PAUT procedure ED - AMSYCO 500-8-2 Rev 00.pdf

Procedure No. : AMSYCO 500-8-2 First Issue Date : May-20-2011 Revision No. : 00 Revision Date : NIL Title: Ultrasonic Contact Phased Array Examination Page 1 of 34

Cover Page

CONTRACT

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PROJECT

Revision record :

Ver.No. Date Changes Made Doc. Approver 00 May-20-2011 First Issue Tae Young Shin

1. Originator 2.Reviewer 3. Approving Officer

Ed Trotter Keith Baldam Tae Young Shin Specialized Equipment

Division Manager NDT and VID Division Manager General Manager

ASNT Level III UT # XXXX ASNT Level III UT #11863

Sig. : Sig. : Sig. :


Table of Contents

Cover Page ................................................................................................................................... 1

1.0 Scope ................................................................................................................................. 3

2.0 General Requirements ....................................................................................................... 3

3.0 Weld Configuration, Materials and Forms .......................................................................... 4

4.0 Ultrasonic Instrumentation ................................................................................................. 5

5.0 Examination ....................................................................................................................... 8

6.0 Procedure Qualification and Reference Calibration Blocks .............................................. 14

7.0 Acceptance / Rejection Criteria ........................................................................................ 14

8.0 Records and Report ......................................................................................................... 15

Drawing 1: Amplitude Reference Level Blocks ........................................................................... 17

Appendix A (Page 1 of 10).......................................................................................................... 18









Appendix A (Page 10 of 10)........................................................................................................ 27

Appendix B: Specific Instructions and Report Form (Page 1 of 5) .............................................. 28

Appendix C (Page 1 of 8) ........................................................................................................... 29




1.0 Scope

1.1. This procedure is used for the Ultrasonic examination of Welds and the dimensioning of indications for comparison with standards established in the acceptance/rejection criteria included in this document.

1.2. The following information is included in this procedure:

1.2.1. Personnel Qualification/Certification requirements

1.2.2. Procedure Qualification/Demonstration requirements

1.2.3. Instrumentation characteristics and requirements

1.2.4. Calibration Blocks

1.2.5. Extent of examination and examination volume

1.2.6. Acceptance/Rejection criteria

1.2.7. Documentation, records and marking requirements

1.2.8. Report requirements

2.0 General Requirements

2.1. This procedure is Qualified and Demonstrated within specific parameters; this information is clearly defined in this procedure any deviation within the specific ranges, limits or specifications regarding the following Essential Variables will require additional Qualification/Demonstration of this test procedure:

2.1.1. Personnel Qualification/Certification and performance requirements

2.1.2. Weld Configuration, material P‐Class, thickness, dimensions and material product form.

2.1.3. Techniques (straight beam, angle beam, contact, etc.). Manual, Semi‐automated (encoded in passive axis), fully automated method

2.1.4. Angles, angle range and wave mode propagation

2.1.5. Transducer, wedges, sizes, number of crystals, frequency, shape. Surface condition and coupling requirements

2.1.6. Ultrasonic Instrument characteristics. Instrument set‐up and recording requirements

2.1.7. Calibration technique and Calibration block description and characteristics

2.1.8. Scanning technique, overlapping, surface from which the examination will be performed, directions and extent of scanning.

2.1.9. Method for sizing indications.

2.1.10. Discrimination between geometric and flaw indications, indications sizing technique

2.2. Reference Documents

2.2.1. ASME B31.1 – 2007, Chapter VI “Inspection, Examination and Testing”; Par: 136.4.6 Ultrasonic Examination.


2.2.2. ASME B31.3 – 2007, Chapter VI “Inspection, Examination and Testing”; Par: 136.4.6

2.2.3. ASME Code for Boilers and Pressure Vessels, Section V, 2007

2.3. Personnel Qualification/Certification Requirements

2.3.1. A Level II UT ASNT Certified inspector in ultrasonics is required to perform this test. The NDE personnel collecting and analysis UT data shall have demonstrated their ability to perform an acceptable examination using this procedure.

2.3.2. The AMSYCO Written Practice for Personnel Qualification and Certification in Non Destructive Testing shall be used as a reference.

2.3.3. Specific qualification requiring a minimum of 24 hrs of Phase Array Instrumentation training is required.

2.3.4. A Level III ASNT certified inspector will review and assure the quality of the inspection results. The final data package shall be reviewed by a UT Level III individual.

3.0 Weld Configuration, Materials and Forms

3.1. This procedure can be used for welds with a maximum thickness of 5 inches on the base metal.

3.2. Materials included in P‐class numbers 1, 3, 4, 5A and 5X are considered equivalent. This procedure cannot be used for high alloy and high nickel materials.

3.3. Two sets of calibration blocks are required:

3.3.1. Basic Calibration Blocks: These blocks are used for general instrument calibration and performance verification. The manufacturer of Omniscan has a specific sequence for calibration of the instrument. This information is included in Appendix A of this document. The blocks required for this general instrument calibration are the IIW type blocks and side drill hole blocks as described in that appendix.

3.3.2. Reference Calibration Block: Piping calibration blocks (See figure from T‐434.3 at Drawing 1) of the same nominal size and schedule shall be used. Alternatively, the

Basic Calibration block (Drawing 1) and provisions of T‐434.1.7 may be used where it is demonstrated that side‐drilled hole sensitivity is equal to or greater than that of the ID and OD notches. This demonstration shall be documented and on a probe‐specific basis.

3.4. Prior to start the inspection the following information is required:

3.4.1. Base material nominal thickness

3.4.2. Diameter, curvature and other geometric configuration characteristics

3.4.3. Obstructions and other accessories located from the weld center line within 6 times the thickness of the base material.

3.4.4. Bevel dimensions, shape and angles.


3.4.5. Root characteristics, including the presence of backing strips, counter bore and geometry.

3.4.6. Welding technique

3.4.7. Root and Hot passes NDE inspection requirements, inspection results and repairs.

4.0 Ultrasonic Instrumentation

The ultrasonic examination shall be performed using a device employing automatic computer based data acquisition. Data is recorded in unprocessed form. A complete data set with no gating, filtering, theresholding for the response in the examination volume shall be included.

4.1. Instrument

4.1.1. This procedure is specific for the Phase Array Instrument manufactured by RD‐Tech, Model Omniscan.

4.1.2. The Omniscan software used for this service will be revision 2.0R2 or newer. This

needs to be compatible with the AMSYCO’S license for operation of the TOMO‐VIEW Post‐Analysis software.

4.2. Analysis Software

4.2.1. The analysis of the data will be performed using the RD‐Tech, TOMO‐VIEW 2.4 or newer, installed in a Lap‐top computer.

4.2.2. In order to analyze this data, the files will be transferred to this computer at the end of inspection of every weld, or with the frequency and conditions indicated later in this Procedure.

4.3. Transducer

4.3.1. A 16 element (or higher) phase array transducer will be used for this test. Model and Serial number will be recorded in the Specific Instructions, See Appendix “B”.

4.4. Encoder, Scanner and Transducer Mounting

4.4.1. A semi‐automated technique, encoding the passive axis of the transducer will be used for this test. The maximum resolution for encoding position will be 0.039”.

4.4.2. The encoder will be calibrated so that the accuracy shall be within ± 1% per 20 inches of scanning length.

4.4.3. The transducer will be mounted in such a manner that probe spacing from the weld

centerline will be maintained. An automated or semi‐automated device (carriage, sledge, cradle, etc.) appropriate for component geometry and capable of ensuring accurate x and y coordinate movement shall be used. Circumferential movement of the apparatus can be manually assisted.

4.4.4. The encoded Olympus HSP‐XY01 semi‐automated scanner will be used for examinations.

4.5. Transducer Frequency

4.5.1. 5 MHz will be used for base materials with thickness not exceeding 1.0 inches.


4.5.2. 2 MHz will be used for base materials from 1.0 to 6.0 inches.

4.5.3. This procedure cannot be used for material base exceeding 6 inches.

4.6. Wedge: A 45° or 60° Wedge can be used for this inspection. Angular shear waves are produced and used for this inspection.

4.7. Wedge Shape: For parts with diameters below 20” in diameter; wedge shaping is allowed to help on the coupling and transducer stability, using carbide inserts to provide stability to the wedge can also be used. The same wedge design, and/or carbide insert positions should be used for the qualification of the test procedure.

4.8. Phase Array Technique and Angle Interval

4.8.1. This procedure requires the use of “S‐Scan” and/or “L‐Scan” techniques and views. “A, B, and C–Scans are also used for the detection and sizing of flaws.

4.8.2. The technique used in this procedure is not based in amplitude for the detection or flaw sizing. Other techniques are used for this purpose as described later.

4.8.3. DAC and other amplitude based references are not allowed for detection or sizing.

4.8.4. The instrument will be calibrated in Sensitivity and Delay for a interval not exceeding 35° to Any restriction on the angle interval calibration will be considered on the design of the specific scanning technique, and included in the Specific Instructions as described later.

4.9. Surface Condition and Coupling

4.9.1. The area within 4 times the thickness of the base material from the weld center line has to be free from spattering, loose materials, and other surface condition that will prevent the transducer from getting and keeping acoustic coupling.

4.9.2. The material used for coupling will provide enough wetability to avoid any air bubbles to build in the shoe/material interface.

4.9.3. The coupling product should not be detrimental to the material being examined

4.9.4. The Brand name and grade of the couplant used will be recorded in the report for this service.

4.9.5. Coupling between the transducer and the wedge shall be visually checked every 4 hours.

4.10. Instrument Calibration.

4.10.1. Instrument Calibration and Set‐Up

4.10.1.1. The RD‐Tech Omniscan instrument requires specific calibration sequences as indicated by the manufacturer to insure that the system is performing within the design specifications. The Complete calibration sequence specified in the Instrument Operating Manual will be used for this calibration. This calibration includes the Screen High Linearity check and the Amplitude Control Linearity checks.

4.10.1.2. A Set‐Up file will be constructed for each focal‐length.


4.10.1.3. Appendix “A” is attached to this procedure showing the applicable pages of the Omniscan Operation Manual indicating the sequence for calibration.

4.10.1.4. The focal distance will be selected as calculated at 1.0 times the pipe

thickness. This calibration will be used for scanning at the ID, mid‐wall and OD indications.

4.10.1.5. The Full Instrument Calibration will be performed:

a) Before every shift

b) If the transducer or transducer wedge are replaced.

4.10.2. Instrument Calibration Record: The instrument calibration set‐up will be recorded in the Omniscan media. The file name used will contain the following characters:

C2_SETUP_####.OPS

Where:

C2: Weld Identification number

#### is a sequential number

This name will be kept in the test Log Book.

4.10.3. Instrument Calibration Verification

4.10.3.1. This verification will be used as reference for Instrument Calibration and instrument verification only. Other techniques not based in amplitude will be used for the detection and sizing of flaws as described later.

4.10.3.2. A calibration verification will be performed:

a) Every four (4) hours

b) When changing inspectors

4.10.3.3. The calibration verification sequence includes:

a) Distance/range calibration verification using the IIW block 4 inches circumference side. For this verification, change the Screen Rulers to “Half path”.

b) Verification of operation on all the angles intervals and positioning. The 0.060” hole located in the IIW block will be used for. For this verification, return the Screen Rulers to “Truth Depth”.

c) Verification of reference amplitude using the Amplitude Reference Level Block and reflector(s) used for this setting.

4.10.4. Instrument Recording

4.10.4.1. The instrument will be set to record every “A‐Scan” obtained for all angles and encoder positions. This information will be used for post‐processing and future reference.

4.10.4.2. A file name for each scan will be used. The scan designation shall include:

ID7777‐US‐P1‐####.OPD


Where:

ID7777: Is the weld identification number as indicated by the Customer

US or DS: Up‐stream or Down‐stream, as explained in Paragraph 5.64

P1: Scan Position Sequence

####: Scan serial number.

NOTE: These names will be kept in the log book.

4.10.4.3. Those scans that are considered “Valid” will be marked as “OK”, the scans that will not be used for analysis will be marked as “N/G”, not good. This will be stated in the “Comments” column of the Scans Table.

4.10.4.4. Data BackUp: The data files and set‐up files will be backed‐up in other media

every weld. The back‐up data will be kept in two different media at the same time.

5.0 Examination

5.1. Specific Instructions: Specific instructions (scan plans) will be prepared and submitted for review and approval prior to examinations.

5.1.1. This information will be included to the documentation presented in Appendix “B”.

5.1.2. Appendix “B” Is the form that will be used for the specific instructions for each weld. This form includes all the information necessary to perform the weld inspection in accordance with this Test Procedure.

5.1.3. Specific instructions for each weld will be specified before the start of the inspection.

5.1.4. The specific instructions will cover details regarding the weld and bevel geometry, part geometry, diameters and other information that is used for the specific examination on each weld.

5.1.5. These specific instructions will be obtained from: Calculations, plotting and simulation.

5.1.6. The specific instructions are part of this procedure and will be Qualified under then Procedure Qualification program.

5.1.7. The following information and other discussed previously will be included in those instructions:

5.2. Examination Coverage Volume

5.2.1. The ultrasonic examination shall include the volume of the weld plus the heat affected zone.

5.2.2. The weld should be inspected in both sides, unless obstruction or inaccessibility prevents the inspection from one side. In this case, this situation shall be discussed and approved by the customer or the Quality Assurance personnel from the customer.


5.2.3. The scan plan drawing [cross‐section] will need to show complete coverage and include material type(P# is OK), beam plots, refracted angles, probe index spacing

(from weld centerline), overlap, frequencies, thickness, cross‐section geometry, weld joint configuration and dimensions, weld crown width and profile, two‐directional beam coverage (minimum), and location of calibration reflectors.

5.2.4. The scan plan will be used to define the transducer positions to the weld center‐line and be included in the Specific Instructions. This document will be attached to the Specific Instructions document presented in Appendix “B”.

5.3. Ultrasonic Scanning Technique

5.3.1. Straight Beam Inspection: The volume of metal that will be used to transmit sound from either side of the weld will be examined to detect planar reflectors or other inclusions that may prevent the efficient transmission of the sound in these areas.

5.3.2. Reflectors Parallel to the Weld Seam: The welds will be scanned to detect any flaws that are located parallel to the weld center line within the examination coverage volume.

5.3.3. Reflectors Transverse to the Weld Seam:

5.3.3.1. The welds will be scanned to detect any flaws that are located transversal to the weld center line within the examination coverage volume.

5.3.3.2. The ultrasonic transducer shall be aimed parallel to the weld center‐line. The transducer will be manipulated so that the ultrasonic beam pass‐through all the examination volume and adjacent base metal. Scanning shall be done in two directions 180°. to each other and on both sides of the weld to the extent possible. Areas blocked by geometric condition shall be examined at least one direction. Any indication detected will be sized with the techniques indicated later and compared with the Acceptance/Rejection criteria included in this test procedure.

5.4. Fusion Face, Bevel Angle and Ultrasonic Incidence Angle

5.4.1. It is considered that the maximum intensity of ultrasound reflection will happen when the flaw is oriented perpendicular to the ultrasonic beam, and within 5° of that direction.

5.4.2. Using Phase Array technologies allows for increasing the probability of detection based on the presence of sound in a diverse interval of angles interrogating the weld.

5.4.3. It is also clear that fusion lines, inclusions and other flaws are oriented primarily in the same angle as the weld bevel face.

5.4.4. Plotting or simulation of the weld shall be used to ensure that 100% of the volume of the weld and the HAZ are inspected.

5.4.5. With this consideration the following ultrasonic technique will be used:

5.4.5.1. Considering the bevel design two or more “S‐Scans” or “L‐Scans” will be obtained on either side of the weld, by moving the transducer parallel to the weld center line at specific distances.


5.4.5.2. Plotting or simulation of the weld geometry shall be used to calculate what is the angle, range and distance from the weld center line to obtain maximum amplitude reflection from flaws located at the fusion face surface, root and weld crown.

5.4.5.3. The fusion face inspected shall not be more that the area covered by an interval of 5° from the calculated maximum amplitude angle.

5.4.5.4. It is expected that for thickness of 1.5 inches or less at least 2 scans will be necessary and 3 or more will be necessary for thickness of more than 1.5 inches.

5.4.5.5. The crown of the weld shall be inspected using the smallest angle that allows

the shortest sound path in a full‐skip (i.e. 40°‐55°).

5.4.5.6. The root and the mid‐wall of the weld shall be inspected with the angle that on the first leg reaches the area with the shortest sound path. (i.e. 50°‐65°).

5.4.5.7. If crown obstructions prevents from getting a complete volume coverage of

the midwall section, then a two‐leg inspection with the shortest sound path shall be used.

5.5. Angular Interval for Each Scan

5.5.1. The phase array instrument is calibrated for “S‐Scan” angular aperture within 35° to 70°, as indicated in the specific instructions for each weld design. Using this angular interval will increase the probability of detection of flaws within the weld and the HAZ.


5.5.2. 5.5.2 Special attention will be placed to those angles that are expected to produce maximum amplitude from reflectors located at the fusion face, crown toe cracks or weld root flaws.

5.5.3. The angular interval must ensure that 100% of the volume and the HAZ are interrogated.

5.5.4. Presentations type: “A, B, and C” are used in conjunction with “S‐Scans” and “L‐Scans” to obtain the highest quality information and increase the flaws probability of detection when compared with the Acceptance/Rejection Criteria indicated later in this procedure.

5.6. Scan Designation and Sequence

5.6.1. The Specific instructions will indicate the number and position of the Scans performed on each weld.

5.6.2. Information regarding the length of each scan and file designation will also be included in that document.

5.6.3. A zero and scan direction stamp will be pre‐marked on the welds to inspect, and will be used as reference start point for all measurements and for scanning direction. The symbol used will be:

>

5.6.4. The zero marking will be designated as 12:00 o’clock position. The Index and Scan definitions indicated will be used as references for indication and scans positions

and directions. Forward or Down‐stream and Backward or Up‐Stream direction are defined as follows:

5.6.5. If an obstruction is present on the scan transducer path, stop and save the file at the point before the obstruction and continue after the obstruction. The names of both


files and the distance between the stop and the start will be documented and included.

5.7. Scanning Sensitivity Level, DAC Curve and Discontinuity Detection

5.7.1. A Reference Calibration Block will be used to set a Reference Level.

5.7.2. Piping calibration blocks (See figure from T‐434.3 at Drawing 1) of the same nominal size and schedule shall be used. Alternatively, the Basic Calibration block

(Drawing 1) and provisions of T‐434.1.7 may be used where it is demonstrated that side‐drilled hole sensitivity is equal to or greater than that of the ID and OD notches. This demonstration shall be documented and on a probe‐specific basis.

5.7.3. The calibration block shall comply with the dimensions and characteristics included in the Table, General Notes and Note included in Drawing 1.

5.7.4. A DAC Curve shall be established using the reflectors included in the Basic Calibration Block. The angle beam shall be directed toward the calibration reflector that yields the maximum response, and the instrument shall be set to obtain an 80% of full screen height indication. This shall be the reference level.

5.7.5. The transducer then shall be manipulated to obtain –without changing instrument settings to obtain the maximum responses from the other calibration reflectors to generate a DAC curve.

5.7.6. This calibration shall establish the sweep range and the distance amplitude correction.

5.7.7. The examination coverage volume will be scanned with a Hardware Gain (Hard

Gain) at Reference Level plus no more than 6 dB. The detection analysis in TOMO‐VIEW will be performed with gain at Reference Level plus at least 6 db more gain, but not more than 14 db of Software Gain (Soft Gain) than the reference gain used during the actual scanning.

5.7.8. This process is intended for the detection of discontinuities, both relevant (flaws) and nonrelevant (geometric, metallurgical).

5.7.9. Sizing of these discontinuities will be performed using the methods indicated later.

5.8. Indications Record

5.8.1. All indications that produced reflection exceeding 20% of the Reference Level shall be recorded and investigated.

5.8.2. Ultrasonic indications of geometric and metallurgical origin shall be classified as follows:

5.8.2.1. Indications determined to originate from the surface configuration.

5.8.2.2. Indications produced by variation on the metallurgical structure of the materials.

NOTE: The following steps should be taken to classify an indication as geometric:

5.8.2.3. Interpret the area containing the reflector in accordance with the Notes and Recommendations included in APPENDIX “C”.


5.8.2.4. Plot and verify the reflector coordinates on the weld geometry.

5.8.2.5. Review fabrication or weld preparation drawings.

5.8.2.6. Alternatively other NDE methods may be applied to classify an indication as geometric.

5.8.3. Indications determined not to be from geometric or metallurgical origin and exceeding 20% of the DAC Reference Level will be considered relevant. Relevant indications shall be sized and characterized to obtain the following information:

a) Determine if it is a Crack, Lack of Fusion or a Lack of Penetration

b) Reflectivity compared to the DAC curve used as Reference Level

c) Length of indication

5.8.3.1. 5.8.3.1 To determine the characteristics of the indication APPENDIX “C” includes a series of techniques based on:

a) Echo‐dynamics

b) Amplitude Behavior

c) Weld position

These methods shall be used to determine if any indication is a crack, lack or fusion or lack of penetration, regardless of its length.

5.8.3.2. For length measurement the following technique shall be used:

5.8.3.3. Length, measured parallel to the surface, designated as “l”, using the following techniques:

a) Instrument SetUp: gate length and positioning are required for flaw detection and sizing of indications. The starting position of the gate will have to include all parts of the first leg data excluding the wedge noise which shows up in the initial part of the first leg. The gate should also include the information up to half way of the third leg. This way we get information about what is happening in the entire metal path and no indication will be lost.

b) Analysis: The analysis will be done by a combined analysis of the C‐scan and the Sector or Linear scan views and also by obtaining any additional

information from the A‐scan. For sizing it is necessary to locate the extreme dimensions of the indication. In many cases, the root or OD indications might be masked by some reflections of the root or cap. These reflections, although do not occur in the same time frame, can

overlap over the flaw indications in the C‐scan. This will mean an obvious compromise in the length of the indication. The method to overcome this is to scan along the length of the Cscan and look for a maximum indication of the flaw in the sector scan. Then, gate out this dimension of the flaw only in the sector scan. This will provide us with indications only from the flaw helping the sizing procedure greatly.


c) (CAUTION) Encoder Positioning: It is important to note the encoder position at the start of each scan. Also care should be taken to ensure the encoder slippage is minimum. This can be verified by checking the length of the scan at the end of each scan and comparing that to the actual circumference that had to be scanned. Identifying the correct starting and ending position of the flaw is important for any rework to be done. The encoder accuracy shall be within ± 1% per 20 inches of scanning length.

d) Flaw Length Sizing: For deeper ID/OD indications: The amplitude fall off

is gradual for a while and then drops off suddenly. The sudden drop‐off points are going to be the ends of the indication.

For Shallow ID/OD indications: In this case, the energy of the beam hitting the flaw is not very high. Hence, the amplitude response is not going to follow the profile of the indication. In this case, the amplitude change will be gradual. The sizing will be taken to the end of the visible indication or a 20% amplitude change in the signal.

For Mid‐Wall indications: The sizing of the length will be treated in a similar fashion to the sizing of the deep and shallow ID/OD indications.

6.0 Procedure Qualification and Reference Calibration Blocks

6.1. This Procedure including the Specific Instructions will be qualified to assure that

discontinuities located on the ID, OD surface as well as in the sub‐surface of the weld are detected and sized correctly.

6.2. Calibration blocks prepared by welding or hot isostatic process will contain indications

located on the ID, OD and mid‐wall.

6.3. The calibration blocks shall be examined in accordance with the Ultrasonic procedure and specific instructions.

6.4. The Procedure shall demonstrate to perform acceptably on the calibration blocks.

7.0 Acceptance / Rejection Criteria

7.1. Welds that are shown to have discontinuities which produce an amplitude greater than 20% of the Reference Level shall be investigated to determine their shape, identity and location so that each indication may be evaluated for acceptance in accordance with (7.1) and (7.2).

7.2. Any indication from cracking, lack of fusion or lack of penetration will be considered rejectable regardless of length.

7.3. Any other indication that exceeding the DAC Reference Level will be considered rejectable if additionally has the following characteristics:

7.3.1. For thickness (t) up to ¾”, the indication length is more than ¼”

7.3.2. For thickness (t) from ¾”up to 2.5” the indication length is more than t/3


7.3.3. For thickness above 2.5” the indication length is more than 0.750”.

7.3.4. NOTE: If the weld joins two members having different thicknesses at the weld, t is the thinner of these thicknesses.

8.0 Records and Report

8.1. Test Log: A book will be prepared for each weld. All the drawings, specific instructions, forms, inspection results and other documentation and records will be maintained in this book. All calibration and calibration verification records will be maintained in this book.

8.2. Test Report: Appendix “B” Includes the form that will be used for the report of the examination. The inspector must generate a Report per Weld including as a minimum:

8.2.1. Identification of Job/Project/ Service; Date and Time of Data Acquisition; Date of Data Analysis.

8.2.2. Personnel and Certification Level

8.2.3. Procedure ID and revision

8.2.4. Search unit ID, s/n, type, frequency, and element size and number, couplant type.

8.2.5. Search unit cable used, type, and length

8.2.6. “Special equipment used” i.e. Scanner manufacturer and model, Data acquisition increment

8.2.7. Omniscan software version, Set‐up file names

8.2.8. Data analysis (Tomoview) software name and version

8.2.9. Calibration simulator information, if used

8.2.10. Reference level gain for all applicable scans.

8.2.11. Calibration data including reference reflectors, indication amplitude(s), and distance reading(s). Calibration block identification and calibration records

8.2.12. Focal law parameters, including as applicable, angular range, focal depth, element numbers used, angular incremental change, and wedge angle.

8.2.13. Scanning surface from which the examination was conducted, surface condition, number of positions and distances to weld center‐line, scanning sequence, files names used to save Data Files.

8.2.14. Scan plan [cross‐section] will need to show complete coverage and include material identification, beam plots, refracted angles, probe index spacing (from weld

centerline), overlap, frequencies, thickness, cross‐section geometry, weld joint configuration and dimensions, weld crown width and profile, two‐directional or multiple beam coverage.

8.2.15. Details of restricted access or inaccessible welds.

8.2.16. Map or record of indications detected, including dimensions, positions and characterization, as well as any other pertinent information. Accepted or Rejected.

8.2.17. Comments


8.3. Deliverables: The report formats are included as Appendix “B” on this procedure.

8.3.1. A handwritten Report will be generated for each weld, and will be delivered to the customer indicating the position of rejectable indications, if any.

8.3.2. The rejectable indications will be marked on the surface of pipe with a “paint‐pen” showing their position and length.

8.4. Data Back‐Up

8.4.1. The data and set‐up files will be transferred to a PC‐Computer hard‐disk every weld.

8.4.2. The data and set‐up files and any other electronic documentation will be backed‐up in a external hard‐disk drive or stick memory.

8.4.3. All the data and documents will be stored in a external hard‐disk for permanent storage. Two copies will be made. The customer will receive a copy and AMSYCO'S will retain the other copy.


Drawing 1: Amplitude Reference Level Blocks


Appendix A (Page 1 of 10)




















Appendix B: Specific Instructions and Report Form (Page 1 of 5)


Appendix C (Page 1 of 8)

Identifications of flaws in the welded joint can be performed based in three independent criteria or by combination of either technique.

These techniques are:

Echo‐dynamics and echo behavior

Amplitude expected and flaw orientation

Position of the flaw within the weld.

The following tables have descriptions for each one of these techniques:



Figure 1: Echodynamics examples



Figure 3: Weld areas identification and flaw position.

Notes on Positions and flaw characteristics when evaluated with UT

Nonfusion at Root: Several variations can occur.

Lack of Penetration: The internal welding head did not fire or sputtered. No metal is deposited. Ideally this presents 2 smooth root faces, however, welders have been known to see this from the outside and the Hot Pass bug can be run over the area twice. This can cause some metal to

penetrate and reduce the surface area of non‐fused root face.

Nonfusion at Root:

Misalignment: Due to misalignment of the internal head or high low conditions, one side of the root bevel may not get metal deposited on it. The Main Figure shows a missed edge on the right side of the weld. Undercut, shown on the left, is the depression caused by melting of the parent metal next to the weld edge. It would need to be very deep to detect but we could not reasonably see a difference between U/C (U/C=undercut) and a missed edge.

Non-fusion Root:

Nonfusion Root: It may be possible for the root bead to be placed symmetrically but due to oil or arc redirection, an area of the parent metal does not get melted to fuse with the weld puddle. The

bead will appear acceptable on the inside surface but non‐fusion still exists. Although it does not appear to be surface breaking it is considered a surface defect.

Nonfusion Root:

Nonfusion Root and LCP: If a condition of High Low exists or debris is caught between the root bead and corner of the weld prep. at the land area, the nonfusion may span 2 zones. Such a flaw is


difficult to evaluate as one or another condition. If seen mostly by the LCP probe it is called LCP and if seen mostly with the Root probe but with some LCP component it is called a Root indication.

LCP:

Lack of Cross Penetration both identifies the defect and is the term used to identify the zone at the weld land area. This can be associated with the internal welding machine not depositing the bead deep enough, the hot pass weld not penetrating deep enough or is often associated with conditions of high low. With welder problems the condition may be more symmetric (seen with approximately equal length and amplitude upstream and downstream) whereas high low conditions could cause one side to be more pronounced that the other. The adjacent channels (Root and hot pass 1) are usually examined to see if the LCP extends inwards or outwards.

Nonfusion

Hot Pass:

With its 45° orientation, the hot pass bevel was a difficult problem for radiographic testing. Due to the surface length of this area it has been divided into 2 zones, hot pass 1 and hot pass 2. UT signals here are clear and due to the large angular difference between the 45° hot pass bevel and the 90° LCP below it and the 85° Fill above, signals from the hot pass zone are not confused with adjacent zone defects. (If they were detectable by RT these would have been called LFSS).

Lack of Fusion Fill 1:

The sources of this defect are the same as for any non‐fusion defect in the fill passes. Fill 1 non‐fusion is often associated with the corner where the hot pass bevel and the fill bevel meets.

Lack of Fusion Fill 2 and 3:

This defect can be simple sidewall nonfusion, or it may have a component of cold lap to the Fill 1 pass. In light wall pipe only 2 fill pass probes are used to cover the Fill 1, Fill 2 and Cap passes. Undercut, if deeper than 1 mm would occur in the Fill 2 zone as well. The operator cannot

discriminate where the non‐fusion exists. This must be determined by the hand scanner who would have to plot any defects called for repair. If during the manual evaluation no undercut is seen it is assumed the flaw is subsurface. For heavier wall pipe where 3 or 4 fills are required the concerns are the same as for fills 1 & 2.

Stacked Defects:

When a welder stops a weld in the middle of the process (to clean a cup or clear bad wire, etc., they must then restart the weld in the same area. If the arc stutters or the stop was not properly cleaned out a vertical component will be seen that can extend to 2 or more zones. If the chart indicates the situation exists on 3 or more adjacent zones, it is recommended to investigate further using manual ultrasonics even if length is less than 25mm.


Burnthrough:

This occurs when the heat of the melt is sufficient to weaken the weld metal laid down previously and pokes through thereby removing a volume of metal from the inside surface of the weld/pipe.

The amount of material may be very small, typically 5‐6 mm diameter and only be sufficient to remove the bead surface. This would produce little or no indication on the root probe channel.

However, if the situation is more pronounced, metal could be removed from the hot pass and bead as well as material from the parent metal. This would be seen on Root, LCP and 1 or 2 hot pass

zones. Associated with this stacked indication would be an arrival time sooner than the normal non‐fusion and some degree of symmetry.

Porosity:

Caused by gasification of impurities on the weld prep. surface or by loss of shielding gas, porosity is seen by the standard probes in the Root and LCP zones. For fill and hot pass occurring porosity, a special probe is incorporated into the system. Signals will typically have irregular amplitudes in the amplitude gates and irregular arrival times in the time gates although with such short time intervals as exist in the Root and LCP this is more difficult to see.

Some symmetry is often noted and if the porosity is heavy, the geometry signal seen from the weld surface will be reduced or even eliminated.

Porosity Bead (See image part: Root Bead Porosity)

Porosity Fill

(See image part: Typical Porosity)

Centerline Cracking:

If too much weld metal is deposited too quickly the heat gradient in the weld nugget will cause shrinkage cracking to occur as it solidifies (also called solidification cracking or shrinkage cracking). This is not likely to occur in the root pass but may occur in any pass made from the outside surface. As this is likely to pass right through the weld nugget its amplitude is usually large and symmetry exists. On a radiograph the crack edges are very fine and may not show clearly, it would then be misinterpreted as LCP as it is approximately centered.

Geometry HighLow:

Not a defect, high low is a geometry condition caused by ovality or poor mechanical fit. Care must be taken by the operator to ensure the indications originating from this are not called for repair. However, this condition can cause genuine defects and the two must be discernible. Large differences in root transit times are usually an indication of high low.

Bead Offset (or wander):


Internal welding is performed using 6 welding heads arranged to align with the weld centerline. If not correctly set one or more heads will deviate from the central position. This may be a head starting on one side and crossing the centerline or it may be a head that moves straight but is offset upstream or downstream. Root transit time indicates this condition.

Other Transition (counterbore):

To allow heavy wall and light wall pipe to be joined the heavy wall pipe is counter bored to the same thickness as the light wall. If the counter bore is made as a taper the counter bored side cannot be UT inspected as the skip angles are no longer correct. If the counter bore is parallel inspection is possible but ovality may result in some areas being thicker than they should be. These results in the gated regions being incorrect for the sound path traveled.

Date post:	03-Dec-2015
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