es-s-60 rev 4

27/4/99 4 Ammendments to Clauses 1.4.5; 2.1;2.4.3 ; 2.5.1 ; 2.5.3; 2.5.4 and 5.2

QAI/2 QA

DATE REV... DESCRIPTION COMPILED BY REVIEWED BY APPROVED

ES-S-60 - SPECIFICATION FOR THE NON DESTRUCTIVE TESTING OF WELDS of 26

QATAR GENERAL PETROLEUM CORPORATION

SPECIFICATION FOR THE NON DESTRUCTIVE TESTING

OF WELDS

ES-S-60

SPECIFICATION FOR THENON DESTRUCTIVE TESTING OF WELDS

Document No. Title Rev.. Date PageES-S-60 SPECIFICATION FOR THE NON DESTRUCTIVE TESTING OF WELDS 4 27/4/99 2 of 26

REVISIONS: All revision 4 items are marked by a vertical line in the right hand border.

Distribution list :

CONTROL COPY REF. INDICATOR

NUMBER 1 OM(O)NUMBER 2 OM(M)NUMBER 3 OM(D)NUMBER 4 MC(O)NUMBER 5 MC(M)NUMBER 6 MC(D)NUMBER 7 EBNUMBER 8 EDNUMBER 9 EENUMBER 10 EFNUMBER 11 EMNUMBER 12 FSNUMBER 13 DRNUMBER 14 GSNUMBER 15 MTNUMBER 16 MCI(O)NUMBER 17 MCI(M)NUMBER 18 MCI(D)NUMBER 19 QACNUMBER 20 QAC/1NUMBER 21 QAC/2NUMBER 22 QAI/1NUMBER 23 QAI/2NUMBER 24 QAI/3NUMBER 25 ENE/8



CONTENTS

1. INTRODUCTION ..............................................................................................................................51.1 SCOPE .................................................................................................................................................................... 51.2 DEFINITIONS, LANGUAGE AND UNITS ................................................................................................................ 51.3 ABBREVIATIONS .................................................................................................................................................... 51.4 REFERENCED SPECIFICATIONS AND STANDARDS.......................................................................................... 5

1.4.1 American Petroleum Institute. ....................................................................................................61.4.2 American Society for Testing and Materials. ..............................................................................61.4.3American Welding Society...........................................................................................................61.4.4 British Standards . ......................................................................................................................61.4.5 Other Specifications....................................................................................................................6

2. METHOD OF OPERATION AND PERSONNEL QUALIFICATION ..................................................72.1 INTRODUCTION...................................................................................................................................................... 72.2 QUALITY ASSURANCE .......................................................................................................................................... 72.3 REPORTING............................................................................................................................................................ 72.4 NDT PERSONNEL .................................................................................................................................................. 7

2.4.1 NDT Co-ordinator .......................................................................................................................72.4.2 NDT Supervisor ..........................................................................................................................72.4.3 NDT Operatives ..........................................................................................................................7

2.5 QUALIFICATION OF NDT PERSONNEL ................................................................................................................ 82.5.1 Qualifications ..............................................................................................................................82.5.2 NDT Co-ordinator .......................................................................................................................82.5.3 NDT Supervisor ..........................................................................................................................82.5.4 NDT Operative............................................................................................................................8

3. MAGNETIC PARTICLE INSPECTION..............................................................................................93.1 INTRODUCTION...................................................................................................................................................... 93.2 MPI PROCEDURE................................................................................................................................................... 9

3.2.1 Procedure - General ...................................................................................................................93.2.2 Procedure - Qualification ............................................................................................................9

3.3 TECHNIQUE IN GENERAL ..................................................................................................................................... 93.3.1 Surface Preparation....................................................................................................................93.3.2 Detecting Media..........................................................................................................................93.3.3 Magnetisation .............................................................................................................................93.3.4 Flaw Indicators and Field Strength Meters .................................................................................103.3.5 Inks .............................................................................................................................................10

3.4 PRACTICAL PROCEDURES................................................................................................................................... 103.4.1 Application of External Magnetic Field........................................................................................103.4.2 Application of Detecting Media ...................................................................................................10

3.5 REPORTING............................................................................................................................................................ 103.6 CHECKS ON CONSUMABLES AND EQUIPMENT................................................................................................. 103.7 DEMAGNETISATION .............................................................................................................................................. 11

4. LIQUID PENETRANT TESTING.......................................................................................................124.1 INTRODUCTION...................................................................................................................................................... 124.2 PENETRANT PROCEDURES ................................................................................................................................. 124.3 TECHNIQUES IN GENERAL................................................................................................................................... 12

4.3.1 Penetrant - Consumables...........................................................................................................124.3.2 Approved Techniques.................................................................................................................12

4.4 REPORTING............................................................................................................................................................ 124.5 CLEANING............................................................................................................................................................... 13

5. ALTERNATING CURRENT FIELD MEASUREMENT (ACFM) .........................................................145.1 INTRODUCTION...................................................................................................................................................... 145.2 NDT PERSONNEL .................................................................................................................................................. 145.3 EQUIPMENT............................................................................................................................................................ 14

5.3.1 Topside .......................................................................................................................................145.3.2 Sub-Sea......................................................................................................................................145.3.3 Probes ........................................................................................................................................145.3.4 Operational Test Block ...............................................................................................................14



5.4 SURFACE PREPARATION ..................................................................................................................................... 145.4.1 Magnetic State............................................................................................................................15

5.5 PRACTICAL PROCEDURES................................................................................................................................... 155.5.1 General Information....................................................................................................................155.5.2 Scan Data ...................................................................................................................................155.5.3 Detailed Indication Record..........................................................................................................15

5.6 PROBE DEPLOYMENT........................................................................................................................................... 155.7 TEMPERATURE...................................................................................................................................................... 155.8 MATERIALS............................................................................................................................................................. 15

6. ULTRASONIC EXAMINATION.........................................................................................................176.1 INTRODUCTION...................................................................................................................................................... 166.2 NDT PERSONNEL .................................................................................................................................................. 176.3 EQUIPMENT............................................................................................................................................................ 17

6.3.1 Flaw Detector..............................................................................................................................176.3.2 Calibration Blocks .......................................................................................................................176.3.3 Ultrasonic Probes .......................................................................................................................17

6.4 PERFORMANCE MONITORING CHECKS ON ULTRASONIC EQUIPMENT......................................................... 186.4.1 Flaw Detector..............................................................................................................................186.4.2 Probes ........................................................................................................................................18

6.5 ULTRASONIC TEST PROCEDURES...................................................................................................................... 186.5.1 Test Procedures in General........................................................................................................186.5.2 Test Procedures - Qualification ..................................................................................................19

6.6 PREPARATION FOR EXAMINATION ..................................................................................................................... 196.7 SENSITIVITY ........................................................................................................................................................... 20

6.7.1 Scanning Sensitivity....................................................................................................................206.7.2 Reference Sensitivity ..................................................................................................................20

6.8 REFERENCE CALIBRATION BLOCK..................................................................................................................... 206.8.1 Calibration Block.........................................................................................................................20

6.9 SCANNING PATTERN ............................................................................................................................................ 206.10 DISCONTINUITY LOCATION................................................................................................................................ 206.11 FLAW SIZE EVALUATION .................................................................................................................................... 206.12 DEFECT ACCEPTANCE LEVELS......................................................................................................................... 206.13 REPORTING OF FLAWS ...................................................................................................................................... 206.14 REPORT FORMAT................................................................................................................................................ 21

7. X RAY AND GAMMA RADIOGRAPHY ............................................................................................227.1 INTRODUCTION...................................................................................................................................................... 227.2 RADIOGRAPHIC PROCEDURE ............................................................................................................................. 22

7.2.1 Procedure - General ...................................................................................................................227.2.2 Procedure Sheets .......................................................................................................................227.2.3 Qualification of Radiographic Procedure ....................................................................................23

7.3 TECHNIQUE IN GENERAL ..................................................................................................................................... 237.3.1 Sources and Techniques............................................................................................................237.3.2 Screens.......................................................................................................................................237.3.3 Films ...........................................................................................................................................237.3.4 Film Identification........................................................................................................................247.3.5 Image Quality Indicators (IQI).....................................................................................................247.3.6Exposure Geometry.....................................................................................................................247.3.7 Focus to Film Distance ...............................................................................................................247.3.8 Film Density ................................................................................................................................247.3.9 Film Overlap ...............................................................................................................................24

7.4 FILM PROCESSING................................................................................................................................................ 247.5 FILM STORAGE ...................................................................................................................................................... 257.6 INTERPRETATION AND REPORTING ................................................................................................................... 25

TABLE 1 - REFERENCE BLOCK THICKNESS...................................................................... 26



1. INTRODUCTION

1.1 SCOPE

This specification defines the requirements for conducting non destructive testing of welds and materialsin structural steelwork, pipelines, process piping, pressure vessels, etc., for QGPC Installations in theArabian Gulf.

1.2 DEFINITIONS, LANGUAGE AND UNITS

The following definitions apply throughout this specification:

EMPLOYER Shall mean QATAR GENERAL PETROLEUM CORPORATION (QGPC) orappointed MANAGING CONSULTANT

CONTRACTOR The party which entered into contract with the EMPLOYER for the execution ofactivities as mentioned in a written agreement.

The following use of language applies throughout this specification:

i) 'shall' is used where a provision is mandatory,

ii) 'should' is used where a provision is preferred,

iii) 'may' is used where alternatives are equally acceptable.

The term 'approve' as applied to the EMPLOYER is used where the EMPLOYER does not wish workto proceed unless certain features have been agreed in writing with the CONTRACTOR. This doesnot mean that all the details of a document have been considered by the EMPLOYER and does notabsolve the CONTRACTOR of his responsibilities.

All communication both documentary and spoken shall be in the English Language and alldimensions and weights shall be in SI (Systeme International d' Unites) units.

1.3 ABBREVIATIONS

The following abbreviations are used throughout this specification:

API American Petroleum Institute

ACFM Alternating Current Field Measurement

ANSI American National Standards Institute

ASNT American Society for Non-Destructive Testing

ASTM American Society for Testing and Materials

BS British Standard

DAC Distance Amplitude Correction

IQI Image Quality Indicator

LPI Liquid Penetrant Inspection

MPI Magnetic Particle Inspection

NDT Non-Destructive Testing

PCN Personnel Certification in Non Destructive Testing

QA Quality Assurance

QC Quality Control

RT Radiographic Testing

UT Ultrasonic Testing

1.4 REFERENCED SPECIFICATIONS AND STANDARDS

The following standards are referenced in this specification. A reference in this specification to thesedocuments involves the latest published issue together with any amendments.



1.4.1 American Petroleum Institute.

API RP 2X Ultrasonic Examination of Offshore Structural Fabrication and Guidelines forQualification of Ultrasonic Technicians.

1.4.2 American Society for Testing and Materials.

ASTM A435 Straight Beam Ultrasonic Examination of Steel Plates.

ASTM E94 Standard Recommended Practice for Radiographic Testing.

ASTM E142 Standard Method for Controlling Quality of Radiographic Testing.

ASTM E165 Standard Practice for Liquid Penetrant Inspection Method.

ASTM E709 Standard Practice for Magnetic Particle Examination.

ASTM E747 Controlling Quality of Radiographic Testing Using Wire Penetrameters.

ASTM E1032 Radiographic Examination of Weldments.

1.4.3 American Welding Society

AWS A2.4 Symbols for Welding and Non Destructive Testing.

1.4.4 British Standards .

BS 2704 Specification for Calibration Blocks for use in Ultrasonic Flaw Detection.

BS 3683 Glossary of Terms used in Non Destructive Testing.

BS 4069 Specification for Magnetic Flaw Detection Inks and Powders.

BS 4331 Guidance on the In-Service Monitoring of Probes (excluding immersion probes)

BS 4489 Method for Measurement of UV-A Radiation (black light) used in NDT.

BS 6072 Method for Magnetic Particle Flaw Detection.

BS EN 462-1

BS EN 571-1

BS EN 1435

BS EN 1714

BS EN 1060

1.4.5 Other Specifications.

ASNT-TC-1A Personnel Qualification and Certification in Non Destructive Testing.

PCN/GEN/97 App E2Iss 32

Requirements for PCN Certification of Personnel engaged in Liquid Penetrantinspection.

PCN/GEN/927 App E1Iss 3

Requirements for PCN Certification of Personnel engaged in Magnetic ParticleInspection.

PCN/GEN/W/97RT1App C2 (Alt) Iss390

Specific requirements for PCN Certification of Personnel engaged in theRadiographic Testing of Welds.

PCN/GEN/97W/UT1App C1 Iss 3.90

Specific requirements for PCN Certification of Personnel engaged in theUltrasonic Testing of Fusion Welded Ferritic Steels.



2. METHOD OF OPERATION AND PERSONNEL QUALIFICATION

2.1 INTRODUCTION

This section of the specification defines the requirements for conducting non destructive testing of welds& materials and the minimum qualification requirements for CONTRACTOR NDT personnel engaged inultrasonic, radiographic, magnetic particle, liquid penetrant testing and ACFM where applicable..

2.2 QUALITY ASSURANCE

Before the commencement of work on the contract, the CONTRACTOR shall submit the followingdocumentation for approval by the EMPLOYER:

a) An organigram which defines the role of the CONTRACTOR's staff responsible for NDT.

b) An internal quality manual relating to NDT operations.

c) Written NDT procedures, including procedure qualification tests.

d) A list of NDT operatives and supervisory staff, supported by relevant certification andsupplementary evidence.

e) A list of equipment to be used under the contract.

The effectiveness of the quality system and quality plan used by the CONTRACTOR will be subject tomonitoring by the EMPLOYER and in addition may be audited following an agreed period of notice.

2.3 REPORTING

The CONTRACTOR shall be responsible for the accuracy and the validity of all NDT reports submittedto the EMPLOYER. Site NDT reports produced during the contract shall be collated, processed by theCONTRACTOR and used to produce a post contract report. The style and the format of the postcontract report shall be subject to approval by the EMPLOYER.

2.4 NDT PERSONNEL

Personnel offered for work on the EMPLOYER contracts shall fully comply with the requirements givenin Clause 2.5. Authenticated copies of original certification of all personnel shall be submitted to theEMPLOYER for approval prior to the commencement of operations. Verification of claims of experienceshall be by copies of log books, references and certificates which shall be submitted by theCONTRACTOR. Details of NDT training and performance shall be available for EMPLOYER scrutiny toconfirm adequate job experience.

2.4.1 NDT Co-ordinator

The CONTRACTOR shall employ an NDT co-ordinator who will liaise with the EMPLOYER on alloperational and technical matters related to NDT. The responsibilities of the NDT co-ordinator are asfollows:-

a) Submission of necessary documents.

b) Specification and running of procedure qualification tests.

c) Control of all NDT activities.

d) Data collection and reporting.

2.4.2 NDT Supervisor

Supervision of all NDT operatives on sites shall be carried out by NDT supervisors, who may also be theNDT co-ordinator described in Clause 2.4.1. Their function is to:-

a) Endorse all NDT reports issued by the NDT operatives.

b) Ensure and witness that the mandatory checks on NDT equipment and consumables iscarried out and reported in accordance with EMPLOYER specifications.

c) Ensure that the examination coverage satisfies the requirements defined in the specifications.

2.4.3 NDT Operatives

The EMPLOYER will assess the suitability of any NDT operatives prior to his being accepted forcontract duties. AAt the discretion of the EMPLOYER’S sponsoring department this assessment shallbe carried out in the form of a trade test. The ttests shall be conducted by the EMPLOYER or an



independent inspection agency approved by the EMPLOYERY. The EMPLOYER may audit theperformance of all NDT personnel as necessary and instruct the CONTRACTOR that he ceases to usepersonnel whose performance is considered unsatisfactory.

2.5 QUALIFICATION OF NDT PERSONNEL

2.5.1 Qualifications

Either of the following qualifications shall be accepted by the EMPLOYER:

a) CSWIP/PCN Level II with a minimum of 2 years post qualifying experience.

b) ASNT recommended practice SNT-TC-1A to Level II proficiency with a minimum of 2 yearspost qualifying experience.

NNo consideration shall be given to any other qualifications without the EMPLOYER’s approval.

NNDT operatives qualified in accordance with ASNT recommended practice SNT-TC-1A Level II shallbe ccertified, prior to his being acceptable for contract duties, by an ASNT Level III certifiedqualifiedpperson acceptable toapproved by the EMPLOYER. The EMPLOYER at its discretion may seekindependent certification iif operational circumstances dictate.

All personnel shall be required to furnish proof of having been examined in the preceding 12 months bya competent medical authority to prove a natural or corrected near vision acuity for reading J-1 letters onJaegers Standard Test Chart at a distance of not less than 300mm, a natural or corrected distanceacuity of not less than 20/40 and colour blindness to ISHIHARA for all NDT techniques iin thisspecification.

2.5.2 NDT Co-ordinator

The NDT co-ordinator shall have ultrasonic or radiographic qualifications conforming to therequirements of Clause 2.5.1. When the NDT co-ordinator takes on the function of the NDT supervisor,the minimum qualification requirements shall be as that of the NDT supervisor.

2.5.3 NDT Supervisor

The NDT supervisor shall have full ultrasonic, radiographic, magnetic particle, and liquid penetrant andACFM qualifications, applicable to the scope of work given within the schemes given in Clause 2.5.1;plus at least 5 years site experience since qualifying. NDT supervisors shall have a thorough knowledgeof the CONTRACTOR's Quality Assurance Documentation.

2.5.4 NDT Operative

The NDT operative shall have relevant qualifications in accordance with Clause 2.5.1. Furtherrequirements for approval of ACFM and ultrasonic operatives are specified in Clauses 5.2 and 6.2respectively.



3. MAGNETIC PARTICLE INSPECTION

3.1 INTRODUCTION

This section covers the site inspection of plate, pipe and structural weld connections by wet and drymagnetic particle inspection (MPI) methods. The techniques and procedures used shall be inaccordance with BS 6072 or ASTM E709 except as modified herein.

3.2 MPI PROCEDURE

3.2.1 Procedure - General

A written procedure shall be submitted to the EMPLOYER for approval, and shall include the followinginformation:

a) Surface preparation.

b) Magnetic ink and method of application.

c) Means of external magnetisation and the equipment used.

d) Means of ensuring the adequacy of the magnetic flux density.

e) Consumables and equipment tests and their frequency.

f) Technique sketch indicating the direction, coverage of the applied magnetisation and theprobing pattern.

g) Reporting format.

h) Acceptance levels.

i) Operator qualifications.

3.2.2 Procedure - Qualification

The approved procedure shall be qualified by the CONTRACTOR in the presence of the EMPLOYER.The following techniques, when employed, shall be qualified on sample pieces of relevant geometry:

a) Any technique to be used for examination of variable geometry welds.

b) Flexible cable or coil techniques.

c) Permanent Magnet.

d) Electromagnet (AC/DC Yoke).

e) Fluorescent ink technique.

The qualification tests shall demonstrate:-

a) Satisfactory surface preparation including the application of contrast coating.

b) Provision of an adequate magnetisation level and direction, see Clause 3.4.1.

If required by the EMPLOYER, the CONTRACTOR shall provide test pieces containing weld flaws so asto demonstrate the sensitivity of the technique.

3.3 TECHNIQUE IN GENERAL

3.3.1 Surface Preparation

The tested surface shall be free from grease, oil, scale, rust, flux, spatter and any form of protectivecoating. If necessary the surfaces shall be dressed out with a light grinding so that the surfaceroughness or irregularities present do not interfere with the interpretation. The grinding direction shall notcoincide with the expected orientation of the flaws. Proprietary contrast coats shall be used to enhancethe area under inspection. The coating shall tightly adhere to the surface, forming a thin and coherentfilm.

3.3.2 Detecting Media

Magnetic and fluorescent inks shall comply with the requirements of BS 4069 or ASTM E709.

3.3.3 Magnetisation

The preferred techniques for applying the external magnetic field are: -

a) A.C. yoke with adjustable pole pieces.



b) Flexible cable or coil carrying a.c. or d.c.

The use of permanent magnet yokes shall require the approval of the EMPLOYER.

A.C. prods shall not be used.

3.3.4 Flaw Indicators and Field Strength Meters

Burma-Castrol type II flaw indicators (or other type approved by the EMPLOYER), and portable fieldstrength meters shall be used on each length of weld examined. Before fillets or variable geometrywelds are examined, two flaw indicators orientated at right angles to each other shall be attached flatonto the vertical plate surface as near to the weld as possible. When magnetised and sprayed with inkall three lines on each flaw indicator shall be clearly visible.

3.3.5 Inks

All MPI shall be conducted using wet inks. The use of fluorescent inks is allowed in those work areaswhich can be shaded so as to reduce the ambient light level to below 10 lux.

The use of dry powder techniques shall only be permitted for hot checks with the approval of theEMPLOYER.

3.4 PRACTICAL PROCEDURES

3.4.1 Application of External Magnetic Field

The direction of magnetisation shall be such as to detect both longitudinal and transverse orientatedweld flaws. The maximum pole spacing of the yoke shall not exceed 170mm. The area of magneticcoverage of a yoke is considered to be a circle inscribed between the pole pieces, except that the zoneadjacent to the poles having a width of 15mm shall not be evaluated. The degree of overlap ofsuccessive areas during examination shall be 25% minimum.

3.4.2 Application of Detecting Media

The magnetic media shall be applied during continuous magnetisation of the part. Inspection shall becarried out whilst the magnetic field is present. Excess magnetic particles may be removed by blowingof the area under inspection.

3.5 REPORTING

All indications shall be assessed in accordance with the acceptance levels given in the appropriateQGPC application specification. Indications which are not permitted shall be reported and may befurther investigated either by repeating the test or by light dressing (not exceeding a depth of 1mm)followed by an MPI retest. If the retest shows that the indication still remains outside the coderequirements, any subsequent surface treatment shall be classed as a weld repair.

The results of MPI shall be recorded and the report shall contain at least the following information:

a) Date and time of inspection

b) Name of Inspection Company.

c) Identification of the workpiece.

d) State if edge or weld; for the latter, the welding process and stage of inspection.

e) Surface conditions.

f) Technique number and essential parameters.

g) The commercial name of the examination medium and the identification number of themagnetising medium.

h) Inspectors name and signature.

i) Level of inspectors qualification.

j) The test results.

3.6 CHECKS ON CONSUMABLES AND EQUIPMENT

Where magnetic inks are prepared on site, their concentration shall be tested at a minimum of once perday and the containers shall be appropriately marked to record the test.



Variable current transformers shall be checked at agreed intervals and the results recorded. Theintensity and wavelength of black light at the surface shall be in accordance with BS 4489 or ASTME709. These shall be tested at intervals agreed by the EMPLOYER and the results of the test recorded.

At the beginning of each shift the lifting power of the electromagnetic yokes shall be tested and theresults of the test recorded in the calibration log. The lifting power shall exceed 4.5 Kg for the maximumpole spacing. For permanent magnets the lifting power shall exceed 18Kg for the maximum polespacing, if this is greater than 75mm or 0.24Kg per millimetre of pole spacing , if this is less than 75mm.

3.7 DEMAGNETISATION

If the component to be tested exhibits residual magnetism then demagnetisation shall be carried out inaccordance with Clause 22 of BS 6072 or ASTM E709.



4. LIQUID PENETRANT TESTING

4.1 INTRODUCTION

This section of the specification covers the inspection of welded and brazed joints by Liquid PenetrantInspection (LPI) methods. The techniques and procedures used shall be in accordance with BS 6443 orASTM E165, except as where modified herein.

4.2 PENETRANT PROCEDURES

A written procedure shall be submitted to the EMPLOYER for approval and shall include the followinginformation:

a) Penetrant inspection materials.

b) Application range of the procedure.

c) Surface preparation.

e.g., the pre-cleaning method, cleaning agent, allowable range of controllable parameters (i.e.temperature range, surface roughness)

d) Application of penetrant.

e.g., the method of application, range of permissible contact times, range of permissible temperaturesfor the component and the penetrant.

e) Removal of penetrant.

e.g., the cleaning agent and method of application, range of permissible temperatures for thecomponent, criteria that define the completion of the operation.

f) Developing:-

e.g., the developer used, method of application, range of permissible development times.

g) Control tests of penetrant inspection materials.

h) Reporting format.

i) Operator qualifications

If required by the EMPLOYER , the procedure shall be qualified on relevant test pieces.

4.3 TECHNIQUES IN GENERAL

4.3.1 Penetrant - Consumables

All LPI materials, including cleaning agents, shall be of the same manufacture and belong to the samegroup.

The halogen content of consumables shall be limited to 1%, except that for examination of austeniticstainless steels, halogen free materials, as certified by the penetrant manufacturer, shall be used.

4.3.2 Approved Techniques

LPI shall be carried out by either the visible or the fluorescent solvent removable penetrant techniques,used in the temperature range 15 - 60oC , or within the temperature range specified by themanufacturer. Any deviation shall require the approval of the EMPLOYER.

4.4 REPORTING

All indications shall be assessed in accordance with the acceptance levels given in the referencingcode. Rejectable indications shall be reported. A retest is permitted, provided that no additional surfacepreparation to that specified in the original test procedure is to be applied. The indications shall not bedressed out by grinding or other abrasive method without the approval of the EMPLOYER. The resultsof LPI shall be recorded and the report shall contain at least the following information:

a) Date and time of inspection

b) Name of Inspection Company.

c) Identification of the workpiece.

d) State if edge or weld; for the latter, the welding process and stage of inspection.

e) Surface conditions.



f) Technique number and essential parameters.

g) The commercial name of the examination medium.

h) Inspectors name and signature.

i) Level of inspectors qualification.

j) The test results.

4.5 CLEANING

Upon completion of the examination, all tested parts shall be thoroughly cleaned to remove all traces ofthe Penetrant inspection material.



5. ALTERNATING CURRENT FIELD MEASUREMENT (ACFM)

5.1 INTRODUCTION

This section highlights the procedural requirements for the use of Alternating Current Field Measurement (ACFM)for the Non Destructive Testing of welds. ACFM can be used for detection and sizing (length & depth) of surfacebreaking cracks in metal structures, components or welds. As a detection tool ACFM can be considered as areplacement for MPI.

5.2 NDT PERSONNEL

Experienced topside operator with a pass certificate from one of the following approved courses:

1. Lloyds Register approved training course for topside operators for the inspection of tubular joints.2. CSWIP (ACFM)3. PCN/GEN/97 App C3B.

For sub-sea operations the diver is not required to be ACFM qualified. The diver should hold CSWIP 3.1U and mustbe briefed by the ACFM operator on probe handling and scanning procedure.

For two man topside operation (e.g. rope access), the probe handler should ideally be experienced in general NDTbut is not required to be ACFM qualified. The ACFM operator must brief the probe handler on probe handling andscanning procedures.

5.3 EQUIPMENT

ACFM is proprietary equipment of TSC Ltd, Milton Keynes, UK. Several models exist, however the most relevant forgeneral NDT purposes in QGPC are as follows:

5.3.1 Topside

The Crack Microguage Model U9b is the latest version of the portable unit. This unit can be battery or mainsoperated. The software QFM version 2.2 should be used with this instrument. This instrument can be used in ACFMand ACPD modes.

The U9a together with QFMv1.1 is also capable of performing ACFM and ACPD measurements.

5.3.2 Sub-Sea

The ACFM Crack Microguage Model U21R is the latest version of the subsea model. This version has beenruggedised to withstand harsh local conditions. The unit should be used with WAMI version 4.4 or later. Thestandard U21R is ACFM only.

The predecessor to the U21, the U11 is capable of performing ACFM and ACPD measurements. The softwarepackages WAMIv3.8 (ACFM) and QPDv1.1 (ACPD) should be used.

5.3.3 Probes

All ACFM / ACPD probes should be approved by manufacturer.

5.3.4 Operational Test Block

ACFM does not require calibration. However the contractor should verify correct system operation using anoperational test block. This usually consists of a flat welded plate with semi-elliptical EDM slots of 50x5mm and20x2mm.

5.4 SURFACE PREPARATION

The use of ACFM does not require the removal of coatings prior to inspection. This includes coatings several mmthick. However smooth probe travel over the surface is required. Anything likely to interfere with probe travel shouldbe removed. This included loose paint and rust.

For subsea applications the removal of hard marine growth is required. This can usually be achieved using a highpressure water jet. It is NOT necessary to clean to bright shiny metal.



5.4.1 Magnetic State

It must be ensured that the surface being inspected is in an unmagnetised state. Remnant magnetisation (e.g. fromprevious MPI inspection) can produce signals that may be mistaken for defect signals. Therefore the procedure forany previous magnetic technique must include demagnetisation of the surface.

5.5 PRACTICAL PROCEDURES

It is essential that a detailed written record be maintained for all ACFM inspection. Failure to do so will severely limitthe usefulness of the electronically stored ACFM scans and will render off-line interpretation difficult. Each datasheet should include the following information

5.5.1 General Information

DateOperators NameProbe Operator’s NameComponent IDProbe IDProbe File

5.5.2 Scan Data

FilenamePage Number (WAMI / QFM)Position on Weld (e.g. Brace toe, Chord toe, Weld Cap)Scan direction (A or C)Clock or tape positionsInspection Summary

5.5.3 Detailed Indication Record

FilenamePage numberPosition on WeldStart of Defect (Tape reference)End of Defect (Tape reference)Length of Defect (mm)Depth of Defect (mm)RemarksSketch of Geometry

5.6 PROBE DEPLOYMENT

A standard weld probe has a scan width of approximately 20mm. The recommended scan speed is 10 to20mm/sec. Where the weld cap is greater than 20mm multiple passes should be made. ACFM requires that theprobe be scanned along a line parallel to the defect. Defects that lie at an angle greater than approximately 25º tothe weld may not be detected. In general defects are constrained to a weld toe and this does not represent aproblem. However if transverse cracking is suspected then procedures for the detection of transverse cracking havebeen developed and should be adopted.

5.7 TEMPERATURE

ACFM is routinely used on live plant at elevated temperatures. Special probes are available for operation attemperatures in excess of 500ºC.

5.8 MATERIALS

ACFM can be used on magnetic and non-magnetic materials. When used on non-magnetic materials, defectdetection and signal interpretation is similar to that for magnetic materials although the display scaling may need tobe adjusted. The ACFM defect sizing routines only apply to carbon steels and the use of ACFM to size defects in



non-magnetic material requires some calibration to be conducted. The equipment manufacturers are able to offeradvice on these aspects.

6. ULTRASONIC EXAMINATION

6.1 INTRODUCTION

This section of the specification covers manual ultrasonic examination (UT) of full penetration buttwelds, structural joints and tubular intersections in thicknesses of 6mm and greater.



The ultrasonic techniques used shall be in accordance with this specification and the appropriateconstruction/fabrication specification.

6.2 NDT PERSONNEL

All ultrasonic operatives shall be qualified in the relevant test category as stated below (for ASNTQualified Personnel this shall be in addition to their qualification) :-

a) Plate.

b) Butt weld (including longitudinal and girth weld seams in tubulars 610mm diameter and above).

c) Pipe welds.

d) Structural T-welds

e) Nozzle welds.

f) Tubular intersections.

They will be required to produce evidence of relevant site experience of at least 6 months in the 12months preceding the date of the assignment.

6.3 EQUIPMENT

6.3.1 Flaw Detector

The A-scan flaw detector shall comply with the requirements of BS 4331 : Part 1 or ASME V, Article 4,Section T- 431.

6.3.2 Calibration Blocks

The following test blocks shall be used by the operatives during the test:-

A2 Block (either type) )

A4 Block ) to BS 2704

A5 Block )

A7 Block ) to BS 2704

Reference Block (see Clause 6.8)

6.3.3 Ultrasonic Probes

All probes shall be marked with a unique probe identification number. The following data shall berecorded for each probe on a separate probe sheet:-

a) Date of issue.

b) Probe manufacturer.

c) Nominal beam angle.

d) Nominal frequency.

e) Toe-in angle (twin crystal probes).

f) Size and shape of crystal.

g) Vertical plane beam profile along the 20dB lines.

h) Results and dates of mandatory probe checks (see Clause 6.4.2).

All ultrasonic probes shall meet the following requirements:-

6.3.3.1 Resolution

All compression and shear wave probes shall have been checked and certified capable of resolving thesmallest step in the resolution block A7 in accordance with BS 3923:Part 1. The steps are said to beresolved when the echoes from the two radii are clearly separated at half maximum echo height orbelow.



6.3.3.2 Overall Gain

All compression wave probes shall have been checked and certified to have at least 50dB of gainremaining with the first echo from the 25mm dimension of the A2 block set to half screen height.

All shear wave probes shall have been checked and certified to have at least 50dB of gain remainingwith the first echo from the 100mm radius of the A2 block set to half screen height.

6.3.3.3 Probe Internal Echoes

All probes shall have been checked as follows:

Compression Wave Probes

At testing ranges above 15mm for twin probes and 30mm for single probes the gain required to bringthe internal probe echoes to 10mm in height shall exceed the setting obtained under Clause 6.3.3.2 byat least 40dB.

Shear Wave Probes

At testing ranges above 5mm for twin probes and 30mm for single probes the gain required to bring theinternal probe echoes to 10mm in height shall exceed the setting obtained under Clause 6.3.3.2 by atleast 40dB.

6.4 PERFORMANCE MONITORING CHECKS ON ULTRASONIC EQUIPMENT

6.4.1 Flaw Detector

The following equipment checks shall be carried out at the intervals specified:-

a) Time base calibration at every change of probes, change of location, after each switching on ofthe instrument.

b) Time base linearity and amplifier gain (BS 4331:Part 1) to be checked after 24 hours of operationor once in a working week, whichever is the shorter period.

6.4.2 Probes

The results and dates of the probe performance tests specified below shall be recorded:-

a) Every working shift or every 8 hours of operation, whichever is shorter:

• probe index (+ 1mm),

• beam angle (+ 2.0o change),

• beam width in vertical plane (+ 2mm),

• beam alignment (squint) (within 5o),

(tests (i) - (iv) carried out to BS 4331 : Part 1).

b) Every working shift:

• resolution,

• overall gain,

• reverberation.

c) Complete beam profile (BS 4331:Part 3) shall be checked and redrawn at least once in a workingweek or whenever a significant change of index, beam angle, squint or width indicates that it maybe required.

Note that all tests shall be carried out with the noise suppression circuitry switched off.

6.5 ULTRASONIC TEST PROCEDURES

6.5.1 Test Procedures in General

Written test procedures, which shall be subject to approval by the EMPLOYER, shall be in accordancewith the requirements of this specification and contain a statement to this effect. They shall be devisedto detect the defects specified by the agreed acceptance criteria, and shall be qualified on testspecimens of relevant geometry in accordance with Clause 6.5.2.

The following information shall be included in the test procedures:-



a) List of equipment to be used.

b) Details of surface preparation and ultrasonic couplant to be used.

c) Individual and numbered technique sheets for each technique specified. The selection oftechniques provided shall be sufficient to cover the examination of all types of welded joints whichare to be covered under the scope of the procedure. The following information shall be given:-

• Parent material and weld material designation

• Material thickness and curvature (range)

• Weld configuration and edge preparation

• Welding process

• Type of probes to be used

• Sketch showing the joint configuration, beam coverage, accessible external surfaces fromwhere the scan shall be conducted, extent of probe scan and examination coverage.

d) Means of setting up the reference and scanning sensitivity levels, including measurement oftransfer correction and the distance amplitude curve.

e) Means of weld marking and fit-up checks for root face location.

f) Scanning patterns to be used.

g) Means of discontinuity location (taking into account the effect of curvature).

h) Flaw reporting levels.

i) Flaw acceptance levels (referencing code).

j) Format of the test report.

6.5.2 Test Procedures - Qualification

The requirement to qualify ultrasonic test procedures applies for the examination of: -

a) Variable geometry welds such as tubular intersection welds and branch to pipe connections.

b) Partial penetration welds and fillet welds.

c) All closing welds.

d) Transitional welds of unequal thickness.

e) Longitudinal and circumferential welds in tubulars where the thickness to diameter ratio exceeds0.03

When required the CONTRACTOR shall submit details of test pieces of relevant geometry anddimensions. The welds shall contain artificial and natural defects relevant to the type and position of thewelding. The qualification tests, which will be witnessed by the EMPLOYER, shall demonstrate that:-

a) The specified weld coverage can be achieved by the techniques proposed in the procedure.

b) All reportable defects can be found at the specified sensitivity.

c) The flaws can be classified and dimensioned to decide their acceptance or rejection inaccordance with the acceptance criteria.

6.6 PREPARATION FOR EXAMINATION

The ultrasonic operative shall make himself thoroughly familiar with the weld edge preparation geometryby reference to the specification and the construction/erection/fabrication and isometric drawings. Priorto ultrasonic weld examination, the operative shall carry out visual inspection of the weld in so far as todetect and note any surface and weld imperfections which would interfere with a meaningful ultrasonicexamination. He shall clearly record any individual areas not covered due to scan limitations, indicatingwhether the obstruction is temporary or permanent.

In order to facilitate weld root location in critical T, K and Y connections and single sided closure welds intubular braces, the member from which the scanning is to be performed shall, prior to the welding of the



root pass, be scribed at a specific surface distance from the root face under the supervision of theEMPLOYER. Joints requiring this reference marking will be identified by the EMPLOYER.

6.7 SENSITIVITY

6.7.1 Scanning Sensitivity

The sensitivity used for the parent material scanning shall be the primary reference sensitivity plus 6dB.

6.7.2 Reference Sensitivity

6.7.2.1 Buried Indications

The reference reflector shall be a 1.6mm diameter side drilled hole at least 22mm long in a calibrationblock which corresponds to the specified thickness range. A distance-amplitude correction curve (DAC)shall be prepared, to cover the beam path lengths between the minimum and maximum range to beused in the test. The thickness of the block and the position of the holes shall be as stipulated in Clause6.8.1. A correction in instrument sensitivity is required to compensate for differences between referencestandard surface roughness, contact area and acoustical attenuation characteristics.

6.7.2.2 Surface Breaking or Near Surface Defects

The reference reflectors shall be API RP 2X V-notches at least 22mm long.

6.8 REFERENCE CALIBRATION BLOCK

6.8.1 Calibration Block

Where examination involves beam path trajectory along the curved cross section of the tested part, thereference block should represent the curvature of the tested part if either the diameter is smaller than500mm or the thickness to diameter ratio exceeds 0.03.

A single curved reference block may be used to examine parts whose curvature is between 0.9 and 1.5times the reference block curvature.

The thickness of the reference block shall be the same as that of the tested part, or as specified inTable 1.

6.9 SCANNING PATTERN

Scanning patterns shall include a separate examination of weld root. Welds shall be examined for bothlongitudinally and transversely orientated flaws. Submerged arc weld metal shall be examined fortransverse (chevron) cracking using a 45o probe positioned on the cap.

The speed of probe movement shall not exceed 100mm/sec.

6.10 DISCONTINUITY LOCATION

Where appropriate, an allowance shall be made for the effect of curvature on beam angle and soundpath distance.

6.11 FLAW SIZE EVALUATION

Flaw size assessment shall be based upon beam boundary intercept methods (6dB and 20dB drops),and maximum amplitude technique, as necessary. Generally the 6dB technique shall be used formeasurement of defect length.

6.12 DEFECT ACCEPTANCE LEVELS

Defect acceptance criteria shall be in accordance with the referencing code, except that no cracks orplanar defects, such as lack of fusion or lack of penetration are allowed.

6.13 REPORTING OF FLAWS

All discontinuity echoes equal to or greater than the 50% reference level shall be located, sized forlength, through thickness dimension (if 3mm or greater) and recorded, giving their maximum amplitudeas a percentage of the reference level.

Reportable flaws shall be classed as follows:-

a) Cracks,



b) Inclusions,

c) Porosity,

d) Planar indications.

If a flaw is found to exceed either the reportable or rejectable acceptance criteria specified, additionalinformation shall be provided to identify all responses from all surfaces used to assess the defect. Whena transverse indication is found in submerged arc weld metal it shall be recorded irrespective of signalamplitude and a second examination shall be performed by the NDT supervisor.

6.14 REPORT FORMAT

The amount of information given on a test report shall be sufficient to reproduce the test conditions andall the relevant test parameters of the original examination.

The information provided shall include:-

a) Weld and welder identification,

b) Type of weld, weld preparation and joint geometry,

c) Material thickness,

d) Technique and procedure number,

e) Referencing code for acceptance criteria,

f) Type of ultrasonic probes and their identification number,

g) Effective probe angles on curved surfaces,

h) Type of flaw detector and couplant used,

i) Time base setting for each probe,

j) Scanning sensitivity, including transfer correction,

k) Calibration block used,

l) Any restrictions or departures from the approved procedure,

m) Sketch of the weld showing the position and dimensions of all reportable flaws,

n) Amplitude of reportable indications for each probe used in the examination.

o) Results of examination.

Prior to being submitted to the EMPLOYER, the ultrasonic reports shall be checked and endorsed bythe NDT supervisor.



7. X RAY AND GAMMA RADIOGRAPHY

7.1 INTRODUCTION

The EMPLOYER will approve the safe working procedures established for the transport, storage anduse of radioisotopes. Copies of certificates of authorisation relevant to the use of radioisotopes shall beprovided by the CONTRACTOR.

This section of the specification covers RT of structural piping, vessel, pipeline butt welds in thethickness range 5 - 50mm. The radiographic techniques used shall be in accordance with BS 2600:Part1, BS 2910 or ASTM E1032 for structural members, except as modified herein .

7.2 RADIOGRAPHIC PROCEDURE

An RT procedure containing the information required in Clauses 7.2.1 and 7.2.2 shall be submitted tothe EMPLOYER for approval, after which the procedure shall be qualified by submitting radiographsproduced by such a procedure for EMPLOYER approval. The details of each qualified radiographicprocedure shall include the complete results of tests and radiographs qualifying the procedure inaccordance with Clause 7.2.3.

7.2.1 Procedure - General

The general part of the procedure shall include the following information:-

a) Scope.

b) Equipment.

c) Density and sensitivity.

d) Intensifying screens.

e) Masks and filters.

f) Film type and format.

g) Type of penetrameter (IQI) and their placing.

h) Limit of film coverage and film overlap.

i) Processing and viewing conditions.

j) Reference code and defect acceptance criteria.

k) Operator qualifications.

l) Format of radiographic report and marking of radiographs.

7.2.2 Procedure Sheets

The detailed part of the procedure shall consist of a number of procedure sheets covering the range ofdiameters and thicknesses to be examined. Each procedure sheet shall cover only one group of theessential parameters shown below; a change in any of these will require a new procedure sheet. Theessential parameters are:-

a) Type of radiation source (X-ray or type of gamma source).

b) Type of film (grade and type of cassette used).

c) Intensifying screen thickness and material.

d) Film shielding and beam collimation.

e) Source dimensions or focal spot size.

f) Tube voltage or type, minimum isotope activity and the corresponding minimum exposure timefor the top of the thickness range.

g) Exposure geometry.

h) Number of exposures per completed weld or maximum length radiographed.

i) Number of penetrameters per film or exposure.

j) Material type (carbon steel, low alloy steel, stainless steel, cupro-nickel, etc..).

k) Material thickness

l) Maximum focal spot size.



m) Minimum film to source distance.

n) Maximum calculated geometrical unsharpness.

o) Typical range of exposure times for any X-ray source.

7.2.3 Qualification of Radiographic Procedure

Each RT procedure shall be qualified by radiographs produced to that procedure. Generally, one (1)radiograph shall be sufficient to qualify a procedure sheet, however, for each pipe size below NPS 2 aspecific qualification shall be required.

The qualification radiographs submitted to the EMPLOYER for approval shall demonstrate that thefollowing criteria have been satisfied:-

a) The required sensitivity with the IQI on the source side (and if required, the film side) can beproduced at the minimum density allowed.

b) The weld length being examined is covered by interpretable film in one or more views.

7.3 TECHNIQUE IN GENERAL

7.3.1 Sources and Techniques

a) Preference shall be given to X-ray equipment. Where the use of X-ray equipment is notpracticable, iridium 192 sources may be used.

b) Preference shall always be given to a single wall technique if this is possible.

c) Preference shall be given to a source inside/film outside technique if this is possible.

d) If a double wall technique is necessary, it shall be with X-ray whenever possible.

e) Where there is a choice between gamma-ray source inside/single wall and X-rays outside/doublewall/single image, the former is preferable.

7.3.2 Screens

Lead intensifying screens shall be used for RT at the thickness indicated below :

Radiation Screen Material Front ScreenThickness (mm)

Back ScreenThickness (mm)

X-ray

< 120 kV Lead None 0.1min..

120kV to 250kV Lead 0.02 to 0.125 0.1min..

250kV to 400kV Lead 0.05 to 0.16 0.1min..

Gamma-ray192Ir Lead 0.02 to 0.16 0.16min..

The amount of back- scattered radiation shall be checked by placing a lead letter 'B' at the back of eachcassette. Fluorometallic screens may be used, subject to the approval of the EMPLOYER. Fluorescentsalt screens shall not be used.

7.3.3 Films

Fine-grain high contrast film shall be used in conjunction with X ray sources. Ultra fine grain highcontrast film shall be used for gamma radiography and may be used with X-ray equipment.

In cases where the film is to be held flat or where the weight of the component is partly or fully taken bythe cassette, rigid metal cassettes shall be used. For curved surfaces, where the film is to be curved,flexible cassettes may be used provided adequate precautions are taken to ensure good film-screencontrast.

Where ready packed film cassettes are used, it is necessary to ensure that the thickness of the packedlead screens is adequate, see Clause 7.3.2. Films packed with lead foil of 0.02mm thickness shall onlybe used if vacuum packed and provided that the material thickness does not exceed 40mm.



7.3.4 Film Identification

Each radiograph shall have suitable symbols affixed to identify the job, the joint and the section of thejoint. Radiographs of weld repairs shall be identified by the letter 'R' followed by the number of times therepair has been attempted, e.g. R1, R2 etc..

7.3.5 Image Quality Indicators (IQI)

a) Type of IQI

Wire type IQI's conforming to BS 3971 or ASTM E747 shall be used with each radiograph. Theminimum sensitivity achieved shall be in accordance with BS 3971.

b) Placement of IQI

Where possible, IQI's shall be placed on the source side of the weld. If the surface of the weld facing theradiation source is inaccessible for placement of an IQI, the procedure outlined in 13.2 of BS 2910 shallbe followed. IQI's shall be placed on the weld at the edge of the area of interest with the wires orientatedtransversely to the fusion line, with the thinnest wire to the outside. The thickness of the material underan IQI shall be within 10% of the maximum thickness under examination. If the thickness range to becovered is large, an appropriate IQI shall be placed on both the maximum and minimum thickness toappear on each radiograph.

c) Number of IQI's

The requirements for structural welds shall be two (2) IQI's, one at each extremity of the area to beinspected or one at the centre of the radiation beam and one at the extremity of the area to beinspected. For panoramic exposures, at least three IQI's shall be used spaced 120o apart. When alength less than 125mm is inspected, only one (1) IQI is required, located at the extremity of the area tobe inspected.

7.3.6 Exposure Geometry

The double wall, single image technique for outside diameters above 24"NPS shall only be used whenno access to the bore surface is possible.

When branches are subjected to RT they shall be radiographed using a multiple single exposuretechnique. Panoramic exposure of branch connections shall not be permitted.

The length of weld under examination at each exposure shall be such that the thickness of the materialat the extremities, measured in the direction of the incident beam, does not exceed, by more than 10%,the actual thickness at that point.

7.3.7 Focus to Film Distance

The minimum values of focus to film distance shall be such that the calculated geometrical unsharpnessshall approach the inherent unsharpness of the film screen combination, but in any case theunsharpness value shall not exceed 0.2mm for X-ray and 0.4mm for gamma ray radiography.

7.3.8 Film Density

The film density over the entire weld length should lie within the range 2.0 to 3.0. Viewing conditionsshall be suitable for viewing films of density upto 3.5.

7.3.9 Film Overlap

The minimum film overlap shall be 20mm

7.4 FILM PROCESSING

Radiographs shall be processed to allow storage of the film without deterioration for the durationspecified in the relevant fabrication specification. The method of demonstrating this shall be identified inthe procedures submitted in Clause 7.2.1.

The radiographs shall be free from imperfection due to processing or other defects which wouldinterfere with satisfactory interpretation.

The radiographic contractor may be required at any time to demonstrate that the film can be processed,using the site facilities, to have a fog level of not more than 0.3.



Radiographs should be stored in individual plastic pockets, in an environment with temperature andrelative humidity controlled to levels recommended by the film manufacturer.

Storage of radiographs in a microfilm form shall not be acceptable.

7.5 FILM STORAGE

All unexposed films shall be stored in a clean dry place where the surrounding conditions will notdetrimentally affect the emulsion. Open packages of film should be stored in a controlled environment ata temperature and relative humidity recommended by the film manufacturer. If there is any concernabout the condition of the unexposed film, the EMPLOYER may request that the sheets from the frontand back of each package (or a 900mm length from the front of each roll) be processed withoutexposure and shall satisfy the above stated fog level.

7.6 INTERPRETATION AND REPORTING

All films shall be interpreted in the dry condition.

Prior to being submitted to the EMPLOYER for final acceptance the radiographs and radiographicreports shall be accepted/rejected by the Radiographic Interpreter and reviewed by theCONTRACTOR's Inspector and endorsed.

The radiographic report shall include the following information:-

a) Procedure number.

b) Radiographic number.

c) Job identification.

d) Date

e) Weld & welder identification

f) Radiographers name & qualifications

g) Interpreters name & qualifications

h) Strength of source

i) Sensitivity.

j) Density.

k) details of screens, technique and film type.

l) Results of examination.

TABLE 1 - REFERENCE BLOCK THICKNESS



MATERIAL THICKNESS CALIBRATION BLOCK 'T' HOLE LOCATION

T <= 25mm 20mm T/2

25 < T <= 50mm 35mm T/4 & T/2

50 < T <= 100mm 75mm T/4 & T/2

es-s-60 rev 4

Documents