Ultrasonic Testing Procedure

 

Ultrasonic Testing Procedure

ULTRASONIC TESTING PROCEDURE

   

GSOP2032, Ultrasonic Testing Procedure Revision 03, issued: 29-01-2017, page 1 of 19

 

Ultrasonic Testing Procedure

CONTENTS COVER PAGE

1

CONTENTS

2

1

AIM / SCOPE AI

3

2

DEFINITIONS

3

3

REFERENCES

3

4

SAFETY

3

5

PROCEDURE REQUIREMENTS

3

6

PERSONNEL QUALIFICATION

4

7

EQUIPMENT AND ACCESSORIES

4

8

EQUIPMENT CALIBRATION

6

9

PRE - TEST REQUIREMENTS

10

10

TEST REQUIREMENTS

10

11

METHOD FOR SIZING INDICATIONS

12

12

METH METHOD OD FOR FOR DIS DISCR CRIM IMIN INAT ATIN ING G GEO GEOME METR TRIC IC FROM FLAW INDICATIONS

12

13

EVALUATION (ACCEPTANCE CRITERIA)

12

14

RECORDS

13

APPENDIX  A

CALIBRATION TECHNIQUES TECHNIQUES

15-17

B

ACCEPTANCE CRITERIA

18

ATTACHMENT UT REPORT FORM

REVISION SUMMARY TABLE Revision 00 01 02 03

Date 20-02-2005 01-08-2008 099-0 066-2 2012 299-0 011-2 2017

Summary First issue. Logo change. Technical re revision b ba ased on on AS ASME co code 20 2007 ed edition. Logo Logo ch cha ange. nge. Tech echnica ical rev revis isio ion n bas base ed on on AS ASME cod code e 20 2010 edi editi tion on.. Logo Logo ch cha ange, nge, Tech echnica ical rev revis isio ion n bas base ed on on AS ASME cod code e 20 2015 edi editi tion on..

   

GSOP2032, Ultrasonic Testing Procedure Revision 03, issued: 29-01-2017, page 2 of 19

 

Ultrasonic Testing Procedure

1.0

AIM / SCOPE This procedure describes the requirements for Ultrasonic Testing on weldments of plates and pipes (Except TKY joints and category D Nozzle welds), to ASME Boiler and Pressure Vessel Code, Section V, Non-destructive Examination, and similar codes. The typical weldments that are covered with this procedure is limited to a minimum thickness of 10 mm and a minimum diameter of 10” NPS.

2.0

DEFINITIONS UT FSH DAC Cl Clie ient nt Comp Co mpan any y

3.0

Ultrasonic Testing Full Screen Height Distance Amplitude Correction wi with th whom whom St Stor orkk-Co Coop oper erhe heat at ha has s a dir direc ectt cont contra ract ctua uall a agr gree eeme ment nt En End d Use Userr / O Own wner er

REFERENCES The following documents shall be referred to in conjunction with this procedure: GSOP500 GSO P5003, 3, Procedu Procedure re for Training Training,, Qua Qualific lificatio ation, n, and Certifica Certification tion of Non-dest Non-destruct ructive ive Testing Testing Personnel (SNT-TC-1A, 2006))  ASNT SNT-TC-1A (Edition 2006), Recommended Recommended Practice for Qualification Qualification and Certification of  Non-destructive Testing Personnel GSOP500 GSO P5004, 4, Procedu Procedure re for Training Training,, Qua Qualific lificatio ation, n, and Certifica Certification tion of Non-dest Non-destruct ructive ive Testing Testing Personnel (ASNT CP-189, Edition 2011)  ASNT CP-189, CP-189, Standard for for Qualifica Qualification tion and Ce Certification rtification of N Non-destru on-destructive ctive Testing Personnel Personnel  ASME B31.1, B31.1, Edition 2014, 2014, Power Piping Piping  ASME B31.3, B31.3, Edition 2014, 2014, Process Piping Piping  API 1104, Welding Welding of pipelines pipelines an and d related fa facilities. cilities.  ASME Section V, Edition 2015, 2015, Article 4 4,, Non-destructive Non-destructive Examination Examination  ASME Section VIII – Division 1, Edition Edition 201 2015, 5, Rules for C Construction onstruction of of Pressure Vessel Vessel  

4.0

5.0

SAFETY 4.1

Stork-Co Stork-Cooper operheat heat safety safety requir requireme ements nts and pr projec ojectt specific specific safety safety instructio instructions ns shall be met met at all times.

4.2

The area area shall shall be well well ven ventilat tilated ed while while carryin carrying g out the the test specifi specificall cally y in confined confined area areas. s.

PROCEDURE REQUIREMENTS Requirements – Ultrasonic Examination shall be performed in accordance with this procedure which shall as a minimum contain the requirements listed in Table 1. Procedure Qualification – When procedure qualification is specified by the referencing code section a change of a requirement in Table 1 identified as essential variable from the specified value, or  range of values, shall require re-qualification of the written procedure by demonstration.

 

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Ultrasonic Testing Procedure

 A change of a require requirement ment identified as nonesse nonessential ntial variable does not require re-qualification of  the procedure. All changes of essential or nonessential variables from those specified within the written procedure shall require revision of, or an addendum to the written procedure. Table – 1 Requirement

6.0

7.0

Essential Variable X

Nonessential Variable ---

Weld configurations to be examined, including thickness, dimensions and base material product form (pipe, plate etc.) The surfaces from which the examination shall be performed Techniques (straight beam, angle beam, contact, and or immersion  Angles and mode of wave wave propa propagation gation in th the e material Search unit type, frequency , and element size/ shape Special search units , wedges, shoes, or saddles ,when used Ultrasonic instrument Calibration ( calibration block and technique ) Directions and extent of scanning Scanning (manual / automatic)

X X X X X X X X X

-------------------

Method for discriminating geometric from flaw indications Method for sizing indications Com Co mputer ter enhance ced d data acquis quisiition tion,, wh whe en use sed d Scan overlap Perrsonn Pe onnel perfo erforrmanc ance requ equire irements, ts, wh whe en require ired Personnel Qualification requirements Su Surf rfac ace e co cond ndit itio ion n (exa (exami mina nati tion on surf surfac ace, e, cali calibr brat atio ion n bl bloc ock) k) Couplant: brand name Post-examination cleaning technique  Automatic alarm alarm and or/ or/ recordin recording g equipm equipment, ent, when ap applicable plicable Records, including minimum calibration data to be recorded

X X X X X ---------------

--------------X X X X X X

PERSONNEL QUALIFICATION 6.1 6.1

Pe Pers rson onne nell pe perf rfor ormi ming ng ultr ultras ason onic ic test testin ing g shal shalll be qu qual alif ifie ied d in ac acco cord rdan ance ce wi with th St Stor orkkCooperheat procedure as referred in item 3.0 herein.

6.2

Perso Personn nnel el having having othe otherr qual qualifi ificat catio ion n suc such h as PCN may use this pro proced cedur ure e wit with h specific specific written approval of the Owner representative.

6.3

Personn Personnel el involved involved iin n ultr ultrason asonic ic testi testing ng sha shallll be qua qualifi lified ed to minimum minimum NDT NDT UT Level Level II.

EQUIPMENT AND ACCESSORIES 7.1

Equipment a) The ultrason ultrasonic ic flaw dete detector ctor sha shallll be of the pulse-echo pulse-echo type having having A-scan A-scan presenta presentation tion,, capable of generating frequencies over the range of at least 1 to 5 MHz with a valid calibration certificate.

 

GSOP2032, Ultrasonic Testing Procedure Revision 03, issued: 29-01-2017, page 4 of 19

 

Ultrasonic Testing Procedure

b)

Inst Instru rum men ents ts oper operat atin ing g at other other fre freq que uenc ncie ies s may be us use ed if demon emonst stra rate ted d an and d documented.

c)

Screen Height Linearity The ultrasonic instrument shall provide linear vertical presentation within ± 5% of the full full scr scree een n heig height ht for 20% to 80% 80% of the calibra calibrated ted screen screen he heig ight ht (b (base ase line to maximum calibrated screen points). Method Position an angle beam on a calibration block so that indications from the ½ and ¾ T holes gives a 2:1 ratio of amplitudes between the two indications. Adjust the gain so that the larger indication is set at 80% of ffull ull screen height (FSH). Without moving the search unit adjusts gain to successively set the larger indication from 100% to 20% of  full screen height in 2 dB increments and read the smaller indication at each setting. The reading shall be 50% of the larger amplitude within 5% of FSH. Screen height linearity check shall be performed at intervals not to exceed 3 months for analog type instruments and one year for digital type instruments or prior to first use thereafter.

d)

Amplitude Control L Liinearity The ultrasonic instrument shall utilise an amplitude control accurate over its useful range to ± 20% of the nominal amplitude ratio, to allow measurement of indications beyond the linear range of the vertical display on the screen. The amplitude control linearity shall be performed at intervals not to exceed 3 months, for analog type instruments and one year for digital type instruments or prior to first use thereafter. Method Position an angle beam search unit on a basic calibration block so that the indication from the ½ T side drilled hole is peaked on the screen. When adjusting the gain, the indications shall fall within the specified limits below:

e)

Indication at % of full screen

Control change dB

Indication limits of full screen %

80 80 40 20

-6 - 12 +6 + 12

32 - 48 16 - 24 64 - 96 64 - 96

The pro proper per funct functio ionin ning g of tthe he equ equipm ipmen entt shall shall be be check checked ed and and the the equ equipm ipmen entt shall shall be calibrated by the use of the calibration standard as a minimum, at the following stages: 







beginning and end of each examination  After 4 hours hours of oper operation ation when examination personnel are changed at any time the malfunctioning is suspected

   

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Ultrasonic Testing Procedure

If during any check it is determined that the testing equipment is not functioning properly, the entire product that has been tested since the last valid equipment shall be re-examined. f)

Th The e ffol ollo lowi wing ng make make an and d mod model els so orr e equ quiv ival alen entt c can an be us used ed;; 





7.2

Panametrics / Olympus NDT - EPOCH 5, 4, Epoch III and IIIB. Krautkramer / GE USN 50, USM Go or equivalent  Any other equivalent equivalent to the abov above e make an and d model.

Probe Units a)

Pr Prob obe e unit unit m may ay c con onta tain in eit eithe herr si sing ngle le or or du dual al pro probe be ele eleme ment nts. s.

b) Probe unit with with con contoured toured contact wedges may be be used used to aid ultrasonic ultrasonic coupling. Such cases, calibration shall be done with the contact wedges used during the examination. c) The cr crystal ystal sizes sizes for a angle ngle b beam eam pr probes obes may may be 10 mm d diam iameter eter or 8 x 9 mm mm,, and 10 mm to 24 mm diameter for straight beam probes. d) Th The e nom nomin inal al fr freq eque uenc ncy yo off pro probe bes ss sha hall ll be up to 1 tto o 5 MHz MHz e) The sizes sizes and freq frequen uencies cies other other than st stated ated in c) and d) ab above ove may be used used to assure assure adequate penetration or better resolution.

8.0

EQUIPMENT CALIBRATION 8.1

Calibration Blocks The basic calibration reflectors shall be used to establish a primary reference response of  the equipment. 8.1.1

Calibration Block Material

 

The material from which the block is fabricated shall be of the same product form, and material specification or equivalent P-number grouping as the material(s) being examined.. Calibration blocks examined blocks for dissimilar metal welds, the mate material rial selection shall be based on the material on the side of the weld from which the examination will be conducted

8.1.2

Calibration Block Thickness When two or more base material When material thic thicknes kness s are involved, involved, the calibration calibration block thickness shall be determined by the average thickness of the weld

8.1.3

Calibration Block Surface Finish The finish on the surfaces of the block shall be representativ representative e of the surface finishes on the components to be examined.

8. 8.1. 1.4 4

Ba Basi sic c Cal Calib ibra rati tion on Refl Reflec ecto tor  r 

 

The basic calibration reflectors may be located either in the component material or in a basic calibration block.

 

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Ultrasonic Testing Procedure

Basic Calibration Block Detail (Reference to ASME Section V, T- 434.2.1) Weld thickness

Basic calibration block

(T) mm 25 or less Over 25 to 50 Over 50 to 100 Over 100

thickness (T) mm 19 or t 38 or t 75 or t t ± 25

  Hole diameter  mm 2.5 3.0 5.0 See Note

Notch size, mm Width = 6mm max. Depth = 1.6%T to 2.3% T Length = 25mm min.

Note:: For each increase in weld thickness of 50mm or fraction thereof over Note 100mm, the hole diameter shall increase 1.5mm. 8. 8.1. 1.5 5

Cu Curv rved ed Test Test Su Surf rfac aces es a) Material Materials s with diam diameter eters s greater greater tha than n 508 mm For examination in materials where the examination surface diameter is greater  than 500 mm, a block of essentially the same curvature, or alternatively, a flat basic calibration block, shall be used. b) Material Materials s wit with hd diame iameters ters 500 mm or less less For examination in materials where the examination surface diameter is 500 mm and less, the curved block shall be used. A single curved basic calibration block may ma y be used used to calibr calibrate ate for the exam examina inatio tion n on surfac surfaces es in the range range of  curvature from 0.9 to 1.5 times the basic calibration block diameter.

8.2

System Calibration Calibration Calibratio n shall include the complete ultrasonic examination system. The original calibration must be performed performed on the basic calibration calibration block. Checks shall be made made to verify the sweep rang range e ca calib librat ratio ion n and and dis distan tance ce am ampli plitud tude e corre correcti ction. on. Check Checks s shall shall inclu include de the entir entire e examination system. 8.2.1

 

Angle Beam Calibration The calibration shall provide the following measurements: 8.2.1.1 Sweep Range Calibration Sweep range calibration shall be performed using minimum two reflections from the quadrant IIW–V1 or IIW–V2 calibration block to calibrate the sweep range. Example 1: 1: To achieve 0 to 100 mm range using IIW-V1 calibration block: a) Po Posi siti tion on the the an angl gle e be beam am pro probe be towar towards ds th the e 10 100 0 mm quadr quadran antt an and d maxim ma ximise ise the echo echo respo response nse by moving moving the pr prob obe e fro front nt an and d back back parallel to the sides of the calibration block, without any angulations. (Rotation of the beam into the corner formed by the hole and the side of  the block may produce higher amplitude at a longer beam path; this beam path shall not be used for calibration).

 

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Ultrasonic Testing Procedure

b)

To sta start rt with with,, adju adjust st the initial initial e echo cho at zero zero divisio division n on the scree screen. n.

c)

Adju Adjust st the the fi first rst back reflecti reflection on to to tenth tenth division division

d) By us usin ing g dela delay y cont contro roll br brin ing g fi firs rstt back back re refl flec ecti tion on to zero zero divisi division on of  screen e) Set Set the the seco second nd ba back ck refl reflec ecti tion on at te tent nth h di divi visi sion on of th the e sc scre ree en by adjusting both range and delay controls f)

Usin Using g on only ly del delay ay con contr trol ol,, br brin ing g th the e fi firs rstt back back ref refle lect ctio ion n to zero zero scal scale e position (the initial response need not coincide with zero position of the scale).

g) Now th the e tenth scale scale divisio division n of th the e screen screen represe represents nts 100 mm metal metal path in steel. Note: Figure 2 represents the above setting Example 2: 2: To achieve 0 to 100 mm range using IIW-V2 calibration block a) Position Position the the angl angle e beam p prob robe e towards towards the 25 mm or 50 50 mm quadra quadrant nt and maximise the echo response by moving the probe front and back parallel to the sides of the calibration block, without any angulations, to avoid beam reflecting from the corner of the block. b) To start start with with,, adju adjust st the initial initial e echo cho at zero zero divisio division n on the scree screen. n. c)

Set th the e first a and nd sec second ond ba back ck reflectio reflections ns to 2.5 and and tenth tenth scale scale divisions divisions for the probe position towards 25 mm quadrant by adjusting both range and delay controls. Then for verifying the calibrations keep the probe towards 50 mm. Now the first back reflection shall be at fifth scale division.

d) Now the tenth tenth div divisio ision n of the scre screen en represe represents nts the 100 100 mm steel metal metal path distance. Note: Figure 3 represents the above setting sequence. 8.2.1.2 Distance Amplitude Amplitude Correction Correction (DAC) ‘Reject control’ of the equipment shall be set in ‘OFF’ condition. a) Position Position the the prob probe e for maximum maximum respon response se from ¼ T hole hole and adjust adjust the gain setting to provide an indication height of 80% (± 5% of full screen height) and mark the peak of the indication on the screen b) Position Position the the pro probe be for ma maximu ximum m response response from from ½ T hole and and mark mark the peak of the indication on the screen c)

Posi Position tion the the pro probe be for m maxim aximum um respon response se from from ¾ T hole hole and mark mark the the peak of the indication on the screen.

d) Conn Connec ectt the the scre screen en mark marks s fo forr th the e si side de-d -dri rill lled ed ho hole les s to pr prov ovid ide e th the e distance amplitude curve.

   

GSOP2032, Ultrasonic Testing Procedure Revision 03, issued: 29-01-2017, page 8 of 19

 

Ultrasonic Testing Procedure

e) Record Record p prob robe e da data ta an and d eq equipm uipment ent setti settings. ngs. 8.2.1 8.2.1.3 .3 Whe When n an ele electr ctron onic ic dis distan tance ce ampli amplitud tude e co corr rrect ection ion devic device e is used used,, the primary reference response response shall be equalised at a nominal constant screen height of between 40% to 80% of full screen height over the distance range or employed in the examination. 8.2.2

Straight Beam Calibration

 

The calibration shall provide the following measurements: 8.2.2.1 Sweep Range Calibration For sweep range calibration IIW-V1 calibration block thickness (25 mm or  100 mm), IIW-V2 calibration block thickness (12.5 mm or 20 mm) or ASTM basic calibration side drilled holes reflection can be used. Example  3 - Calibration of 100 mm using IIW-V1 block 25 mm thick Example a) To start start with with,, adju adjust st the initial initial e echo cho at zero zero divisio division n on the scree screen n b) Position the straight be beam am prob probe e on the IIW-V1 IIW-V1 block 25 mm mm thick side and maximise the first reflection. b) Adjust Adjust the first, first, secon second, d, thir third d and fourth fourth back reflec reflections tions to 2.5, 2.5, 5.0, 7.5 and tenth scale divisions by using range and delay controls. d) Now the tenth tenth div divisio ision n of the scre screen en repres represents ents the 100 100 mm metal metal path path distance in steel. Note: Figure 1 represents the above setting sequence sequence..

8.3 Calibrat Calibration ion Confir Confirmati mation on Calibration confirmation shall be performed prior to use of the system in the thickness range under examination. examination. A calibration check sha shallll verify the sweep range calibr calibration ation and distancedistanceamplitude correction. 8.3.1 8.3. 1 Sweep Sweep Rang Range e Calib Calibrati ration on If any point on the DAC curve has moved on the sweep line more than 10% of the sweep division divis ion reading, reading, corr correct ect the swee sweep p ran range ge calibrat calibration ion and note the correctio correction n in the examination record. If recordable reflectors are noted on the data sheets, those data sheets shall be voided, a new calibration shall be recorded, and the voided examinations shall be repeated 8.3.2 DAC Curve If any point on the distance-amplitude correction (DAC) curve has decreased 20% or 2 dB of its amplitud amplitude, e, all data sheets since the last calibration calibration or calibration check shall be marked void. A new calibration shall be made and recorded and the voided examination areas shall be re-examined. If any point on the distance-amplitude correction (DAC) curve has increased by more than 20% or 2 dB of its amplitude, all recorded indications since the last valid calibration or calibration check shall be evaluated with the corrected calibration, and their values shall be changed on the data sheets.

   

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Ultrasonic Testing Procedure

8.4 Calibrat Calibration ion C Check heck on Ba Basic sic Ca Calibr libratio ation n Bloc Block k  A calibration calibration check on at least three of the basic reflectors in the basic calibration calibration block shall be made at the beginning beginning , every 4 hours and at the end of each examination examination or whenever  examination personnel are changed and at any time that malfunctioning is suspected. 8.5 Beam Sp Spread read Angle Determinati Determination on for Angle B Beam eam Pr Probe obe by 20dB Method Method a)

Se Sett the the maxi maximu mum m am amplit plitud ude e fr from om the the ¼ T ho hole le at 10 100% 0% of fful ulll s scr cree een. n.

b)

Move ove pro probe be tow towar ard d th the e h hol ole e un unti till in indi dica cati tion on equ equal als s 10% 10% of ful fulll scre screen en.. Mark Mark bea beam m centre line ‘toward’ position on the block.

c)

Set back back tth he m ma axim ximum a am mplitu litud de fr from om the the ¼ T ho hole at at 1 100 00% % of of ful full scr screen. Move Move probe away from the hole until indication equals 10% of full screen. Mark beam centre line ‘away’ position on the block.

d)

Po Posi siti tion on the the sea searc rch h uni unitt for for 100% 100% of fful ulll scr scree een n amp ampli litu tude de fr from om th the e ¼ T hol hole. e. Move Move probe right without pivoting the beam toward the reflector until the indication equals 10% of  full screen. screen. Mar Mark k the beam centre line line ‘right’ position position on the block (when (when manually manually positioning the right search unit, straight edge used tong guide unitnt while moving movi ng to the and lefta to ensu ensure re thatmay axial axiabe l positioni posi tioning and the beam beasearch m alignme alignment are maintained).

9.0

e)

Move ove prob probe e left left w wit ith hou outt pi pivo voti ting ng tthe he bea beam m towa towarrd the the refl reflec ecto torr unti untill the the indi indica cati tion on equals 10% of full screen. Mark the beam centreline ‘left’ position on the block.

f)

Repeat sett settiing and m me easu surrements of ‘to ‘towar ward’, ‘aw ‘away’ ay’, ‘rig ‘righ ht’ t’,, and ‘left ‘left’’ posi siti tio ons marked on the block for the ½ T and ¾T side drilled holes.

g)

Reco Record rd tthe he d dim ime ens nsio ions ns ffrrom ‘‘to towa ward rd’, ’, ‘aw ‘away ay’, ’, ‘ri ‘righ ght’ t’,, and and ‘lef ‘left’ t’ pos posit itiion ons s mark marke ed on the block for the ¼ T and ¾T side drilled holes.

PRE-TEST REQUIREMENTS 9.1

Client Client shall shall supply supply suffic sufficient ient inform informatio ation n to the tec technic hnician ian enablin enabling g the item for for testing testing to be identified.

9.2

Datum Datum loca locatio tions ns s sha hallll b be e cl clea early rly ma marke rked. d.

9.3

The test surface shall be free of irregularities; irregularities; loose loose foreign foreign matter or coatings, coatings, which may interfere with ultrasonic wave transmission.

10.0 TEST REQUIREMENTS 10 10.1 .1 Pr Proc oced edur ure e Variation from this test procedure shall only be undertaken with the prior written approval of  the Client. Client. Each Each variat variatio ion n sha shallll be noted noted on the ult ultra rason sonic ic re repor portt and and a rel releva evant nt test test technique or procedure produced, if required.

   

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Ultrasonic Testing Procedure

10 10.2 .2 Co Cou upla lan nt 10.2.1 Couplant such as Chemetall UCA-2M, Ultragel, cellulose paste or equivalent may be used. Couplant used on nickel base alloys shall not contain more than 250ppm couplant used on austenitic stainless steel or titanium shall not contain more than 250ppm of  halides (chlorides plus fluorides). 10.2.2 Specific consideration shall be given to the service and material of the component tested. Such considerations shall include, but not limited to oil or ‘raw’ water where such could be injurious or hazardous in certain applications and materials. 10.3 10.3 Rat Rate e of Probe Probe Movem Movement ents s The rate of search unit movement for examination shall not exceed 150 mm / second unless calibration shall be verified at intended scanning speed. 10.4 10.4 Exa Examin minati ation on Cover Coverag age e 10.4. 10.4.1 1 The volume volume sha shallll be exam examine ined d by mo movin ving g the search search un unit it over over th the e examin examinati ation on surface so as to scan the entire examination examination volume. volume. Each pass of the probe shall shall ov over erla lap p a mini minimu mum m of 10 10% % of th the e pr prob obe e (p (pie iezo zo-e -ele lect ctri ric c el elem emen entt di dime mens nsio ion n perpendicular to the direction of the scan). 10.4.2 For weld testing, scanning scanning shall be done from bot both h the sides of same face of material. In case both the sides of same face are inaccessible the information shall be recorded in the report. 10.4.3 The entire volume volume of the weld needs to be covered, if necessar necessary y two or more angle beams need to be used to ensure full volume coverage. 10.5 Scanning of Plate Plate for Lamination Lamination u using sing Str Straight aight Beam Probe For plate lamination lamination testing testing,, usin using g strai straight ght beam probe, probe, the area area to be tested tested shall shall be scanned in grid pattern. The grid dimensions shall be 225 mm width by 225 mm breadth unless otherwise previously specified and agreed with the Client. 10.6 10.6 Sc Scan anni ning ng Le Leve vell Scanning shall be performed at a gain setting of at least two times the primary reference level. When the referencing code requires detection and evaluation of all indications exceeding 20% DAC, the gain should be increased an additiona additionall amount so that no calibration reflector  indication is less than 40%FSH. As an alternate, the scanning sensitivity level may be set at 14dB higher than the reference level gain setting. 10.7 10.7 Ev Eval alua uati tion on Lev Level el Evaluation shall be performed with respect to the primary reference level. 10.8 10.8 Sc Scan anni ning ng Surf Surfac ace e

   

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Ultrasonic Testing Procedure

Scanning surface shall be free of weld spatter, dirt and corrosion products. Forged or rolled surfaces having reasonably smooth surfaces are acceptable. 10.9 10.9 Sc Scan anni ning ng of of we weld ld   9.9.1 Scanning of adjacent base metal using straight beam probe The scanning of the adjacent base metal shall be performed to detect reflectors that might mig ht affec affectt inter interpr preta etatio tion n of angle angle beam resu results lts,, an and d is no nott to be used as an acceptan acce ptance-r ce-rejec ejection tion exa examina mination tion.. Locatio Locations ns and areas areas of such reflecto reflectors rs shall shall be recorded. 10.9.2 Scanning for reflectors oriented parallel to the weld using angle beam probe The angle beam shall be directed approximately approximately right angles to the weld axis from two directions directio ns wher where e poss possible ible.. The probe shall shall be manipula manipulated ted so that the ultrason ultrasonic ic energy passes through the required volumes of weld and adjacent base metal. 10.9.3 Scanning for reflectors oriented transverse to the weld using angle beam probe The angle beam shall be directed essentially parallel to the weld axis. The search unit shall be manipulated so that the angle beam passes through the required volumes of  weld and adjacent base metal specified by the referencing code section. 10.1 10.10 0 Po Post st Clean Cleanin ing g   Post Examination Cleaning When post-examination cleaning is required by the procedure, it should be conducted as soon as practical after evaluation and documentation using processes that not adversely affect the post.

11.0 METHOD FOR SIZING INDICATIONS 6dB drop Technique

Used to size defect dimensions which are larger than the beam, such as the length of lack of  sidewall fusion in a weld. The probe is moved off the end of the defect until the signal amplitude is reduced by 50 % (6dB). The position of the centre of the probe is then marked onto the material surface. The probe is now in a position where the beam is half on and half off the defect. If this is repeated at the other end of the defect then the distance between the marks represents its length.

12.0   METHOD FOR DISCRIMINATING 12.0 DISCRIMINATING GEOMETRIC GEOMETRIC FROM FLAW FLAW INDICATIO INDICATIONS NS 12.1 All ultr ultrason asonic ic reflector reflectors s do not indicate indicate flaws flaws as certain certain metallurgic metallurgical al disconti discontinuiti nuities es and geometric geometri c conditions may produc produce e indications that are not relevant. Included in this category are plate segregates in the heat affected zone that become reflective after fabrication. Under  straight beam examination, examination, these may appear as spot or line indications. Under angle beam examination, indications that are determined to originate from surface conditions such as weld root geometry may be classified as geometric indications. 12.2 The identity, identity, maximum maximum amplit amplitude ude,, loca location tion,, and extent of reflecto reflectorr causing causing a geometri geometric c indication shall be recorded.

   

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Ultrasonic Testing Procedure

12.3 Interpr Interpret et the area containi containing ng the reflecto reflectorr in accorda accordance nce with the applicable applicable examinatio examination n procedur proc edure. e. Plot and veri verify fy the refl reflector ector coordinates coordinates.. Prepare Prepare a cross-sec cross-section tional al sketch sketch showing reflector position and surface discontinuities such as root. 12.4 Review fabrication or weld preparation drawings.

13.0 EVALUATION (ACCEPTANCE CRITERIA) 13.1 It shall be responsibility responsibility of NDT UT Level II to evaluate and report report within the the limits of criteria criteria as per appendix B. 13.2 13.2 Exami Examina natio tion n us using ing a DA DAC C  

Any reflector, which causes an indication in excess of 20% of DAC, shall be investigated to the extent that it can be evaluated in terms of the acceptance criteria of the reference code section.

13.3 Examination using other than DAC For examination using other than DAC, evaluation shall be according to the requirements of  the reference code section. 14.0 RECORDS 14.1 NDT UT Level Level II sh shall all re repor portt in the UT rrepor eportt form form.. 14.2 Reports Reports shall shall contain the follo following wing inf informa ormation tion as a minimum minimum.. This would include include (where available): a) b) c) d) e) f) g) h) i)  j) k) l) m) n) o) p) q) r) s) t)

Client PO / rre equ ques estt no. no. St Stor orkk-Co Coop oper erhe heat at job job no no.. Line/Dra Line/Drawing wing/Com /Compone ponent nt and / o orr join jointt iden identifica tification tion Ac Acce cept ptan ance ce cr crit iter eria ia Pr Proc oced edur ure e and and re revi visi sion on Dimens Dimension ions s an and d/o orr ar area ea of of te test st Mater Material ial/we /weld ld type type and and con condit ditio ion n Ma Mate teri rial al S Sur urfa face ce temp temper erat atur ure e Calibration block and s serial erial numb number er Tes Testt equip equipme ment nt type type an and d ser serial ial n numb umber  er  Detail Details so off p pro robe be,, fre frequ quenc ency ya and nd size size Remarks/r Remarks/refer eference ence Sketches Sketches Coupla Couplant nt u used sed and and br bran and d na name me Search Search unit unit cabl cable e used, used, type and leng length th Instru Instrumen mentt refe refere rence nce gai gain n Cali Calibr brat atio ion n data data Int Inter erpre pretat tatio ion n and and test test rresu esults lts Tech Technicia nician n nam name, e, qu qualif alificati ication on le level, vel, si signat gnature ure & stamp stamp Date of test

14.3 Probe Probe details details shal shalll include the type, crystal crystal dime dimensio nsions, ns, nominal nominal angles and frequen frequencies. cies. The evaluation sensitivity / reference level shall also be included. The scanning sensitivity / test level shall be in accordance with item 8.0 herein.

   

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Ultrasonic Testing Procedure

14.4 The test results results shall include include deta details ils (when avai availabl lable) e) of the item under under test, welded welded joint or  plate tested, welding operator identification and the outcome of the test as detailed in item 8.0 herein. 14.5 When When testing plate / parent mate material rial for thickness thickness measurem measurement ent / corrosio corrosion n monitoring, monitoring, any relevant discontinuity noted shall be recorded and the size and depth from the scanned surfac sur face e noted noted.. Any inter internal nal pittin pitting g or cor corro rosio sion n found found du duri ring ng the testin testing g shall shall also also be recorded. 14.6 Recorded / rejected rejected refle reflectors ctors shall shall have the follo following wing information information noted: a) Test n nu umber  b) Di Disc scon onti tinu nuit ity y type type c) Le Leng ngth th of of refl reflec ecto tor  r  d) Refer Referenc ence e he heig ight ht o off refle reflecto ctor  r  e) Locat Locatio ion n to datum datum of rrefl eflect ector  or  f) Assess Assessme ment nt per per acc accep eptan tance ce criter criteria ia g) Sketches Sketches of refle reflector ctor cro cross-se ss-sectio ctional nal position positions s and / or location location drawings drawings 14 14.7 .7 All All repo report rts s shal shalll be ha hand nded ed ov over er ag agai ains nstt si sign gnat atur ure e in th the e pi pink nk copy copy to th the e Cl Clie ient nt representative and maintained at site as evidence for the handover of report. The Original, white and blue copies shall gat signed by all parties. The blue copy will be on job file, the white foronly the Client and the original is site, meant for invoicing. thetwo stage of handing of thecopy report the pink copy will be at which will only At have signatures at over  that stage, Stork-Cooperheat and the Client. 14.8 Stork-Co Stork-Cooper operhea heatt resp responsi onsibilit bility y shall be limi limited ted to ensuring ensuring the integrity integrity of the weld or part within the confines of the ultrasonic test requirements of the governing governing specification.

 

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Ultrasonic Testing Procedure

APPENDIX APPE NDIX - A

CALIB CALIBRATIO RATION N TECH TECHNIQU NIQUES ES

System Calibration (Refer item 8.2) Figure 1

Straight beam range calibration

Figure 2

Angle pr probe rra ange ca calibration ((V V1)

Figure 3

Angle pr probe rra ange ca calibration ((V V2) Distance amplitude correction - DAC (Refer item 7.3)

Figure 4

Construction Constructi on of DAC curve plot

   

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Ultrasonic Testing Procedure

Straight beam range calibration IIW-V1 block range 0 – 100 mm Fig. 1  

0

1

2

3

4

5

6

7

8

9 

25 mm

10

Angle probe range calibration IIW-V1 block range 0 – 100 mm Fig. 2a

0

1

2

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4

5

6

7

8

9

10

100 mm R

Fig. 2b 0

1

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5

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9 

10

Angle probe range calibration IIW-V2 block range 0 – 100 mm

25 mm R FIRST ECHO

Fi . 3a

0

1

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8

9

50 mm R SECOND REPEAT

10

Calibration check

Fig. 3b 0

1

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7

   

8

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10

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Ultrasonic Testing Procedure

+

+

¼T

½ T  

 5/4 T ¾ T

+

+

STEP 1: Maximise response from reflectors STEP 2: Mark each peak on screen

100

90

80

70

60

50

40

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20

10

0  0

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STEP 3: Connect marks for curve Fig 4: Construction of DAC curve plot    

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Ultrasonic Testing Procedure

APPENDIX – B, ACCEPTANCE CRITERIA ITEM 1

2

CODE ASME SME B31 B31.3 .3

ACCEPTANCE / REJECTION CRITERIA A lin linea earr typ type e di disc scon onti tinu nuit ity y iis s un unacc cce epta tab ble if th the e am amplitu litud de of of tth he indication exceeds the reference level and its length exceeds: a) 6 mm (¼ inch for Tw ≤ 19 mm (¾ inch) b) Tw / 3 for 19 mm < Tw ≤ 57 mm (2 ¼ inch) c) 19 mm for Tw > 57 57 mm (2 ¼ inch) Imperfections which produce a response greater than 20% of reference level shall be investigated to the extent that the operator can determine the shape, identity, and location of all such imperfections and evaluate them in terms of the acceptance standards given in a) and b) below. a) Indi Indica cati tion ons s ch char arac acte teri rise sed d as as crac cracks ks,, llac ack k of of fusi fusion on or incomplete penetration are unacceptable regardless of length. b) Othe Otherr impe imperf rfec ecti tion ons s ar are e un unac acce cept ptab able le if th the e in indi dica cati tion ons s exceeds the reference level amplitude and have lengths which exceed : ¼ inch (6.0mm) for t up to ¾ inch (19.0 mm) ⅓ t for t from ¾ inch (19.0 mm) to 2 ¼ inch (57.0 mm)

ASME Sec VIII, Division 1

  

¾ inch (19.0 mm) for t over 2 ¼ inch (57.0 mm) where t is the thickness of the weld excluding any allowable reinforcement

 

 

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Ultrasonic Testing Procedure

   

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