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1. NDT Technology Group TWI Ltd Best Practice Conduct of NDT www.twi.co.uk

2. What is NDT? A method of determining … • the integrity of a material, component or structure • or the characteristic of an object … without rendering it unfit for further use!

3. Conventional NDT methods • Ultrasonic Testing (UT) • Magnetic Particle Inspection/Testing (MPI/MT) • Penetrant Testing (PT) • Eddy Current Testing (ET) • Radiographic Testing (RT)

4. Advanced NDT methods • Time of Flight Diffraction (TOFD) • Phased Array Ultrasonic Testing (PAUT) • Digital Radiography • Alternating Current Field Measurement (ACFM) • Acoustic Emission (AE) • Laser Shearography • Remote Field Eddy Current • Magnetic Flux Leakage (MFL)

5. Use of NDT methods – WHY? • Flaw Detection and Evaluation • Dimensional Measurements • Structure and Microstructure Characterization • Estimation of Mechanical and Physical Properties • Material Sorting and Chemical Composition Determination

6. Application of NDT methods

7. Application of NDT methods

8. Application of NDT methods

9. HSE Best Practice Guides • Part 1 – Manual Ultrasonic Inspection • Part 2 – Magnetic Particle and Dye Penetrant Inspection • Part 3 – Radiographic Inspection in Industry • Part 4 – Ultrasonic Sizing Errors and their Implication for Defect Assessment

10. HSE Best Practice Guides – Scope • The measures contained in the documents ‘are recommended by the HSE’ for the conduct of UT, MT, PT & RT • ‘They are intended to promote the adoption of good practice and apply to in-service inspection of existing plant and to repairs’ • ‘The guidelines could also be applicable to the inspections carried out during the manufacture of new or replacement plant’ • They contain ‘notes on good practice which are not compulsory but which you may find helpful in considering what you need to do’

11. HSE Best Practice Guide Sources • Existing literature regarding the reliability of the application of each method. • Collective experience and expertise of the committee. Conclusions • If incorrectly chosen or incorrectly applied, inspection methods can be ineffective. Defects may be overlooked or, alternatively, spurious indications may be mistaken for genuine defects, leading to unnecessary rejection of components or repairs. Content • An analysis of potential problems in method / technique application together with a list of the measures which can be adopted in response.

12. HSE Best Practice Guide – MT & PT 3. CURRENT PRACTICE FOR DESIGN AND CONTROL OF INSPECTIONS • Many inspections are designed on the basis of a national or international standard. • Procedure for the inspection is frequently written to reflect simply the requirements of the standard in terms of the application of the equipment and the consumables. However, technique sheets are often provided to reflect plant and technique details. • The authority to approve a procedure for a specific inspection based on the more general requirements of a code or standard requires skills and qualifications additional to those required of the operators who apply the inspection in the field. • Such qualifications are denoted as MT or PT Level 3 and involve demonstrating a greater understanding of the particular inspection method than expected of the Level 1 or 2 operators who normally carry out the inspection.

13. HSE Best Practice Guide – MT & PT 4. THE NEED FOR ADDITIONAL REQUIREMENTS (selected items) • Defect type • Inspection design should be based on defect descriptions (why?) • Inspection procedures should be designed or approved by an MT or PT Level 3 inspector as appropriate. • Component Geometry • The specific geometry and magnetic properties (for MT) of the component should be considered when designing the inspection procedure. • Component Material • Inspection procedures for non-standard materials should be designed or approved by MT/PT Level 3 inspectors as appropriate with specific knowledge of such inspections. The procedure should be developed using representative test pieces in the same material as the component if the Level 3 judges that this is necessary. • Operator performance • Operators should be given practice on realistic test pieces prior to the inspection if judged beneficial by the Level 3 inspector.

14. HSE Best Practice Guide 5. INSPECTION IMPROVEMENTS AND COMPONENT RISK • A major factor in determining which additional measures should be used is the role of the inspection and the effectiveness required from it in reducing the risk of component failure. • The risk of component failure is determined by a combination of both the consequence and the probability of failure. • Inspection effectiveness is assigned a value of 1 (low), 2 or 3 (high) according to the reduction of probability of failure that it produces in a particular case. • To reduce the probability of a component failure from high to low would require a high level of inspection effectiveness, whereas to reduce the probability from medium to low would require a medium level inspection effectiveness

15. POD • Probability of Detection Probability of detecting a defined flaw type and size in the area covered by the inspection method. 'the probability of detecting a crack in a given size group under the inspection conditions and procedures specified' ‘…what is the smallest flaw that can be detected by an NDT method?’ ‘…what is the largest flaw that can be missed?’ • Inspection Effectiveness

18. Procedure • Scope • Standards and References • Definitions • Safety • Personnel • Identifications and datum points • Surface preparation • Extent of inspection • Equipment specification • Equipment calibration • Equipment checks • Assessment of test results • Reporting of test results • Non-compliance statement • Attachments Content

19. Technique • Foreword, status and authorization • Personnel • Apparatus to be used • Product/area to be tested • Test conditions • Detailed instructions for application of test • Recording and classifying results • Reporting Content

20. Codes – BS EN ISO 583-1

21. Codes – ASME Article 4 - UT Procedure shall establish a single value or range for each requirement

22. Codes – ASME Article 4 – UT

23. Codes – ASME Article 6 – PT

24. Codes – ASME Article 6 – PT

25. Codes – ASME Article 7 –MT

26. Procedure Qualification ASME Code Case 2235 – Enables use of UT in lieu of RT for ASME VIII Division 1 and 2 vessels Requires the procedure to be demonstrated on a qualification block representative of the components to be inspected (dimensions, configuration, material)

27. NDT Certification Central Certification Employer Based Certification • Standardisation • Harmonisation • Independence • Training and certification directed closely at the needs of the particular company's NDT business.

28. NDT Certification Central Certification Employer Based • EN 4179 • SNT-TC-1A • CP 189 • EN 473 • ISO 9712

29. TWI’s NDT Services • Levels 2 and 3 services eg UT and LRUT: • Procedure approval • Procedure qualification/validation • eg to ENIQ or ASME methodology • Procedure • Audits • Working practice assessments • SNT-TC1A supervision. • NDT as part of Inspection, Assessment and Repair • Critical defect sizing for ECAs • Procedure development • Inspection of repairs • Defect monitoring