up, scan and processing times

• DRT Project Case Study

Comparison- Film versus Digital in Pipeline Industry

Conventional Film Radiography

• Applied and accepted for the past 40

years

• Use of Roll films, processing

chemicals, darkroom facilities

• RT film storage and handling for long

term retention of information

Digital Radiography:

• Gaining acceptance since 2005

•Use of Imaging Plates (CR) or Digital

Detector Arrays (DDA)

• Chemicals and Darkroom processing virtually eliminated

• “On the fly” scan of weld, real time review, analysis and reporting (With DDAs)

• Correct welding process errors to avoid

persistent defects

• Common data file for viewing using multiple software (DICONDE)

The Past The Future

Quality Improvements

• Digital RT system Design

• Robust mechanical

construction to withstand

rough handling

• Improved design to

accommodate a large array

• Pixel pitch of 127μm

• Shield rating improved to

300kV- extends durability of

the panel

Quality Improvements

• Image Quality and Processing

• Detector static during image capture-

eliminates image distortion due to vibration

• IQI present in every image

• Advanced software feature to stitch images

generating seamless weld image

• No image artifacts (except for non-

functional pixel displays) compared when

using Roll pack film or Imaging Plate(CR)

Quality Improvements

• Code Compliance

• Meets ASME Section V-

• Image quality class B acc. ISO

19232-5, ISO 10893-7, ISO 17636-2

• 2% sensitivity or better

• Simplified process to ensure system

performance

• Data Review, reporting & retention

• DICONDE data format

• Viewer software features for basic

review

• Evaluation to Code criteria simplified

using image measurement tools

Productivity Improvements

• Mechanized System Design features

• Light and Robust mechanical construction to withstand

rough handling

• Operating temperatures -40c to +65c, IP67

• Latching mechanisms for easy install and removal of

Monoblock unit

• Wireless/battery operated

• Laptop optional for acquisition (internal memory of the

Monoblock unit can store up to 200 welds)

• Set up time 2 min for any pipe diameter (faster with

practice! )

• 3 or 4 man crew can process 10 to 12 welds per hour in a

typical pipeline construction environment (120 to 150

welds per shift)

Comparative Case Study- Pipeline Project

System Crew # of welds

per shift

Labor

cost/shift

Equipment

cost/shift

Total

Cost/

shift

Cost

per

weld

DRT 3-man 100 $2220 $225 $2445 $24

Film* 4- man 100 $2400 $125 $2525 $25

• Project

details/Assumptions

• Pipe Diameter: 24”• 0.375” wall• Crawler –Panoramic

• 12 hour shift

• DRT 3-man Team Labor rate:

$ 185/hour

• Film RT 4 man Team Labor

rate:$ 200/hour

• Shift covers set up,

examination, data

interpretation and reporting

• Data based on info provided by a Pipeline NDT service provider

• Includes crawler crew time and costs

• DRT equipment budget: $140K (including maintenance, 3 year payback)

Conclusion

• With improved quality and productivity with Digital

radiography on pipeline welds:

• High capital investment can be justified to gradually replace

conventional RT

• Enable remote oversight by client/client representatives on quality

(data review using viewer software)

• Correct weld production process errors early and save follow up

costs

Thank You!- Questions?