dgs-mw-002-rev-1

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Abu Dhabi Oil Refining Company

WELDING, NDE AND PREVENTION OFBRITTLE FRACTURE OF PIPING

DGS-MW-002Rev-1 March 2009

Takreer DGS-MW-002-Rev-1 March-2009 Printed 26-Apr-0908:27:06

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WELDING, NDE AND PREVENTION OF

BRITTLE FRACTURE OF PIPING

Amendment History

01 Nov-08 5578-AMD-MW-002-001BECHTEL Addendum sheet

Pages 34-37

AAS/DDC QAM Mar-09

No Date Amendment Description Proposed Approved Incorporated

DGS History

1 March 2009 DGS-MW-002-Rev-1 5578-AMD-MW-002-001BECHTEL AAS/DDC QAM/ MAY

0 Dec 2008 DGS-MW-002-Rev-0 Welding, NDE and Prevention ofBrittle Fracture of Piping

AAS/DDC ETSDM / EPDM

No Date Description Source Reviewed Approved

DGS-MW-002-Rev-1

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TABLE OF CONTENTS

1.0 GENERAL 4 1.1 INTRODUCTION 4 1.2 PURPOSE 4 1.3 DEFINITIONS 4

2.0 CODES AND STANDARDS 4 3.0 REFERENCE DOCUMENTS 5 4.0 DOCUMENT PRECEDENCE 6 5.0 SPECIFICATION DEVIATION/CONCESSION CONTROL 6 6.0 QUALITY ASSURANCE/QUALITY CONTROL 6

6.1 NONDESTRUCTIVE EXAMINATION (NDE) 6 6.2 CONTROL OF WELDER/OPERATOR QUALITY 8

7.0 DOCUMENTATION 8 7.1 WELDING PROCEDURES 8 7.2 WELD M AP 8 7.3 ELECTRODE STORAGE 9 7.4 POSTWELD HEAT TREATMENT PROCEDURES 9 7.5 NONDESTRUCTIVE EXAMINATION PROCEDURES 9 7.6 WELD REPAIR PROCEDURES 10 7.7 WELDER PERFORMANCE REGISTRATION 10

8.0 SUBCONTRACTORS/VENDORS 10 9.0 HANDLING 10 10.0 MATERIALS - WELDING CONSUMABLES 10

10.1 GENERAL 10 10.2 FILLER M ATERIALS FOR DISSIMILAR METAL JOINTS 11

10.3 AUTOMATIC AND SEMIAUTOMATIC PROCESSES FILLER M ATERIALS 12

10.4 SHIELDED METAL ARC FILLER M ATERIALS 12 11.0 FABRICATION 13

11.1 GENERAL 13 11.2 WELD PROCEDURE AND PERFORMANCE QUALIFICATION 14 11.3 ACCEPTABLE WELDING PROCESSES 14 11.4 WELD JOINT PREPARATION 15 11.5 SHIELDING G ASES 16 11.6 THERMAL TREATMENT 16 11.7 WELD REPAIRS 18 11.8 EXTENT OF NDE 18

12.0 TESTING 19 12.1 PRODUCTION H ARDNESS TESTING 19

12.2 IMPACT TESTING (CHARPY V-NOTCH) 20 12.3 POSITIVE M ATERIAL IDENTIFICATION (PMI) 20 12.4 FERRITE TESTING 20

APPENDIX 1 20 APPENDIX 2 22 APPENDIX 3 23 APPENDIX 4 24 APPENDIX 5 27 ADDENDUM SHEET 35

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List of Authorized Signatures/ Initials

DGS Discipline Committee Member, ADRD ------------------------------

DGS Discipline Committee Member, RRD ------------------------------

DGS Discipline Committee Member Leader, E&PD Alaa Atef Salama (AAS)

Engineering & Technical Services Manager, E&PD Quazi Abdul Matin (QAM)

Engineering & Projects Division Manager, E&PD Mohamed Al Yabhouni (MAY)

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1.0 GENERAL

1.1 INTRODUCTION

This specification defines the welding, thermal treatment, examination, and testing re-quirements for shop and field fabrication of process and utility piping. Limits on minimumdesign temperature and other special requirements to prevent brittle fracture in low tem-perature, liquified gas and toxic services are also included.

1.2 PURPOSE

This specification supplements the codes listed in Section 2.0 of this specification, thepiping specifications, drawings, and the Purchase Order.

1.3 DEFINITIONS

For the purposes of this specification, the following definitions shall apply:

CONCESSION REQUEST — A deviation requested by the SUBCONTRACTOR orVENDOR, usually after receiving the contract package or purchase order. Often, it refersto an authorization to use, repair, recondition, reclaim, or release materials, componentsor equipment already in progress or completely manufactured but which does not meet orcomply with Takreer requirements. A CONCESSION REQUEST is subject to COMPANYapproval.

SHALL — Indicates a mandatory requirement.

SHOULD — The use of the word “should” indicates a strong recommendation to complywith the requirements of this document.

2.0 CODES AND STANDARDS

It shall be the VENDOR’S responsibility to be, or to become, knowledgeable of the re-quirements of the referenced Codes and Standards.

The following codes and standards shall, to the extent specified herein, form a part of thisspecification. The latest edition in force shall apply.

American Society of Mechanical Engineers (ASME)

Boiler and Pressure Vessel Code

Section I Power Boilers

Section II, Part C Welding Rods, Electrodes and Filler Metals

SFA – 5.2 Specification for Carbon and Low Alloy Steel Rods for Oxy Fuel

Gas Welding

Section V Nondestructive Examination

Section IX Welding and Brazing Qualifications

B31.1 Power Piping

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B31.3 Chemical Plant and Petroleum Refinery Piping

American Society of Nondestruct ive Test ing (ASNT)

SNT-TC-1A Recommended Practice for Nondestructive Testing PersonnelQualification and Certification

American Society for Test ing and Materials (ASTM)

A833 Indentation Hardness of Metallic Materials by Comparison Hard-ness Testers

E10 Test Method for Brinell Hardness of Metallic Materials

E92 Test Method for Vickers Hardness of Metallic Materials

E110 Standard Test Method for Indentation Hardness of Metallic Materi-als by Portable Hardness Testers

E140 Standard Hardness Conversion Tables for Metals

American Welding Society (AWS)

A2.4 Standard Symbols for Welding, Brazing, and Nondestructive Ex-amination

A3.0 Standard Welding Terms and Definitions

A4.2 Standard Procedure for Calibrating Magnetic Instruments to Meas-ure the Delta Ferrite Content of Austenitic and Duplex Austenitic-Ferritic Stainless Steel Weld Metal

European Committee For Standardization

EN 10204 Types of Inspection Documents - Metallic Products

International Organization For Standardization (ISO)

ISO 9001 - 2000 Quality Management System Requirements

ISO 9004 - 2000 Quality Management Guidelines for Performance Improvement Sys-tem

ISO 19011 Guidelines for Quality and/or Environmental System Auditing

3.0 REFERENCE DOCUMENTS

The following reference documents, to the extent specified herein, form a part of thisspecification. When an edition date is not indicated for a document, the latest edition inforce at the time of VENDOR’S proposal submittal shall apply.

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DGS-PU-003 Technical Specification for Piping Systems

DGS-MW-004 Materials and Fabrication Requirements for Piping and Equipmentin Severe Service

DGS-MW-006 Positive Material Identification of Equipment and Piping

4.0 DOCUMENT PRECEDENCE

The VENDOR shall notify the CONTRACTOR and the COMPANY of any apparent con-flict between this specification, the related data sheets, the Codes and Standards andany other specifications noted herein. Resolution and/or interpretation precedence shallbe obtained from the CONTRACTOR and the COMPANY in writing before proceedingwith the design/manufacture.

5.0 SPECIFICATION DEVIATION/CONCESSION CONTROL

Any technical deviations to this specification shall be sought by the VENDOR onlythrough CONCESSION REQUEST format. CONCESSION REQUESTS require CON-TRACTOR’S and COMPANY’S review/approval prior to the proposed technical changesbeing implemented. Technical changes implemented prior to COMPANY approval aresubject to rejection.

6.0 QUALITY ASSURANCE/QUALITY CONTROL

VENDOR’S proposed quality system shall fully satisfy all the elements of ISO 9001 -2000 and ISO 9004 - 2000. The quality system shall provide for the planned and sys-tematic control of all quality-related activities performed during design/development, pro-duction, installation or servicing (as appropriate to the given system). Implementation of

the system shall be in accordance with the CONTRACTOR’S Quality Manual and ProjectSpecific Quality Plan, which shall both together with all related/referenced procedures, besubmitted to COMPANY for review, comment and approval as required by pur-chase/contract documents.

6.1 NONDESTRUCTIVE EXAMINATION (NDE)

The minimum extent of NDE shall be in accordance with Paragraph 11.8 of this specifica-tion.

All NDE methods, acceptance criteria, and additional general requirements shall be inaccordance with the following subparagraphs. All NDE shall be performed by personnelcertified in accordance with ASNT Recommended Practice SNT-TC-1A or the VEN-DOR'S own certification program that has been authorized by the CONTRACTOR andthe COMPANY. Interpretation of results shall be performed by personnel certified LevelII or III.

6.1.1 Visual Examination

a. Visual examination procedures shall be in accordance with ASME Section V, Article9.

b. Visual examinations shall be performed on accessible surfaces of all completedwelds.

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c. The evaluation of indications and the acceptance criteria for visual inspection shall

be in accordance with ASME B31.1 or ASME B31.3, whichever is applicable.6.1.2 Magnetic Particle Examination

a. Magnetic particle examination procedures shall be in accordance with the require-ments and methods specified in ASME Section V, Article 7.

b. Magnetic particle examination of welds shall include a band of base metal at least 25mm wide on each side of the weld.

c. The evaluation of indications and the acceptance criteria shall be in accordance with ASME B31.1 or ASME B31.3, whichever is applicable.

d. The magnetic yoke method shall be used.

6.1.3 Liquid Penetrant Examination

a. Liquid penetrant examination procedures shall be in accordance with ASME SectionV, Article 6.

b. Penetrant materials shall meet the requirements of ASME Section V, Article 6 for sul-fur and halogen content regardless of the type of material to be examined.

c. Liquid penetrant examination of welds shall include a band of base metal at least 25mm wide on each side of the weld.

d. The evaluation of indications and the acceptance criteria shall be in accordance with ASME B31.1 or ASME B31.3, whichever is applicable.

6.1.4 Ultrasonic Examination

a. Ultrasonic examination procedures shall be in accordance with the requirements and

methods specified in ASME Section V, Article 5(for materials), Article 4(for welds) or ASME B31.3, whichever is applicable.

b. The evaluation of indications and the acceptance criteria shall be in accordance with ASME B31.3.

c. Ultrasonic Testing may be performed in lieu of Radiographic Testing,subject to theconditions defined in Appendix 5.

6.1.5 Radiographic Examination

a. Radiographic examination procedures shall be in accordance with the requirementsand methods specified in ASME Section V, Article 2.

b. The evaluation of indications and the acceptance criteria of radiographs shall be inaccordance with ASME B31.1 or ASME B31.3, whichever is applicable.

6.1.6 The final non-destructive testing of welds for acceptance purposes shall be carried outafter completion of any PWHT, if applicable. If the VENDOR prefers to check weld qual-ity,of welds in P1 material, before PWHT by radiography, the results of this radiographyand an ultrasonic examination after PWHT can be substituted for radiography subject toCOMPANY approval.

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6.2 CONTROL OF WELDER/OPERATOR QUALITY

When progressive examination in accordance with ASME B31.3, Paragraph 341.3.4(Progressive Examination) is required, then the following additional requirements shallapply.

If any of the items examined in accordance with Paragraph 341.3.4 (c) reveals a defect,then the welder or welding operator shall be considered unacceptable for any furtherwelding to that Welding Procedure Specification (WPS) with respect to the CONTRAC-TOR’S work done to this Specification without requalification and the agreement of theCONTRACTOR and the COMPANY.

Timing is essential for the control of welder or operator quality; therefore, the progressiveexaminations required by Paragraph 341.3.4 shall be completed within 16 working hoursof the first rejection, unless otherwise agreed to by the CONTRACTOR and the COM-PANY.

Welders shall not be permitted to weld production joints of any type while waiting for re-sults of qualification.

7.0 DOCUMENTATION

7.1 WELDING PROCEDURES

Welding Procedure Specifications (ASME Form QW-482 or equivalent) and ProcedureQualification Records (ASME Form QW-483 or equivalent) shall be submitted to theCONTRACTOR prior to the start of fabrication. Welding shall not proceed until thesedocuments are returned to the VENDOR with authorization to proceed.

All Welding Procedure Specifications (WPS) and Procedure Qualification Records (PQR)for purchased items subcontracted by the prime VENDOR shall be reviewed by the prime

VENDOR for content and contract compliance prior to submittal to the CONTRACTOR.

7.2 WELD M AP

The VENDOR shall submit a detailed weld map or welding procedure summary detailingthe application of individual welding procedures with regards to types of joints and pipingmaterial line classes to the CONTRACTOR at the time of WPS/PQR submittal. Fabrica-tion shall not start until the weld map or summary is returned with instruction to proceed.Welding symbols shall be in accordance with AWS A2.4. The weld map or summaryshall contain, as a minimum, the following information:

• WPS to be used for each type of joint of same design and similar thickness. Forexample, large diameter buttweld, small diameter buttweld, branch connection (set-in, set-on, or integrally reinforced), fillet weld (pressure retaining or non-pressure at-

tachments), socketweld, etc.• Minimum Design Temperature and whether impact-tested WPS is/are required.

• Actual range of joint thickness where each WPS is to be used.

• Preheat temperature to be applied to each type of joint.

• PWHT if required and reason (Process or Code).

• Filler metal to be used for each WPS.

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7.3 ELECTRODE STORAGE

The VENDOR shall submit his procedure for the storage and handling of electrodes, fillermetals and fluxes to the CONTRACTOR for review prior to the start of fabrication. Theprocedure shall include moisture, cleanliness and identification controls, (i.e. materialtraceability).

7.4 POSTWELD HEAT TREATMENT PROCEDURES

PWHT procedures shall be submitted to the CONTRACTOR and authorized prior to use.Postweld heat treatment procedures shall include support types, number and locations;thermocouple types, number, method of attachment, locations and calibration method;heating and cooling methods, heating and cooling rates and holding temperature, holdingtime and furnace atmosphere.

7.5 NONDESTRUCTIVE EXAMINATION PROCEDURES

Nondestructive Examination (NDE) procedures and a NDE map shall be submitted to theCONTRACTOR. Examination shall not proceed until authorized by the CONTRACTOR.The NDE map or drawing(s) shall show each procedure to be utilized. In the case ofsimple components and piping, a NDE procedure utilization summary is acceptable inlieu of the NDE map. In addition, all other records pertaining to inspection and certifica-tion shall be available for review by the CONTRACTOR'S Inspector. The minimum in-formation to be listed in NDE procedures is as follows:

7.5.1 Magnetic Particle (MT)

Scope; surface preparation; areas to be examined; stage(s) at which examined (i.e. afterwelding, after heat treatment, after hydrotest, etc.); magnetizing technique (e.g. ACYoke); demagnetizing technique equipment used; magnetic ink trade name; frequency ofcalibration of equipment and test of bath strength; coverage and direction of magneticfield; measurement of field strength; application of examination media; acceptance level;reporting format; operator qualifications.

7.5.2 Liquid Penetrant (PT)

Scope; surface preparation; cleaning and drying; temperature limitations; penetrant appli-cation method and time; removal of excess penetrant; drying; application of developer;development time; acceptance level; reporting format; operator qualification; stage per-formed.

7.5.3 Radiography (RT)

Scope; source type (e.g. X-ray, IR912, etc.); material type; material thickness; pipe di-ameter for pipe components; maximum KV of X-ray source; maximum focal spot size;minimum film to source distance; exposure time; sketch of component and source; filmand penetrameter placement for components other than simple shape; intensifyingscreens type and thickness; image quality indicator type and pattern; technique (e.g.double wall single image, etc.); sensitivity; film density; viewing conditions for high den-sity; back scatter checks/protection; marking and identification of radiographs; film over-lap; film storage; acceptance criteria; reporting format; operator qualifications; stage per-formed.

7.5.4 Ultrasonic (UT)

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Scope; equipment; probe type and details; surface preparation, cleaning and couplant;

technique sheet for each technique specified (number of techniques to be sufficient tocover all type of joints to be covered by the procedures scope); material; weld material (ifdifferent); sketch showing joint configuration, beam coverage; extent of scan; scanningpattern; material thickness and curvature; calibrations and frequency; means of settingand scanning sensitivity levels and DAC curves; flaw location and size evaluation; accep-tance criteria; reporting format; operator qualifications.

7.6 WELD REPAIR PROCEDURES

Weld repair procedures shall be submitted to the CONTRACTOR prior to equipment re-pair. The procedure shall state, as a minimum, the following information:

• Means of excavating defect from weld.

• NDE method used to verify complete defect removal.

• WPS used to fill excavated area.

• NDE method used to verify repair weld is sound.

• Other required tests (PMI, Ferrite Tests, Hardness, etc.).

• PWHT procedure, if applicable.

7.7 WELDER PERFORMANCE REGISTRATION

In order to maintain the validation of performance qualification, a welder performanceregister should be kept up to date. This register should at least contain the followingdata:

• Welder's name and stamp

• Date of weld inspection and inspection results

• Materials (base and consumable)

• Configuration data (diameter, wall thickness, etc.)

• Reference to WPS used

• Heat treatment, if any

• All other essential variables

8.0 SUBCONTRACTORS/VENDORS

(Not Applicable.)

9.0 HANDLING

(Not Applicable.)

10.0 MATERIALS - WELDING CONSUMABLES

10.1 GENERAL

Filler metal shall be as specified in ASME Section II, Part C. AWS specification fillermetal is acceptable.

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• Where PWHT of the joint is required, the ferritic material (P-No.1 through P-

No.7) shall be buttered with either ASME Classification E/ER 309L or highnickel filler metal and PWHT prior to welding to the austenitic stainless steel.Such joints shall be qualified in accordance with ASME Section IX, QW-283.

d. For dissimilar joints in base metals consisting of an austenitic stainless on one sideand a nickel-chrome on the other, the filler metal shall be ENiCrFe-2 or ERNiCr-3for high temperature applications (above 315°C). ENiCrMo-3, ENiCrFe-2 or ER-NiCrMo-3 shall be used for low temperature (up to and including 315°C) applica-tions.

e. High nickel filler metal shall not be used in services that contain sulfur compoundsat service temperatures greater than 370°C unless specific authorization is obtainedfrom the CONTRACTOR and the COMPANY.

f. High nickel filler metal shall not be used in hot hydrogen service (above 500°C andhydrogen partial pressure above 150 kg/cm2).

g. For dissimilar joints in base metals consisting of carbon steel or low alloy steels (P-No. 1 through P-No. 7) on one side and Alloy-400 (P-No. 42) on the other, the fillermetal shall be ENiCu-7 or ERNiCu-7.

10.3 AUTOMATIC AND SEMIAUTOMATIC PROCESSES FILLER M ATERIALS

Solid wires for automatic welding processes shall contain the principal elements requiredfor the deposited weld metal. Welds deposited by the submerged arc process shall notderive any principal elements from the flux.

Fluxes that the flux Manufacturer recommends for single pass welds shall not be used formultiple pass welds. Active fluxes are not permitted.

Filler wires in specification ASME SFA-5.2 shall not be used for welding with gas tung-sten-arc process.

Submerged arc flux shall be clearly identified in moisture-proof containers and shall bestored in a dry location at a temperature above 20°C. Submerged arc, gas metal arc andflux-cored wire shall be clearly identified and shall be stored in a dry location at a tem-perature above 20°C. The identification shall state manufacturer, grade and batch num-ber. Unidentifiable wire shall not be used.

Submerged arc, gas metal arc and flux-cored arc consumables shall be withdrawn fromstorage only when required for immediate use. Unused consumables shall be returned tostorage on completion of the welding operation. Batch numbers shall be recorded on is-sue. After issue from storage, flux shall be held in a heated silo at 70°C.

Submerged arc flux may be recycled but shall be free from fused flux, millscale, dirt orother foreign matter. Before reuse, the flux shall be rebaked in accordance with theMANUFACTURER'S instructions. Wet flux shall be discarded.

Submerged arc welding of production parts shall be performed using same name brandand grade of flux and the same name brand and grade of wire as used for the PQR.

10.4 SHIELDED METAL ARC FILLER M ATERIALS

When using the shielded metal arc welding process, low hydrogen electrodes shall beused for all pressure retaining welds or attachments to pressure boundaries. For carbon

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steel piping welded from one side only, E6010 may be used for the root pass. Electrodes

of the following ASME Classifications are not acceptable for pressure retaining welds:E6012, E6013, E6020, E7014, E7020, E7024, and E7028.

Low carbon steel and 0.3-0.5% Mo low hydrogen electrodes shall be used within 8 hourswhen stored in quivers. Low hydrogen Cr-Mo steel electrodes shall be used within fourhours when stored in quivers. Electrodes stored in quivers, but not used within the speci-fied time, shall be restored in ovens. No electrodes shall be left lying about the site or inthe shop. Electrodes so left shall be scrapped.

Fine-grained low-carbon-manganese steels shall be welded with basic low-hydrogen typeof electrodes. The electrode deposits shall have the minimum specified yield strengthand the required minimum toughness properties at least equal to those of the base mate-rial.

11.0 FABRICATION

11.1 GENERAL

Fabrication to this specification shall conform to the requirements of ASME B31.1 orB31.3. Compliance with this specification and authorization of WPS, PQR and weld mapshall in no way relieve the VENDOR of the responsibility of providing welds which aresound and suited to the services for which they are intended.

Welding terms and definitions shall be in accordance with the AWS A3.0.

Tack welds shall be made by qualified welders and with the same ASME Classificationconsumable that is used for the root pass.

Peening is only permitted to the extent necessary to clean slag from the weld.

All fillet (including slip-on flanges and non-pressure attachments) and socket welds shall

be two (2) pass minimum unless otherwise agreed to by the CONTRACTOR and theCOMPANY.

Piping requiring special cleaning and all piping 2 inch and smaller, shall have the rootpass of open butt welds deposited with the gas tungsten arc process. The backside ofthe root pass shall be purged with inert gas.

For piping welds on P-5A material and higher, the root pass shall be made with theGTAW process and an inert back purging gas. The back purge shall be maintained untilat least 6 mm thickness of weld metal has been deposited or the weld joint is filled,whichever is less.

Open-root welds, made with low hydrogen electrodes or GMAW (Spray or GlobularTransfer) require backgouging and rewelding.

Temporary attachments, backing rings or bars intended to be removed after weld comple-tion shall essentially match the chemical analysis of the base metal.

Contamination of austenitic stainless steel and nickel alloys by zinc and other low meltingpoint metals shall be avoided. Galvanized structural components such as vessel clipsand pipe attachments shall not be welded directly to stainless steel. Direct contact be-tween galvanized structural components and stainless or chrome alloy steel shall be al-

lowed only when metal temperatures are less than 370°C.

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The clip portion of any support that is attached directly to stainless steel should be

stainless steel with provision for bolting or clamping to the galvanized structure. If carbonsteel is used for the clip it shall not be galvanized; it shall be painted with a zinc rich paint

after welding, provided metal temperatures are less than 370°C.

Any attachment or support welded directly to carbon steel piping, vessels or equipmentshall be either stripped back after galvanizing for a distance of 50 mm from the weld orshall not be galvanized. The completed weld and uncoated surface shall be painted withzinc rich paint.

No welding shall be carried out when the parts to be welded are wet or during periods ofhigh wind (greater than 8 km/hr), unless the welder and the work are properly protected.

11.2 WELD PROCEDURE AND PERFORMANCE QUALIFICATION

WPS, PQR, and Welding Operator/Performance Qualification shall conform to the re-

quirements of ASME Section IX and to the requirements of this specification.

Welds that are deposited by procedures differing from those authorized by the CON-TRACTOR may be subjected to complete removal at VENDOR'S expense.

For double welded butt joints (joints welded on both sides), the WPS shall specify VEN-DOR’S standard inspection procedure used to assure metal soundness after gouging andcleaning the backside of the weld.

Welding procedure qualification hardness testing for piping in SEVERE SERVICE shallbe in accordance with Project Specification DGS-MW-004.

Welding procedure qualification hardness testing for P-No. 3 through P-No.6 materialsshall be required for all welding processes. Tests shall be conducted in the weld metaland heat affected zone by either the Brinell or Vickers method in accordance with ASTM

E10 or ASTM E92 as applicable. The average of three readings in each area shall be re-ported. Hardness results shall not exceed 225 HB for P-No. 3 and P-No. 4 materials and241 HB for P-No. 5 and P-No. 6 materials. Vickers numbers shall be converted to Brinellin accordance with ASTM E140.

11.3 ACCEPTABLE WELDING PROCESSES

Welding Process AWS Letter Designation

Shielded Metal-Arc Welding SMAW

Gas Tungsten-Arc Welding GTAW

Automatic Submerged Arc Welding SAW

Gas Metal Arc Welding(Spray or Pulsed Arc Transfer)

GMAW

Other welding processes, such as Gas Metal Arc Welding - Short Circuit Transfer,(GMAW-S), Manual Submerged Arc Welding, and Flux Cored Arc Welding require spe-cific written authorization from the CONTRACTOR. Submit all pertinent data, previousexperience and intended application of said process for evaluation. Application of theseprocesses shall not be assumed acceptable by the VENDOR during bid preparation.

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If GMAW-S process is authorized for a particular application it will be limited to (other limi-

tations may be applied):a. Carbon steel only.

b. 0.9 mm minimum wire diameter.

c. 19.5 volts minimum.

d. Root pass and weldout through 10 mm wall thickness. Root pass only on wall thick-ness greater than 10 mm.

e. Root passes can be made in any direction, but fill and cap passes shall not bemade in the downhill direction below the two o'clock position.

f. The first five welds of every welder, evenly spread over diameters, wall thickness,materials, positions, weld preparations, etc. shall be 100% inspected by RT or UT.

With good results and previous experience, the normal rate of inspection can be re-sumed.

If FCAW process is authorized for a particular application it will be limited to (other limita-tions may be applied):

a. Carbon steel only.

b. Gas shielding is required.

c. On open butt joints, weld-out only. Not acceptable for open groove joint rootpasses.

For wall thickness greater than 10 mm and in the down hand position, the filling and cap-ping can be performed by the spray arc metal transfer mode, with either solid or FCAW.Welding shall be carried out in a protected environment (building, tent, etc.).

If electrical resistance welding (ERW) or friction welding (FRW) is authorized with ownerapproval, it will be limited to base metals meeting the following impurity restrictions:

- 0.006% maximum Sulfur

- 0.020% maximum Phosphorus

11.4 WELD JOINT PREPARATION

Weld joint preparation shall be made by machining, grinding, or thermal cutting. Whenthermal cutting is performed, the joint surfaces shall be mechanically cleaned to soundmetal prior to welding by removal of a minimum of 2 mm metal. Oxy-fuel thermal cuttingshall not be used on P-No. 6 and higher base materials.

Double welded butt joints are preferred and shall be implemented wherever the size ofthe pipe or plate cylinder makes it practical. Permanent backing strips may not be used.If temporary backup rings are used and then removed, the weld area shall be dressedand examined for cracks and other defects. Examination of the weld surface shall beperformed visually and by magnetic particle or liquid penetrant method in accordancewith Paragraph 6.1 of this specification, whichever is applicable. Unacceptable defectsshall be removed and repaired. Consumable root inserts may be used with prior agree-ment from the CONTRACTOR and the COMPANY When consumable root inserts areused, the chemistry of the insert shall match the material to be joined. Care shall be

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taken in positioning and use of consumable inserts to assure complete consumption of

insert.For butt welding of all piping components, pipe ends, fittings and welding neck flanges, auniform root opening, as specified below, is required.

• 1.5 mm for pipe diameters < 50 mm

• 1.5 - 2.5 mm for pipe diameters 50 mm to 250 mm

• 2.5 - 3.5 mm for pipe diameters > 250 mm

Surfaces to be welded shall be clean and free from paint, oil, dirt, scale, oxides, and otherforeign material detrimental to the integrity of the weld for a distance of 25 mm beyondthe substrate surface actually touched by the arc.

Cleanliness shall be maintained during fabrication welding. All stubs, rods, flux, slag, and

other foreign material shall be removed from inside and outside the pipe.Grinding wheels and austenitic stainless steel wire brushes to be used on austenitic orother higher nickel and nonferrous alloys shall not have been previously used on ferrousmaterials, copper alloys, aluminum or zinc coatings (paint or galvanizing).

Grinding of titanium or zirconium shall be done with carborundum or corund grindingwheels with an oil coolant.

11.5 SHIELDING G ASES

Shielding Gases for GTAW

• No oxidizing elements are permitted in GTAW shielding gas.

• For welding of reactive metals, e.g. Ti, Ta and Zr, the application of extreme pure

inert gases such as Ar (99.996% vol) or He (99.996% vol) with a dew point of -59°Cor lower is required.

• Gas compositions for materials susceptible to hydrogen embrittlement and/or hy-drogen porosity, e.g. low/medium alloyed steels, martensitic stainless steels, Al and Al alloys and Cu and Cu alloys, shall be limited to Ar, He or a mixture thereof.

Shielding Gases for GMAW

• The filler wires used should be compatible with the type of gas. In case of activegases, e.g. CO2, de-oxidizing elements shall be present in the filler wire.

• Shielding gas for low-carbon grades of stainless steel shall contain 3% or less CO2.

• Shielding gas for nickel alloys shall be argon or a mixture of argon and 5-10% hy-

drogen.There shall be no hydrogen in the shielding gas for stainless steels.

11.6 THERMAL TREATMENT

11.6.1 Preheat

Preheat temperatures for thermal cutting, gouging, tack welding and welding shall be asspecified in Appendix 1 of this specification or the applicable ASME Code (ASME B31.1or B31.3), whichever is more restrictive. When the required preheat temperature is

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150°C or higher, the metal temperature shall be maintained at preheat temperature until

the weld is completed.The following requirements shall be adhered to for the preheating zone:

• The minimum width of the heated zone shall be 2t (t = wall thickness) or 100 mmwhichever is greater.

• Special attention shall be paid to the extent of heated bands in order not to aggra-vate the problems related to residual stress distribution, such as cracking, bucklingand distortion.

For preheat temperatures above 200°C (regardless of thickness) or material of wall thick-ness greater than 25 mm with preheat temperature at or above 80°C, preheating shall bedone by electric resistance or induction heating.

Low alloy steels (P-No.3 through P-No.6) shall be PWHT’d immediately after completionof welding (before the weld is allowed to cool below preheat temperature).

11.6.2 Interpass Temperature Limits

Maximum interpass temperature limits shall be specified for stainless steel and non- fer-rous materials on the WPS. The maximum interpass temperature for austenitic stainlesssteel and high nickel alloys shall be 150°C and for Alloy 20 (UNS N08020) shall be 93°C.

11.6.3 Postweld Heat Treatment

Postweld Heat Treatment (PWHT) time and temperature shall be in accordance with Ap-pendix 1 of this specification or the applicable ASME Code (ASME B31.1 or B31.3),whichever is more restrictive. The operation of PWHT shall be in accordance with ASMEB31.1 or B31.3 (as applicable).

If PWHT is executed in the field, the minimum heating band shall be5 D T

and the mini-mum insulation width shall be 1 0 D T where D = inside diameter in mm and T = wallthickness in mm.

PWHT for process shall be performed when required by Project SpecificationDGS-PU-003, Line Class Index.

PWHT for piping subject to special service conditions shall be noted on the CONTRAC-TOR'S isometric drawings.

PWHT requirements for piping in severe service shall be in accordance with ProjectSpecification DGS-MW-004.

PWHT of P-No.1 through P-No.6 materials shall be accomplished after all lugs or attach-ment welds are complete.

A maximum of two complete PWHT cycles is permitted for each weld. Further PWHT cy-cles shall not be carried out without the authorization of the CONTRACTOR and theCOMPANY.

Low alloy steels (P-No. 3 through P-No. 6) shall be cooled from PWHT temperature to260°F under insulation.

Thermocouples shall beattached by capacitance disharge welding(heat input less than25W-s) or mechanically bonded to the pressure boundary. All thermocouple attachments

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shall be adequately insulated to avoid temperature misreading caused by the effect of ra-

diation.For locally heat treated piping, the minimum number of thermocouples to be used is asfollows:

• 1 for pipe diameters < 40 mm

• 2 for pipe diameters from 40 to 250 mm

• 3 for pipe diameters > 250 mm

Temperature shall be continuously recorded. A chart of the heatup, soak and cooldownwhile at temperature above 260°C is required. Temperature shall be recorded at regulartime intervals and shall be clearly indicated.

Thread and gasket surfaces shall be suitably protected from excessive oxidation during

heat treatment.

11.7 WELD REPAIRS

Unacceptable discontinuities shall be completely removed by chipping, gouging, grinding,or other methods (for the type of material being repaired) to clean, sound metal, and theexcavated area shall be examined by magnetic particle (preferred for ferrous materials)or liquid penetrant methods to assure complete removal of defects.

Repairs to correct weld defects shall be made using the same WPS used for the originalweld or other previously authorized WPS.

The repaired areas shall be re-examined using the same examination method and pro-cedure by which the defect was originally detected.

Two repair attempts will be allowed on any one defective area. No further attempts to re-pair shall be carried out without the authorization of the CONTRACTOR.

Cast Iron Repairs

a. Cold repair welding with high Nickel consumables is allowed only for castings innoncorrosive service. A preheat and interpass temperature of 150-200°C must beused to level off temperature gradient stresses. Heat input used shall be as low aspossible. Shrinkage stresses shall be minimized by suitable selection of the weld-ing sequence.

b. Hot repair welding with carbon steel consumables must be applied for castings incorrosive service and when repairs over large areas are required. Preheating shallbe maintained during welding. Under no circumstances shall the temperature dropbelow 400°C. After welding, the temperature shall be maintained for 1 hour fol-

lowed by slow cooling in an insulating firebrick or refractory blanket. The coolingrate shall not exceed 50°C per hour. For corrosive service, a PWHT at 580-620°Cmust be applied. For Ni-resist, a low-hydrogen consumable with a matching com-position shall be used. Preheat for Ni-resist material shall be 450-600°C.

11.8 EXTENT OF NDE

The minimum extent of NDE shall be in accordance with Appendix 3 and ASME B31.1 orB31.3, whichever is applicable.

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For jacketed piping, 10% of the circumferential and 100% of the longitudinal welds shall

be examined by radiography.The evaluation of indications and the acceptance criteria shall be in accordance withParagraph 6.1 of this specification.

When using the GMAW or the SMAW process for socket weld piping, the first five weldsof every welder shall be 100% inspected visually and by either MT or PT examination.

12.0 TESTING

12.1 PRODUCTION H ARDNESS TESTING

Personnel performing hardness testing shall be familiar with all hardness testing proce-dures and test methods.

Procedures and test methods used for portable hardness testing shall be in accordance

with ASTM A833 or ASTM E110 as applicable. A hardness test shall consist of three hardness readings in the deposited weld metal.The average of these three readings shall be reported as the test result.

Hardness tests shall be performed on the side exposed to the process fluid when possi-ble.

Hardness testing results shall be expressed in Brinell numbers. The hardness reportshall indicate actual hardness reading for the test method used plus Brinell conversion.The use of methods other than portable Brinell tester require CONTRACTOR approval.Conversion shall be in accordance with ASTM E140.

Hardness tests shall be performed after PWHT when PWHT is required.

The hardness test report shall indicate type of hardness tester, personnel conducting

hardness tests, type of material, and last calibration date.The COMPANY representative(s) may witness the performance of production hardnesstesting. The documented test results shall be submitted to the CONTRACTOR when re-quested.

Production hardness testing for piping in severe service shall be in accordance withSpecification DGS-MW-004.

Production hardness testing is not required for carbon steel piping in utility service (lowpressure steam at 5 kg/cm2 maximum, water or air).

For piping in general service, production hardness tests are required as follows:

• For P-No.1 materials, hardness testing is required where automatic or semiauto-matic welding processes are used. One test from each butt weld is required.

Hardness results shall not exceed 200 HB.

• For P-No.3 through P-No.6 materials, hardness testing shall be conducted on 10%of welds in each furnace heat treated batch and 100% of those which are locallyheat treated. Hardness results shall not exceed 225 HB for P-No.3 and P-No.4 ma-terials and 241 HB for P-No.5 and P-No.6 materials.

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12.2 IMPACT TESTING (CHARPY V-NOTCH)

Welding procedure qualification and production Charpy V-Notch impact tests shall be per-formed when required by and in accordance with Appendix 4 of this specification and/orthe appropriate ASME piping code.

All welds in austenitic stainless steels shall be qualified by impact testing at the colder of -196°C and the MDT.Impact test procedures and acceptance criteria shall be as designcode.This requirement for impact testing of austenitic stainless will limit the tractabilitycontrols requirments.

12.3 POSITIVE M ATERIAL IDENTIFICATION (PMI)

PMI testing shall be performed when required by and in accordance with SpecificationDGS-MW-006.

12.4 FERRITE TESTING

Ferrite testing shall be performed on equipment manufactured from solid austeniticstainless steel. The Ferrite Number (FN) shall be between 3-10 FN as determine by amagnetic instrument such as a Severn Gauge or Ferrite Scope calibrated in accordancewith AWS A4.2, or calculated using the Welding Resource Council (WRC) 1992 FerriteDiagram. Documentation of test results shall be available for review by the CONTRAC-TOR.

APPENDIX 1

PREHEAT AND PWHT TEMPERATURES

PREHEAT INTERMEDIATE FINAL PWHT PWHT(7)

MATERIAL

WallThick-ness(mm)

MinimumTemp.

(°C)(NOTE 2)

WallThick-ness(mm)

Required WallThickness

(mm)

Tempera-ture

Range

(°C)

HoldingTime

(Minutes/mmThickness)

Carbon and Car-bon-

≤ 25 20(5) All No ≤ 19

Manganese Steels >25 80 (5) > 19 593-649 2.5(3)

Low Nickel All 100-150 All No≤ 19

Alloy Steels > 19 593-635 2.5(3)

0.3 - 0.5 Mo≤ 20 20 All No All 593-660 2.5(3)Steel > 20 100-150

1 Cr - 1/2 Mo, All 150 All Yes (6) All 704-746 2.5(4)1 1/4 Cr - 1/2 Mo (Note 8)

2-1/4 Cr - 1 Mo All 200 All Yes (6) All 704-746 5(4)

(Note 8)

5 Cr - 1/2 Mo, All 200-250 All Yes (6) All 720-760 5(4)9 Cr - 1 Mo (Note 8)

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3.5 Ni All 93 All No ≥ 16 593-635 2.5

12-17 Cr All 200-300 All No All 700-790 2.5Martensitic Steels

NOTES:

1. Deleted

2. If ambient temperature is below 5°C, preheat to 40°C is recommended.

3. Minimum holding time one hour.

4. Minimum holding time two hours

5. 100°C minimum if UTS is greater than 450 N/mm.

6. Unless PWHT is performed immediately after welding, an intermediate PWHT is required. In-

termediate PWHT time and temperature shall be in accordance with Appendix 2. This must beauthorized by the CONTRACTOR and the COMPANY.

7. PWHT for process (service) may require special application. When applicable, these require-ments will be noted in Project Specification DGS-MW-004, DGS-PU-003, or piping drawings.

8 PWHT temperature shall be at least 20°C below the actual tempering temperature

of the material.

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APPENDIX 2

INTERMEDIATE PWHT HOLDING TIMES (HOURS)

HOLDING TEMPERATURE

Thickness (mm) 150°C 200°C 250°C 300°C

10-20 1.5 1 1 0.5

20-30 6 3 2 1.5

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APPENDIX 3

INSPECTION LEVELS IN %

Material Service ASME

Class

Radiography(2) (3) (4) (5)

MT(6)

LiquidPene-trant

CarbonSteelincluding

Utility:Utility:

150300/600

510

0.3 Mo and0.5 Mo

Process: Liquid Gas,Hydrogen Services (1)

All ratings 100 10

Process: Toxic Service All ratings 100 100

Process: All Other Services 150 - 600 10

> 900 100 10Buttwelds on Piping Spools re-quiring Impact Testing (7)

All ratings 100 10

Ferritic AlloySteel notIncluding0.3 Mo and0.5 Mo Steel

All Services All ratings 100 100

Austenitic AlloySteel

Process: Liquid Gas,Hydrogen Services (1)Toxic Service

All ratings 100 100

All Other Services 150 5 5

300 10 10

> 600 100 100DissimilarMetalWeldments

All Services All Ratings 100 100

NOTES:

1. Partial hydrogen pressure ≥ 7 kg/cm2.

2. Ultrasonic examination may be applied if the configuration precludes radiography.

3. The indicated percentage of welds to be radiographed shall apply to all welders involved.

4. Small bore nipples to be included.

5. The following film qualities shall be applied.

- For X-ray-fine grain may be used, e.g., Agfa D4, Kodak Industries MX.- For J-ray ultra-fine grain film shall be used, e.g., Agfa D4, Kodak Industries MX.

6. MT - Magnetic Particle Inspection.

7. Refer to Appendix 4. Para. A4-8.0

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APPENDIX 4

ADDED REQUIREMENTS FOR LOW TEMPERATURE,LIQUIFIED GAS AND TOXIC SERVICES

A4-1.0 SCOPE

This Appendix gives the minimum added requirements to prevent brittle fracture of pipingwhich operates at, or may be exposed to, low temperatures. These requirements includepossible impact testing of materials, limits on materials selection and added welding,nondestructive evaluation (NDE) and postweld heat treating details. In this Appendix, low

temperature is defined as below 15°C; however, piping operating at 15°C and above maybe required to meet impact test requirements if required by the applicable design code.

This Appendix also gives added requirements for toxic, liquified gas and H 2S-containing

services to provide improved resistance to brittle fracture. These services may also haveother material requirements which are given in other project specifications or the equip-ment data sheets to avoid other cracking or corrosion mechanisms.

Ferritic and austenitic steels, and copper and nickel alloys are within the scope of thisdocument. Both base metals and weldments are included. All Duplex stainless steels

(except exchanger tubes) shall be impact tested at -50°C for material quality reasonsrather than brittle fracture resistance. Hence, Duplex stainless steels are not included inthe scope of this document.

A4-2.0 DEFINITIONS

PIPING — Shall mean any piping, fittings, valves, in-line instruments or part thereof un-der internal pressure. Transmission pipelines are excluded from this Attachment.

TOXIC SERVICES — In this Attachment, are those which are single exposure of a verysmall quantity, is dangerous to life on breathing or bodily contact even if prompt restora-tive measures are taken. Examples are hydrofluoric acid, chlorine and streams contain-ing greater than 3000 ppm of H2S. Approval of COMPANY or CONTRACTOR is requiredbefore deeming other services to be “Toxic.”

LIQUIFIED GAS — Shall mean a product which is gaseous at ambient temperature andatmospheric pressure, and is maintained in a liquid state by means of pressure or coolingor a combination of the two.

MINIMUM DESIGN TEMPERATURE (MDT) — Shall be the lowest temperature that theequipment shall be permitted to attain while under pressure (during normal operation,starting up, shutting down or pressure testing).

AUTOREFRIGERATION — Is the temperature drop often accompanied by icing that oc-curs as liquified gas is depressurized. The depressurizing can occur due to a crack orflange leak (which leak to atmosphere) or a valve which leaks through the seats.

MICROALLOYED STEELS — In this Appendix, are carbon steels containing a deliberateaddition of greater than 0.01% columbium, 0.01% vanadium, 0.01% titanium or 0.0005%boron.

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A4-3.0 TOUGHNESS TESTING REQUIREMENTS

Impact testing requirements of carbon and low alloy steels shall be determined using ASME B31.3. Minimum design temperature shall be determined in accordance with Sec-tion A4-4.0 of this Appendix, and shall be used in evaluating the testing requirements.

Austenitic stainless steels, copper alloys and nickel alloys do not require impact testingunless otherwise noted on the piping drawing or if required by ASME B31.3.

For bolting materials, the minimum MDT which can be used without impact testing shallbe as indicated in ASME B31.3, Table A-2.

A4-4.0 DETERMINATION OF MDT

Except for the services and materials covered in 4.2 and 4.3, the MDT shall be the lowestof:

• 15°C (which is based on the Lowest One Day Mean Ambient Temperatures within Abu Dhabi, lowered by a safety margin),

• The minimum process operating temperature (all phases of operation shall be con-sidered, e.g., start-of-run, end-of-run, startup, shutdown, regenerations, etc.), or

• For non-hydrotested piping, 0°C.

For liquified gas services, the MDT shall be the lowest of:

• 0°C for shop fabricated piping and -20°C for site erected piping,

• The minimum process operating temperature, or

• For possible autorefrigeration, the temperature corresponding to the process tem-perature at atmospheric pressure.

• For Toxic services, the MDT shall be the lower of 0°C or the minimum process oper-ating temperature.

A4-5.0 SAMPLING AND TEST METHOD

All base metal sampling and toughness test procedures shall be per the ASME B31.3Code. Testing shall be done at the MDMT.

Impact testing details for welds, both during procedure qualification and during productionshall be per ASME B31.3.

A4-6.0 ADDED MATERIALS RESTRICTIONS

No microalloyed steels or nickel-steels shall be used unless approved by the COMPANY.The certified material test report shall include analysis for columbium, vanadium, titanium

and boron.

All flanges shall be normalized.

No SA 36 or SA 283 steels shall be used for piping components exposed to services in-cluded within the scope of this Attachment.

SA 285 Grade C, SA 299, SA 455 and SA 515 Grade 65 shall be limited to 12.5 mmthickness for piping components exposed to services included within the scope of this At-tachment.

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A4-7.0 ADDED WELDING REQUIREMENTS

If postweld heat treatment (PWHT) is required, no welding shall be done after PWHT,unless approved by CONTRACTOR.

Undercutting, overlapping at the toe, or bad profile shall be avoided or corrected by care-ful grinding.

After removal of temporary lugs, erection cleats and other fitup attachments, any remain-ing weld metal protuberance shall be ground flush with the surface of the part, and thearea shall be inspected for cracks using liquid penetrant or magnetic particle testing.

A4-8.0 ADDED NDE REQUIREMENTS

(1) Except for piping components included in A4-8(2), if a piping spool contains anycomponents requiring impact testing, then all butt welds on that spool shall be100% RT inspected.

(2) If only non-welded components (eg. seamless pipe or forged fittings) are impacttested for a piping spool, then no increase in the amount of RT is required.

A4-9.0 ADDED HEAT TREATMENT REQUIREMENTS AFTER FORMING OR WELDING

All ferritic steel plates which have been hot formed or which have been cold-deformed bydishing, flanging or rolling to an internal radius less than 10 times the plate thickness(more than 5% deformation) shall be given a normalizing heat treatment.

If material was not purchased with a normalizing heat treatment, but subsequently formedand normalized, all mechanical tests shall be redone on actual base material.

All ferritic steel piping which has been bent (with or without local heating) to an internalradius less than 10 times the outside diameter of the pipe shall be given a normalizing

heat treatment. A4-10.0 ADDITIONAL HYDROTESTING LIMITS

The temperature of the test fluid shall be between the MDT and 20°C, but not less than

5°C, unless otherwise approved by COMPANY.

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APPENDIX 5

USE OF AUTOMATED ULTRASONIC TESTINGIN LIEU OF RADIOGRAPHIC TESTING

TABLE OF CONTENTS

1. Scope2. References3. Definition of Terms4. General Requirements5. Personnel Qualification and Certification Requirements6. Equipment7. Qualification / Demonstration8. examination

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1.0 SCOPE

1.1. This document establishes the requirements for examination of welds when it is de-sired to utilize automated ultrasonic examination in lieu of radiographic examination ofwelds in components fabricated in accordance with the codes referenced in 2.0. Theserequirements apply only to welds of P-1/3/4/5 materials. Refer to 4.4. Any use of ultra-sonic examination for acceptance of welds is subject to compliance with design coderequirements, written agreement of COMPANY, and the direction provided from withinthis specification supplement.

1.2. This document does not address the performance of UT for examination of welds fab-ricated in accordance with AWS or API requirements. These must be addressed on acase-by-case basis.

2.0 REFERENCES

2.1. ASME B&PV Section VIII, “Rules for Construction of Pressure Vessels”

2.2. ASME B&PV Section I, “Power Boilers”

2.3. ASME B31.1,”Power Piping”

2.4. ASME B31.3, “Process Piping”

2.5. ASME B&PV Section V, “Nondestructive Examination”

2.6. ASME B&PV Code Case 2235-X, UT in Lieu of RT (Latest Version)

2.7. B31 Code Case 181, UT in Lieu of RT (Latest Version)

2.8. ASME V, Article 4, Appendix VI, “E-scan & S-scan Linear Scanning Techniques” (ap-proved, but not published as of June 11, 2008)

3.0 DEFINITION OF TERMS

3.1. The definitions of ASME V, Article 1, Appendix I, I-130 shall apply as applicable.

3.2. The definitions of ASME V, Article 5, Appendix III, III-540 shall apply as applicable.

3.2.1. Automatic Ultrasonic Testing (AUT): Techniques of ultrasonic testing performed withequipment and search units that are carriage mounted, remotely operated, mechani-cally guided, and motor-controlled (driven). The equipment used to perform the exami-nations shall be capable of recording the ultrasonic response data including the scan-ning positions, by means of an integral encoding device, such that imaging of the ac-quired data can be performed.

3.2.2. Semi-Automatic Ultrasonic Testing (SAUT): Techniques of ultrasonic testing performedwith equipment and search units that are mechanical carriage mounted, mechanicallyguided, and may be manually assisted. The equipment used to perform the examina-tions shall be capable of recording the ultrasonic response data including the scanningpositions, by means of an integral encoding device, such that imaging of the acquireddata can be performed. Note: Scanning where probe and encoder displacement is con-trolled by hand without mechanized scanning apparatus do not constitute SAUT tech-niques.

3.2.3. Manual Ultrasonic Examination (or Encoded Manual Ultrasonic Examination); Tech-niques of ultrasonic testing performed with search units that are manipulated by hand.

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Note: Manual techniques may be encoder equipped, but do not constitute Semi-

Automatic Ultrasonic Testing (SAUT) or Automatic Ultrasonic Testing (AUT) techniquessince the entire examination process is controlled by hand.

3.2.4. Mechanized Scanning; Automatic or Semi-Automatic scanning apparatus in which arigid probe carriage apparatus mounted with rollers or wheels provides for linear scan-ning motion with motor-controlled or manually assisted displacement.

3.3. Procedure; A written set of instructions that establishes minimum requirements for per-forming NDE in accordance with this specification addendum. AUT procedures forcompliance with this specification addendum must meet the requirements of ASME V, Article 4, T-421 and applicable code case(s).

3.4. Flaw; an imperfection or discontinuity that may be detectable by NDE and is not nec-essarily rejectable.

3.5. Simulated Flaw; a machined side-drilled hole or notch that depicts the ultrasonic reflec-tance of a real flaw. Machined notches used to simulate flaws must be parallel to therepresentative production weld’s fusion line.

3.6. Calibration; the process of establishing a standardized system setup for a particularweld joint configuration in accordance with code and procedure requirements.

3.7. Qualification; the process of documenting the proven adequacy of the UT procedure,system, and calibration.

3.8. Demonstration; the process of performing an examination on the appropriate flawedblock specified by the applicable code and / or code case(s). Flaws in the block shallbe oriented to simulate flaws parallel to the fusion line of the production weld.

3.9. Calibration Block; The block designed, fabricated, and verified to provide a consistent

approach to UT system standardization (calibration).

3.10. Qualification / Demonstration Block; A block which provides a depiction of the produc-tion weld with regard to material, thickness, weld joint configuration, weld geometry,and contains real flaws of a specified type and location.

3.11. Scan Plan: The documented examination strategy for AUT or SAUT scans that pro-vides a standardized and repeatable methodology for weld acceptance. The scan planshall contain sufficient information to show complete coverage and include the materialspecification and product form or equivalent P-Number, weld thickness, cross-sectiongeometry, extent of clad (if present) weld joint preparation configuration and dimen-sions, extent of the Heat Affected Zone (HAZ) and additional coverage, weld crownwidth and profile, beam plots for all refracted angles used, extent of coverage, calibra-tion reflectors, probe index spacing (from weld centerline), and zonal coverage over-

lap.

3.12. Full Volume Coverage: Two-directional beam coverage through the weld, HAZ, andadditional base material as specified by the referencing code (or code case). Completetwo-directional weld volume coverage shall impinge the weld HAZ (on each side) at anangle as close as normal as practical. Complete weld volume coverage may be ob-tained by scanning from both sides of the weld, or by using an extended sound pathfrom one side of the weld. Where possible, scans shall be performed from both sidesof the weld. Alternatively, complete weld volume coverage may be obtained from one

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side of the weld where it can be demonstrated that flaw detection is at least compara-

ble to that obtained when scanning from both sides of the weld.4.0 GENERAL REQUIREMENTS

4.1. Ultrasonic examination will be performed in accordance with an approved examinationprocedure. Procedures and techniques shall be in accordance with ASME V, Article 4,T-421 (latest edition). Examination procedures shall be submitted to COMPANY suffi-ciently in advance of production for technical review and approval. The procedure shallhave been demonstrated to perform acceptably on the applicable calibration block anda qualification block with embedded flaws.

4.2. Procedure qualification applies. The qualification of the Mechanized UT system shallbe demonstrated and documented. The documentation shall be relevant for the mate-rial and weld geometry to be tested.

4.3. Phased-Array, Pulse-Echo, ToFD, or combinations of these techniques may be util-ized. Unless otherwise authorized, ToFD techniques shall not be used independently. As a minimum, ToFD techniques must be augmented with a pulse-echo or phased-array technique. Where ToFD is utilized, the provisions of ASME V, Article 4, AppendixIII shall be considered mandatory.

4.4. All UT scans must produce a permanent record with each data point encoded andtraceable to a length, width, and depth point of the weld.

4.5. The requirements contained in this specification addendum may be applied only to P-1, P-3, P-4, and P-5 materials.

4.6. Examination of high alloy steel welds, stainless steel, high nickel alloy welds, dissimilarmetal welds, or other coarse-grained and/or a directionally-oriented weld structure maybe approved on a case-by-case basis pending successful demonstration on a weldmockup containing calibration reflectors and depicting the production examination jointconfiguration containing known reflectors.

4.7. The AUT or SAUT system accuracy must be demonstrated and validated. Scanningmust be performed by automated mechanized equipment capable of recording theecho data and scanning position. The scanning system shall utilize a rigid apparatuscapable of maintaining precise alignment through the full circumference of the weld. Approval for the use of semi-automated scanning techniques is subject to review andapproval by COMPANY. Manually displaced probes with an integral encoding deviceare not acceptable for use for other than supplemental scans.

4.8. Straight beam scans for reflectors that could interfere with the angle beam examinationshall be performed. The straight beam scans may be performed (1) manually, (2)

documented as part of a previous manufacturing process, or (3) during the automaticUT examination provided detection of these reflectors is demonstrated.

4.9. Scans for defects oriented transverse to the weld shall be performed. A pulse-echo orphased array may be used for this. ToFD scans are not permitted for scans performedto detect flaws oriented transverse to the weld.

4.10. A documented examination strategy or scan plan shall be provided showing transducerplacement, movement, and component coverage. The scan plan must provide for astandardized and repeatable methodology for weld acceptance. Complete scan-plan

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documentation for each weld configuration shall be made available to COMPANY.

Configuration parameters are those as stipulated in ASME V, Article 4, T-421.4.10.1. For scan plan content, see “Definitions of Terms” (3.0).

4.11. Complete weld volume coverage shall be obtained. Where complete weld volume cov-erage cannot be obtained, radiographic examination shall be performed.

4.11.1. Complete weld volume coverage is defined as two-directional beam coverage throughthe weld, HAZ, and additional base material specified by the referencing code (or codecase).

4.11.2. Complete two-directional weld volume coverage shall impinge the weld HAZ (on eachside) at an angle as close as normal as practical.

4.11.3. Complete weld volume coverage may be obtained by scanning from both sides of theweld, or by using an extended sound path from one side of the weld. Where possible,

scans shall be performed from both sides of the weld. Alternatively, complete weld vol-ume coverage may be obtained from one side of the weld where it can be demon-strated that flaw detection is at least comparable to that obtained when scanning fromboth sides of the weld.

4.11.4. For single-sided scans, a scan plan shall be submitted for review and approval show-ing full volume coverage from the side of the weld from which scanning will be per-formed.

4.11.5. Where single-sided scanning is used to obtain coverage, the weld crown shall be con-toured such that scanning can be performed the examination volume unless it can bedemonstrated and documented in the scan plan that full volume coverage is being ob-tained without weld crown contouring.

4.11.6. Inaccessible, restricted, or other area where partial coverage is obtained shall bedocumented. Where full volume coverage cannot be obtained, either (1) radiographyshall be performed, or (2) the condition shall be documented via Supplier DeviationDisposition Request (SDDR) or Field Change Request (FCR).

4.12. To maintain accuracy and resolution of the UT system and equipment, the maximumtemperature differential between the search units, the calibration block and the pipewall shall be established. The written examination procedure shall indicate the tem-perature range over which the UT system will operate.

5.0 PERSONNEL QUALIFICATION AND CERTIFICATION REQUIREMENTS

5.1. Ultrasonic Examination personnel shall be certified in accordance with a nationallyrecognized certification scheme such as ANSI / ASNT-CP-189 or SNT-TC-1A as LevelII, or III.

5.2. Personnel performing analysis of data shall have received additional specific training inthe data analysis techniques used in the procedure qualification and shall successfullycomplete the procedure qualification.

5.3. Personnel collecting UT data (“acquisition”) shall have demonstrated their ability toperform an acceptable examination and evaluation in accordance with the perform-ance and acceptance criteria requirements using demonstration blocks which meet the

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applicable fabrication requirements. Personnel who acquire AUT data shall be trained

in the use of the AUT equipment and participate in the performance demonstration.5.4. Personnel analyzing UT data (“analysis”) shall have demonstrated their ability to per-

form an acceptable examination and evaluation in accordance with the acceptance cri-teria using test block(s) approved by Company. In addition, personnel who acquire andanalyze AUT data shall be trained using the equipment in use, and participate in thedemonstration. Personnel who acquire and/or analyze UT data shall be trained in theuse of the AUT equipment and participate in the performance demonstration. Person-nel who evaluate, interpret the results of, and/or report the results of examinationsshall be certified to Level III.

6.0 EQUIPMENT

6.1. Ultrasonic Equipment

6.1.1. The Automated Ultrasonic Examination system shall be capable of meeting all applica-ble examination requirements for the weld diameters, wall thickness, and joint configu-rations detailed herein.

6.1.2. The ultrasonic examination shall be performed using a device employing automaticcomputer enhanced data acquisition.

6.1.3. The ultrasonic examination shall be performed using a system capable of recording theultrasonic examination data, concurrent with scanning positions, to facilitate the analy-sis of the scan data by a third party and ensure the repeatability of subsequent exami-nations, should they be required.

6.1.4. Data location encoding devices shall be capable of locating the position of weld indica-tions within the accuracy required for application of the evaluation, recording, and ac-ceptance criteria.

6.1.5. For ToFD data, a method of monitoring the required acoustic coupling shall be includedin the examination procedure and demonstrated to perform satisfactorily.

6.1.6. Automated UT examination system components shall be sufficiently shielded preventdata degradation due to non-integral electrical interference.

6.2. Data / Data Recording Equipment

6.2.1. Data is to be recorded in unprocessed form. A complete data set with no gating, filter-ing, or thresholding shall be included in the data record. A-scan presentation shall beavailable within the examination data.

6.2.2. Final examination data shall be sufficient as to permit duplication of scan parameters,location of discontinuities in the examination volume, weld ID, reference sensitivity, ref-

erence reflector, disposition of indications, and any other information deemed pertinentto disposition of the weld.

6.3. Calibration

6.3.1. Calibrations shall be adequate to examine the full weld volume and evaluate indica-tions for acceptance / rejection in accordance with the specified criteria. Preliminarycalibration data shall be provided to COMPANY for review prior to commencement ofexaminations.

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6.3.2. Examination parameters including pulse length and repetition rate shall not vary from

those utilized for demonstration of dynamic calibration.6.3.3. Any parameters necessary to consistently reproduce a calibration shall be included in

the report documentation. Examination report content shall be in accordance with ASME V, Article 4, T-492 (and applicable code case(s) if used). Examination reportcontent shall include scanner manufacturer, model, data analysis software and version,calibration data file name, examination data file name, focal law parameters, includingas applicable, angular range, focal depth, element numbers used, angular incrementalchange, data acquisition increment, details of restricted access or inaccessible welds.

7.0 QUALIFICATION / DEMONSTRATION

7.1. Procedure / AUT System Demonstration and Qualification: The terms "demonstration"and "qualification" shall imply the same result (e.g. these terms can be used inter-changeably). AUT system demonstration / qualification specified by ASME B31.1paragraph 136.4.6(A.2 & A.3), B31 Code Case 181(c), and B&PV Code Case 2235-9(c) shall be performed for all of the following applicable thickness ranges; .50 to 1.0inch, 1.0 to 2.0 inch, 2.0 to 4.0 inch, and 4.0 to 6.0 inch. Needs for demonstration /qualification for welds greater than 6.0 inches shall be on a case-by-case basis.

7.2. The effectiveness of proposed non-destructive procedures shall be demonstrated andapproved prior to use. Work shall not commence where the applicable procedure hasnot been approved for use by COMPANY. The procedure validation testing and dem-onstration shall be performed on welds made using approved welding procedures,relative to the weld joint configuration being examined. A specific procedure, with in-struction detail for each thickness and weld bevel preparation required, shall be pre-pared.

7.3. The automated UT examination system shall be considered qualified by successfuldemonstration of dynamic calibration on the calibration / reference standard and suc-cessful dynamic demonstration on flawed samples.

8.0 EXAMINATION

8.1. The definitions of 3.2.1, 3.2.2, and 3.2.3 apply for the allowable scan types detailedfollowing.

8.2. Encoded manual scans will only be permitted for scans of partial coverage areas, sup-plemental scans, or other interrogatory scan. Non-encoded scan data may be allowedfor use on a case-by-case basis.

8.3. Linear scan types may employ automated or semi-automated scan apparatus.

8.4. Any scans employing raster-type displacement shall be performed using a fully auto-

mated AUT system capable of X-Y displacement.

8.5. Procedures and scan plans shall be approved prior to the commencement of produc-tion examination.

8.6. Encoded manual scans are permitted for the performance of transverse defect scans.

8.7. Non-encoded manual scans are permitted for the performance of straight beam basematerial scans.

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8.8. Where ECA-type acceptance criteria is to be applied, it shall be demonstrated that in-

dication sizing accuracy and tolerances can be maintained.

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ADDENDUM SHEET

All revisions to this DGS subsequent to the issue of Rev Zero shall be recorded in this addendumsheet and shall be incorporated into the DGS in the next revision.

Date Proposed Revision Remarks

March2009

AMD-DGS-MW-002-BECHTEL

Amendments to clause 2 – Codes and Standards

Delete – “ISO 9011 Quality Management Guidelines for Performance Im-provement System”Replace with – “ISO 19011 Guidelines for quality and/or environmental man-agement systems auditing”

Amendments to clause 5 – Speci ficat ion Deviat ion/Concession Control

First paragraph, first sentence. Delete “and its attachments”.

Add new c lause 6.1.4 (a)

Replace-

“Ultrasonic examination procedures shall be in accordance with the require-ments and methods specified in ASME Section V, Article 5,…..”

With-

Ultrasonic examination procedures shall be in accordance with the require-ments and methods specified in ASME Section V, Article 4 (for welds), Article5 (for materials),……….”

Add new c lause 6.1.5 (c)

“Ultrasonic Testing may be used in lieu of Radiographic Testing, subject tothe conditions defined in Appendix 1.”

Amendments to clause 6.1.6 – NONDESTRUCTIVE EXAMINATION (NDE)

Replace –

“If the vendor prefers to check weld quality before PWHT….”.

With-

“If the vendor prefers to check weld quality, of welds in P1 material, before

PWHT….”.

Amendments to clause10.1 – MATERIALS- WELDING CONSUMABLES,GENERAL

Replace-

“A minimum of EN 10204 2.3 certification is required………….”

With-

Incorporatedin Rev 1

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1 1/4 Cr -

1/2 Mo

2-1/4 Cr - 1Mo

All 200 All Yes (6) All 704-746 5(4)

5 Cr - 1/2Mo,

All 200-250

All Yes (6) All 720-760 5(4)

9 Cr - 1 Mo

With-

1 Cr - 1/2Mo,

All 150 All Yes(6)

All 704-746(8)

2.5(4)

1 1/4 Cr -

1/2 Mo

2-1/4 Cr - 1Mo

All 200 All Yes(6)

All 704-746(8)

5(4)

5 Cr - 1/2Mo,

All 200-250

All Yes(6)

All 720-760(8)

5(4)

9 Cr - 1 Mo

8. PWHT temperature shall be at least 20°C below the actual tempering tem-perature of the material

Amendments to APPENDIX 3 – INSPECTION LEVELS

Replace-

“Lethal substances”

With-

“Toxic Service”

Amendments to APPENDIX A4_6.0 ADDED MATERIALS RESTRICTIONS

Replace

“No microalloyed steels or nickel-sheets”

With

No microalloyed steels or nickel-steels

ADD NEW APPENDIX 5

USE OF AUTOMATED ULTRASONIC TESTING IN LIEU OF RADIO-GRAPHIC TESTING

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