ut procedure for longitudinal seam welds

8/16/2019 UT Procedure for Longitudinal Seam Welds

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RAY DONKIN SERVICESROPERY WORKSHENDON ROADSUNDERLAND SR1 2HA

Tel 0191 5108600

Procedure: RDS/UT/04Issue No: 1 Rev No: 1

1.0

Index

2.0 Scope

3.0 References

4.0 Equipment

5.0

Equipment Calibration

6.0 Operators

7.0 Information

8.0 Conditions

9.0

Parent Metal Examination

10.0 Weld Examination

11.0 Sensitivity Setting

12.0 Evaluation of Results

13.0

Reporting of Results

14.0 Basic Calibration Block

15.0 Technique Sheet


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2.0 Scope

2.1 This procedure covers methods for manual ultrasonic examination oflongitudinal seam welds and parent metal material

2.2 Techniques employed shall be in accordance with ASME V

3.0 References

3.1 In the compilation of this procedure reference was made to the following:a)

BS EN 12668-3:2000b)

BS EN 10160c)

BS EN 1714d)

ASME V / ASME VIIIe)

RDS/NDT/Appendix 1

4.0

Equipment

4.1

A pulse echo ‘A’ scan display presentation shall be usedKrautkramer portable flaw detectors shall be used

4.2

Single and/or twin crystal probes, having a testing frequency within the range 2-6MHz shall be used.The frequency chosen will be as high as possible consistent with obtainingsatisfactory transmissionCrystal diameter shall be 10mm

4.3 Couplant shall be cellulose paste

4.4 Calibration blocks shall be of substantially the same material as that under testand shall be identified

4.5

Each pass of the probe shall overlap a minimum of 10% of the transducer width

4.6 The rate of probe movement shall not exceed 6”/second


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5.0 Equipment Calibration

5.1 Performance characteristics of the ultrasonic flaw detection equipment shall be inaccordance with BS EN 12668-3:2000 and RDS/NDT/Appendix 1

5.2 Calibration/sensitivity checks shall be made at the start and finish of each testperiod and after any change of any part of the equipment

5.3 Calibration certificates for all flaw detectors used shall be available for inspectionby the client’s representative as required

6.0 Operators

6.1 Ultrasonic operators shall be qualified to SNT-TC-1A / PCN Level II

7.0 Information

7.1

The operator shall be given the following information before ultrasonicexamination commences:

a)

Type of materialb)

Weld preparation detailsc)

Method of weldingd)

Item identificatione)

Weld identificationf)

Details of heat treatmentg)

Details of any repair work carried out

8.0 Conditions

8.1 Environment

8.1.1

No examinations shall take place outside the temperature range of 5°C-50°C

8.2 Surface8.2.1 The examination surfaces shall be free from irregularities, loose foreign

matter or coatings which interfere with ultrasonic wave transmission


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9.0

Parent Metal Examination

9.1

Prior to initial angle beam examination, the base material through which theshearwaves will travel, shall be scanned with a compressional wave probe todetect laminar type defects which might affect the interpretation of angle beamresults

9.2 This must be carried out whether or not the parent material has beenultrasonically tested previously

9.3 Sensitivity shall be set by adjustment of the second backwall echo off the parentmaterial to full screen height

9.4

Sizing of indications shall be by the 6dB drop method

10.0 Weld Examinations

10.1 Scanning techniques used shall be as detailed in ASME V

10.2 Wherever feasible the examination shall be carried out from both sides of theweld10.2.1 The beam shall be pointed at the weld length normally

10.3

Where access and the surface condition allows, a compressional probe shall beused to test the weld as well as angle probes

10.4

As a minimum for weld testing two different angle probes shall be used10.4.1

In addition, the 45° probe shall be used for transverse defect scanning

11.0

Shearwave Sensitivity Setting

11.1 A distance amplitude correction (DAC) curve shall be constructed on theoscilloscope screen based on reflection from 3mm side drilled holes

11.2

Method11.2.1 The probe is placed on the top of the reference block over the 1/4t SDH11.2.2 Echo response is set to 80% full screen height. This is the primary

reference response (PRR)11.2.3 Without alteration of the gain control, the procedure is repeated for each

proceeding test distance, marking the positions on the screen11.2.4 Connect the screen marks to provide the DAC


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11.2.5

A further 6dB will be added for scanning

11.3

Defect assessment shall be carried out at the PRR sensitivity

12.0 Evaluation of Results

12.1 Any indication able to produce a response greater than 20% of the PRR shall beinvestigated

12.2 Any indications shall be evaluated in accordance with ASME VIII Appendix 12paragraph 12-3

13.0 Reporting of Results

13.1 For each ultrasonic examination the following shall be recorded:a) contract numberb) order numberc) surface conditiond) code/specificatione) materialf) stage of manufactureg)

ultrasonic procedure numberh)

make, model and serial number of flaw detector

i)

calibration/reference blocks j)

type, size and angle of probes usedk)

settings and attenuation transfer decibels for each probel)

couplantm)

examination personnel, signature and qualificationn)

date of examinationo)

drawings and full details of any recordable discontinuitiesp)

scanning/test limitations and locations


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14.0

Basic Calibration Block

50mm

W

L1/2T 3/4T T

D

L = Length

W = WidthT = 12.5mm or nominal production material thicknessD = 3.0mm side drilled hole

15.0

Technique Sheet

15.1 Technique as per ASME V for Pipe Welds

15.2 Equipment

15.2.1

Krautkramer portable type flaw detector

15.2.2 0 10mm 5 MHz Twin Crystal

70 10mm 2 - 4MHz Transducer60 10mm 2 - 4MHz Transducer45 10mm 2 - 4MHz Transducer


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15.3

Technique

15.3.1 Scanning Technique

1 – Compression Test of Parent Material

2 – Compression Test through Outer Cap Surface (where possible)

3 – Scans with 45, 60 & 70 degree probes from Outer Surface from both sides of theweld

4 – 45 degree probe transverse defect scan

ut procedure for longitudinal seam welds

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