Time of Flight Diffraction To FD Topics What

  • Slides: 22
Download presentation
Time of Flight Diffraction (To. FD)

Time of Flight Diffraction (To. FD)

Topics Ø What is To. FD Ø History Ø How does it work Ø

Topics Ø What is To. FD Ø History Ø How does it work Ø Applications Ø Advantages Ø Challenges Ø Performance & Cost Ø Conclusion

What is To. FD ? Ø To. FD = Time of Flight Diffraction Ø

What is To. FD ? Ø To. FD = Time of Flight Diffraction Ø To. FD = Highly accurate Ultrasonic inspection technology, principally intended for weld inspection Ø Technology Design has also developed a rastered To. FD application for effective area scanning

History Ø To. FD discovered in the 1950’s by Maurice Silk & others of

History Ø To. FD discovered in the 1950’s by Maurice Silk & others of AEA (UK) Ø Developed in the early 1970’s by AEA (UK). Ø Gained wider acceptance in the 1980/90’s by the efforts of Sonomatic & others Ø Equipment more portable and efficient in the 90’s – Technology Design leads the way Ø Development of QC codes in late 90’s/2 K’s

How does To. FD work?

How does To. FD work?

How it works PLANK BRICK Reflection Back

How it works PLANK BRICK Reflection Back

How it works cont’d PLANK BRICK Diffraction

How it works cont’d PLANK BRICK Diffraction

How it works cont’d Rx Tx DEFECT Diffraction

How it works cont’d Rx Tx DEFECT Diffraction

How it works cont’d Practically Rx Tx

How it works cont’d Practically Rx Tx

How it works cont’d Rx Tx Lateral Wave + Pos Amplitude d. B Time

How it works cont’d Rx Tx Lateral Wave + Pos Amplitude d. B Time m seconds - Neg

How it works cont’d Rx Tx Diffracted Signals + Pos Amplitude d. B Time

How it works cont’d Rx Tx Diffracted Signals + Pos Amplitude d. B Time m seconds - Neg

How it works cont’d Rx Tx Backwall Reflection + Pos Amplitude d. B Time

How it works cont’d Rx Tx Backwall Reflection + Pos Amplitude d. B Time m seconds - Neg

How it works cont’d Data Collection 6 5 4 3 2 1 Rx Tx

How it works cont’d Data Collection 6 5 4 3 2 1 Rx Tx

How it works cont’d Phase Reversal + Pos Amplitude d. B Time = µ

How it works cont’d Phase Reversal + Pos Amplitude d. B Time = µ seconds or Millimetres - Neg

How it works (cont’d) Greyscale Image Presentation ace Surf Depth fect f de o

How it works (cont’d) Greyscale Image Presentation ace Surf Depth fect f de o Top wall Back Bo fect f de o ttom Length

Depth/Time µ Seconds or mm To. FD Scan Length mm

Depth/Time µ Seconds or mm To. FD Scan Length mm

APPLICATIONS Ø Critical plant items in construction and in-service Ø Pressure Systems – Vessels,

APPLICATIONS Ø Critical plant items in construction and in-service Ø Pressure Systems – Vessels, pipelines, pipe-work Ø Storage facilities – Tanks, spheres Ø Tubed Vessels - Boilers, Heat Exchangers, Condensers Ø Service induced defects & structural damage Ø Stress/chemically assisted micro-cracking - SCC, LTHA, HHA, SOHIC Ø Corrosion/erosion profiling - especially weld root erosion Ø Thick wall components > 300 mm Ø Clad/lining interface bond/cracking Ø Fabrication QC - includes ‘in-situ’ construction

Advantages of To. FD Ø Highly Accurate and Sensitive Ø Increased Evidence Ø Fast

Advantages of To. FD Ø Highly Accurate and Sensitive Ø Increased Evidence Ø Fast Ø Comprehensive Coverage Ø Meaningful Presentation Ø Fast Reporting / Decision Making Ø Permanent Record of All Parameters Ø Offline Interpretation and Measurement Ø Objective Assessment. Ø Excellent Repeatability.

Challenges Ø Reduced near surface resolution (approx. 3– 5 mm) Ø Additional B-scans necessary

Challenges Ø Reduced near surface resolution (approx. 3– 5 mm) Ø Additional B-scans necessary for transverse positioning Ø Sees everything (down to grain structure) so interpretation can be complicated if material/weld quality is poor Ø Should not be used with conventional ultrasonic acceptance criteria

Performance & Cost Ø Most validated of all NDT techniques - DDT trials in

Performance & Cost Ø Most validated of all NDT techniques - DDT trials in UK, PISC (International), NIL (Netherlands), EPRI (US) Ø TOFD outperformed other methods in trials Ø Faster, safer and more cost effective Ø Increased defect detection ability (POD) = safer, added value to plant Ø Reduced ‘false calls’(FCR) = less repairs and production downtime

In Conclusion Ø To. FD as an Inspection Tool Is: • Fast • Proven

In Conclusion Ø To. FD as an Inspection Tool Is: • Fast • Proven • Cost Effective Ø To. FD PROVIDES: • High POD and Low FCR • Accuracy • Real-time Sentencing • Transparent Recording of Results • Permanent Record • Repeatability

Thank you for your attention

Thank you for your attention

Time Of Flight Diffraction Technique Time Of FlightTime Of Flight Diffraction Technique Time Of Flight
XRay Diffraction and XRay Crystallography Diffraction l DiffractionXRay Diffraction and XRay Crystallography Diffraction l Diffraction
Diffraction Light bends History of diffraction Diffraction solutionDiffraction Light bends History of diffraction Diffraction solution
Applications of Diffraction Outline Interference Diffraction Examples DiffractionApplications of Diffraction Outline Interference Diffraction Examples Diffraction
diffraction methods diffraction methods Why are different diffractiondiffraction methods diffraction methods Why are different diffraction
Diffraction and Interference Double Slit Diffraction Diffraction isDiffraction and Interference Double Slit Diffraction Diffraction is
Diffraction 27 7 The Diffraction Grating Diffraction gratingDiffraction 27 7 The Diffraction Grating Diffraction grating
Lecture 8 Diffraction Diffraction of Light Diffraction isLecture 8 Diffraction Diffraction of Light Diffraction is
Logging Flight Time Logging Flight Time The allLogging Flight Time Logging Flight Time The all
DABEX Aircraft flight summary Flight summary table FlightDABEX Aircraft flight summary Flight summary table Flight
IFR Flight Considerations IFR Flight Planning Flight OverviewIFR Flight Considerations IFR Flight Planning Flight Overview
FLIGHT CONTROLS AND HYDRAULICS FLIGHT CONTROLS The flightFLIGHT CONTROLS AND HYDRAULICS FLIGHT CONTROLS The flight
Chapter 10 Diffraction February 25 Fraunhofer diffraction theChapter 10 Diffraction February 25 Fraunhofer diffraction the
Benchtop Xray Diffraction Spectroscopy Introduction XRay Diffraction XRDBenchtop Xray Diffraction Spectroscopy Introduction XRay Diffraction XRD
Diffraction Light bends Diffraction assumptions Solution to MaxwellsDiffraction Light bends Diffraction assumptions Solution to Maxwells
refraction reflection diffraction questions previous next Diffraction isrefraction reflection diffraction questions previous next Diffraction is
Students will learn about Refraction Diffraction Diffraction isStudents will learn about Refraction Diffraction Diffraction is
Diffraction of Sound Waves Diffraction involves a changeDiffraction of Sound Waves Diffraction involves a change
Interference Diffraction Polarization interference diffraction polarization light asInterference Diffraction Polarization interference diffraction polarization light as
Diffraction Monday Nov 18 2002 1 Diffraction theoryDiffraction Monday Nov 18 2002 1 Diffraction theory
Diffraction gratings By M Ravi Kiran Introduction DiffractionDiffraction gratings By M Ravi Kiran Introduction Diffraction