general specification piping fabrication and pressure testing

GENERAL SPECIFICATION

SPECIFICATION

FOR

PIPING FABRICATION

AND

PRESSURE TESTING

11 100806 JRO Update Table for Piping Penetrations/Sleeves JRO DZO

10 060406 JRO Update JRO DZO

9 240902 JRO Change of Layout JRO DZO

8 130201 GvS Name Change JRO CvB

7 071100 GvS General Update JRO CvB

6 290799 JRO Change Name JRO CvB

REV DATE ORIG. DESCRIPTION CHECKED APPROVED

Specification Sheet Revision

GDF PRODUCTION NEDERLAND B.V.502 1 of 27 11

GDF Production Nederland B.V.Specification 502, Rev. 11 2 of 27

CONTENTS

1.0 SCOPE

2.0 CODES, STANDARDS AND SPECIFICATIONS

3.0 PIPING FABRICATION

3.1 General3.2 Drawings3.3 Pre-Fabrication3.4 Welding Carbon Steel3.5 Pipe support fabrication and installation3.6 Flange jointing and bolting3.7 Threaded connections

4.0 PIPING INSTALLATION

4.1 Remarks for piping installation

5.0 REQUIREMENTS FOR NON CARBON STEEL AND GALVANISED PIPING

5.1 Requirements for Duplex Steel piping (class ..DS)5.2 Requirements for Cunifer piping (class 15UK)5.3 Requirements for Poly Ethylene piping (class 15UP)5.4 Requirements for hot-dip Galvanised piping (class 15U)5.5 Systems that require extra grade of cleaning

6.0 FLUSHING AND PRESSURE TESTING

6.1 Scope6.2 Flushing6.3 Testing and test systems6.4 Safety during pressure testing

7.0 QC PIPING FABRICATION

7.1 General7.2 Inspection on piping fabrication7.3 Inspection on piping installation7.4 Non Destructive Testing

8.0 DOCUMENTATION

9.0 ATTACHMENTS

Attachment I - Welding of ferritic/austenitic stainless steelAttachment II - Weld History Sheet.


1.0 SCOPE

This specification is intended to supplement and confirm good working practice during fabrication,assembly and erection of piping onshore and offshore.The fabrication and assembly shall be in accordance with specifications and "Approved for ConstructionDrawings".

2.0 CODES, STANDARDS AND SPECIFICATIONS

All piping shall be designed, fabricated and inspected per subject General Specifications and accordingto PED and/or NEN 3650.

If piping is actually subject to authorisation per PED:- this will be clearly indicated on the "Approved for Construction drawings,- all required fabrication and testing approvals for subject piping shall be obtained.

All piping shall be welded and fabricated per this specification and as specified by the latest revision of:ANSI B31.3 : Petroleum Refinery Piping,ASME : Boiler and Pressure Vessel Code,ANSI B.1-20.1 : Pipe Threads, General PurposeANSI B.1.1 : Unified Inch Screw ThreadsNEN-EN 13480 : Metallic Industrial Piping – All parts.

All materials shall be in accordance with the latest revision of the Company Specification 503 - GeneralSpecification for Pipe, Fittings and Valves.

All surfaces shall be coated in accordance with the latest revision of the Company Specification 525 -General Painting and Coating Specification.

All welding of duplex steel shall be per subject attachment to this specification.

All pipe supporting shall be in accordance with the latest revision of the Company Specification 504 -General Specification for Pipe Supporting.


3.0 PIPING FABRICATION

3.1 General

Fabrication will take place according to a QC-plan prepared by fabricator. This plan is to be approved byCompany before start of fabrication. As a minimum the QC-plan will include the applicable itemsindicated in this specification.

During all stages of the work all materials used, shall be traceable and shall comply with all relevantdocuments and certificates.Appropriate fabrication / shop / material administration will be prepared and followed, system subjectto approval by Company.

If pipes are to be cut into shorter lengths the identification marks shall be re-stamped on the outersurface of the pipe witnessed by Notified Body (NoBo) prior to cutting.

All material shall be visually inspected upon arrival on the construction site for damage, corrosion,proper protection and marking, and certification.Any deviations shall be reported to Company. All material shall be stored according to therecommendations of the Supplier, until required for use.Piping under fabrication for Company shall be fabricated and stored at all times separate from otherpiping under fabrication. Detailed records of required, delivered, used, over and abortive materials willbe kept at all times.

Fabrication will take place under suitable conditions (shop), at all times spools/piping will be kept clean(inside mainly for debris/dirt, outside especially for metallic contamination of other (piping) metalcontamination.If any construction is to be carried out in the vicinity of piping or equipment already installed then,before such construction work commences adequate protection shall be provided to prevent anydamage from weld spatter, arc cutting droplets etc.

Care shall be taken to avoid overstressing, damage or deformation in any of the piping components atall stages of the work. Shrinking or hot bending is not allowed in any case.

No field or other welding or other hot work shall be carried out before, where applicable, a hot workpermit has been obtained.

3.2 Drawings

Piping fabrication shall take place from isometric and/or other drawings containing all requiredinformation for material identification, fabrication, testing, coating, etc.Piping installation shall take place from isometric and/or GA’s, support and penetration drawings, andother drawings containing all required information.Information for piping fabrication and installation shall be subject to approval by Company. Based onall drawings the exact as built situation shall be recorded and made available to Company.


3.3 Pre-fabrication

During all stages of the prefabrication all used materials shall be traceable and shall comply with allrelevant documents and certificates.During all stages of the fabrication, all pipe spools shall be properly tagged with their unique spoolnumber. Labels shall remain on the spool up to the installation. Labels shall be selected and attached sothat during and after blasting and painting the spool number remains readable.All piping shall be identified at the beginning and the end of each line with low-stress hard-stamped,clearly readable marking indicating line-number, pipe-class number, design pressure and max./min.temperature, and if applicable “PED/DAD registratie nummer”.Piping spools shall be selected such that they can be handled in all stages of the work without damagesor overstressing and that tension free installation is ensured.

Piping spools shall be fabricated such that dimensional inaccuracies due to welding are minimised. Allmeasures shall be taken to ensure correct positioning and fit-up of the components to be welded.

Before lining-up, the weld ends shall be cleaned to remove all foreign particles.

Fit -up and tackwelding shall comply with the welding procedures.Bullets from the pipematerial shall be used for tackwelding.Removal of bullets shall be done by grinding only.

3.4 Welding Carbon Steel

(For welding of duplex steel see Attachment I to this specification.)

3.4.1 General

Fit-up and welding for piping will be per applicable codes and specifications, and shall further fulfil allrequirements as described in the welding procedures.Further to obtain a clean piping system the welding process for the root and first following layer will beTIG- or MIG-based (to exclude the chance on slag on the inside of the weld).

3.4.2 Welding Procedure Qualification

Contractor shall demonstrate to Company and if applicable to NoBo, that welding procedures andrepair welding procedures that will be applied have been qualified in accordance with the applicablePED prescriptions.All welding shall be multiple pass.All weld caps shall be multiple pass for WT of 8mm and above.No welding shall be carried out before the Welding Procedure Specifications and the procedurequalification records are completed and approved by Company.


3.4.3 Welders Competence

Contractor shall demonstrate that the welders have been rated adequate in accordance with theapplicable PED prescriptions.Each welder shall carry evidence of his qualification with him.Each welder shall stamp each weld directly adjacent to the weld metal made by himself with hisidentification mark (low stress stamps).

3.4.4 Welding preparation

Internal and External surfaces to be welded shall be clean and free from paint, slag, spatter, oil, rust,scale, salt or other material that would be detrimental to either the weld or the base metal underwelding conditions.

Butt weld end preparation is acceptable only if the surface is reasonably smooth, true and all slag fromoxygen or arc cutting is cleaned from flame cut surfaces. Discoloration (for carbon steel only) whichremain on a flame cut surface is not considered to be detrimental oxidation.

When material subject to "NoBo approval" is thermally removed, the place of attachment, aftergrinding, must be subjected to a complete surface examination. (This consists of welded-on-partsaccessories, surplus material, etc. cut or gouged away.)

Complete weld preparation (inside diameter, alignment on inside diameter, root-opening, wallthickness etc.) shall be as defined in the procedure qualification.

If the external surfaces of the two components are not aligned, the weld shall be tapered between thetwo surfaces. (Tapering 1: 4)

When bevelling on a weld (for instance to reduce misalignment) is obtained by weld reinforcement,this reinforcement must be subjected to a complete non-destructive examination.

3.4.5 Welding Consumables

Only welding consumables from Control Las approved "welding consumables" latest edition shall beused.

Electrodes shall be supplied in fully sealed packages and stored in a dry storage room and handledaccording to the manufacturer's recommendations. All manual type electrodes shall be properlyidentifiable up to the time of usage, each electrode being distinguished by proper coding. If the codingis destroyed by baking, handling, or other causes, the electrodes shall not be used.

Electrodes used for stainless steel shall not be stored in heating cabinets containing electrodes of othertypes.

Wire spools for automatic and semi-automatic processes shall be stored in cabinets with supplierwrapping not removed and remain clearly identifiable up to the time of usage. Unidentifiable wireshall not be used.


Each batch of wire shall be labelled with the information from the supply container. The labels withbatch number shall be recorded for reference in relation to the actual welding work.

Manual electrodes and wire shall be of the same type as those used in the procedure qualification tests.Welding approved currents and voltage shall be within the range specified in the welding procedure.

All unidentifiable, damaged, wet, rusty or otherwise contaminated consumables shall not be used.Electrodes with visible stains as well as partially used electrodes (once melted) shall not be used.

All bottles containing shielding or backing gas shall have clear identification labels.

3.4.6 Weld numbering

The weld numbering shall clearly show the history of a weld, including any repairs and/or re-welds

For every weld the following information shall be gathered and maintained up to date in summarysheets, which shall be made available at regular intervals and of which the final version shall becomepart of the as built package.

a. Weld number and type (Shop, Field or Offshore Hook-up)b. Isometric drawing numberc. Pipe spool numberd. Line numbere. Size of weld (Nominal Bore and Wall Thickness)f. Weld procedure(s) and filler type and brand name if not on procedure(s)g. Welders name(s) and registration number(s)h. Date weldingi. Base material typej. NDT type(s) and results and report number(s)k. Status (based on QC-plan)

A weld is considered complete after visual inspection and approval by Company and completed andapproved X-ray examination, for NoBo classified systems also after the approval from NoBo.

3.4.7 Production welding

Welding shall be performed according to Company and NoBo approved Welding Procedures.Procedures shall be available at actual work location at all times.

Each bead shall be thoroughly cleaned of all scale, slag and other foreign matter by chipping, grindingand wire brushing prior to application of succeeding bead.

Any piping material which is burned during welding shall be cut out and re-welded.

If lamination or split ends occurs during welding the joint shall be trimmed to remove the defect.

Any bevelled edge that has been damaged shall be repaired and (where required by the applicablerules for welding) NDT-tested.


Welds which do not meet the requirements of the welding procedure, which are burned or oxidised orotherwise found to be defective, shall be repaired or cut out at the direction of Company'srepresentative.Immediately after welding the weld shall be thoroughly cleaned by removing all scale, slag weld-spatter, etc..

At each welding location, at least one electronic backing gas detector and electronic temperaturemeter shall be present. If the welding procedure requires backing gas and/or controlled pre-heat andinterpass temperatures, no welding shall be performed without the presence and use of these devices

3.4.8 Repairs

If the results of the examination are not acceptable, the weld in question may be repaired onceaccording to a dedicated and approved repair procedure. Each repair performed on the strength of theabove must be non-destructively re-examined, and the final result shall satisfy the same requirements.

3.4.9 Post Weld Heat Treatment

If according to the PED-"Heattreatment of Unalloyed and Low Alloy Steel/Pipes", PWHT is required, thetemperature time chart shall show that the heat treatment has been performed in accordance with thePED.

3.5 Pipe support fabrication and installation

Pipe supports shall be fabricated and installed per drawings and specifications (General specifications504 and the drawings for (typical) descriptions of pipe supports, GS 201 for materials and fabricationtechniques and GS 525 for coating).Pipe support drawings supplied by Company shall be checked for dimensions and completed forconstruction details.Additional pipe supports shall be detailed similar to the submitted supports and have the next supportnumber in sequence.Pipe support detail drawings shall be on A4 format and shall have not more than one type of supportand shall show as a minimum :a. Pipe support numberb. Line number and sizec. Isometric number and piping plan numberd. Deck name, location key-plan with distance to grid-linese. Structural steel beam where support is attachedf. For main steel, the structural detail drawing- and weld numberg. Detailed support membersh. Indication of field welds required on the pipe supporti. All field installed items such as clamps, bolting, spring supports etc. with clear identification to

avoid mistakesj. Special installation instructionsk. Any further required information for fabrication and installation.


Location for (field) supports for lines smaller than 2inch and drain tubing shall be designed byContractor and approved by Company.All supports shall be installed such that piping system are fully and properly supported. Each supportshall be capable to and actually carry the load for which it is designed.Painting on supports shall be the same as for the adjacent structural steel. Painting or repair paintingshall not affect piping.Security locks and tabs for spring supports shall not be removed.Stainless steel or duplex piping shall never be in direct contact with the supports, during installation thecorrect measures shall be taken.

3.6 Flange Jointing and Bolting

3.6.1 Scope

This section covers the bolt tension and bolting-up requirements for pipe and pressure vessel flangejoints in all ratings as specified in ANSI-B16.5 and or API-6A (5000, 10000 rating), for raised flat face andring type joint flanges.

For bolting-up requirements for non standard large bore flange-type connections (pipelines, vesselheads, etc.) in all cases the applicable drawings must be checked and followed.

Bolting materials shall consist of materials as defined in specification 503 (General Piping MaterialSpecification).

3.6.2 Codes

The following codes are applicable:- American Society of Mechanical Engineers (ASME)

Boiler and Pressure Vessel Code - Section VIII. Div. 1 Appendix 2.Rules for Bolted Flange Connections.

- PED- API-6A

3.6.3 Bolting-up Requirements and selection of tools

Tightening of bolts in flange connections is normally done by means of spanners and torque wrenches.This may result in uneven stress distribution in bolting and uneven gasket seating pressure. Especiallywhen applied in higher pressure classes and larger diameters, this method may lead to flange leakage.When flange joints are leaking additional force is often applied to the bolts in the area where the leakoccurs. This may result in more deformation of the flange and its facing, thus increasing the tendencyto leak.

An improved method of tightening is the application of hydraulic bolt-tension equipment.

For the selection of the correct tool for bolt tension the tables 3.6.3.A, 3.6.3.B in this section shall beused.


For the bolt tension and torque see table 3.6.7.A, in all cases pay attention to the restricting notes atthe bottom of the table, and carefully check the tables and/or graphs for this purpose that should at alltimes be present with the selected tools.

Table 3.6.3.A

The following flange joints shall be made up by hand using ring spanners ofappropriate dimensions. Lengthening of spanners by means of pipe, crowbarsor similar is prohibited.

ANSI – B16.5 CLASS NOMINAL PIPE SIZE150 LB (PN20) 1/2" up to and including 24"300 LB (PN50) 1/2" up to and including 20"600 LB (PN100) 1/2" up to and including 6"900 LB (PN150) 1/2" up to and including 3"1500 LB (PN250) 1/2" up to and including 2"2500 LB 1/2" up to and including 1-1/2"

Table 3.6.3.B

The following flange joints shall be made up by hand using torque wrenches ofappropriate dimensions.

ANSI – B16.5 CLASS NOMINAL PIPE SIZE600 LB (PN100) 8" up to and including 14"900 LB (PN150) 4" up to and including 12"1500 LB (PN250) 3" up to and including 6"2500 LB (PN420) 2" up to and including 4"

API - 6A RATING NOMINAL PIPE SIZE5000 PSI up to and incl. 6"10000 PSI 1/2 inch up to and including 2"

Table 3.6.3.C

The following flange joints shall be made up by means of a hydraulic bolt-tension (torque or stretch) device.

ANSI – B16.5 CLASS NOMINAL PIPE SIZE600 LB (PN100) 16" and larger900 LB (PN150) 14" and larger1500 LB (PN250) 8" and larger2500 LB (PN420) 6" and larger

API - 6A RATING NOMINAL PIPE SIZE5000 PSI 8" and larger10000 PSI 3" and larger


Table 3.6.3.D

The following flange joints shall be made up by means of a hydraulic bolt -tension (stretch, e.g. "Hydratight", etc.) device.

CLASS NOMINAL PIPE SIZE APPLICATIONANSI 900 & 1500 LB 2" and larger under waterAPI 5000 & 10000 2" and larger under waterANSI 900 20" and larger critical connections

ALL If required per drawing

3.6.4 Flange Inspection and Preparation

Check the condition of the flange faces for smoothness, scratches, dirt, scale, and weld spatterprotrusions. Wire brush clean as necessary. Deep scratches, dents or combinations of defects will requirere-facing with a flange facing machine.

Check alignment of mating flanges. Use of force to achieve alignment is prohibited.

All threads and bearing surfaces shall be free from sand, chips or any other foreign material which mayinfluence the torque during tightening.

Check coating on flanges, all face-surface outside groove (RTJ) or packing surface (RF or FF), includinginside bolt holes shall be coated to specification.

3.6.5 Gasket / ring Inspection and Preparation

Only new gaskets shall be used. Damaged gaskets (including loose spiral windings) shall be rejected.Gasket dimensions, gasket material and type, shall be checked to be per specification. Non-specificationsituations, unless specifically defined on the drawings, are not acceptable.

3.6.6 Stud / nut inspection and preparation

Check thread on stud and nut. Minor damage of tread on stud well in between the nuts may berepaired, including coating.Complete coating must be in tact.Nut to flange contact surface shall be clean and smooth, avoid damage to coating in consultation withCompany.Studs area for nuts to be lubricated with approved lubricant. The same lubricant should be usedconsistently on all joints especially when controlled bolt tightening is required (see tables 3.6.3).


3.6.7 Installation Procedure - Tensioning

Install gasket and all bolts and nuts before any tensioning.

Note: It is recognized that applied torque to a nut member is only one of several ways toapproximate tension and unit stress in a studbolt. Tabulated values (table 3.6.7A)arepresented for convenience and guidance only. Some factors which affect the relationshipbetween nut torque and boltstress are :- Tread pitch, pitch diameter, and tread form.- Surface finish of thread faces and nut bearing surface area.- Degree of parallelism of nut bearing area with flange face.- Type of lubrication and coating of the treads and nut bearing surface area.- Table can be used as a guideline for general purpose application (shaded area). For non

standard applications dedicated calculation based on found materials, geometry’s andcircumstances can be made.

Develop the required bolt stress as per table 3.6.7.A "Bolt torque values" in a minimum of three steps,following a tightening-up procedure as outlined per figure 3.6.7.B "Bolt-up sequence description".

Note: if more than 30 % of the final bolt stress is applied during the first step, serious damage willbe done to the spiral-wound gasket and subsequent tightening cannot offset this damage.Gasket shall be rejected.

Requirements are based on bolts with UNC/8UN Thread; friction coefficient of 0.12 or 0.13. Lubricantwith another coefficient of friction will require interpretation of table or recalculation of bolt torque.

3.6.8 Tools and Lubricants

All tools used for tightening shall fit the hexagon of bolts and nuts without damaging the width acrossflats and be suitable for matching nuts in accordance with ANSI B 18.2.2.

Hydraulic Torque Wrench DeviceThe torque bolt tensioning device, including adapters, shall be suitable for matching boltsize. EachTorque Wrench Device shall be accompanied with a clear manual (in language of personnel involved),indicating clearly the relationship between read-out hydraulic pressure and moment applied on nut.


Table 3.6.7

Recommended bolt tension and bolt torque for ANSI B 16.5 flange connections

Torque required NmBoltsize &thread inch

BolttensionkN

Min.yieldMpa

Molycote{0.067}

Copperb.{0.100}

API-5A{0.117}

Pract.fig.{0.13}

Mach. oil{0.150}

Dry {0.2}

1/2 UNC 33 725 80

5/8 UNC 53 725 153

3/4 UNC 78 725 142 194 222 266 274 344

7/8 UNC 108 725 230 318 363 424 451 557

1 8UN 141 725 347 484 555 643 692 831

1 1/8 8UN 185 725 496 699 803 930 1004 1220

1 1/4 8UN 233 725 688 970 1116 1292 1398 1715

1 3/8 8UN 288 725 920 1302 1501 1737 1883 2329

1 1/2 8UN 348 725 1198 1703 1964 2272 2470 3073

1 5/8 8UN 414 725 1527 2178 2515 2910 3166 3985

1 3/4 8UN 486 725 1911 2734 3158 3654 3983 5029

1 7/8 8UN 564 725 2354 3377 3905 4516 4928 6256

2 8UN 650 725 2861 4113 4759 5505 6012 7653

1 1/4 8UN 834 725 4081 5892 6824 7892 8635 11027

2 1/2 8UN 1041 725 5606 8120 9413 10884 15282

2 3/4 8UN 1267 725 6760 9824 11386 14549 18596

Notes: - Tensioning to be done in (min.) 3 steps of 0.30, 0.65 and 1.00 * indicated bolt torque- Calculation based on API spec. 6A - Appendix D- Stress basis is 362 MPa (being 50% yield of ASTM A320M - L7 bolting)- Friction factor as indicated depends on numerous aspects.- For non-standard and very critical connections dedicated calculations must be made.

3.6.9 Bolt-up Sequence

The bolt-up sequence indicated in the figure is as an example applicable for all types of fastening tools,orientation can be changed to suit very minor differences in distance between flange facings (resultingfrom fabrication tolerances, not out-of angle welded flanges).


3.7 Threaded Connections

3.7.1 Guidelines for the making of small-bore NPT connections

Threaded (NPT) piping connections and the application of various types of PTFE tape and threadsealant.

General rules to check NPT thread connections (ANSI B1.20.1).- correct selection of materials for services, pressure and temperature (specification!),- check state and installation of cutting blocks (direction & following order) if male tread is

cut on pipe, use cutting oil- use of proper and undamaged thread on both male and female thread side,- the proper use of suitable sealant or tape,- correct installation and supporting of pipe,- both male and female thread must be smooth, no burrs, cuts or other irregularities can be

accepted,- minor corrosion can be removed from the thread, actually corroded thread can not be accepted,- without tape or sealant the parts to be connected should allow 4 to 5 rotations, at least 4 threads

should be engaged,- with tape or sealant it should be possible to make up the parts 3 to 4 rotations without excessive

force.

DO NOT:- unscrew an already made up thread connection after application of sealant, not even a little,- use extra sealant or tape to fix a doubtful thread,- use excessive force to make up of (non-fitting) threads.

Special care is required for the mounting/installing of plugs.Plugs are often used numerous times on the same or a new location and therefore the threads can beworn.

Threaded connections used for instrumentation (actual instrument, instrument air, and others) areconsidered to be made per piping specifications.

For SS tubing connections, as widely in use within instrumentation and otherwise, the pipingspecifications are not to be used.All instrument tubing systems to be made according to specifications and manufacturersrecommendations.

The Use of PTFE TapeAlthough PTFE tape can be applied without problems for numerous applications, it should be realisedthat the application is limited by the physical properties of PTFE tape. The table in this section gives asummary of the possibilities for various types of tape and sealant. This table is based on themanufacturer recommendations and practical experience.

At this moment no "tailor made" code is available for all situations.

Most commercially available tapes are of "Giveg class 0.2".Based on experience it can be said that the use of PTFE tape can give acceptable results. The "Givegkeurmerk" indicates that subjected tapes are fabricated controlled and the chemical properties arechecked. Therefore this must be checked before use.


PTFE tape shall be applied as follows:In the diameter range up to 1" the PTFE tape (thickness 0.1 mm) can be used (See table.)Tape to be applied to male thread, starting away from and working towards the pipe end, with a tapeoverlap of 50%, wrap under slight tension to ensure that tape conforms to thread contours.Only 3 to 4 layers can be applied, not more.Do not use this tape for connections in pipe with a diameter above 1".

Alternative Thread CompoundsAs alternative or addition to PTFE tape, numerous more or less liquid sealing materials are available. Atall times the manufacturers recommendations for these materials must be checked and followed. Some(widely used) examples are included in table 3.7.1.A..Any other brand, not listed, shall be submitted to company for approval.

3.7.2 Material problems in making threaded connections

The available piping specifications often leave the question for a practical solution for connecting ormatching two different materials un-answered. Specially on equipment with various materials used,problems can occur.Examples: - SS and duplex are very difficult materials to cut tread "in the field",

- Installation of threaded connections in duplex steel are very difficult, duplex-duplex connections must be avoided completely (the male tread will cut into thefemale side, far before the required number of treads is installed, "galling").

- Tools (cutting blocks and others) for SS must be used for SS only.Described problems should be identified and eliminated.


Table 3.7.1.A, Table Thread Joining Components

Thread Sealant

ServicesNominalPipe Size(Inch) *

WorkingTemp.

(C)Remarks

PTFE tape 0.1 mmGiveg Class 0.2

All ex. BreatherAir

up to 1 inch -20 to +150

PermaBond A131 &A134 anaerobicadhesive/ sealant

All ex. lowtemp. cyclicduties

up to 1 inch -55 to +150

Loctite 577 hydraulicseal

For small diam.,clean systems

up to 3/4 inch -60 to +150

Omnifit 222 All "generalsealant"

up to 1/2 inch -60 to +150

ThreeBond All "generalsealant"

up to 1/2 inch -60 to +150

ThreeBond 1346 Small diam.,clean systems

up to 3/4 inch -60 to +150

Loctite 542 For small diam.Clean systems

up to 3/4 inch -60 to +150

Omnifit 5ON All "GeneralSealant"

up to 1/2 inch -60 to +150

* See specification 503 for max. sizes threaded connections various pipe classes.

3.7.3 Galvanic corrosion and threaded connections

A possible problem with threaded connections is galvanic corrosion. Screwed connections made upwith different materials can result in a difference in electrical potential with the right (wrong) mediumthis can cause galvanic corrosion. The sharp edges of the (usually male) thread can be affected veryquickly (without the possibility to detect this from the outside). This will result in a complete collapse ofthe connection without warning.

Risk for galvanic corrosion can and must be identified during piping design, however could be causefor problems during day to day off-shore maintenance.


4.0 PIPING INSTALLATION

4.1 Remarks for Piping Installation

Prior to installation all spools and piping components shall be checked for damage and absence of anydirt inside.Valves and in-line items shall be checked for loose internals or foreign matters.All components shall be identifiable, pipe spools shall be clearly labelled and piping items shall betagged.All flange facings, specially gasket area's, shall be checked for damage.

All piping and pipe spools shall be installed without imposing excessive stresses.Where flanges do not meet, additional field welds shall be made.No excessive pulling or jacking to force a system in position is allowed.Company shall have the right to check potential stress in piping by unbolting or otherwise.Flange connections to equipment shall be individually checked for stress-free assembly and alignment.Supplier’s instructions shall be adhered to.

Pipe supports shall be installed together with the piping system. Where required temporary supportsshall be used.Pipe supports shall be designed, fabricated and installed per the applicable general specifications orotherwise indicated requirements.

Piping penetrations/sleeves.

General- Pipe will be in the middle of the applicable penetration and will at no time be in contact with

the sleeve- Penetrations/sleeves for piping penetrations shall be included on the structural (fabrication)

drawings.- Where practical piping penetrations can be combined, tailor-made (oblong) sleeves can be

drawn and used.

Sleeves in decks:- Penetrations shall not affect structural integrity of the deck.- Sleeves 130mm above deck, 10mm in deck plate and 10mm under deck (see table).- Sleeves to be prefabricated and installed in deck during fabrication of deck and coated with

deck where possible.- Sleeves in deck to be welded above and below deck with fillet weld = WT sleeve to the deck.

Material comparable to deck plate material.

Sleeves in grating :- Penetrations shall not affect structural integrity of the grating.- In removable grating penetrations to be avoided, possibly half-sleeves with opening to side of

grating can be used.- Sleeves 75mm above grating, 30mm (or 50mm) in grating (see table).- Sleeves to be welded in grating during grating fabrication and to be Hot-dip-galvanised with

grating where possible. Material as material for grating


Sleeves/penetrations in beams :- Penetrations shall not affect structural integrity of the beam, calculation for each typical

application required, in general penetrations near the middle of the web- Use of rings made from plate, fillet-welded to the web, on one or both sides, can be

considered.- Sleeves to be prefabricated and installed in beam during fabrication of deck and coated with

deck where possible. Material as material for beams.

Penetrations through rated walls :- For penetrations through gas-tight or firerated walls the rating shall not be affected by the

construction or materials used for the penetration. Dedicated design to be made and approvedfor each application.

Field welds shall be made after insuring that piping is installed in the correct position. Shrinking asresult of field weld shall be calculated for. Special care shall be taken not to damage already installedpiping and equipment or affect their surfaces by grinding or weld spatter. Proper cover shall beapplied.

Installed piping shall comply the construction drawings.

Vents and drains shall be installed on high and low points where appropriate (All vents and drains shallbe indicated on the isometric drawings.)

Instruments, drain tubing, valve controls etc. shall be installed after piping installation.

Thread nipples shall be fabricated by Contractor of stock lengths of pipe. The ends of all field threadedpipe shall be reamed to remove any burrs. If indicated on the drawings nipples shall be hexagon type.Threaded connections shall not be back welded unless specified or approved by Company.A sealing compound or tape approved by Company shall be used on all threaded connections. (Seeapplicable section of this specification.)After completion of branch welds, the header shall be cleaned before the final weld or flangeconnection eliminates access to the inside of the fabricated section.


Process Pipe diameter in inches Sleeve (pipe diameter) Length (grating 30/50)

3/4 6" Sched. 40 150mm (105 / 125 mm)

1 6" Sched. 40 150mm (105 / 125 mm)

1 1/2 6" Sched. 40 150mm (105 / 125 mm)

2 6" Sched. 40 150mm (105 / 125 mm)

3 8" Sched. 40 150mm (105 / 125 mm)

4 8" Sched. 40 150mm (105 / 125 mm)

6 10" Sched. 40 150mm (105 / 125 mm)

8 12" STD 150mm (105 / 125 mm)

10 16" STD 150mm (105 / 125 mm)

12 18" STD 150mm (105 / 125 mm)

14 18" STD 150mm (105 / 125 mm)

16 20" STD 150mm (105 / 125 mm)

18 22" STD 150mm (105 / 125 mm)

20 24" STD 150mm (105 / 125 mm)

24 28" STD 150mm (105 / 125 mm)

NOTE:When process pipe is insulated, the diameter of the sleeve has to be increased with the insulationthickness (2x).


5.0 REQUIREMENTS FOR NON CARBON STEEL AND GALVANISED PIPING

5.1 Requirements for Duplex Steel (Class … DS)

(Ferritic/austenitic stainless steel from material type "Werkstoff Nr 1.4462").Duplex piping in general to be coated per General Specification 525.

5.1.1 Handling Duplex steel - See Attachment I to this specification.

Duplex steel shall never be in direct contact with pipe supports. During installation the correct measuresshall be taken to ensure this.

5.1.2 Welding of Duplex steel

For the requirements of welding of Duplex steel reference is made to the applicable attachment to thisspecification.

Any welding of / to Duplex steel shall be performed in strict accordance with this document(Attachment I).

5.1.3 Pickling and passivating of Duplex steel

After welding and before coating all duplex pipe spools shall be pickled and passivated by method ofbath emersion (specification to be submitted by Fabricator and approved by Company).Field welds shall be avoided; in case field welds can not be avoided completely, a dedicated procedurefor welding and treatment after welding shall be prepared by Contractor and submitted to Companyfor approval.

5.2 Requirements for Cunifer Piping (Class 15UK)

5.2.1 General

Cunifer as per ASTM B466, is often referred to as "Cunifer 10" or "offshore quality Cunifer". Cunifermaterial can deviate from standard material specifications for dimensions and shape of specially tee'sand flanges.Cunifer is used with wt's far less than wt for comparable CS piping. For this reason the spools are rathervulnerable, therefor extra attention in handling and supporting is required.

Cunifer piping shall not be coated, CS parts (flange backing-rings, valves, studbolts & nuts etc. andobviously supporting) are to be coated.(Note : only possible method to coat CS backing-rings to spec. is to coat these before assembling spools,backing rings are also delivered HD-galvanised, this is in general also acceptable.)


5.2.2 Handling

Any direct contact between Cunifer and carbon steel components shall be avoided.

Dedicated tools that have not been used on any other material shall be used.Earthing clamps for welding and cutting shall be made of bronze.Handling equipment, such as slings, hooks and lift truck forks shall be protected by clean wood, cloth orplastic buffers to avoid contact with the surface.

Cunifer shall be stored indoors, it shall be protected from moisture, dust, salt, iron particles and othermatters that may initiate corrosion.

Cunifer shall never be in direct contact with CS pipe supports. During installation the correct measuresshall be taken to ensure this.Supporting of Cunifer shall be based on (plastic) lined U-bolts with lining pieces.

5.2.3 Welding

Welding of Cunifer will be performed to requirements as laid down in the general weldingrequirements description in this specification, with the following additional remarks :- welding process will be a non-slag process (in general considering the small wallthickness a TIG

process will be used), welding process and consumables will suit the Cunifer and weldingmaterial producers guidelines for processing same.

- weld material and HAZ will have mechanical and corrosion qualities at least comparable tooriginal material.

5.3 Requirements for Poly Ethylene Piping(Class 15UP)

PE-piping in general requires specialists to fabricate and install. In general material to be processed topiping system to manufacturers recommendation for design, welding (fusing) supporting (entirelength), etc..PE-piping not to be coated.

5.4 Requirements for Hot Dip Galvanised Piping (Class 15U)

Spools class 15U will be HD-Galvanised (per specification 525) after fabrication of spools. Field weldsare not allowed. After galvanising and before installation flange facings to be checked for and ifnecessary cleaned from excessive zinc.

5.5 Systems that require extra grade of cleaning.

Some systems require extra cleaning by means of pickling and flushing because of their processfunction. This is always the case for the systems indicated below, and further as indicated on thedrawings and further documents. Procedure to be prepared by Contractor and approved by Company.Systems to be pickled and passivated as a system for process reasons :- Hydraulical- and lube-oil systems- piping upstream gas-compressors downstream last filter (note possible bypass loops to be

included).See also remarks with “testing” and “medium”.


6.0 FLUSHING AND PRESSURE TESTING

6.1 Scope

In this specification described method of flushing and testing is applicable for piping systems onplatforms and installations. For (subsea) transportlines dedicated procedures per applicable codes arerequired.

6.2 Flushing

After installation and before pressure testing piping systems shall be thoroughly flushed. Result shall bea clean piping system. At least all debris and contamination of the piping system shall be removed.Depending on the use of the piping system, further requirements shall be applicable (hydraulic systems,fuel systems, etc.).Flushing in general shall take place with fresh water ; if water in the system is a problem, alternativesshall be used (air for air-system, oil for hydraulic system, etc.)

Flushing water used for CS shall not be used for SS or DS.Water for SS shall not contain more than 20 ppm chlorides.

Where in-line items can be expected to become any obstruction to flush-out debris, or where thepossibility of damage to system or in-line items exists, these items shall be removed before flushing (alltypes of valves, instruments, filters, etc.).

6.3 Testing and Test Systems

6.3.1 Procedure

Prior to initial operation, each installed piping system shall be pressure tested in accordance with PEDand Company standard practice to assure mechanical strength and tightness. Table 6.3.1.A is forinformation only. DAD’s prepared per PED give required test pressure. All Pressure testing shall be donein accordance with a Contractor prepared and Company approved hydro test procedure. A testdiagram shall be made for determining the test systems.Test pressure shall be indicated on the AFC-drawings.Contractor to check allowed test pressure for all components that are includedPressure test procedures shall be made in accordance with NEN-EN 13480 and Company standardpractice.

In general complete systems shall be tested. Piping shall be tested in the installed position with all pipesupports fitted. If piping has to be dismantled additional supporting shall be provided to preventoverstressing of the system.Spring supports shall remain in the locked position .


Table 6.3.1.A.

Hydrostatic Test Pressures

PipeClass.

Max.design(Barg)

Temp.rangeC

Test press.(Barg)

Remarks

15 17.7 -20/+95 25.0

15C 17.7 -70/+95 25.0

15U 17.7 -20/+95 25.0

15UK 17.7 -20/+95 25.0

15UP 10.0 -10/+50 14.0

30 46.4 -20/+95 62.3

30W 43.8 -20/+200 59.0

30H 38.1 -20/+315 >> For ambient tempe-rature, use 62.3 Barg

60 92.8 -20/+95 122.6

90 139.0 -20/+95 182.7

90H 131.5 -20/+200 >> For ambient tempe-rature, use 182.7 Barg

250 386.0 -20/+95 503.8

15DS 20.0 -20/+100 28.0

30DS 51.5 -20/+95 69.0

90DS 148.0 -20/+180 194.4

250DS 418.0 -20/+150 545.4

15S 16.2 -20/+95 22.7

500S 351.7 -20/+95 459.2

Notes: - test medium at ambient; temperature "ambient"Ta defined as 12Ta 25 C.

Where practical, appurtenances (valves, small vessels etc.) can be left in place as part of the system.

In general instruments can be left in place, if necessary instruments can be blocked off at designpressure and monitored with a PI (applicable for i.e. LG's). Alternatively process instrument connectionscan be disconnected, system to be tested can be blinded off (plug or cap).


At all times the following items shall be considered :- the extra weight of vessel system contents (deck structure, supporting) if testing with water- check for all items on maximum allowable pressure or possibly vacuum,- check for all valves to allowable pressure in open position and if applicable in closed position,

check required position ball / internals,- check for the absolute absence of chance on damage of internals appurtenances or vessels

either by pressure, by weight or by medium as result of pressure testing or presence. Filters andfilter type vessel internals shall not be part of pressure test with water.

Operation and/or maintenance instructions on items involved shall be carefully checked for requiredposition before, during and after pressure test.

Control, relief- and check valves shall be removed. Temporary spools may be used to avoid splitting thetest system.No test systems shall be coupled by tubing.

6.3.2 Medium

Medium for testing shall be clearly indicated in the testing procedure.In general for piping nitrogene with Helium shall be used. Only in case where such test is not practical,hydrates will be permitted subject to approval Company. Corrosion inhibitors shall be added (200 ppmof a suitable and Company approved make, all to be clearly indicated in pressure test procedure).

Fuel and instrument air piping shall be tested with dry air or nitrogen.Drain systems and vent relief systems can be tested with a soap solution.

Lube and seal oil systems which could be impaired by the presence of water shall be alternatively testedin accordance with manufacturer's/company's recommendation.

Test and flushing water that has been used for carbon steel systems shall not be used for stainless steelor duplex piping. Water for stainless steel or duplex shall not contain more than 20 ppm chlorides.

6.3.3 Testing and recording

Piping systems shall be thoroughly flushed and filled with medium selected for testing (see above). Themedium shall have ample time for setting and to allow the entrapped air to be vented.

For system tests each pressure test shall be monitored by one recorder, a thermometer and twopressure gauges one of which is connected to the highest point of the test system.Recorders and gauges shall be calibrated and certified in accordance with the NoBo requirements andapproved and accepted by Company.The certificates shall be kept ready for inspection on site.No testing shall be performed when ambient temperature is below 10 degrees C.The minimum test pressure shall be measured at the highest point of the system.

The test system shall be kept under pressure for settling until all entrapped air is dissolved into thewater. After approval of NoBo or Company the testing period starts and shall be recorded. Thepressure shall be maintained for the period mentioned in the pressure test procedure or as long isrequired by NoBo or Company.


If pads or saddles have been installed at branch connections, ventholes shall be carefully inspected toreveal any leakage during testing.Ventholes shall be left open or plugged with a soft material not being able to sustain any pressure.

Each weld, flange connection and piece of equipment shall be carefully checked for leaks during thetest. Any leaks found shall be corrected after de-pressurising the system.After correction of leaks or defects Contractor shall retest the system.

If, during the test period, the pressure changes due to temperature variations of the test water acorrection calculation shall be part of the test report.If the ambient temperature is considerably higher than the testwater, care shall be taken that, due toexpansion of the water, the pressure does not exceed the maximum test pressure.

6.3.4 Preparation system after testing

After successful completion of the test, the system shall be flushed and drained promptly and beblown dry with compressed air.The system shall be filled with nitrogen if Company requires so.Care shall be taken that each high point is vented and each low point is drained.Draining shall be slow enough not to create a vacuum that possibly can be detrimental to the system.Prior to blowing all bottom plugs shall be removed.

All duplex systems shall , after completion, prior to load out, be cleaned and flushed with an approvedsolvent, dried with hot air and filled with nitrogen at 1 Bar min. and sealed off.

System(s) shall be closed with blind-plates and spades, fabricated from plate / supplied by Contractor.For duplex flanges stainless steel liners and spades shall be used. Spades shall be painted red and clearlyvisible, all studs / nuts shall be installed, the original gaskets etc. shall be attached to the spade. Achecklist showing all spades shall be made to enable off shore re-installation of the joints.

6.3.5 Alternative methods

If no pressure testing is possible, alternative/additional testing might be acceptable but only afterconsultation of and approval from Company- and if applicable NoBo representative.

6.3.6 Inspection and witnessing

All test shall be witnessed and approved by Company, and where applicable by NoBo" representative.During the test the system shall be accessible for proper and safe inspection.

6.4 Safety during Pressure Testing

Precautions shall be taken to ensure that the pressure test is done in a safe manner. It should be kept inmind that a considerable amount of energy is present in the test medium under high pressure.Only personnel directly involved in the test shall be permitted in the vicinity.Further if applicable the use of N2 to fill systems after pressure testing and draining the system, shall bereason for extra attention, note N2 if inhaled in larger quantities is lethal.Systems filled with N2 shall at all times be clearly marked with appropriate warning signs.


7.0 QC PIPING FABRICATION

7.1 General

The nature and extend of supervision and inspection during fabrication, installation and testing shall beagreed between Company, NoBo (if applicable) and Contractor.The general contents agreed shall be laid down by Contractor in a quality control plan.

7.2 Inspection Piping Prefabrication

Inspection on prefabrication shall guarantee as a minimum the following items:- check on use correct materials and adherence to material control procedures,- visual examination materials before use,- visual examination fit-up before welding,- inspection on working (incl. welding) per specifications- visual examination after welding- inspection on dimensions (both dimensions from drawing as fabrication-results (square,

straddled, straight, etc.),- Non Destructive Testing- Heat treatment- Coating- Dimensional inspection to drawings- Inspection as required for Class. Authority for piping where applicable- Documentation incl. As Built.

7.3 Inspection Piping Installation

Inspection on installation shall guarantee as a minimum the following items:- inspections as indicated for prefabrication where applicable- handling, transport and storage of spools- strain-free installation of piping- extra attention of closing system to avoid contamination of piping systems and equipment to be

connected- Non Destructive Testing field welds- Coating inspection- Supporting

7.4 Non Destructive Testing

7.4.1 Quantities

Welds in piping shall be tested with NDT techniques.In general the following scheme shall be adhered to.- Welds on piping subject to NoBo approval must be 100 % NDT tested.- Any weld in class 30 and up must be 100 % NDT tested.- Welds on piping not subject to NoBo approval and not in class 30 and up must be as, a minimum,

10 % NDT tested.


7.4.2 Types and standards for NDT

NDT will be done per approved procedures and standards and by qualified personnel. Procedures andqualifications shall be based on ASMI (V for procedure and VIII for acceptance), and will as a minimumfulfil the NoBo requirements as laid down in the subject sheets. The locations of the weld examinedshall be indicated on a drawing in such detail, that the precise location of each checked weld can betraced. NDT on a weld will include type of check per table included.

NDT on welds CS and Duplex

Radiographic Ultrasonic +Magnetic Particle

Magnetic Particle

FP butt-weld *

FP K-weld *

Non FP-weld *

Scars / burns *

Notes: - In all applications NDT-results must give clear view on the quality of the weld to beexamined. If necessary NDT-technique will be adapted to suit this goal.

- For SS-types (including Duplex) MPI will be replaced by Dye-Penetrant Inspection.

8.0 DOCUMENTATION

During fabrication and installation all relevant information shall be tabulated on the "Weld HistorySheet" attached to this specification or on an approved similar Quality Control Document, and shall beissued to Company.

The extent of further documentation to be issued shall be agreed between Company and Contractor.

GENERAL SPECIFICATION

ATTACHMENT I

TO SPECIFICATION 502

WELDING OF FERRITIC/AUSTENITIC STAINLESS STEEL

11 100806 JRO Update Table for Piping Penetrations/Sleeves JRO DZO

10 190406 JRO Update JRO DZO

9 230902 JRO Change of Layout JRO DZO

8 111200 CZY Name Change JRO CvB

7 071100 GvS Update paragraph 1.4 JRO CvB

6 040899 GvS Change Company JRO CvB

REV DATE ORIG. DESCRIPTION CHECKED APPROVED

Sheet Revision

GDF PRODUCTION NEDERLAND B.V.ATTACHMENT I

to Specification 502 1 of 20 11

GDF Production Nederland B.V.Attachment I to Specification 502 Rev.9 Appendix I, page 1 of 1

TABLE OF CONTENTS

1.0 GENERAL

1.1 Scope1.2 References1.3 Abbreviations and Description1.4 Transport, Storage and Preparation1.5 Documentation

2.0 WELDING CONSUMABLES

2.1 Electrodes, Wire and Flux2.2 Condition of Storage

3.0 WELDING PROCEDURES

3.1 General3.2 Welding Procedure Specification3.3 Welding Procedure Qualification3.4 Procedure Qualification Record3.5 Inspection of Procedure Qualification Test Welds3.6 Quality Requirements

4.0 WELDER'S COMPETENCE CERTIFICATES

4.1 General4.2 Making of Welds4.3 Applicability of Welder and Welding Operator4.4 Retests4.5 Welder Qualification Record

5.0 PRODUCTION WELDING

5.1 General5.2 Weather Protection5.3 Handling and Usage of Welding Consumables5.4 Welding End Preparation5.5 Backing Strips5.6 Welding Process, Position and Progression5.7 Argon Gas Purging inside Pipes5.8 Heat Input Preheating and Interpass Temperatures5.9 Weld Interruption5.10 Cleaning5.11 Size of Welds5.12 Distance between Welds5.13 Socket Welds5.14 Weld Finish5.15 Post Weld Heat Treatment


6.0 FABRICATION

6.1 General6.2 Bending6.3 Alignment and Fit-ups6.4 Finishing of Surfaces6.5 Protection of Pipe-Ends6.6 Repair and Remedial Procedures

7.0 INSPECTION AND TESTING

7.1 General7.2 Methods of Inspection, Testing and Quality Requirements


1.0 GENERAL

1.1 Scope

This document as part of Specification 502 covers the requirements of welding and inspection ofduplex stainless steel shop and field fabricated piping.Duplex stainless steel shall refer ferritic/austenitic stainless steel with a chemical compositionand mechanical properties as defined in VdTüV Werkstoffblatt Nr. 418, DIN Werkstoff Nr.1.4462.

1.2 References

The following specifications, codes and standards are to be considered where applicable. Allconflicts between the requirements of these relevant shall be referred to Companyfor resolution.In case of conflicts between the documents listed and this document, the most stringentrequirement shall govern. The latest editions of the following standards and codes shall apply:

- "Pressure Equipment Directive" hereafter indicated as PED.- ASME Boiler and Pressure Vessel Codes, Section V, Section VIII Division 1 and Section

IX.- List of approved welding electrodes of "Controlas"- International Welding Institute

* IIW/IIS 492-75 Recommended practice for the radiographic inspection ofcircumferential welded butt joints in steel pipes upto 2" (50 mm) wall thickness.

* IIW/IIS 62-60 Recommended practice concerning radiographic image quality indicatorsI.Q.I.

- DIN 54109, Teil 1, May 1976, and Blatt 2, October 1964."Bildgüte von Durchstrahlungsaufnahmen an metallischen Werkstoffen".

- NEN 2512 (1977) Radiografisch onderzoek van lasverbindingen in staal.- NEN 2517 - Radiografisch onderzoek van lasverbindingen in staal - Minimum beeld

kwaliteitswaarden- ASNT SNT-TC-1A None-destructive testing- ASTM A 262-85 Recommended practices for detecting susceptibility to intergranular

attack in austenitic stainless steel.- ASTM A 370-77 Methods and definitions for mechanical testing of steel products.- ASTM E 94-84a- Guides for radiographic testing.- ASTM E 165-80 (1983) Practice for liquid penetrant inspection.- ASTM G 30-79 (1984) Practice for making and using U-bend stress corrosion test

specimens.- ASTM G 48-76 (1980) Test methods for pitting and crevice corrosion resistance of

stainless steel and related alloys by the use of ferric chloride solution.- ISO 2560 Covered electrodes for manual arc welding of mild steel and low alloy steel -

Code of symbols for identification- Specification no. 503, Specification for pipe, fittings and valves.


1.3 Abbreviations

BM : Base MetalEFN : Extended Ferrite NumberGMAW : Gas Metal Arc WeldingHAZ : Heat Affected ZoneIIW : International Institute of WeldingNDT : None Destructive TestPQR : Procedure Qualification RecordQA : Quality AssuranceQC : Quality ControlSAW : Submerged Arc WeldingSMAW : Shielded Metal Arc WeldingWM : Weld MetalWPS : Welding Procedure SpecificationsWPQ : Welding Procedure Qualifications

1.4 Transport, Storage handling and Preparation

The following recommendations shall be adopted in every step in the manufacturing process toreduce the risk of surface contamination of this type of stainless steel.

a. Any contact between stainless steel and carbon steel components shall be avoided.Fabrication of pipe spool shall be carried out in a separate area.

b. Before transportation and field installation each pipe spool shall be protected with tape.c. Only stainless steel wire brushes that have not been used on any other material shall be

used. Grinding wheels used for stainless steel shall not have been used for other purposes.Earthing clamps for welding and cutting should be made of stainless steel.

d. Moisture shall be removed by carefully and controlled heating with a torch. Skintemperature shall not exceed 150 °C.

e. Acetone (or approved equivalent) may be used for cleaning stainless steel surfaces.Caution: Acetone is extremely flammable.

f. Arc cutting shall be done by using only plasma arc process.g. Contamination of Duplex stainless steel with zinc, etc. shall not be permitted.h. Handling equipment, such as slings, hooks, and lift truck forks, shall be protected byclean

wood, cloth, or plastic buffers to exclude contact with the stainless steel surface. Theseprotection means shall be immediately replaced after any contact with carbon steel.

i. Stainless steel shall be stored indoors, or otherwise protected from moisture, dust, salt,iron particles, and other matter that may initiate or cause corrosion.

l. If any construction activity is to be carried out in the vicinity of installed duplex orstainless steel piping and/or equipment, adequate protection shall be provided to preventany damage before such construction work commences.


1.5 Documentation

The following documentation shall be supplied by the Contractor:- Mill certificates of materials used if the material is supplied by the Contractor (See

specification 503 and "PED")- Welding Procedure Specifications, Procedure qualification records and welders certificates- Procedures and methods for assembly, fabrication and handling- Procedures for repairs- Inspection and QC procedures- Non destructive testing records and radiograph films- Drawings indicating material and NDT locations- Hydrotest records, including instruments calibration data

2.0 WELDING CONSUMABLES

2.1 Electrodes, Wire and Flux

Consumables from Company approved suppliers only shall be used (see Appendix to thisattachment). Consumables shall have a similar chemical analysis to that of the base material,however, the nickel content shall at least be 7.7 percent.

The weld metal should have a corrosion resistance equal to, or better than, the base metal.

2.2 Condition of Storage

Electrodes, wire and flux shall be supplied in fully sealed packages and stored in a dry storageroom. All manual type electrodes shall be properly identifiable up to the time of usage, eachelectrode being distinguished by proper coding. In the coding is destroyed by baking, handling,or other causes, the electrodes shall not be used.

Consumables used for welding duplex stainless steel shall not be stored in heated cabinetscontaining electrodes of other types, such as rutile or organic type electrodes or consumables forwelding other types of stainless steel e.g. AISI Type 316L.

Wire spool for automatic and semi-automatic processes shall be stored in cabinets with supplierwrapping not removed and remain clearly identifiable up to the time of usage.

Unidentifiable wire shall not be used.

Flux shall be supplied and stored, in accordance with manufacturers instructions.

Each batch of flux and wire shall be labelled with the information from the supply container.The labels with batch number shall be recorded by reference in relation to the actual weldingwork.All non-identified, damaged, wet, rusty or otherwise contaminated consumables are to bescrapped. Electrodes (once melted) or with white spots on the flux shall not be used.

All bottles containing shielding gases shall have clear identification labels.


3.0 WELDING PROCEDURES

3.1 General

Detailed welding procedure shall be established and qualified in accordance with NoBo as perPED and as further as required in this Specification (see also OW 291 of ASME Section IX, PartQW-201).

No production welding shall commence until the appropriate procedure tests have beencompleted and approved.

Repair welding procedures are to be established and, where necessary, qualified.

3.2 Welding Procedure Specifications WPS

A written welding procedure specification together with test certificates indicating mechanicalproperties and chemical analyses of both base materials and welding consumables shall besubmitted to the Company representative for preliminary approval.

No procedure qualification tests shall be performed until the procedure specification has beengranted preliminary approval by the Company representative.

Welding procedure specifications shall contain the following "applicable parameters" with allexplanatory details necessary (see also ASME Section IX, part QW-250):

- Material specification of base metals.- Welding process.- Wall thickness and diameter range used for procedure qualification (chemical analyses and

mechanical properties of the base material and welding consumables used for theprocedure tests shall be included in the welding procedure qualification record).

- Geometry of welding groove showing allowable tolerances.- Root gap showing allowable tolerances.- Welding position and direction.- Filler metal classification.- Specification of flex.- Specification of flux.- Gas shielding - flow, mixture, composition (to include back purging).- Number and sequence of the important passes (indicate stringer or weave beads).- Welding current range, voltage range and polarity.- Travel speed or electrode runout length for each pass and range.- Heat input range.- Preheat and interpass temperatures.- Method of cleaning, cutting and machining if applicable.

When any changes in these parameters are made, the welding procedure qualification shall beset up as a new WPS, and shall be completely re-qualified.


3.3 Welding Procedure Qualification WPQ

A qualified welding procedure specification is one which is tested to and has achieved therequirements of this Specification, and has been witnessed and approved by the Company'srepresentative and the Certifying Authority.

The Contractor shall conduct the tests required to qualify each procedure and tests shall bewitnessed by the Company representative and the Certifying Authority. The results of previouswelding procedure qualification tests may be accepted by the Company's representative and theCertifying Authority providing:

a. Welding specifications and resulting test certificates are authenticated by the originaldocumentation, or by certified copies.

b. The Contractor submits documentation, for the approval of the Companyrepresentative, todemonstrate that all the appropriate test requirements, applicable parameters, weldingconditions, equipment and materials as used in the original welding procedurequalification tests, comply with and fulfil all the appropriate test requirements of thisSpecification.

All services in connection with the establishment of welding procedures, welders performancequalifications, related tests and additional corrosion tests shall be by the Contractor.

Qualification of a welding procedure is restricted to the Contractor or Subcontractor where thetest weld was produced.

Welding procedure and welders performance qualification shall be new and subject to approvalby Company's representative.

Welding procedure qualification tests shall be conducted to verify the WPS's, and shall simulate,as far as practical the conditions and materials to be used for production welding.

A qualified procedure is valid only for diameters and thickness in accordance with PED andfurther rules.

3.4 Procedure Qualification Record PQR

The specific facts of the WPS and test results of the WPQ shall be recorded in the procedurequalification record PQR, signed by the responsible welding engineer, QA engineer andNoBo.

3.5 Inspection of Procedure Qualification Test Welds

The base material, welding consumables and welding process shall be equal to those as specifiedin the welding procedure specification WPS.

Dimensions of the weld samples shall be sufficient to provide for the required test pieces asdefined in the PED.

During welding, the welder's name and all data listed in the WPS shall be recorded.


3.6 Quality Requirements

All weld samples for the procedure qualification shall be subject to NDT (radiographic,ultrasonic testing and surface examination) and acceptance in accordance with this Specificationprior to mechanical testing. The acceptance criteria for mechanical testing shall be in accordancewith PED.

A cross-section of the weld shall be made for microscopic and a macroscopic investigation. Thecross-section shall clearly show the weld metal, fusion line and heat affected zone. The ferritecontent shall be measured using a magna-gage equipment or an alternative tool approved by theCompany. At least 5 measurements shall be made. The ferrite content shall be expressed in aextended ferrite number EFN and the average value shall be between 40 and 65 for the weldmetal and heat affected zone. Any single value shall not exceed a 10% of these values.

Hardness tests shall be carried out at one line 2 mm away from both surfaces of weld cross-section and halfway between these surfaces. Zones of indentations should give three values inthe base material BM on both sides of the weld in addition to those in the weld metal WM andheat affected zone HAZ.

The minimum distance between the indentations should be two and half times the width of theprevious indentation. The maximum allowable hardness measured is 305 HV 30 (305 Vickershardness measured on 30 kg load). Maximum allowable hardness variation between any pointindicated may be 100 HV 30.

Charpy-V notch impact test shall be carried out when the wall thickness of pipe or fittingexceeds 5 mm.Three notch impact test pieces (standard specimen 10 x 10 mm) shall be taken in transversedirection on the weld and shall be tested at Vt-test temperature in accordance with Stoomwezenrequirements for an Vc-assessment temperature of minus 20 degrees centigrade. The averageimpact value shall not be less than 52 Joule with only one value lower, but not below 39 Joule.The dimensions, preparation and testing of the impact test specimens shall be in accordance withISO 2560.Subsized specimen may be used when standard specimen cannot be prepared. In this case therequired values may be lowered accordingly.

4.0 WELDERS'S COMPETENCE CERTIFICATES

4.1 General

Welders and welding operators shall be qualified in accordance with the requirements of thePED in accordance with the applicable requirements and of this Specification. Whereradiography is specified only X-ray shall be used. Mechanical testing as required. By PED.


4.2 Marking of Welds

The welder shall clearly mark the pipe adjacent to his weld with the identification mark assignedto him in his qualification certificate prior to starting the root pass.

Tack welding of components should not be marked.

Marking shall be done with weather-proof chalk (chloride-free crayon).

The use of stamps for marking the welds is not allowed.

The welder/operator who makes the root pass shall write his code at the top of the pipe; if,however, two welder/operators weld the root pass, each welder/operator shall mark the top ofthe pipe with his identification code on the side on which has worked. Subsequentwelders/operators shall write their identification codes below the first code in the sequence inwhich they work. The identification marks may not be removed until after the welds have beeninspected both visually and non-destructively.

4.3 Applicability of Welder and Welding Operator Qualification

The Contractor shall ensure that qualified welders and welding operators are employed duringfabrication onlyon welding the type, process and position of weld for which their qualificationtest so qualifies them. Proven previous qualifications can be submitted to Company foracceptance. A welder or welding operator may also be required to re-qualify if inspection duringfabrication reveals that repairs are necessary due to unacceptable defects.

The Contractor shall maintain an accurate record of the performance of each welder whichshould show the repair rate.

The repair rate should be indicated as a percentage of the total length of weld produced.

4.4 Retests

Retests are not accepted and only considered after consulting Company's representative.

4.5 Welder Qualification Record

A Welder's qualification record, which includes references or the corresponding WPS nr., theapplicable parameters and the test results, shall be issued for each welder or welding operatorand for each test.


5.0 PRODUCTION WELDING

5.1 General

No welding shall be carried out before the welding procedures and procedure qualificationrecords are completed and approved and the welders have been qualified.

Preparation and welding of pipe components shall be in accordance with the appropriatequalified welding procedure specifications. Manual electrodes, wire and flux shall be of thesame type and manufacture as those used in the procedure.No welding shall be done until as much of the pipeline or piping system as will be stiffenedthereby has been properly aligned.

Every buttweld preparation, before welding, will be inspected and approved by Company'srepresentative.

The Company will have the right to carry out any concurrent test deemed necessarywhen anydeviation from this specification is made.

Attention is to be given to the necessity of achieving adequate firm support of the pipecomponents in both the vertical and horizontal plane.

Alignment and fit-ups for two pipe components shall be in accordance with para. 6.3.

Current return cables of welding equipment shall be connected directly to the pipe on whichwelding work is to be done using stainless steel clamps.

Marking of welds shall be in accordance with para. 4.2.

5.2 Weather Protection

Shelters giving adequate protection at all times to the weld area from wind, rain and moistureshall be provided.

No welding shall be carried out when the weld surfaces are wet, moist or when the work area isexposed to winds.

Following is required:

- Weld surfaces to be thoroughly dried by heating. High metal skin temperature shall beavoided and shall not exceed 150 deg. C.

- Provisions to be made for maintaining a satisfactorysurrounding temperature and freedomfrom the effects of wind.

- Provisions to be made to reduce distortion as could occur due to differences in temperaturebetween components.


5.3 Handling and usage of welding consumables

Welding rods, electrodes, filter metals and fluxes shall be handled and used in accordance withthe manufactures recommendations.

5.4 Welding End Preparation

The equipment used for edge preparation and cleaning (e.g. plasma cutting, grinding, machining,emery cloth, grit blasting using alumina shot, wire brushing using a stainless steel wire brush,etc.) shall cause no detrimental metallurgical effects upon the edges to be welded.

Edge preparations may be made by shearing machining or hand grinding to an accurate form.

Preparation of weld edges by plasma cutting shall, wherever practical, be done with amechanically guided torch. Edges shall be left free of slag, spatter, scale, dirt, grease, salt,protective coating or other foreign matter which might effect the quality of the weld and the cutsurface shall be ground to a smooth bright uniform surface by removing approximately 0.5 mmof metal. After grinding the weld edges shall be visually examined to ensure freedom fromdefects.

Any bevelled edge that has been damaged shall be restored within the tolerances required by thewelding procedure to be applied.Restoration involving welding shall not be permitted.

The welding end preparation shall be carried out in accordance with minimum requirementsstipulated in Appendix II and shall be subjected to Company approval.

5.5 Backing Strips

Backing strips shall not be allowed.

5.6 Welding Process, Position and Progression

The welding process, procedures and specifications shall be subjected to Company approval.

5.6..1 Gas Tungsten Arc Welding GTAW (TIG)To ensure a high-quality weld with a smooth surface inside the pipe, GTAW-welding is requiredfor the root-bead.

Manual and automatic GTAW process in the uphill progression only.Special care shall be taken to protect the weld area from any draught, both externally andinternally.

99.998 percent argon backing and shielding gas is always required throughout welding.Oxidation caused by the welding procedure and/or process shall not be allowed. Flushing withargon before welding will be required. The oxygen content of the backing gas directly beforewelding shall be determined with oxygen measuring equipment and shall be less than 0.05percent.


Between welding passes, the metal should be allowed to cool to approximately 150 deg. C.For a high quality of welding, ferritic austenitic stainless steel material should be at atemperature of at least 15 deg. C before welding.

Overheating may also cause cracks, and these, too, must be removed and repaired(see paragraph 6.6).

When welding pipe, for best results weld short passes on alternate sides of the pipe. On pipe lessthan 6 inch in diameter, each pass should be not over 2 inch in length for pipe 6 inch, or over indiameter, each pass may be 3 inch in length.

5.6.2 Submerged-Arc Welding SAWThis shall be done in a flat position and the pipe shall be rotated. This process shall only be usedfor filling and capping. Wire and flux shall be from the same manufacturer.

5.6.3 Shielded Metal Arc Welding SMAWElectrodes shall only be used for filling and capping and only in the position recommended bythe manufacturer.

5.7 Argon Gas Purging inside Pipes

In order to avoid surface oxidation during welding process ferritic/austenitic stainless steel pipesmust be purged with 99.998 percent argon backing gas sufficiently to remove all oxygen insidethe pipe in the weld area. The usual way to achieve this is to seal off a small length of the pipeon each side of the weld groove. This restricted volume is then purged with a suitable inert gas,sufficient to remove all oxygen.Devices and procedures shall be subjected to Company approval.

5.8 Heat Input, Preheating and Interpass Temperatures

Heat input during welding should be kept low to reduce the danger of unwanted structures andprecipitates.

For this reason the degree of dilution must be kept low. Two layers with little weld metaldeposited are better than one layer with higher heat input and more deposited weld metal.

Preheating is usually not required. A limited preheating may be required in highly constraintconditions and only considered after consulting Company's representative. The maximumpreheat and interpass temperature shall not exceed 150 deg. C.

5.9 Weld Interruption

Welding of each weld shall be a continuous operation unless the maximum interpasstemperature is reached.Line up clamps shall not be removed nor shall the pipe be moved until the root and the secondpass have been completed.


5.10 Cleaning

During welding any part of the weld metal of parent plate exposed to the air at elevatedtemperature will become oxidised, the oxidation is ranging from light tinting to a black scale.Oxide shall be removed after each welding root, otherwise preferential corrosion may result,either from its difference in electrochemical properties or from its crevice action.

Upon completion of each welding pass, the weld shall be cleaned of spatter, slag and fluxdeposits.After welding is completed, adjacent surfaces shall be thoroughly cleaned of all spatter anddeposits, pickled and passivated in accordance with an approved procedure by Company'srepresentative.

To ensure the corrosion resistance of pipelines and piping systems and the passage of pipelinescrappers and other similar devices through the completed lines it is of particular importancethat the internal surface of pipes be as smooth as possible and free from all internal weldingbeads, slag particles, weld spatter etc.

Special care shall be given to the selection of the cleaning equipment and the rules defined inpara. 1.4 shall be followed.

5.11 Size of Welds

All welds shall be continuous and multipass. They shall be properly sized to develop the fullstrength of the thinner of the two pipe components joined.

5.12 Distance Between Welds

The number of welds shall be as small as possible. In general the minimum allowable distancebetween circumferential welds is 3 times the external diameter of the pipe.

If any 3 m a maximum of 2 welds is allowed unless otherwise specified on the drawings.

5.13 Socket Welds

Socket weld fittings shall be used in special cases only with preliminary approval by theCompany's representative.

Where socket weld fittings or valves are used pipe sections shall be spaced approx. 1.5 mmapart to avoid "bottoming" which can result in excessive weld stress. Approved weldingprocedures are to be adhered to.

5.14 Weld Finish

Welds shall be left as welded and not be treated with a torch or by any mechanical meansoutside the allowances of the welding procedure specification to change their appearance.


5.15 Post Weld Heat Treatment

Post weld heat treatment is not permitted.

Any uncontrolled heating of the pipe may impede the corrosion resistance of the material andshall be reported to the Company.

6.0 FABRICATION

6.1 General

All measures shall be taken to ensure correct positioning and sizing of the components to bewelded.

Work shall not be performed when the weather and/or lack of sufficient protection does notpermit satisfactory workmanship or when conditions prevent adequate inspection.

If any fabrication is to be carried out in the vicinity of equipment already installed than, beforesuch fabrication work commences, adequate protection shall be provided to prevent anydamagefrom weld spatter, cutting droplets etc.

Care shall be taken to avoid overloading, damage or undue deformation in any of the pipecomponents at all stages of the work.

Care shall be taken to avoid any zinc contamination of the stainless steel e.g. by overspray ofzinc containing coatings.

Handling of the stainless steel pipe components shall be done with great care and the measuresoutlined in para. 1.4 shall be followed.

6.2 Bending

Bending of duplex stainless steel pipe requires great care and procedures shall be approved bythe Company before any bending commences. It is usually required to heat treat the materialafter bending (1050 deg. C/water quench).

6.3 Alignment and Fit-ups

Internal line-up clamps of appropriate material shall be used where possible

Only for tie-in welds such as riser tie-ins and for special welds e.g. joints connecting valves,flanges and fittings external line-up clamps may be used.

When the internal diameter is 100 mm or less an external line-up clamp may be used.


Inside diameter misalignment of the adjoining welding ends shall not exceed 1/8 of the wallthickness with a maximum of 1 mm. If the misalignment exceeds the above value trimming atthe internal diameter of the thicker joint to a taper of 1 : 4 should be properly corrected.

Stainless steel spacing tools shall be used in conjunction with the line-up clamp to assure theproper joint spacing which shall be in line with the applicable welding procedure.

Any longitudinal welds in pipes shall be so positioned that the weld is at the top 120of the pipeand any two adjacent longitudinal welds shall be at least 45apart.

6.4 Finishing of Surfaces

When fabrication is completed, all welds shall be ground as indicated in the welding proceduresor on the drawings to allow proper radiographic or ultrasonic inspection, and to remove alldetrimental spatter, burrs, tack welds and other marks. Where so required the damage shall berectified in accordance with an agreed procedure.

6.5 Protection of Pipe Ends

A circular tight cap, of a design which will not damage pipe ends shall be used to cover the openends of the pipe and shall be placed on the line at the end of each day's work to prevent entry offoreign material. Caps shall not be removed until commencement of the following day's work.The requirements to protect the stainless steel as defined in para. 1.4 shall be adhered to.

All open ends of pipe ate to be capped off and sealed once installation in completed. Thisprotection shall be in line with para. 1.4.

6.6 Repair and Removal Procedures

Defective welds shall not be repaired before approval of Company in obtained.

All repairs shall be executed by qualified welders according to approved procedures and allrequirements of this Specification shall be met.

The removal of weld metal or portions of the base metal may be done by machining or grinding.High metal skin temperature shall be avoided and shall not exceed 150 deg. C. The unacceptableportions of the weld shall be removed without substantial removal of the base metal and shall bedone in such a manner that the remaining weld metal or base metal is not nicked or undercut.The grooves are to be free from scale and to have acceptable contours, and shall be visually anddye penetrant inspected prior to re-welding to ensure the defect has been completely removed.

Additional weld metal to compensate for any deficiency in size shall be deposited usingprocedures as required in the making of the original weld. The surfaces shall be thoroughlycleaned before depositing the additional weld metal.Local repairs shall normally be inspected 100% by the method prescribed for the original weldwith due regard to confirming that the original defect has been removed.


Every possible care shall be taken with repairs to minimise welding stresses.

If planar defects (cracks, lamellar tears, etc.) have to be repaired, every effort shall be made toprevent propagation of the defect during its removal. Dye penetrant inspection shall be carriedout to check for the complete removal of the defect.

A weld with unacceptable defects may only be repaired once by Company approved repairprocedure. If the repair is not acceptable the complete weld shall be removed.

An unacceptable weld shall be repaired or replaced in accordance with all above clauses. Whererepair is selected, the following measures are required:

- Overlap or excessive convexity - remove excessive weld metal.- Excessive concavity of weld or craters, undersized welds, undercutting - prepare surfaces

and deposit additional weld metal.- Excessive weld porosity, excessive slag inclusions, heavy metal inclusions, incomplete

fusion or planar defects - remove unacceptable portions and re-weld.

7.0 INSPECTION AND TESTING REQUIREMENTS

7.1 General

Written NDT procedures approved by the Company shall be prepared. All operations shall beperformed in accordance with these procedures.

All personnel performing welding inspection or non-destructive testing shall be qualified, asrequired by ASNT Recommended Practice No. SNT-TC-1A, to NDT Level II in the techniqueto be applied, or to a Company approved equivalent qualification.

7.2 Methods of Inspection, Testing and Quality Requirements

7.2.1 Radiographic Examination (as noted or NoBo approved equivalent)All radiography shall be carried out in accordance with the method described in PED andASME.

Radiography implies the use of only X-ray tests. Gamma-ray tests may, in specific cases, beaccepted by an approved procedure. Cobalt-60 isotapes shall not be used.

Radiographs shall be supplemented by ultrasonic testing accompanied by dye penetrant testingwhere there is reason to suspect planar defects such as cracks or lack of fusion.

Radiographs shall be made using a film equal to ASTM E-94 Type 1.


Film

Type Speed Contrast Grain Examples1 Slow Very High Very Fine Kodak Industrex M

Kodak Industrex TMXKodak Industrex TAgfa D2Agfa D4

Prepacked films e.g. roll pack may be used.Rigid or flexible cassettes may be applied.Only lead screens shall be used.

Penetrameters of the wire type (DIN or IIW) shall normally be used.

As far as practical internal sources i.e. crawlers shall be used. This is possible for pipelines of 8"diameter and larger. In cases where the source can not be placed inside the pipe the double wall,single image technique shall be applied as much as possible. Measures shall be taken that thestainless steel pipe shall not be contaminated by the inspection equipment.

The sensitivity shall be 2% or better. The film density shall be between 2 and 3. Denserradiographs are acceptable if adequate viewer capacity is available.

A continuous numbering system shall be used for each individual sheet of film. Lead lettersshould be affixed to each section of the weld being radiographed. The images of these lettersshall appear on the radiograph to ensure unequivocal identification of the section.

Markers, in the form of lead arrows or other symbols, shall be placed alongside of the weld sothat its position can be identified on the radiograph.

The film shall be processed in accordance with the manufacturer's recommendation. Theradiographs shall be free from imperfections due to processing, or other defects which wouldinterfere with interpretation.

7.2.2. Ultrasonic ExaminationUltrasonic examination may be used in lieu of radiographic examination. The method shall beselected such that the progress of the construction is not affected.

All ultrasonic examination work shall be carried out in accordance with the methods describedin PED or ASME, and per NoBo approved procedure.

Since the experience with ultrasonic examination of welds in duplex stainless steel is limited theinspection procedure shall be qualified on a weld produced with the welding procedure to beused for the project and with the IIW reference blocks VI and V2.Welds shall be judged in accordance with para. 7.2.7.


7.2.3 Dye Penetrant ExaminationDye penetrant inspection shall be carried out in accordance with ASTM E-165 or similar,procedure to be NoBo approved.

Any weld or area which is tested by means of dye penetrant testing shall be judged unacceptableif any crack, regardless of size, is revealed.

7.2.4 TestpiecesA test piece may be requested to be made during normal production welding to allow ametallurgical examination and corrosion testing of the deposited weld.

When NDT cannot be carried out or gives inconclusive results, a section of the component orwelded area shall be cut out and removed for testing and the joint shall be restored by weldingback in a piece of duplex stainless steel similar in quality, thickness and size to that removed.

Subsequent mechanical testing shall be carried out in accordance with this Specification.

7.2.5 Pre-Welding InspectionAll materials shall be subject to visual inspection for surface defects, laminations at ends, etc.

All preparations and repaired preparations shall normally be inspected.

7.2.6 Inspection After WeldingAll weld surfaces shall be visually inspected and there shall be free of dents, cracks, craters,pinholes, weld spatter, residual slag, pits, laps and other harmful surface defects.

All welds shall be fully radiographed.When radiography is not practical or where the Company's representative requires a furtherexamination of a weld to assist in the evaluation of suspected defects, ultrasonic examinationand/or dye penetrant testing may be used.

7.2.7 Standards on Inspection- Porosity (I.I.W. Codes-Aa and Ab)The maximum dimension of any individual gas pocket shall not exceed 2 mm or 25% of thewall thickness, whichever is the lesser. The sum of the diameters of the individual gas pocketsshall not exceed twice the wall thickness (2t) in any continuous 300 mm length of weld.

Cluster porosity is a series of gas pockets (5 or more) in a 25 mm length of weld. Thepermissible diameter of each gas pocket shall be exceed 2 mm or 25% of the wall thickness,whichever is the lesser. The sum of the diameters of gas pockets in a cluster shall not exceed alength equal to the wall thickness. In any continuous 300 mm length of weld there shall be notmore than two clusters which shall be separated by at least 100 mm of sound weld metal.

Worm holes shall not be longer than the pipe wall thickness and shall be separated by at least adistance equal to the length of the longest worm hole.


Discontinuous worm holes in the weld penetration are permitted provided that theyare less than1.5 mm in diameter and each uninterrupted section does not exceed two times the pipe wallthickness in length and provided that the distance separating the individual sections of wormhole is also at least two times the wall thickness. Worm holes running in a radial or roughlyradial direction are not permitted.

- Separated Slag Inclusions (I.I.W. Code - Ba)Separated slag inclusions shall not exceed 3 mm measured in any direction or 25% of wallthickness if this is less than 3 mm.The total length of these inclusions in any continuous 300 mm length of weld shall be less than12 mm. The separated slag inclusions shall be spaced at least 50 mmapart, the intervening weldbeing of good quality.

- Slag Lines (I.I.W. Code - Bb)Slag lines shall not exceed 6.6 mm in length or 1.5 mm in depth and width. The total length ofslag lines in any continuous 300 mm length of weld shall be less than 50 mm. Individual slaglines shall be separated from each other by a distance of at least 150 mm the intervening weldbeing of good quality. Parallel slag lines shall be regarded as individual weld defects of theirwidths exceed 1 mm.

- Lack of Fusion (I.I.W. Code -C)Lack of fusion in the welds run is acceptable.

- Burn-Throughs (I.I.W. Code - D)Any individual burn-through in a weld shall not exceed 12 mm in length. The sum of the lengthsof individual burn-throughs in any continuous 300 mm length of weld shall not exceed 25 mm.The total length of burn-throughs in each completed weld shall not exceed 500 mm. Individualburn throughs shall be separated from each other by a distance of at least150 mm, the intervening weld being of good quality. Burn-throughs shall under nocircumstances be sharp and shall not exceed a depth of 25% of the pipe wall thickness with amaximum of 2 mm.

- Excess PenetrationThe weld penetration must be sufficient, but not more than 2 mm in general.Individual excessive penetration (droplets of weld material) due to local sag-through of the weldpool is permitted up to a maximum of 3 mm. The total size of the penetration in one weld shallnot exceed 4% of the total weld length of that particular weld. The distance between individualexcessive penetration areas shall not be less than 50 mm.

- Incomplete Penetration (I.I.W. Code - D)Sharp incomplete penetration is not accepted. Concave incomplete penetration shall not exceeda length of 25 mm in any continuous 200 mm length of weld, the depth of this hollowincomplete penetration not exceeding 10% of the pipe wall thickness with a maximum of 1 mm.Individual occurrences of incomplete penetration shall be separated from each other by adistance of at least 100 mm, the intervening weld being of good quality. In double-sided welds,root defects are not permitted.

- CracksNeither welds with cracks nor crater cracks caused by shrinkage are permitted.


- UndercuttingBoth external and internal undercutting shall not exceed 50 mm in length or 0.5 mm in depthand it shall not be of a sharp nature.

- Combination of Weld DefectsIf the total length of all weld defects mentioned in the preceding paragraphs amounts to 10% ormore of the total weld length, the weld shall be rejected. The weld shall also be rejected if thetotal length of weld defects exceeds 50 mm in any continuous 300 mm length of weld.

- Weld LengthIn the case of a total weld length of 300 mm or less the length of the permissible defects and therequired length of sound material between these defects shall be decreased proportionally.

7.2.8 Weld Rejection ReportThe report on each rejected weld shall state the identification number of the weld and the nameof the welder/operator as well as the reason for rejection of the weld.The International Institute of Welding code shall be used for indicating the reason.

7.2.9 Right of RejectionSince non-destructive testing methods show only dimensions of defects, Company may rejectwelds if the depth of the defects effects the strength of the weld irrespective of the fact that thesewelds seem to meet the standards of inspection.

7.2.10 Assessment of Indications on Radiographs in the Pipe Material Adjacent to Welds BeingInspectedWelds and adjacent pipe material showing indications the pipe material next to the weld hasbeen damaged in any way whatsoever (e.g. arc burns, damage of a sharp or deep nature, weldbeads, defects in the longitudinal seam of longitudinally welded pipe, etc.) shall beunacceptable.

7.2.11 Retests of Mechanical PropertiesIf a test piece does not meet the requirements, the cause should be established where possible.The tests shall be repeated on two pipes or components taken at random from the same productlot, to determine whether to reject or approve the whole lot. The contractor may considerreheattreating the complete product lot. Above matters always to be performed in consultationwith Company.

PROJECT NR:

PLATFORM: REV.:

ACCEPTED BY: DATE:

APPR.: APPR.: APPR.: 1-Jan-00

NAME: NAME: NAME:

SIGN.: SIGN.: SIGN.:PAGE 1 OF 1

HYDROTEST

PRESSURE:

BARG,

COMPANY:

AUHTORITY:

CONTRACTOR:

LINE NR:

MATERIAL INFORMATION

WELD HISTORY SHEET

FABRICATION/INSPECTION INFORMATION

TO

SPECIFICATION 502, REV. 11

ATTACHMENT IICONTRACTOR COMPANY AUTHORITY

WELDNUMBER ITEM NR MATERIAL

CERTIFICATEINDEX NR

DRAWING NR:

AUTHORITY SEQ. NR :

REMARKS

ASSESSMENT/ACCEPTANCE BY :

MT/PTEXAMIN.

CONTRAC-TOR

COMPANY AUTHORITYX-RAY

REPORTNR

AUTHORITY REG. NR :

DESCRIPTION & SIZEWAS NR

WELDERNR

MPI / DPREPORT

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US EXAMREPORT

NR

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CERTIF. TYPE REMARKS

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