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DOC. NO ULTRASONIC EXAMINATION ISSUED

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PROCEDURE FOR ULTRASONIC EXAMINATION OF FULL PENETRATION WELDS

AND T, K AND Y CONNECTIONS IN FERRITIC STEEL

as per

AWS D1.1

0

REV. NO. DATE APPROVED BY :

LEVEL III

APPROVED BY : APPROVED BY :



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PROCEDURE FORULTRASONIC EXAMINATION OF FULL PENETRATION WELDS

AND T, K AND Y CONNECTIONS IN FERRITIC STEEL(AWS D1.1)

TABLE OF CONTENTS

Description Page No.

1.0 Scope 4 of 29

2.0 Definition 4 of 29

3.0 Personnel Qualification 5 of 29

4.0 Equipment 5 of 29

4.1 Flaw Detector

4.2 Probes

4.3 Couplant

5.0 Equipment Performance Checks 7 of 29

6.0 System Calibration 8 of 29

6.1 System Calibration

6.2 The frequency of System Calibration

6.3 Sweep Range Calibration

6.4 Sensitivity Calibration

TABLE OF CONTENTS CONT’D

Description Page No.



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7.0 Testing Procedure 10 of 29

7.1 Surface Preparation

7.2 Testing Coverage

7.3 Parent Metal Evaluation

7.4 Weld Evaluation

8.0 Defect Evaluation and Sizing 12 of 29

8.1 Defect Evaluation

8.2 Defect Sizing

9.0 Acceptance / Rejection Criteria 14 of 29

10.0 Reports 15 of 29

1.0 SCOPE



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1.1 This procedure describes the method for Ultrasonic Testing to be employed by the company.

1.2 This procedure is intended for the inspection of groove welds in steel structure fabrication with parent metal thickness between 8mm and 100mm.

1.3 This procedure is written in accordance with the requirements of AWS D1.1 (1992 edition), Part C of Section 6.

2.0 DEFINITION

a. Client Company or organisation for whom Contracted to complete scope of work

b. NDT Non Destructive Testing

c. ASNT The American Society for Non Destructive Testing

d PCN Personnel Certification for Non Destructive Testing

e CSWIP Certification Scheme for Weld Inspection Personnel

3.0 PERSONNEL QUALIFICATION



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3.1 All technician carrying out Ultrasonic Testing in accordance with this procedure shall be qualified in Ultrasonic Testing Level II in the weld configuration to be inspected, or qualified in Ultrasonic Testing Level II to a nationally recognised certification scheme.

3.2 Any one of the following nationally recognised certification schemes may be used for the purpose of qualification and certification of Ultrasonic Testing technician:

a. ASNT (in accordance with the company’s Written Practice).

b PCN / CSWIP

4.0 EQUIPMENT

4.1 Flaw Detector

4.1.1 The flaw detector shall be the Krautkramer USK7, Sonatest SS110 or equivalent.

4.1.2 The flaw detector shall be calibrated and certified within 12 months prior to use. A copy of calibration certificate shall be accompanied the flaw detector.

4.2 Probes

4.2.1 A minimum of one (1) zero degree probe and three 93) angle probes (45, 60 and 70) shall be made available on each testing.

4.2.2 Probes to be used shall be selected from but not necessarily limited to the following:-

a. 0, 2-5Mhz, 10-25mm diameter

b. 45, 2-5 Mhz, 8 x 9mm

c. 60, 2-5 Mhz, 8 x 9mmd. 70, 2-5 Mhz, 8 x 9mm

4.2.3 The probe shall produce a sound beam in the material being tested within plus or minus 2.



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4.2.4 Each probe shall be clearly marked to indicate:-

a. frequency (Mhz)

b. beam exit point

c. beam incident angle

d. serial number

4.3 Couplant

4.3.1 The couplant to be used between the probe and inspection surface shall be paste and water mixture of a suitable consistency.

4.3.2 The same couplant shall be used for both system calibration and testing

4.4 Calibration Blocks

4.4.1 The International Institute of Welding (IIW) V1/V2 ultrasonic reference block shall be the standard used for both distance and sensitivity calibration.

4.4.2 The material from which the blocks is fabricated shall be of the same material specification or equivalent P-number grouping as one of the materials being examined.

5.0 EQUIPMENT PERFORMANCE CHECK

5.1 The type of performance checks and their frequency shall be as the following:

a. Horizontal linearity 40 hours

b. dB linearity 2 months

c. Amplifier linearity 3 months

d. Internal reflection of probe 40 hours



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e. Probe contact surface Beginning of shift and after 8 hours

f. Probe beam exit point Beginning of shift and after 8 hours

g. Probe beam exit angle Beginning of shift and after 8 hours

h. Resolution Every change of probe shoe

5.2 Performance checks shall be conducted on the flaw detector and probes to be used for inspection

5.3 All equipment performance checks shall be documented.

6.0 SYSTEM CALIBRATION

6.1 System calibration shall be conducted on each flaw-detector-probes combination. This calibration should include the following:-

a. sweep range calibration

b. sensitivity calibration

6.2 The frequency of system calibration shall be as the following:-

a. at the beginning of each testing

b. every thirty (30) minutes during testing

c. change of test operator

d. change of probe

e. change of battery

f. change of power source

g. change of probe cable

h power failure



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6.3 Sweep Range Calibration

6.3.1 Sweep range calibration shall be conducted using IIW V1 /V2 calibration block for a suitable range for the thickness of material being tested. Table 2 may be use for the selection of sweep range calibration for difference in material thickness.

6.3.2 If a point of a sweep range calibration has moved on the timeless by more than 10% of its original timebase position, the calibration shall be corrected with a note of the correction being made on the report. If any signals have been recorded, all recorded indications shall be re-examined with the corrected calibration and their values corrected accordingly on the report.

6.4 Sensitivity Calibration

6.4.1 The reference level for sensitivity calibration shall be the 1.5mm hole in the IIW V1 /V2 calibration block. The sensitivity of the reflector shall be set at approximately 70% of full screen height.

6.4.2 If a point on the reference level has change by + 20% or 2 dB from its original amplitude, all recorded data since the last valid calibration shall be marked void. A new sensitivity calibration shall be produced with a note to this effect on the report and the voided areas shall be re-examined.

7.0 TESTING PROCEDURE

7.1 Surface Preparation

7.1.1 The condition of all surfaces shall be such that a satisfactory coupling between probe and test surfaces can be maintain.

7.1.2 The visual examination of weldment shall and/or material under test shall be carried out to ascertain any surface defect or condition which may effect the ultrasonic examination.

7.1.3 All spatter, loose scale, rust or coating over the scanning surfaces on any side of the weld shall be removed by wire brushing or light grinding.

7.2 Testing Coverage



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7.2.1 Welded joints requiring Ultrasonic Testing shall be tested for their full length unless partial or spot testing is specified by Client.

7.2.2 The scanning shall be done from each side of the weld axis where possible. The area adjacent to the weld shall be prepared for at least 3 times the thickness of material being inspected both side of weld axis for the smooth scanning surface.

7.2.3 The volume shall be examined by moving the probe over test surfaces so as to scan the entire weld volume and adjacent area. Each pass of the probe shall overlap a minimum, of 50% of the probe dimension

7.3 Parent Metal Evaluation

7.3.1 The entire base metal through which ultrasound must travel to test the weld shall be tested for laminar reflector using a zero degree probe.

7.3.2 The scanning shall be performed at sensitivity setting of those in Table 1. Evaluation shall be performed with respect to the primary reference level.

7.3.3 The probe movement for examination shall not exceed 150mm per second.

7.3.4 If any of base metal exhibits total loss of back reflection or an indication equal to or greater than the original back reflection height is located in a position that will interface with the normal weld scanning procedure, its size, location and depth shall be determined and reported in the ultrasonic test report.

7.4 Weld Evaluation

7.4.1 The beam shall be directed at approximately right angles to the weld axis from two directions where possible. The probe shall be manipulated so that the beam passed through the required volumes of weld and adjacent base metal.

7.4.2 The scanning shall be performed at sensitivity setting of those in Table 1. Evaluation shall be performed with respect to the primary reference level.



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7.4.3 The probe movement for the examination shall not exceed 150mm per second.

7.4.4 For transverse discontinuities, the beam shall be directed approximately 15 to the weld axis.

7.4.5 Figures 1 through 3 illustrate probe movement to be used. Techniques of scanning for different weld configuration shall be as per figures 4 through 7.

8.0 DEFECT EVALUATION AND SIZING

8.1 Defect Evaluation

8.1.1 When a discontinuity indication appears on the screen, the maximum attenuable indication from the discontinuity shall be adjusted to produce a horizontal reference level trace deflection on the screen. This reading in decibels shall be use as the “Indication Level”, “a”.

8.1.2 The “Attenuation Factor” , “c”, on the test report is attained by subtracting 25mm from the sound path distance and dividing the remainder by 12.5. This factor shall be rounded out to the nearest dB value. Table 3 may be used for the determination of “c” values.

8.1.3 The ‘Indication Rating”, “d”, on the test report, represents the differences in decibels between the Indication Level and the “Reference Level”, “b”, with correction for attenuation as indicated in the following expression:-

d = b - a - c

8.2 Defect Sizing

8.2.1 The length of indication shall be determined by measuring the distance between the probe centerline locations where the indication rating for the indication rating amplitude drops 50% (6 dB) below the rating for the applicable classification.

8.2.2 The indication length shall be recorded under “sizing length” on the test report.



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9.0 ACCEPTANCE / REJECTION CRITERIA

9.1 Each weld discontinuity shall be accepted or rejected on the basis of its indication rating and its length, in accordance with Table 4 for Statically Loaded Structure (AWS D1.1 Section 8.15) or Table 5 for Dynamically Loaded Structures (AWS D1.1 Section 9.25), whichever is applicable.

10.0 REPORTS

10.1 A report form which clearly identifies the work and the area of inspection shall be completed by the Ultrasonic Technician at the time of inspection. The report shall be written on Global Inspection Services Sdn. Bhd. “Ultrasonic Testing Report Form (AWS D1.1 Section 6”.

10.2 Those discontinuities which are rejectable need to be recorded on the test report. Discontinuities approaching rejectable size, particularly those about which there is some doubt in their evaluation, shall also be reported.

10.3 Areas for which complete inspection was not accessible for inspection shall also be noted, along with the reason why.

10.4 Each rejected discontinuity shall be indicated on the welds by mark directly over the discontinuity for its entire length. The depth from the surface and indication rating shall be noted on nearby base metal.

TABLE 1

Selection of Probes and Scanning Level for Differences in Material Thickness



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Sound Material Thickness (mm) Scanning Level

Path 0 Probe

45 Probe 60 Probe 70 Probe (+dB)

Distance (mm)

½ skip Full skip

½ skip Full skip

½ skip Full skip

Static Load

Dynamic Load

<64 <64 <45 <22 <32 <16 <22 <11 14 2064-127 64-100 45-90 22-45 32-64 16-32 22-43 11-22 19 25

127-254 - 90-100 45-90 64-100 32-64 43-87 22-44 29 35254-381 - - 90-100 - 64-95 87-100 44-65 39 45

TABLE 2

Selection of Sweep Range Calibration for Difference in Material Thickness



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Sweep Range Calibration (mm) Material Thickness (mm)

0 Probe 45 Probe 60 Probe 70 Probe100 <40 <28 <20 <14125 40-50 28-35 20-30 14-17200 50-80 35-37 30-40 17-27250 80-100 57-71 40-50 27-34300 - 71-85 50-60 34-41375 - 85-100 60-75 41-51400 - - 75-80 51-55500 - - 80-95 55-65

TABLE 3

Determination of Attenuation Factor “c” Value



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Sound Path Distance

(mm)

Attenuation Factor (dB)

Sound Path Distance

(mm)


Sound Path Distance

(mm)


<31 0 144-156 10 269-281 1931-44 1 156-169 11 281-294 2044-56 2 169-181 12 294-306 2056-69 3 181-194 13 306-319 2069-81 4 194-206 14 319-331 2181-94 5 206-219 15 331-344 2194-106 6 219-231 16 344-356 22106-119 7 231-244 17 356-369 22119-131 8 244-256 18 369-381 22131-144 9 256-269 19 - -

TABLE 4Acceptance / Rejection Criteria for Statically Loaded Structure (AWS D1.1 Section 8.15)

Material Thickness (mm) and Probe AngleDiscontinuity 8-19 19-38 38-64 64-100

Class 70 70 70 60 45 70 60 45Class A +5 & +2 & -2 & +1 & +3 & -5 & -2 & 0 &



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lower lower lower lower lower lower lower lowerClass B +6 +3 -1 & 0 +2 & +3 +4 & +5 -4 & -3 -1 & 0 +1 & +2Class C +7 +4 +1 & +2 +4 & +5 +6 & +7 -2 to +2 +1 & +2 +3 & +4Class D +8 &

higher+5 & higher

+3 & higher

+6 & higher

+8 & higher

+3 & higher

+3 & higher

+5 & higher

Note : 1. Class A - Rejectable regardless of length.

2. Class B - Rejectable if length greater than 19mm.

3. Class C - Rejectable if length greater than 51mm.

4. Class D - Acceptable regardless of length and location.

5. Class B and C discontinuities shall be separated by at least 2L, L being the length of the longest discontinuity, except that when two or more such discontinuities are not separated by at least 2L, but the combined length of discontinuities and their separation distance is equal to or less than the maximum allowable length under provisions of Class B or C, the discontinuity shall be considered a single acceptable discontinuity.

6. Class B and C discontinuities shall not begin at a distance of 2L from weld ends carrying tensile stress, L being the discontinuity length.

7. Discontinuities detected at “scanning level” in the root face area of complete joint penetration double groove weld joints shall be evaluated using an indication rating 4 dB more sensitive (subtract 4 dB from the indication rating “d”) when such welds are designated as “tension welds” on the drawing.

8. Indications of discontinuities that remain on the screen as the probe is moved towards and away from the discontinuity may be indicative of plannar discontinuities with significant through throat dimension.

TABLE 5Acceptance / Rejection Criteria for Statically Loaded Structure (AWS D1.1 Section 9.25)

Material Thickness (mm) and Probe AngleDiscontinuity 8-19 19-38 38-64 64-100

Class 70 70 70 60 45 70 60 45Class A +10 &

lower+8 & lower

+4 & lower

+7 & lower

+9 & lower

+1 & lower

+4 & lower

+6 & lower



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Class B +11 +9 +5 & +6 +8 & +9 +10 & +11

+24 & +3

+5 & +6 +7 & +8

Class C +12 +10 +7 & +8 +10 & +11

+12 & +13

+4 to +5 +7 & +8 +9 & +10

Class D +13 & higher

+11 & higher

+9 & higher

+12 & higher

+14 & higher

+6 & higher

+9 & higher

+11 & higher

Note : 1. Class A - Rejectable regardless of length.

2. Class B - Rejectable if length greater than 19mm.

3. Class C - Rejectable if length greater than 51mm.

4. Class D - Acceptable regardless of length and location.

5. Class B and C discontinuities shall be separated by at least 2L, L being the length of the longest discontinuity, except that when two or more such discontinuities are not separated by at least 2L, but the combined length of discontinuities and their separation distance is equal to or less than the maximum allowable length under provisions of Class B or C, the discontinuity shall be considered a single acceptable discontinuity.

6. Class B and C discontinuities shall not begin at a distance of 2L from weld ends carrying tensile stress, L being the discontinuity length.

7. Discontinuities detected at “scanning level” in the root face area of complete joint penetration double groove weld joints shall be evaluated using an indication rating 4 dB more sensitive (subtract 4 dB from the indication rating “d”) when such welds are designated as “tension welds” on the drawing.

8. Indications of discontinuities that remain on the screen as the probe is moved towards and away from the discontinuity may be indicative of plannar discontinuities with significant through throat dimension.

Figure 1

Probe Movement A



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Weldment

Probe

½ probe dimension

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DOC - Welcome | QA/QC Construction · Web viewLEVEL III APPROVED BY : APPROVED BY : PROCEDURE FOR ULTRASONIC EXAMINATION OF FULL PENETRATION WELDS AND T, K AND Y CONNECTIONS IN FERRITIC