Recommended Practice for Ultrasonic and Magnetic Examination of Offshore Structural Fabrication and Guidelines for Qualification of Technicians

API RECOMMENDED PRACTICE 2X FOURTH EDITION, APRIL 2004

REAFFIRMED, OCTOBER 2010

Recommended Practice for Ultrasonic and Magnetic Examination of Offshore Structural Fabrication and Guidelines for Qualification of Technicians

Upstream Segment

API RECOMMENDED PRACTICE 2X FOURTH EDITION, APRIL 2004

REAFFIRMED, OCTOBER 2010

SPECIAL NOTES

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Copyright © 2004 American Petroleum Institute

FOREWORD

This recommended practice is under the jurisdiction of the API subcommittee on Offshore Structures.

Changes between this edition and the 3rd edition have been marked with “change bars” in the margin.

API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure the accuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any federal, state, or municipal regulation with which this publication may conflict.

Suggested revisions are invited and should be submitted to API, Standards department, 1220 L Street, NW, Washington, DC 20005, standards@api.org.

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CONTENTS

APPENDIX A—EXAMPLE QUESTIONS FOR WRITTEN UT TEST 53

APPENDIX B—CONSTRUCTION AND UT EVALUATION OF MOCKUP STRUCTURES 57

APPENDIX C—EXAMPLE OF SCORING UT PERSONNEL PERFORMANCE.. 59 APPENDIX D—EXAMPLES OF UT AND MT REPORT FORMS 63

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APPENDIX E—GLOSSARY OF NONDESTRUCTIVE EXAMINATION TERMINOLOGY 69

APPENDIX F—BIBLIOGRAPHY OF BACKGROUND REFERENCES 77

Figures

1—Weld Profiles Suitable for Preparation of Ultrasonic Test Plates 4

2—Method of Producing Incomplete Fusion “Defects” on Bevel Faces 5

3—Significance of Discontinuities 9

4—International Institutes of Welding (ITW) Ultrasonic Reference Blocks 13

5—Institute of Welding (IOW) Block 14

6—Check of Sweep Linearity 14

7—IIW Block—Determination of Angle Beam Transducer Index 14

8—IIW Block Showing Determination of Transducer Beam Angles 14

9—Determination of Beam Spread 15

10—Measurement of Beam Profile in the Vertical Plane 15

11—Measurement of Beam Spread in the Horizontal Plane 15

12—Weld Root Index 17

13—Weld Root Marking of Members for Installation Pile Splice Welds 18

14—Parameters Associated With Geometry of Pipe Intersection 19

15—Weld Root Examination 20

16—Scanning Patterns 20

17—Weld Scanning 21

18—Transfer Correction Determination 21

19—Graphical Plotting Cards Example 1 22

20—Graphical Plotting Cards Example 2 23

21—Graphical Plotting Cards Example 3 23

22—Graphical Plotting Cards Example 4 24

23—Graphical Plotting Cards Example 5 24

24—Graphical Plotting Cards Example 6 25

25—Graphical Plotting Cards Example 7 26

26—Graphical Plotting Cards Example 8 26

27—Circumferential Beam Path Scan 27

28—Skip Distance Adjustment for Circumferential Beam Path 28

29—Graphical Plotting Card for Circumferential Beam Path 29

30—Alternate Method for Determination of Skip Distance on Current Surfaces ... 30 31—Probe Manipulation for Spherical Discontinuity 30

32—Probe Manipulation for Planar Discontinuity 30

33—Distance Amplitude Correction 30

34—Beam Boundary Technique 31

35—Beam Boundary Plotting 32

36—Maximum Amplitude Technique 34

37—Multiple Reflectors 34

38—Circumferential Direction Beam Profile 34

39—20-Decibel d/B Beam Boundary Method 34

40—Length Measurement Comparison 34

41—Weld Profile Classifications 36

42—Design Curves for Different Weld Profiles Curve X From API RP 2A-WSD . 36 43—Reference for Level “A” Examination Block 37

44—Level A Acceptance Weld Quality 38

45—Internal Reflectors and All Other Welds 39

46—Reference for Level C Examination Block 40

47—Definitions 41

48—T, K, and Y Root Defects 42

49—Longitudinal Field Produced by Electromagnetic Yoke Setup 43

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50—Radial Field Produced by “Single-Leg” Electromagnetic Setup 44

51—Magnetization Plan Setups 46

52—Illustration of API-Recommended Magnetic Field Indicator 46

53—Electromagnetic Yoke Setup for Detection of Longitudinal Discontinuities... 47 54—Electromagnetic Yoke Setup for Detection of Transverse Discontinuities 47

55—Incorrect and Correct Electromagnetic Yoke Setup for T and Y

Joint Connections 48

56—Acceptable Setup for Scanning with “Single-Leg” Electromagnetic

Method 48

57—Single-Leg Electromagnetic Setup for Detection of Longitudinal Discontinuities 48

A-1—Question 17 Diagram 54

A-2—Question 18 Diagram 54

1. 3—Question 19 Diagram 55

2. 1—Technique for Examining Welds Containing Natural Defects 58

3. 1—Example of Key to Placement of Reflectors in Test Plate 60

C-2—Example of Typical Ultrasonic Technician Report of Test Results 61

1. 3—Graphical Evaluation of Technician’s Report 62

2. 1—Ultrasonic Examination Report Rejected Indications 66

Tables

1—Recommended Maximum Time Intervals Between Recalibration and Recertification of NDE Equipment 11

2—Recommended Standards and Maximum Performance Check Intervals

for NDE and Mechanical Measuring Equipment 12

3—Transfer Correction Gain Adjustment 21

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Recommended Practice for Ultrasonic and Magnetic Examination of Offshore Structural Fabrication and Guidelines for Qualification of Technicians

1. Scope

   This recommended practice (RP) for nondestructive exam- ination (NDE) of offshore structural fabrication and guide- lines for qualification of personnel contains guidance on NDE methods which have evolved from fabrication experience with offshore structures. These methods are commonly used and have found acceptance due to their reliable detection of discontinuities. The five NDE methods routinely used in off- shore structural fabrication are visual (VT), penetrant (PT), magnetic particle (MT), radiography (RT), and ultrasonic (UT) examinations. This recommended practice primarily addresses the MT and UT methods. Guidance on VT, PT and RT is incorporated by reference to ANSI/AWS D1.1. Further recommendations are offered for determining the qualifica- tions of personnel using MT and UT techniques. Recommen- dations are also offered for the integration of these techniques into a general quality control program. The interrelationship between joint design, the significance of defects in welds, and the ability of NDE personnel to detect critical-size defects is also discussed.

   
   

   THIS DOCUMENT IS NEITHER A CODE NOR A SPEC- IFICATION AND SHOULD NOT BE UTILIZED AS SUCH BY THE OPERATOR.

   
   

2. References

   The applicable editions of non-API standards referenced herein are as follows. Only the latest editions of these stan- dards should be considered applicable, unless otherwise stated.

   API

   RP 2A-LRFD Recommended Practice for Planning,

   Designing and Constructing Fixed Offshore Platforms—Load and Resistance Factor Design

   RP 2A-WSD Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms Working

   Stress Design

   ANSI1/AWS2

   A3.0 Standard Welding Terms and Definitions

   D1.1 Structural Welding Code—Steel

   B1.10 Guide for the Nondestructive Inspection of Welds

   B1.11 Guide for the Visual Inspection of Welds

   ASNT3

   SNT-TC-1A Recommended Practice for Qualification and Certification of NDE Personnel

   ASTM4

   A 435/A 435M Straight-Beam Ultrasonic Examination of Steel Plates

   A 578/A 578M Straight-Beam Ultrasonic Examination of Plain and Clad Steel Plates for Special Applications

   E 587 Standard Practice for Ultrasonic Angle- Beam Examination by the Contact Method

   E 709 Standard Guide for Magnetic Particle Examination

   E 1444 Standard Practice for Magnetic Particle Examination

   
   

3. Definitions

   The welding terminology used herein is defined in the American Welding Society publication A3.0. Relevant ultra- sonic terminology is defined in the Glossary section, Appendix E, of this document. Other definitions of interest are tabulated in the following. For the purpose of this stan- dard, the following definitions apply:

   1. acceptance criteria: Limit of shape, size, and posi- tion of discontinuities acceptable within the context of the specific design requirements.

   2. agency personnel: Personnel employed and trained by an independent organization, offered to the Operator on a contract basis, for assisting in the construction inspection.

   3. certification: Written testimony of qualification.

   4. designer: The person, firm, corporation, or other orga- nization employed by the Operator during fabrication and installation with responsibility for examining all details of fab- rication to ensure compliance with construction specifications.

   5. inspector: The individual representing the Operator during fabrication and installation with responsibility for examining all details of fabrication to ensure compliance with construction specifications.

   6. NDE examination: An examination of materials and fabrication by qualified personnel responsible to the inspector using equipment for the purpose of locating and sizing discontinuities in materials or welds and reporting

1America National Standards Institute, 11 West 42nd Street, New York, New York 10036.

2American Welding Society, 550 N.W. LeJeune Road, Miami, Florida 33135.

3American Society of Nondestructive Testing, Inc., 1711 Arlington Lane,

P.O. Box 28518, Columbus, Ohio 43228-0518, www.asnt.org.

4ASTM International, 100 Barr Harbor Drive, West Conshohocken, Penn- sylvania 19428-2959, www.astm.org.

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