UT of TKY Connections.pdf

Reliance Contents 1. Purpose 2. Scope 3. Abbreviation and definitions 4. Reference 5. Procedure 6. Evaluation of indication 7. Acceptance criteria 8. Post cleaning 9. Records 10. Scanning Technique sheet of various weld configurations for structural job is given. 11. Technique Sheet No -01 to 11 12. Acceptance criteria for scanning of tubular structural T-,Y- or K- joints welding shall be as per as per 13. Acceptance criteria – AWS D1.1 class –X

EPCMD-2-QM00-JEP-ME-045, Rev. 00 Confidential © Reliance. All rights reserved

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Reliance 1. PURPOSE The purpose of the procedure is to provide guide line to carry out UT of weld joints in tubular structural jobs of TKY configuration. 3. SCOPE

The scope of this documented procedure shall be used for testing tube-to-tube T-, Y- K joints having thickness ranging from 5mm and above and diameter range from 2”and above. AWS D1.1 Annex –K requirement shall have prior approval from EIC.

4. ABBREVIATIONS AND DEFINITIONS DAC Distance Amplitude Curve dB Decibel DRL Disregarded Level = 6 dB less then the SSL EIC Engineer In-charge HAZ Heat Affected Zone HOD Head of the Department IR Indication Rating NDE Non Destructive Examination SSL Standard Sensitivity Level TR Probe – Transmitter – Receiver UFD Ultrasonic Flaw Detector UT Ultrasonic Testing V1 Block –BS 2704 calibration block. (Also known as V1-IIW International Institute of welding) V2 Block- DIN 54122 calibration block DIHERAL ANGLE The angle, measure in a plane perpendicular to line of weld, between tangents to the out side of the tubes being joined at the weld, The exterior dihedral angle, where one looks at a localized section of the connection, such that the intersecting surface’s may be treated as planes

5. REFERENCE 1. 2. 3. 4. 5. 6.

AWS D1.1 and commentary API RP 2X. EPCMD-2-QM00-GUI-ME-002 Guidelines for Surface Preparation for UT. EPCMD-2-QM00-TCR-ME-007 Technical Requirement for UT Services EPCMD-2-QM00-FMT-ME-025 Format for PE Ultrasonic Testing Report EPCMD-2-QM00-FMT-ME-231. Format for MUT/AUT scan plan

6.0. PROCEDURE

6.1 Equipment The UFD for the purpose shall be selected from the following manufacturer which are recommended and are in used. Panamatrics Kraut Kramer Sonatest


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Reliance The ultrasonic examination shall be conducted with a pulse echo ultrasonic instrument capable of generating frequencies over the range of 1 MHz to 6 MHz. The ultrasonic instrument shall provide linear vertical presentation within ± 5% of the full screen height for 20% to 80% of the calibrated screen height. The ultrasonic instrument shall utilize amplitude control linearity over its useful range to + 20% of the nominal amplitude ratio to allow measurement of indications beyond the linear range of vertical display on the screen. The instrument shall be equipped with a stepped gain control calibrated in units of 2.0 db or less. In order to make the ultrasonic test result as permanent record, it is recommended to use UFD with recording facilities and equipment shall have loaded with AWS software for calibration and evaluation.

6.2 Probe The selection of a scanning probe is generally a compromise between sensitivity, coverage, resolution, and mechanical coupling stability. The range selection for scanning by various probes shall be used for scanning of complete volume of weld metal. Select the angle of probe required to scan the job, based on actual job thickness and the weld profile. The use of any other models of UFD& probe than the recommended as above, shall have prior approval from EIC.

The probe may contain either single or dual transducer crystal. The search units with contoured contact wedges may be used to aid ultrasonic coupling. Calibration shall be done with the contact wedges used during the examination. The size and frequency for both longitudinal and angle beam scanning shall be as per the code / specification requirements. The size, frequency and angle of the probe shall be as per the requirement of the AWS D1.1 clause 6.22 for groove weld and T-, Y- K- joints clause No 6.27

6.2.1 Probe and Shoe chart Probe/Shoe Pipe Dia

Probe Size

Selection of angle/shoes

Probe

2" 3"

5-8 mm Ø 5-8 mm Ø

45º,70º,60ºshoe) 45º,70º,60º (shoe)

5-8 mm Ø/ TR

4"

5-8 mm Ø

45º,70º,60º (shoe)

5-8 mm Ø /TR

6"

8×9 & 5mmØ

0º, 45º,70º,60º 8×9mm

5-8 /10 mm Ø /TR

Trans scanner

6 mm

45º,70º (shoe)

6 mm Ø

8×9mm

45º,60º,70º 8×9mm

5-8 /10 mm Ø /TR

8×9mm

TR 45º,60º,70º 5×10mm

5-8 /10 mm Ø /TR

16 mm Ø 25 mm

0º, 45º,60º,70º, 0º, 45º,60º,70º,

Normal Ø /TR Normal Ø /TR

2" above custom shoe & Flat 8" above & Flat Flat Flat

5-8 mm Ø/ TR


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Reliance 6.3 Couplant The couplant shall be preferably being a manufactured gel produced for this purpose. However this may be substituted by oil or cellulose paste or other suitable medium (oil& greases) which is not toxic or corrosive. The couplant must be removed after examination by means of wiping with a cloth or with the help of solvent/detergent. Starch solution may use at site. 6.4.1 Surface Preparation The scanning surface shall be free from loose scale, weld spatter and any other foreign matter that may interfere with the examination. In case of single V /double V butt joint weld caps must be ground to facilitate scanning from the top of the weld if possible Fit up data Datum mark shall be on surface of scanning side (both side of the weld) 6.4.2 Surface temperatures: shall not exceed 50 C / subject to couplant and probe service temperature as per. . 6.5 Calibration blocks 6.5.1 Reference of indication basic calibration block: IIW (V1). Corner reflector for calibration purposes is prohibited. ˚

6.5.2 Recalibration of machine which are recommended and are in used shall be made if following change occurs. Operator. Probe. Coaxial cable. Probe angle of ±2º Electronic failure. Battery 6.6. Reference dB. 6.6.1. Standard sensitivity calibration shall be consisting of the sum of the following: (a + b+ c) The maximized indication from of the standard reflector basic calibration, plus Distant amplitude correction from of the standard reflector range representing of area to be examined if required , plus If transfer correction of instrument sensitivity is required to compensate for differences between the reference standard surface roughness, contact area, and acoustical attenuation characteristics and those of the part being examined. Weldment surface conditioning should be performed if the transfer correction exceeds +6 decibels corrections. 6.6.2. Reference of basic calibration: Single point indication which is in order of 50%-75% FSH shall be established by using response of 1.5 mm SDH at depth of 15mm .The interested weld volume shall be covered by the selected calibration range.

6.6.3. 6 dB drop method; The 50% of indication amplitude both side, at this distance is found by probe index.

6.6.6 TR/ Normal Probe reference dB: 2nd Back Wall Echo from the job shall be adjusted to 40% Full Screen Height. The normal probes shall be used only when thickness of the job is more than 20mm. All reference dB and calibration shall be verified by prior to proceeding job.

6.7. UFD Operator


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Reliance Personal operator shall be qualified as per SNT- TC- 1A and have minimum Level II in UT The operator shall have a sufficient knowledge of the welding process and probable defects in those processes and 5 years relevant experience in this field All the technicians shall under go a selection test and qualify the same prior to the deployment on the job as per “Procedure for the selection of UT technicians.(EPCMD-2-QM00-JEP-ME-038). 6.8 Scanning method: Scanning reference plan shall be made (approved technique sheet)marked physically on the job unless otherwise specified, the refe rence position of scanning direction, skip coverage and location extend of rejectable discontinuities (flaws) shall also be marked physically on the job An increase in sensitivity 12 decibels above that required to produce a ref echo signal from the reference reflector will ensure full-FSH echo signals for discontinuities oriented seven to ten degrees from perpendicular when scanning with the recommended probe. Scan plan (technique sheet): shall contain scan coverage (weld plus HAZ) scan location, beam path, surface distance, frequency, beam angle, surface preparation and reference. 6.8.1 Straight beam examination: Before performing the angle beam examination, a straight beam examination shall be performed on the volume of base material through which the angle beam will travel. The purpose of the scanning is locate any reflectors that can be limit the ability of angle beam examination of the weld volume .TR probe top weld is possible for only butt joint to identify any reflectors which may interfere during angle beam scanning and weld deposition, For scanning atop the reinforcement is not practical. Examination results should be reported. 6.8.2 Angle beam probe: (To detect defect parallel to weld axis) : 6.8.2.1 Scanning from one faces and both side scanning if required when coverage is not cove by one side: The weld joint shall be scanned requirement half skip distance to parallel to weld axis by at least two deferent angle based on AWS D1.1class –X (experience based on fit for purpose) the examination to detect defect parallel to weld axis to be carried out from the weld edge to other side weld up to 1½ to as per requirement beam path distance based on selection of probe & technique. 6.8.2.2 Scanning from faces of the weld axis: The weld joint shall be scanned both side of the weld joint up to requirement skip based on scanning plan if access able. 6.9 Examination coverage Calibration range coverage should be verified with 1: 1 graph plotting and technique sheet. The weld volume shall be examined by moving the search unit over the examination surface so as to scan the entire weld volume. Each pass of the search shall overlap a minimum of 10% of the transducer (piezoelectric crystal) dimension perpendicular to the direction of the scan. The recommended beam angles for different thickness are shall be is based on scan plan.

Incomplete inspection area for which complete inspection was not practicable shall also be marked and noted on the report, along with the reason why the inspection was incomplete. 6.10 Rate of search unit movements The rate of search unit movement for examination shall not exceed 6 in /sec (152 mm/sec).

6.11. Scanning dB


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Reliance All angle beams scanning to be carried out at plus reference 12dB increase in sensitivity above that required to produce a ref echo signal from the reference reflector will ensure fullFSH echo signals for discontinuities oriented seven to ten degrees from perpendicular when scanning with the recommended probe or 6dBor as per AWS D1.1. Evaluation of indication 7.1 Amplitude based level technique: All indications equal to or in excess of 50% reference or - 6 dB of the reference level shall be investigated in order to determine their shape, location, identity and, size shall be given as length and height (depth dimension). All indications detected with one probe may be further evaluated using an appropriate combination of probe angles so that length, depth, orientation can be accurately determined and discontinuity type can be established 7.2. Measurements: The discontinuities shall be sized using 6 dB drop method and maximum amplitude technique as appropriate to discontinuity nature. Nature, location and type of discontinuity Are to be categorized based on graph plotting. 8.1. Acceptance criteria amplitude based level technique: Acceptance criteria for scanning of structural T-,Y- or K- weld joints welding shall be as per 8.1.2 AWS D1.1 Class –X (experience based on fitness for purpose) 8.2. Evaluation of repair weld Where ever weld repair have been carried out, the soundness of the weld/job shall be confirmed by repeating the ultrasonic test as mentioned in this procedure. 9. Post cleaning Couplant (grease/oil) applied to the job surface for ultrasonic testing shall be cleaned by respective NDT agency after completion of the scanning by lint free cloth. 10. Record: Report shall be prepared in approved format; in case of repair print out of indication shall be given along with graph plotting and any imperfection produce a response above DRL of reference shall be recorded from uncorrected area. The reference position and scanning axis and extend of rejectable discontinuities (flaws) shall also be marked physically on the job and same to be mentioned on the report. All applicable scanning result shall be reported. 11. Scanning Technique sheet of various weld configurations for structural job.

Technique Sheets Weld joint Fit up data Thickness

: Tube-to-tube T-Y- or K connection : Datum mark on both side of connection with grounding. : 5 mm and above

Dia of the pipe : 2 inch NB and above


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Reliance Probe/Shoe

Pipe Dia

Probe Size

Selection of angle/shoes weld scan

2" 3"

5-8 mm Ø 5-8 mm Ø

45º,70º,(60º shoe) 45º,70º,60º (shoe)

5-8 mm Ø/ TR

4"

5-8 mm Ø

45º,70º,60º (shoe)

5-8 mm Ø /TR

6"

8×9 & 5mmØ

0º, 45º,70º,60º 8×9mm

5-8 /10 mm Ø /TR

8×9mm

45º,60º,70º 8×9mm

5-8 /10 mm Ø /TR

16 mm Ø 25 mm

0º, 45º,60º,70º ,80º 0º, 45º,60º,70º,80º

Normal Ø /TR Normal Ø /TR

8" above & flat Flat Flat

Probe

5-8 mm Ø/ TR

Probe Frequency: Thickness below 8mm, probe shall have frequency above 4-6 MHz When thickness of the job is more than 8 mm 2.25 MHz shall be used. Scanning technique : optimum angle indication found in the root areas of grove welds in butt joints and along the fusion face of all welds shall be further evaluated with 70, 60, /45 degree search angle, which is nearest to being perpendicular to expected fusion face. The complex geometry of welded connections on offshore structure particularly T, K, and Y connections, typically requires the use of nominal angle transducers (i.e., 45- degree, 60degree, and 70-degree) in multiple scans of the entire circumference and almost always from the brace side of the weld only. The inspection of thin wall sections may not improve with the use of steer angle transducers. Thick wall diagonal braces with full-throated weld connections may also require the use of an 80-degree transducer to ensure that the sound beam intercepts the root area. In all scans the transducer cant angle is continually adjusted to maintain the beam perpendicular to the length of the weld. For definitions of nomenclature associated with tubular member intersections. The recommended effective probe angle for examination of the root area should be that which produces an incident angle nearest to perpendicular to the anticipated weld discontinuity. UT personnel are cautioned to be alert for changes in intercept angles and avoid 30-degree incidence on potential discontinuities which cause mode conversion and a loss of echo signal amplitude. TR probe scanning from connection out side and from on the weld to cover entire weld volume. Angle beam scanning (to detect defect parallel to weld axis) to be carried out either from OD or from ID from ½ skip distance to required (multiples) skip distance based on probe index , angle and also weld edge distance to cover the total weld volume and as per datum marking. Scanning range to be verified with 1: 1 graph plotting. Note: Standard Scanning Technique are given below


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Reliance Fit up datum marking


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Scanning Technique No 1



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Probe movement pattern


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Reliance Acceptance criteria:


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UT of TKY Connections.pdf

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