Paut Procedure -Asme 31.3 Process Piping

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD. DOCUMENT TITLE

ULTRASONIC PHASED ARRAY INSPECTION PROCEDURE FOR PIPE WELD JOINTS

DOCUMENT NUMBER

HT –PAUT-ASME-01

Description

Name

Signature

PREPARED &

M.SATHIASEELAN PCN NDT LEVEL II-UT/PAUT

REVIEWED BY

APPROVED BY

S.ESWARAN ASNT NDT LEVEL III RT/UT/MT/PT/ET/VT TECHNICAL MANAGER

REVISION STATUS

S.No

ISSUE NO

REVISION No.

DATE

DESCRIPTION

1

1

0.0

20.04.2011

REVISED

HT– PAUT-ASME-01

Rev 1

Page 1 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

TABLE OF CONTENTS 1.0

PURPOSE 3

2.0

SCOPE 3

3.0

REFERENCES 3

4.0

ULTRASONIC PHASED ARRAY EXAMINATION EQUIPMENT 3

5.0

PHASED ARRAY INSTRUMENT LINEARITY 5

6.0

PHASED ARRAY PROBE ELEMENT OPERABILITY VERIFICATION 6

7.0

PHASED ARRAY SYSTEM CALIBRATION 6

8.0

SURFACE PREPARATION 10

9.0

EXAMINATION COVERAGE AND SCANNING TECHNIQUE 11

10.0

RECORDING AND AMPLITUDE DETERMINATION 12

11.0

REPORT OF EXAMINATION 14

12.0

POST EXAMINATION CLEANING 15

13.0

DOCUMENTATION 15

APPENDICES 17 APPENDIX-1: PHASED ARRAY SCAN PLANS- FULL VOLUMETRIC COVERAGE PIPE TO PIPE WELDS .................................................................................................................................................................... APPENDIX-2 : TYPICAL GRAPHICAL SCAN PLAN FOR PIPE WELDS............................................................... APPENDIX-3 : BASIC CALIBRATION BLOCK............................................................................................................. APPENDIX-4 : PHASED ARRAY CALIBRATION & QUALIFICATION BLOCK..................................................... APPENDIX-5 : ACCEPTANCE CRITERIA -ASME SEC VIII DIV.1............................................................................. APPENDIX- 6: SAMPLE PAUT INSPECTION REPORT.............................................................................................

HT– PAUT-ASME-01

Rev 1

Page 2 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

1.0

PURPOSE 1.1

This procedure provides requirements for Semi-Automatic OR fully automated with encoded Ultrasonic Examination of pipe welds and base materials using Phased Array.

1.2

Project specific procedures complying with ASME Sec VIII requirements are attached in the Appendices.

DIV 1

2.0 SCOPE 2.1

This procedure establishes the specific phased array ultrasonic examination requirements that shall be used to examine Carbon & Alloy Steel pipe to pipe welds prior to or after Post Weld Heat Treatment (PWHT).

2.2

This procedure is applicable for welds that are 8.0 mm and above in thickness with outer diameter (OD) from 4 inch and above.

2.3

This procedure is designed to demonstrate the Olympus NDT Omni Scan Phased Array System used in this procedure as qualified UT System in accordance with the ASME Sec VIII DIV.1.

2.4

A non-blind test shall be used as a Performance Demonstration for the Omni Scan Phased Array System.

2.5

The Phased Array Scan Plan for each demonstration is outlined in the Appendix 2 &4 with specific requirements for this job .

3.0 REFERENCES 3.1

ASME Sec VIII Division 1: Rules for construction of pressure vessel.

3.2

ASME Boiler and Pressure Vessel Code, Section V, Article 4, Edition 2010.

3.3

ASME Code for Pressure Piping, B31.3 (Latest Edition)

3.4

BV Rules Part B Ch 12 Section 1

3.5

HT-WP-01 (2010) - Company Certification of NDE personnel.

written

practice

for

qualification

and

4.0 ULTRASONIC PHASED ARRAY EXAMINATION EQUIPMENT 4.1 The ultrasonic Phased Array instrument shall be an Omni Scan pulse echo type and shall be equipped with a calibrated dB gain or attenuation control stepped in increments of 2 dB or less. The Omni Scan contains 16 or 32 independent pulser/receiver channels. The system is capable of generating and displaying sector scan images, which can be stored and recalled for subsequent review.

4.2 Phased Array Equipment details:

HT– PAUT-ASME-01

Rev 1

Page 3 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

Equipment Data Acquisition System Phased Array Software PA Probe with cable Wedge

OMNI SCAN MX Olympus - Omniscan MX 16:128PA & 32:128PA Omniscan MXU-2.0R12 5L64A12 llatesthigher SA12-N55S SA12-N55S

4.3 Examination personnel may use a real-time sector scan (also called an S-Scan) image during scanning to assure that proper data has been collected. Sector scan images contain signal amplitude and reflector depth information projected for the refracted angle of the ultrasonic beam. The Omni Scan Phased Array system provides a variety of analysis capabilities including A-scan display and parameter readout associated with software cursors. Images produced by B, C and Sectorial Scan images are a useful aid in evaluation. 4.4 The Omni Scan Phased Array system has on-board focal law generation software that permits direct modification to ultrasonic beam characteristics. The Omni Scan Phased Array System requires the use of an external storage device, or flash card or USB memory Stick. A remote portable PC connected via Ethernet may be used for this purpose. 4.5 In addition to data storage, the PC will also be used by the Data Analysis Personnel for analyzing data subsequent to the completion of data collection. Data display software compatible to that residing on the Omni Scan Phased Array System will also be used on the remote PC for data playback. Reference the manufacturer operating manuals for instrument operation specifics. 4.6 Any control, which affects the instrument linearity (e.g., Reject) shall be in the off or minimum position for instrument calibration, system calibration and examination. 4.7 If any control (e.g., filters, averaging, pulse duration, etc.) are used in calibration, then these controls shall not be adjusted afterwards since they may affect the Omni Scan System Calibration. 4.8 The Ultrasonic Phased Array System shall be calibrated for linearity in accordance with Paragraph 5.0. 4.9 Ultragel II, Sonotrace 40, Sonatech, glycerine, diluted Wall paper paste, water or equivalent may be used as couplant when performing calibrations and examinations. 4.10 The same couplant material used for calibration shall be used for examinations. 4.11 Ultrasonic transducer configurations are specified by the technique used for examination. Linear Phased Array Probe configurations may include from 10 to 128 elements. 4.12 The Phased Array probe frequency shall be between 2 and 10 MHz depending upon material type, thickness.

HT– PAUT-ASME-01

Rev 1

Page 4 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

4.13 Phased Array Wedges should be of a design to accommodate the aforementioned Phased Array Probes. Nominal refracted wedge angles shall be 45, 55, 60 or 70 degree to ensure coverage of the weld and heat affected zone (HAZ). 4.14 An encoder interfaced with the Phased Array instrument may be used to track the Phased Array Probe movement. The encoder shall be calibrated by moving a minimum distance of 500mm and the distance recorded shall be within +/- 1% of actual distance moved. After the initial verification, further verification shall be performed not exceeding one month from the first test and the same test shall be repeated. 5.0

PHASED ARRAY INSTRUMENT LINEARITY 5.1

Ultrasonic instrument linearity shall be verified at the beginning and end of each series of examinations not to exceed 3 months.

5.2

The instrument linearity verification shall be recorded on the Ultrasonic Instrument Linearity Verification (Form 1).

5.2.1

Screen Height Linearity 5.2.1.1

Position a search unit on a calibration block to obtain indications from the two calibration reflectors.

5.2.1.2

Alternatively, a straight-beam search unit may be used on any calibration block that will provide amplitude differences with sufficient signal separation to prevent overlapping of the two signals.

5.2.1.3

Adjust the search unit position to give a 2:1 ratio between the two indications, with the larger indication set at 80% of full screen height (FSH) and the smaller indication at 40% of FSH.

5.2.1.4

Without moving the search unit set the larger indication to 100% of FSH; record the amplitude of the smaller indication, estimated to the nearest 1% of FSH.

5.2.1.5

Successively set the larger indication from 100% to 20% of FSH in 10% increments (or 2 dB steps if a fine control is not available); observe and record the smaller indication estimated to the nearest 1% of FSH at each setting. The reading must be 50% of the larger amplitude within +5% of FSH.

5.2.2

AMPLITUDE CONTROL LINEARITY 5.2.2.1

HT– PAUT-ASME-01

Position a search unit on a calibration block to obtain maximum amplitude from a calibration reflector.

Rev 1

Page 5 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

5.2.2.2

As a minimum, the amplitude control linearity shall be performed to document linearity at both ends of the gain range being used with the equipment.

5.2.2.3

Without moving the search unit, set the indication to the required percent of FSH and increase or decrease the dB as specified on the Ultrasonic Instrument Linearity Verification (Form 1). The estimated signal shall be recorded to the nearest 1% of FSH and shall fall within the limits specified on Form 1.

6.0 PHASED ARRAY PROBE ELEMENT OPERABILITY VERIFICATION 6.1

The Phased Array Probe shall be checked for element performance whenever the examiner suspects an element operability problem. Each phased array probe must be checked to determine each element’s ability to transmit and receive ultrasonic energy.

6.2

This Operability Verification verifies performance of each transmitter/receiver module, and cable conductivity for each channel. Any Phased Array Probe that has greater than 25% defective elements of the useable aperture should be replaced with a new probe. However, if an effective calibration is performed then the probe may not be considered defective.

7.0 PHASED ARRAY SYSTEM CALIBRATION 7.1

Calibration shall be performed from the surface of the calibration block which corresponds to the component surface to be examined.

7.2

System calibration shall include the complete ultrasonic examination system. Screen distance calibration shall be at least 1 and ½ vee paths for the minimum angle that will be used during the examination, unless otherwise specified.

7.3

The system calibration information shall be recorded on the Ultrasonic Data Report Form utilized in the Omni Scan. During scanning, only the gain may be adjusted from the calibrated Reference dB. Adjustment of other controls shall require recalibration.

7.4

Focal law Verification 7.4.1 The transmission and reception of ultrasonic waves of a given angle of incidence is a function of time delays calculated by focal laws using the information provided to the phased array system. Verification that the input information is correct and that the phased array system is working properly must be checked. 7.4.2 Select the Angle Beam Cursor and adjust its position so that it displays A-scan information for the 45 angle of refraction or the minimum angle that will be used in the Sector Scan. 7.4.3 Using the 100mm radius on the IIW block, peak the signal shown on the A-scan display. Note: Although the sector scan may

HT– PAUT-ASME-01

Rev 1

Page 6 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

indicate higher amplitude responses from other angles, only use the A-scan response associated with the45 angle of propagation. 7.4.4 Indicate on the transducer wedge, the beam exit point. This beam exit location is only valid for the 45 angle of propagation. 7.4.5 Using the primary angle of beam refraction exit location, measure the actual angle of propagation by peaking the response in the Ascan display using the plexi-glass insert on the IIW block. Record the actual angle of propagation as indicated on the IIW block using the beam exit point location. 7.4.6 If the measured angle of propagation is 45 +/- 2, then critical focal law parameters are correct. 7.4.7 If the measured angle of propagation is outside the allowable tolerance(45 +/-2), then all transducer and setup parameters must be reviewed for accuracy. If these parameters are correct, then check the shear wave velocity value used for the material. If this is correct, then small adjustments must be made to the transducer wedge velocity entry. If the measured angle is too high, then the wedge velocity must be increased slightly, and repeated. Similarly, if the measured angle is too low, then the wedge velocity parameter must be lowered and repeated until the measured angle is within tolerance. 7.5

Time Base Verification 7.5.1

Position the Angle Cursor and adjust its position so that it displays A-scan information for the 45 angle of refraction. 7.5.2 Place the transducer so that reflections from both the 50 mm and 100 mm radius reflectors on the IIW block are peaked and observed simultaneously on the A-scan display. 7.5.3 Using the A-scan Cursors, measure the distance between the 50 mm and 100 mm signals. This result shall be 50 + 2.5mm. 7.5.4 If the measured separation between the signals is too large (greater than 52.5 mm), decrease the Shear Velocity parameter under the Part Setup Menu. Similarly, if the measured distance is too short (less than 47.5 mm), increase the velocity value. Repeat adjustment until an acceptable value is achieved. 7.5.5

With the transducer remaining in the peaked position, measure the metal path of the 100 mm radius reflector using a cursor in the A-scan Display.

7.5.6

The value should measure to be 100 +/- 2.5 mm. If this measurement is less than 97.5 mm, increase the value of the Delay parameter until the measurement is correct. If this value is greater than 102.5 mm, decrease the Delay parameter until the measurement is correct. The requirements for focal law verification, time base verification and sensitivity adjustments are listed below. Instrument linearity verification and ultrasonic beam spread is not required.

HT– PAUT-ASME-01

Rev 1

Page 7 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

7.5.7

7.6

As an alternative, other calibration blocks may be used to perform the Time Base or Wedge Delay calibration.

Sensitivity And Wedge Delay Calibration 7.6.1

The Omni Scan shall be calibrated for Wedge Delay and Sensitivity. 7.6.2 The Wedge Delay Calibration shall be calibrated for True Depth with the angles used in calibration. 7.6.3 The Sensitivity Calibration will provide the required gain adjustments for each refracted angle and sound path used. 7.6.4 Select a calibration reflector which is approximately one half the thicknesses of the component to be examined, or within the zone of material to be examined. 7.6.4.1

Peak up this signal from the calibration reflector and scan the phased array probe backwards through all the different angles or focal laws.

7.6.4.2

Scan forward over the calibration reflector through all the refracted angles or focal laws.

7.6.4.3

The Omni Scan system will calculate the required gain needed at each focal law to adjust the amount needed

7.7

A Time Corrected Gain (TCG) calibration shall be used to compensate for attenuation in the material at the sound paths utilized during calibration and examination.

7.8

As an alternative, DAC may be used for electronic Scans (E-Scans) of specific angles, e.g., 45, 60 or 70 degrees.

7.9

The examination system calibration may be stored in the Omni Scan System with electronic memory or on an external chip or data storage device. This calibration may be used at a later date provided the system calibration is verified prior to examination.

7.10 A complete Ultrasonic System Calibration shall be performed at least once prior to the examination. 7.11 Temperature Requirements The basic calibration block temperature shall be within 25 degrees F (14 deg. C) of the component temperature. 7.12 System Calibration Verification 7.12.1

System calibration verification shall include the entire examination system. Sweep range and TCG calibration shall be verified on the project specific Qualification block under the following conditions:

HT– PAUT-ASME-01

Rev 1

Page 8 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

7.12.2

Prior to and within 24 hours of the start of a series of examinations

7.12.3

With any substitution of the same type and length of search unit cable.

7.12.4

With any substitution of power utilizing the same type source (e.g., a change of batteries)

7.12.5

At least every 12 hours during the examination.

7.12.6

At the completion of a series of examinations.

7.12.7

Whenever the validity of the calibration is in doubt.

7.12.8

A simulator block (e.g., IIW block, miniature DSC) may be used for the entire exam system calibration verifications

7.12.9

The initial system calibration shall be made using a basic calibration block. Whenever possible, the final system calibration verification should be made using the basic calibration block.

7.12.10

CALIBRATION/QUALIFICATION BLOCKS FOR CODE CASE 181

7.12.10.1 For the validation of calibration a project specific Qualification block shall be made to meet the ASME SecV requirements. See Appendix 5. 7.12.10.2 The procedure shall be demonstrated to perform acceptably on this Qualification block with required reflectors in accordance with ASME Code Case 181. The blocks shall be prepared by welding or made from material having the same or equivalent ‘P’ number grouping and having ultrasonically the same characteristics and shall contain a minimum of three flaws, orientated to simulate flaws parallel to the production weld’s fusion lines as follows. i)

One surface flaw on the side of the block representing the pipe OD surface. ii) One surface flaw on the side of the block representing the pipe ID surface. iii) One Subsurface flaw 7.12.10.3 In addition to the requirements of ASME Sec VIII, the blocks shall also have side drill holes representing various zones in accordance with Article 4 of ASME Section V The minimum requirements of the reference blocks are the following: i) Shall be made of same material as the weld under inspection with regard to sound, velocity, grain noise and surface condition.

HT– PAUT-ASME-01

Rev 1

Page 9 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

ii) The wall thickness shall be equal or up to 1” greater than the nominal wall thickness of the weld under inspection. iii) The width and the length scanning surface shall be adequate to allow probe movement over the reference reflectors. iv) The surface conditions shall be representative of the material surfaces to be examined. v) The block shall also be heat treated the same as the pipe to pipe weld condition (if any). vi) A dynamic calibration is performed on multiple reflectors moving the probes from one end of the block to the other.

HT– PAUT-ASME-01

Rev 1

Page 10 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

7.13 System Calibration Changes 7.13.1

Perform the following if any point on the TCG decreases by 20% or 2 dB of its amplitude, or any point on the sweep line has moved more than 10% of the sweep division reading.

7.13.2

Void all examinations performed after the last valid calibration verification.

7.13.3

Conduct a new system calibration.

7.13.4

Repeat voided examinations.

7.13.5

Perform the following if any point on the TCG has increased more than 20% or 2 dB of its amplitude: 7.13.5.1 7.13.5.2

Correct the system calibration. Re-examine all indications recorded since the last valid calibration verification.

7.13.5.3

Enter proper values on the applicable forms.

7.14 Re-calibration 7.14.1

Any of the following conditions shall be cause for system recalibration: 7.14.1.1

Search unit transducer or wedge change

7.14.1.2

Search unit cable type or length change

7.14.1.3

Ultrasonic instrument change

7.14.1.4

Change in examination personnel

7.14.1.5

Couplant change

7.14.1.6

Change in type of power source

8.0 SURFACE PREPARATION 8.1

Contact Surfaces - the finished contact surface should be free from weld spatter and any roughness that would interfere with free movement of the search unit or impair the transmission of ultrasonic vibrations.

8.2

Weld Surfaces - the weld surface should be free of irregularities that could mask or cause reflections from defects to go undetected and should merge smoothly into the adjacent base materials.

8.3

Conditions which do not meet these requirements shall be recorded as limitations on the Ultrasonic Examination Data Report Form.

8.4

Testing of Base Material & Transverse Defects : 8.4.1 Following inspection shall be considered when appropriate prior to PA scanning:

HT– PAUT-ASME-01

Rev 1

Page 11 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

8.4.2 Prior to PA inspection, the detection for lamination or inclusion in the base material need not be foreseen, when this has already been carried out by the plate manufacturer or the fabricator when plates are cut. However, when laminar defects are suspected, the entire base metal through which ultrasound must travel to test the weld shall be tested for laminar reflectors using a straightbeam search unit. 8.4.3 To ensure the coverage for the detection of transverse defects, transverse notches shall be introduced as depicted on the Qualification block (See appendix4). These transverse notches (both Cap and the Root) shall be detected by the PA technique during the calibration / validation exercise. Satisfactory detection of the transverse notches will ensure sufficient coverage. 8.4.4

Alternatively, manual scanning with shear waves 70° or 60° may be substituted for the detection of transverse defects. The 70° or 60° angle beam shall be directed essentially parallel to the weld axis. The search unit shall be manipulated so that the ultrasonic energy passes through the required volume of weld and adjacent base material. The search unit shall be rotated 180 degree and the examination shall be repeated. Wherever, the weld cap is not machined or ground flat, the examination shall be performed from the base metal on both sides of the weld cap in both weld axis directions.

9.0 EXAMINATION COVERAGE AND SCANNING TECHNIQUE 9.1

The specifics of the examination volume, weld identification and location shall be identified in the Scan Plan.

9.2

The examination volume shall cover the weld metal and HAZ plus 6 mm minimum of base material is examined from the toe of the weld. This area includes the heat affected zone or HAZ.

9.3

The Scan Plan shall demonstrate by plotting or with using a computer simulation the appropriate examination angles for the weld prep bevel angles (e.g., 35 to 60 degrees or 55 to 70 degrees) that will be used during the examination. This Scan Plan shall be documented to show the examination volume was examined. This Scan Plan shall be a part of the Final Examination Report.

9.4

The Omni Scan may use Multi-Groups to establish Sector Scans and EScans for the appropriate angles as identified in Paragraph 9.3 to ensure complete coverage of the weld and heat affected zone.

9.5

To determine the required examination volume and scan area, profiles may be taken on each weld. Profile data will consist of ultrasonic thickness measurements and outside surface contours using a contour gage. Thickness measurements should be taken at a maximum interval of approximately 1/4 inch and should cover the material volume to be examined and recorded. The "T" dimension shall be the nominal wall

HT– PAUT-ASME-01

Rev 1

Page 12 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

thickness. Alternatively, computer simulations with appropriate software can by used to plot the Weld profile. 9.6

Scanning shall be performed using a Line Scan Technique. Each Line scan shall be parallel to the weld using a Sector Scan, (S-Scan) and/or Electronic Scan, (E-Scan).

9.7

Appropriate refracted angles as accepted by ASME will define the positions of the arrays, and hence the angles. These should be detailed in the Ultrasonic Scan Plan.

9.8

A minimum of two (2) line scans shall be performed at two (2) different index points from the center of the weld from both sides of the weld where practical to ensure coverage of the weld and heat affected zone, (HAZ).

9.9

Scans shall be parallel to the weld at Skew 90° and 270° scan axes (where accessible).

9.10 Raster scanning will aid in Flaw Characterization. 9.11 The rate of search unit movement shall be limited to a maximum of 50 mm per second for Pipe to pipe circumferential welds unless calibration has been verified at a higher speed. 9.12 Perform the examination from both sides of the weld, where practical, or from one side as a minimum. All examination volume limitations shall be documented on the Ultrasonic Examination Data Report Form. 9.13 The entire examination volume comprising the weld and adjacent base metal shall be examined with the beam parallel to the weld on either side of the weld where accessible, in two directions, i.e., clockwise and counter clockwise. Phased Array Wedges contoured to the radius of the pipe may be used in the examination to ensure proper contact. 9.14 Full A-Scan & S-Scan data shall be recorded and stored when using encoders. 10.0 RECORDING AND AMPLITUDE DETERMINATION 10.1 Data shall be recorded in unprocessed form. A complete data set with no gating, filtering, or threshold shall be included in the data record. 10.2 All reflectors that exceed 20% of DAC or TCG shall be investigated to the extent to determine the type of reflector. 10.3 Indications that exceed 50% of DAC or TCG and determined to be of geometric or metallurgical origin shall be recorded. 10.4 The position and location of indications shall be recorded. 10.5 Geometric Indication - Recordable ultrasonic indications, of geometric or metallurgical origin, shall be classified as such. Weld reinforcement, root geometry or variations in metallurgical structure of materials (such as cladding to base metal interface) may be classified as geometric indications, and 10.5.1

Need not be characterized or sized.

10.5.2

Need not be compared to allowable flaw acceptance criteria.

HT– PAUT-ASME-01

Rev 1

Page 13 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

10.5.3

10.6

The maximum length and location shall be recorded. For example: 100mm length, one inch above the weld centre line, on the inside surface, from 90 to 95 degrees.

The following steps shall be taken in order to classify an indication to be of geometric or metallurgical origin: 10.6.1

Interpret the area containing the reflector in accordance with the applicable examination instruction;

10.6.2

Plot and verify the reflector coordinates, provide a cross-sectional display showing the reflector position and surface discontinuity such as root or counter bore.

10.6.3

10.7

10.8

10.6.4

All recordable indications shall be resolved to determine the shape, identity, and location of the reflector. Final evaluation and disposition of the indication is the responsibility of owner/user of the component to be examined.

10.6.5

Amplitude Determination - Signal amplitude shall be measured as a percent of the calibrated DAC or TCG.

10.6.6

The appropriate Code or Specification shall be used to determine final acceptance of the weld inspection using the Omni Scan.

Flaw Sizing 10.7.1

Reflectors determined to be flaws shall be sized in accordance with a procedure demonstrated to size similar flaws at similar material depths. Alternatively, a flaw may be sized by manual techniques that have been demonstrated on the calibration block

10.7.2

LENGTH - The length of the flaw shall be drawn parallel to the inside pressure retaining surface.

10.7.3

HEIGHT (DEPTH) - the depth of the flaw as the dimension drawn normal to the inside pressure retaining surface

10.7.4

DEPTH - The true depth of an indication is the dimension measured from OD surface of the pipe to the top of the indication.

Flaw Evaluation 10.8.1

10.9

Review fabrication or weld prep drawings when accessible.

Flaws shall be evaluated in accordance with Appendix 12 of Section VIII, Division 1.

Repair weld 10.9.1All Indication identified by Phased Array and checked by manual UT and found not acceptable in accordance with applicable code will have to be repaired and re-checked. After repair, a length of weld (each side of the repair) equal to 500 mm shall be also reexamined.

HT– PAUT-ASME-01

Rev 1

Page 14 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

11.0 REPORT OF EXAMINATION 11.1 The following items shall be reported in the examination report and this report shall be retained for a period of 5 years. a)

Procedure identification and revision;

b)

Ultrasonic instrument identification(including manufacturer's serial number);

c)

Search unit(s) identification (including manufacturer's serial number, frequency and size);

d)

Beam angle(s) used;

e)

Couplant used, brand name or type;

f)

Search unit cable(s) used, type and length;

g)

Special equipment when used (search units, wedges, shoes, automatic scanning equipment, recording equipment, etc.);

h)

Computerized program identification and revision when used;

i)

Calibration block identification;

j)

Simulation block(s) and electronic simulator(s), identification when used;

k)

Instrument reference level gain and, if used, damping and reject setting(s);

l)

Calibration data [including reference reflector(s), indication amplitude(s). and distance reading(s)];

m)

Data correlating simulation block(s) simulator(s), when used with initial calibration;

and

electronic

n)

Identification and location of weld or volume scanned;

o)

Surface(s) from which examination was conducted, including surface condition;

p)

Map or record of rejectable indications or non-rejectable indications with >=50% reference level detected or area cleared;

q) r)

Areas of restricted access or inaccessible welds; Examination personnel identity and, referencing Code Section, qualification level;

s)

when

required

by

Date of examination;

11.2

A table of all investigated indications shall be provided in a report which includes location and all analysis criteria (See Appendix 5 for Phased Array summary report format).

11.3

The final data package shall be reviewed by a UT level III individual. The review shall include: a)

The ultrasonic data record

b)

Data interpretations

HT– PAUT-ASME-01

Rev 1

Page 15 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

c) Flaw evaluations /characterizations performed by another qualified Level II or III individual. The data review may be performed by another individual from the same organization. 12.0 POST EXAMINATION CLEANING The remaining couplant shall be wiped from the surface at the completion of the examination. 13.0 DOCUMENTATION 13.1

Results of ultrasonic examination shall be reported on the PA UT Report Form shown in the appendix. All Phased Array examination data for each recordable indication, A-scans, B, C, and S Scans shall be saved as a Report File and recorded on a CD/DVD.

13.2

The examiner shall record the results of the examination on the PA Summary Report from (Appendix 6). All recordable indications shall be documented on the examination report. All blocks should be completed with the appropriate data or "NA".

13.3

The Ultrasonic Scan Plan, Ultrasonic Calibration, and Ultrasonic Instrument Linearity verification (if required) shall be considered part of the examination report.

HT– PAUT-ASME-01

Rev 1

Page 16 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

SAMPLE ULTRASONIC INSTRUMENT LINEARITY VERIFICATION - FORM ULTRASONIC INSTRUMENT LINEARITY VERIFICATION INSTRUMENT MANUFACTURER

MODEL NUMBER

RECORD NO.

CALIBRATION BLOCK NO.

INITIAL DATE

FINAL DATE

SCREEN HEIGHT

AMPLITUDE CONTROL LINEARITY

LINEARITY INSTRUMENT WITH FINE dB CONTROL

INDICATION

dB

SET AT % OF

CONTROL CHANGE

INDICATION LIMITS % OF FULL SCREEN

ACTUAL % OF FULL SCREEN **

HI GAIN SETTING

FULL SCREEN

LOW GAIN SETTING

FIRST SIGNAL IN %

SECON D SIGNAL IN % *

100

INITIAL

FINAL

____dB

____d B

INITIAL

____d B

FINAL

____dB

100

90

80

80

-6Db

32 TO 48

40

90 80

70

80

-12 Db

16 TO 24

60

40

70

80

-12 Db

40

+6 Db

20

+12

60

50

40

+6 Db

64 TO 96

40

50 40

30

20

+12 dB

64 TO 96

20

30 20

*READING MUST BE 50% OF FIRST SIGNAL AMPLITUDE WITHIN 5% OF FULL SCREEN HEIGHT. COMMENTS:

INSPECTOR

CERT LEVEL

DATE

SUPV/LEVEL III REVIEW

INSPECTOR

CERT LEVEL

DATE

DATE

HT– PAUT-ASME-01

Rev 1

Page 17 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

APPENDICES

HT– PAUT-ASME-01

Rev 1

Page 18 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD. APPENDIX-1 :

PHASED ARRAY SCAN PLANS- FULL VOLUMETRIC COVERAGE PIPE TO PIPE WELDS

PHASED ARRAY SCAN PLAN - PIPE TO PIPE WELDS S.No 1

S.No 2

ID (mm)

Various

WT (mm)

Weld Seam

12 mm

Pipe to pipe weld

9.53 mm

No.of PA Groups

G1 G2

Technique

Sectorial

Probes & Wedges

Freq. (Mhz )

5L64A12+SA 12-N55S-IHC

Sectorial

G1

Sectorial

G2

Linear

5L64A12+SA12 5 -N55S-IHC

5

Angle Coverage 50° -70° SW 45°-65° SW 50° -70° SW 60°

Note:

HT– PAUT-ASME-01

Rev 1

Page 19 of 26

Index Offset (mm)

Angle Step

No.of Elements used

First Element

Last Element

Focus Depth (mm)

1°

16

1

64

50 mm

1°

16

40

0.5°

16

44

1°

16

31

55 61 N.A

Skew 90° (-)

Skew 270° (+)

12

12

50 mm 50 mm 50 mm

12

12

9

9

9

9

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD. APPENDIX-2

I)

:

TYPICAL GRAPHICAL SCAN PLAN FOR PIPE TO PIPE WELDS

Scanning From OD

HT– PAUT-ASME-01

Rev 1

Page 20 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD. Phased Array Probe Details Wedge: SA12-N55S-IHC Velocity

Primary Offset

Height 1st Element

Length

Widt h

Angle

2.33mm/µs

56.8mm

11.02mm

68.53mm

40m m

36o

Transducer: 5L64-A12 Total Aperture: 38.4mm

Number of Elements: 64

Element Pitch: 0.6mm

Sectorial Beamset (Group-1)

Law Config.: sectorial Wave Type: Shear Element Qty 16

First Element

41

Min Angle

50o

Max Angle

70o

Angle Steps

1.00o

Focus Depth

50mm

Sectorial Beamset (Group-2)

Law Config.: Sectorial Shear

Wave Type:

Element Qty

First Element

16

APPENDIX-3

HT– PAUT-ASME-01

47

Min Angle

Max Angle

Angle Steps

45o

65o

1.0o

Focus Depth

50mm

: PIPING CALIBRATION BLOCK

Rev 1

Page 21 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

HT– PAUT-ASME-01

Rev 1

Page 22 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD. APPENDIX-4

:

QUALIFICATION BLOCK- DIMENSIONS OF QUALIFICATION REFLECTORS

75 mm

Weld CL

Side drilled Hole

ID Notch

OD Notch Length=38 mm, size=2.5 mm

Length=38 mm, size=2.5 mm

CL T/4 Side drilled Hole T/2 Side drilled Hole

19 mm

HT– PAUT-ASME-01

3T/4 Side drilled Hole

Rev 1

Page 23 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

HT– PAUT-ASME-01

Rev 1

Page 24 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD. APPENDIX- 5

:

ACCEPTANCE CRITERIA – ASME B 31.3 APPENDIX 12

APPENDIX -6 PAUT INSPECTION SAMPLE REPORT

HT– PAUT-ASME-01

Rev 1

Page 25 of 26

HI-TECH NDT INSPECTIONS SERVICES (S) PTE. LTD.

HT– PAUT-ASME-01

Rev 1

Page 26 of 26