Specification for Supply and Fabrication of Steel Structure-gas de France

GENERAL SPECIFICATION

SPECIFICATION

FOR

SUPPLY AND FABRICATION OF STEEL STRUCTURES

8 041103 AdJ General Update GvS CvB

7 220201 JRO Change Name JRO CvB

6 061100 GvS Rev. par. 2.2 (matl. Grades) & 3.8 (mouseholes) AdJ CvB

5 050999 AdJ General Update GvS CvB

4 091195 GvS General Update GvS CvB

3 030294 GvS General Update GvS CvB

REV DATE ORIG. DESCRIPTION CHECKED APPROVED

Specification Sheet Revision

GDF PRODUCTION NEDERLAND B.V.201 1 of 18 8

GDF Production Nederland B.V.Specification 201, Rev. 8

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CONTENTS

1.0 SCOPE1.1 General1.2 Certification1.3 QC-plan1.4 Coating

2.0 MATERIALS2.1 General

2.1.1 Structural Steel2.1.2 Delivery

2.2 Material grades2.2.1 Type I - Special High Strength Steel2.2.2 Type II - Primary High Strength Steel2.2.3 Type III - Secondary High Strength Steel2.2.4 Type IV - Mild Steel

2.3 Specifications for steel2.4 Miscellaneous steel

3.0 FABRICATION3.1 General

3.1.1 Drawings3.1.2 Marking3.1.3 Sawing, shearing, flame cutting and chipping3.1.4 Laminations, cracks, or split ends3.1.5 Batten plates, clamps, magnets, setting-up fixtures3.1.6 Shearing

3.2 Pipe and equipment supports, holes, cut-outs, penetrations3.3 Earth lugs3.4 Stiffeners3.5 Sections of pipe3.6 Sections of beams3.7 Ladders3.8 Mouse holes

4.0 WELDING AND INSPECTION4.1 General

4.1.1 Procedure qualification4.1.2 Welder qualification

4.2 Inspection4.3 Repairs

5.0 BOLTED CONNECTIONS5.1 General5.2 Material5.3 Design and use5.4 Bolt coating

6.0 CATHODIC PROTECTION6.1 General6.2 Design criteria6.3 Anodes

7.0 ADDITIONS/AMENDMENTS


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7.1 General7.2 Pipe-sections to be assembled

7.2.1 Material length7.2.2 Out-of-Roundness7.2.3 Bevels7.2.4 Straightness7.2.5 Weld inspection7.2.6 Material toughness

7.3 Main pad-eyes7.3.1 Design7.3.2 Material7.3.3 Fabrication7.3.4 Non-Destructive Testing

8.0 REFERENCES

ATTACHMENTSTable 2.2.a Material GradesTable 2.2.b Charpy V-notch requirements


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1.0 SCOPE

1.1 General

This specification contains the technical requirements for the supply and fabrication of steelstructures. In no way this specification is intended to describe or replace the expected andrequired first class workmanship for the complete fabrication of structural items, both forstrength/technical issues and for visual aspects.

1.2 Certification

Structures and main structure parts shall be fabricated according to the rules laid down in thisspecification, and are further subject to the approval of an appointed Certifying Authority.The Certifying Authority (Bureau Veritas, Lloyd’s Register, Det Norske Veritas, AmericanBureau of Shipping) will be selected and appointed by Company.

1.3 QC-plan

Fabrication and inspection by fabricator shall be based on a for the nature of the structureto be fabricated suitable QC-plan. Such plan shall be prepared by Contractor and shall besubject to approval of Company and Classifying Authorities before start of fabrication.All attachment welding to structural parts will be considered to be per requirements laiddown in this specification.

1.4 Coating

For coating (preparation, application and galvanizing) reference is made to GDF ProductionNederland B.V.'s General Specification 525, latest edition. Unless indicated otherwise allstructural steel that is applied at elevations from El.-4000 (LAT) up, is to be coated as persubject specification.

2.0 MATERIALS

2.1 General

Steel shall be rolled steel of commercial quality, according to NEN-EN 10025, latest edition.The notch toughness of materials will be determined by the use of the Charpy V-notch testas given in NEN-EN 10045. All materials will be as specified in the following paragraphs unlessotherwise stated on the drawings.

2.1.1 Structural Steel

All steel provided for this platform will conform to DIN norm, Euronorm, British Standard,American Society of Testing and Materials, or American Petroleum Institute standardspecifications, with additional considerations given herein.

In order to comply with the Dutch Mining Regulations, it is required to deliver the materialswith a certificate of a classification bureau as commissioned by "Staatstoezicht op deMijnen". Materials Type I, II and III shall be delivered with a 3.1.C certificate in accordancewith EN 10204, unless otherwise approved by Company or/and classifying authority for thesubject part of structure before ordering. Type IV shall be delivered with a 3.1.B Certificate.

2.1.2 Delivery


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Except as given below, all material is to be delivered in accordance with the requirements ofStandard Specification for Delivery of Rolled Steel Plates, Shapes, Sheet Piling and Bars forStructural Use, ASTM Designation A6.Plate and plate for tubular (skelp) produced under DIN standards shall be delivered inaccordance with DIN 1543. Welded tubular produced under DIN standards shall be deliveredin accordance with DIN 1626 and seamless tubular produced under DIN standards shall bedelivered in accordance with DIN 1629, both with the additional requirement for straightnesslisted in Section 7.2.4.Tubular produced under standards other than DIN shall conform to the dimensional tolerancesof API Specification for Fabricated Structural Steel Pipe [API specification 2B] for diameter of24 inch (610 mm) and over, and to the dimensional tolerances of API Specification for LinePipe, API specification 5L, for diameters less than 24 inch, with the additional requirementfor straightness listed in Section 7.2.4. Steel shall be new, reasonably straight and free fromdefects, excessive mill scale and rust.

2.2 Material grades

Materials grouped into four grades of steel using the shorthand notations listed below. Highstrength steel shall be designated on the drawings and in the bills of materials according tothe respective grouping listed below. However, any standard listed within the group whichincluded the designated Euronorm grade may be substituted.

Type I - Special High Strength Steel- S355 incl. TTP and Charpy at -40°C (NEN-EN 10025 Grade S355J4G3).- Defined in Section 2.2.1.

Type II - Primary High Strength Steel- S355 Charpy at -40°C (NEN-EN 10025 Grade S355J4G3).- Defined in Section 2.2.2.

Type III - Secondary High Strength Steel- S355 Charpy at -20°C (NEN-EN 10025 Grade S355J2).- Defined in Section 2.2.3.

Type IV - Mild Steel- S235 (NEN-EN 10025 Grade S235J0)- Defined in Section 2.2.4.

2.2.1 Type I - Special High Strength Steel

Special high strength steel usage:- Jacket leg joints.- Concentration of pad eyes.- Deck legs where indicated on the drawings.- Where indicated on drawing.

For tubular, shapes and plate including skelp for fabricated tubular:- NEN-EN 10025 Grade S355J4G3- BS 7191 Grade 355 EMZ- DIN 17100 Grade St 52-3N- NEN-EN 10025 Fe 510D

The special high strength steel shall conform to all of the requirements of Section 2.2.2 withthe following additional requirements:The maximum carbon equivalent (where a lower value is not part of the specification underwhich the steel is produced, or where the thickness or strength range of that specification is


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exceeded) shall be 0.40 (ladle) calculated using the following formula:

C E CMn Cr Mo V Cu Ni

. . .= + ++ +

++

≤6 5 15

0 40

Unless waived as a requirement on written authorization of the Company's Representative,tensile tests in the thickness direction shall be carried out in the final heat treatmentcondition. Testing shall be in accordance with EN 10164, to meet Quality Class Z35. Thethrough thickness tensile strength shall be at least 80 percent of the minimum specifiedtensile strength. Special high strength steel shall be ultrasonically inspected in accordancewith SEL 072, highest requirements.

Charpy V notch test temperature - 40°C for all plate thickness (min av. 27 Joule, min. ind. 21Joule).

Where special high strength steel is specifically indicated on drawings as “Type I+TMCP” theThermoMechanically Controlled rolling Process shall be applied. This steel shall comply to EN10225 S355G8+M/Z35+US. TTP and US testing shall be in accordance with Type I steel.

2.2.2 Type II - Primary High Strength Steel

Primary high strength steel usage:- Deck legs where indicated on the drawings.- Jacket tubular.- Pile to jacket connection.- Deck tubular.- Plate > 25 mm thick.- Beams with flanges > 25 mm thick.- Where indicated on the drawings.

For tubular, shapes and plate including skelp for fabricated tubular, primary high strengthsteel materials shall conform to one of the following standards with additional restrictionsgiven herein:- NEN-EN 10025 Grade S355J4G3- BS 7191 Grade 355 E- DIN 17100 Grade St 52-3N- NEN-EN 10025 Fe 510D

All material shall conform to the chemical requirements of the specification under which itis produced. Where a lower carbon equivalent is not part of that specification, or where thespecification thickness or strength range is exceeded, the maximum permissible carbonequivalent shall be 0.45 (ladle), calculated as follows:

C E CMn

. . .= + ≤6

0 45

Charpy V notch test temperature to be -40°C (min av. 27 Joule, min. ind. 21 J.).

Hot rolling of tubular has to be done in accordance with DIN 1626, page 3. A mechanical re-test of the base material shall be carried out as well to prove that material has original values.Where primary high strength steel is specifically indicated on drawings as “Type II+TMCP” theThermoMechanically Controlled rolling Process shall be applied. This steel shall comply to EN10225 S355G8+M.

Seamless TubularSeamless tubular may be API 5L Grade X52 [API spec 5L], normalized and fine grained. Ifrequired by specification seamless tubular can be TTP.Z35 tested as specified in Section 2.2.1.

2.2.3 Type III - Secondary High Strength Steel


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Secondary high strength steel usage:- All deck structure main structural beams with flanges < 25 mm.- All main structural plating < 25 mm thick- Where indicated on the drawings.

For tubular, shapes and plate including skelp for fabricated tubulars, secondary highstrength steel; material shall conform to one of the following standards: NEN-EN 10025Grade S355J2- BS 7191 Grade 355 D- DIN 17100 Grade St 52-3U- NEN-EN 10025 Fe 510CCharpy V notch test temperature to be -20°C (min av. 27 Joule, min. ind. 21 J.).

2.2.4 Type IV - Mild Steel

Mild steel usage:- All secondary steel.- Removable beams, brackets.- Deck-plating.- Brackets as indicated on the drawings.

Mild steel materials shall conform to one of the following standards with additionalrestrictions given herein:- NEN-EN 10025 Grade S235J0- BS 7191 Grade 275 D- DIN 17100 Grade ST-37-2 or 3- NEN-EN 10025 Fe 360 B or CCharpy V notch test temperature to be 0°C (min av. 27 Joule, min. ind. 21 J.).

2.3 Specifications for steel

Sections to be used shall conform to the latest editions of Euronorm 19, Euronorm 53,Euronorm 54, Euronorm 55, Euronorm 56 and Euronorm 57.Flats etc. to be used shall conform to the latest editions of Euronorm 58, Euronorm 59,Euronorm 60 and Euronorm 65.Hollow square and rectangular sections shall conform to the latest editions of DIN 59410 orequivalent.

2.4 Miscellaneous steel

Grating shall be Thielco (type double serrated and double anti slip) or approved equivalent,thickness as indicated on the drawings or A5/30 above elevation +16 m and A5/50 30x5 (fullywelded) DAS below +16m. Grating to be fastened with clamps or weld studs for (A5/30) orcontinuous angle iron (A5/50), or approved equivalent. Grating floors shall have a 25 mm.clearance from any vessel, sheeting, pedestal, columns etc. and a clearance of 10 mm fromhand railing, baseplates etc. Grating shall not be cut/adapted etc. after H.D. galvanizing.

Wind-sheeting shall be Robertson Versacor IBR.6-TF-C2S, coated at 2 sides, thickness 0.75mm, fully installed per Vendors specifications for off-shore use, including e.g. lashings, anglepieces, SS-bolting, all above "or approved equivalent".

Handrails shall be fabricated from 11/2 inch Schedule 80 pipe for the vertical members and11/2 inch Schedule 40 pipe for the horizontal members. The handrails shall be hot dippedgalvanized after fabrication in accordance with ASTM A-123. Vent-holes necessary for hot dipgalvanizing shall be on underside of handrail and shall be adequately plugged. Exact split-upbetween part to be galvanized and part to be painted is to be decided an actual applicationand geometry’s.The maximum opening in the hand railing should be 0.4 meter between the horizontalmembers and the minimum height of the hand railing should not be less than 1.10 meter


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relative to top of floor (T.O.G. or T.O.P.). Drawing will prevail. The toe-board should have aminimum height of 150 mm.

Handrail on jacket level shall be made up from CS Hot Dip Galvanized posts, with SS3167*7 12mm PVC-covered wire and SS316 or SSA4 fixation material.

Manufactured items such as cleats, shackles, wire rope clips, thimbles, turnbuckles, chain,woven wire mesh and tie wire shall be hot dipped galvanized in accordance with ASTM A-123. For levels below +10.000 m L.A.T. ( Splashzone ) for manufactured items SS316 or A4shall be applied.

Timber shall be utility grade hardwood (unless indicated otherwise) and shall be reasonablyflat and straight and free of major defects, such as splits or loose knots.

3.0 FABRICATION

3.1 General

These specifications and the accompanying drawings are intended to describe the work,material and quality required to fabricate, coat and load-out the subject platform. Allstructural fabrication, except as modified herein, shall be in accordance with API RP 2A,'Recommended Practice for Planning, Designing and Constructing Fixed OffshorePlatforms', latest edition unless otherwise specified on the Contract Drawings and ANSI/AWSD 1.1 as noted herein.All structural fabrication shall be in accordance with the latest editions of AISC and API RP 2Aand ANSI/AWS D 1.1. whichever is more stringent.

3.1.1 Design

Fabrication Contractor shall prepare the required calculations/design work for handling,lifting, transporting etc. of parts of or complete structures at all stages of the work.Contractor shall prepare and present drawings and calculations timely for approval byCompany and Classification Authority.

3.1.2 Drawings

Fabricator shall check the submitted drawings for fabrication and sea-fastening. If requiredfor fabrication, additional shop / fabrication drawings will be made, such drawings shallfollow general practice at fabricators shop, and shall suit normal requirements of industry.Shop drawings shall be submitted to company for information/ remarks, and shall besubmitted as-built after fabrication. Company supplied AFC (engineering ) drawings shall bemarked red, blue and green for as-built status.Drawings will further serve QC and allow proper and detailed weld and NDT inspection andadministration.

3.1.3 Marking

For all (pre) fabrication of steel sections, shop administration of fabricator shall be submittedfor approval. In general all steel parts and all other supplied and used items shall be matchmarked for field assembly with designated numbers and/or letters, corresponding with thedrawings and material certificates.Marking system shall suit traceability to satisfaction of Company and if applicable ClassifyingAuthority (if required also after coating).


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3.1.4 Sawing, shearing, flame cutting and chipping

Sawing, shearing, flame cutting and chipping shall be done carefully and accurately andwhenever possible by a mechanical guided tool. Structural sections shall be preferable sawed.If, by exception, structural sections are cut, the edges shall be ground. All edges shall be leftfree of slag.

3.1.5 Laminations, cracks, or split ends

Should laminations, cracks, or split ends be discovered in any pipe, plate or section, thedetected section(s) shall be removed to the satisfaction of the Company and shall not be usedin the fabrication of any other part of the work.

3.1.6 Batten plates, clamps, magnets, setting-up fixtures

Wherever practical, batten plates, clamps, magnets, holding devices or other setting-upfixtures shall be used in assembling parts of the structures, so as to avoid tack-welding in theweld-groove, and without damaging (sharp prints) the surface of the structural parts underfabrication.In fit-up where clamps cannot be used, batten plates or spacer strips shall be used to ensurethe correct root gap prior to tack-welding.All tack welds shall be cleaned and ground to sound material.Unless otherwise shown on the drawings, weld connecting structural members shall developa strength not less than that of the weaker member.Cutouts at beam ends for coping shall have an internal radius of 5 millimeters.

3.1.7 ShearingShearing of plates, strips, flats and angles is permitted only if their thickness does not exceed16 mm. Burrs, if any, shall be removed.

3.2 Pipe and equipment supports, holes, cut-outs, penetrations

All required supports, holes, cut-outs, penetrations etc. shall be provided whether or notindicated on the drawings for the installation of the work of other trades requiring same.Pipesupports and equipment supports shall be indicated / integrated on the applicablestructural drawings. Holes, cutouts and penetrations shall be as per approved (typical) details,and the types and locations shall be indicated on applicable drawings (drawings byfabricator). Holes, cutouts and penetration details shall ensure possibility of coatingaccording to specifications.Care shall be taken not to cut any primary shapes without the prior approval ofthe Company.

3.3 Earth lugs

Earth lugs where applicable shall be provided on structural columns near baseplate. Iffireproofing is applied, length of lug shall be extended by the fireproofing thicknessmeasured from the outer edge.


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3.4 Stiffeners

Stiffeners shall be fitted accurately and soundly at all contact surfaces with the member ormembers to which they are fitted. The contact edges shall be machined to ensure an evenbearing and shall be suitably prepared for full strength welding, unless otherwise called foron the drawings.

3.5 Sections of pipe

Sections of pipe of the same diameter and wall thickness may be spliced to economically usematerials. No splice shall be located closer to a joint (including mill welds) than four timesthe outside diameter of the pipe or a minimum distance of 1.2 m whichever is greater, unlessotherwise noted on the drawings. It is not allowed to have more than one splice in any 3.0meters interval of pipe. If pipes contain longitudinal seams, the seams shall be staggered aminimum of 15 degrees at butt joints.

3.6 Sections of beams

Sections of beams with the same cross-sections may be spliced to economically use thematerials. The use of the beam shall determine the location and frequency of splicing. Incantilever beams, there shall be no splice located closer to the point of support than half thecantilever length. For beams employed in any span between supports, there shall be no splicein the middle one-fourth of any span nor in the one-eight of the span nearest any support.No two splices shall be located closer together than four times the depth of the beam or aminimum of 1.2 meters whichever is greater, unless otherwise noted on the drawings.

3.7 Ladders

All ladders and hand railing shall be finished in such a manner as to leave clean and smoothsurfaces. All welds shall be machined smooth and all burrs removed.

3.8 Mouse holes

In general for beam-structures with a beam height of 300 mm or more holes with a radius Rof 30 mm will be applied; for beams with less height no mouse holes will be required.Assemblies, constructions or mouse holes that are to be coated, but inaccessiblefor proper shot blasting and painting shall be avoided, or shall be closed bywelding on/boxing in with a 4 mm plate .

4.0 WELDING AND INSPECTION

4.1 General

Unless noted otherwise in these specifications, all structural welding shall be in accordancewith API RP 2A, 'Recommended Practice for Planning, Designing and Constructionof Fixed Offshore Platforms', and the ANSI/AWS and ASME BPV IX codes, latest revision. Existing and valid procedures, made under Classification Authority supervision and recording,may be submitted for approval. For the subject situation no re-qualification will be required.

4.1.1 Procedure qualification


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Procedure qualification of welds joining High Strength Steel shall include Charpy V-notchimpact testing in accordance with NEN-EN 10045. Test specimens shall be removed and testedas follows (transverse test):- One test in the weld materials- One test in the line of fusion.- One test in the parent metal 2 mm from line of fusion (in HAZ).§ One test shall consist of three specimens.§ Test temperature to be -40°C for plate thickness > 25 mm and -20°C for plate thickness

< 25 mm.§ The average absorbed energy for each test shall be at least 34 Joule with no single

specimen exhibiting less than 27 Joule.

Welding procedure specification (WPS) shall include all relevant information, including butnot limited to welding processes, validity range, material type, position, pre-heat and inter-pass temperature, filler material(s), max. weaving (if any), and detailed weld preparation.WPS shall be available at work location. Procedures shall be made available for tack welding,repairs, buttering and gauging.At each welding location at least one electronic temperature meter shall bepresent. For all welds with a combined wall thickness of 45mm or more,preheating shall be done by means of electrical elements (mats). Preheat,interpass and cool down shall be controlled. Influence of weather beforecomplete cool down of the weld area shall be prevented.

4.1.2 Welder qualification

Welders to be qualified for process and position according to relevant codes and witnessedby an acceptable class authority.

4.2 Inspection

Contractor shall visually inspect all welding preparations, welding and welding area’saccording to API RP 2A, and ANSI/AWS D 1.1, latest revisions. Quantity and type of NonDestructive Testing per requirements in this specification. In general NDT as per Table 4.2.1will be required.Procedures for NDT and acceptance will be based on ASME Boiler and Pressure Vessel (BPV)Code, Sections V and VIII.

NDT field execution and reporting shall be in scope of Contractor.Contractor shall perform dimensional inspection and record and submit results. Dimensionalmeasurements shall prove fabricated construction is as per drawings.All inspection shall be recorded to a reasonable extend to satisfaction of the Company (andClass. Authority if applicable). Administration shall be part of as-built documentation. Theweld numbering shall clearly show the history of a weld.


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Table 4.2.1 General indication NDT requirements for structural fabrication.

Type of structure: Type of NDT: % of NDT: Remarks:

Pad eyes, weldpreparations for padeyes and adjacent areas

UTMPI

100%100%

See Chapter 7.0 of thisspecification

Nodes (all types)UTMPI

100%100% After 48 hours

Main (bearing) structureand all under-water orjacket structure andattachment-welds tomain structure

UT on all FP-weldingMPI on all weldingand on allscars/tack-welding

100%100%

After 48 hours

Secondary structureUT on FP-weldingMPI

15%15%

After 24 hours,locations by Company100 % on repairs

Butt-welds in beams,tubulars and plate

X- or Y-ray asalternative for MPI+ UT

Per subjecttype

Per subjecttype

4.3 Repairs

Defects, except cracks, in weld deposits may be repaired with prior authorization of theCompany Representative. Removal of defects for repair may be by any method, whichproduces a clean uncontaminated surface for installation of the repair weld. Oxygen-acetylene gouging will not be acceptable. All air-arc gouged surfaces shall be power diskground to remove residual carbon.The removal and repairs of cracks in weld deposits or base metal shall be witnessed andapproved by the Company Representative. Any cracks shall be removed by grinding or air-arcgouging to sound metal (plus 2 inch of sound metal on each end of the crack) as determinedby an appropriate non-destructive testing technique. The surface of the chord member intubular intersection joints containing root cracks or transverse cracks shall be magneticparticle and ultrasonically inspected to detect propagation into the base metal, if any. Theintersecting member shall be completely removed if in the opinion of CompanyRepresentative the surface of the chord member cannot be properly inspected or repaired.

5.0 BOLTED CONNECTIONS

5.1 General

All bolted connections shall be made with minimum two bolts, 16 mm diameter unlessotherwise indicated on the drawings.

5.2 Material


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Bolts, nuts, etc. shall be of quality 8.8, and shall conform to the latest edition of NEN 81-II andNPR 1800 (NEN 914, NEN 5513, NEN 5514, NEN 5515, NEN 1555 and NEN 1560). AlternativelyASTM A-320 (bolts and nuts) or ASTM A-193 (Gr. B7, studs with nuts) may be used.High strength friction grip (HSFG) bolts, nuts, etc. shall be of quality 10.9 and shall conformto the latest edition of NEN 81-I and NPR 1800 (NEN 914, NEN 5511, NEN 5512, NEN 5513, NEN5514 and NEN 5560).

5.3 Design and use

High strength friction grip bolts shall be used for the main connections and/or asspecified on the drawings.

Holes for bolted connections shall be drilled and be of a diameter 2 mm larger than that ofthe bolt, except in the case of close-tolerance bolts as called for on the drawings.

Slotted hole connections shall be used for connecting to existing adjacent structures, ifapplicable, or as indicated on the drawings. Correct type of washer to be applied for slottedholes (size and thickness).

Bolt shaft shall be long enough to suit the connecting part, washers, nuts and locking nutsand project at least 3 mm and 10 mm at the utmost, unless indicated otherwise on thedrawings.

Heads and nuts of all bolts, other than high strength friction grip bolts, shall be suitablydrawn tight against the work.Heads and nuts of all bolts shall sit squarely against work or washers where required.

Locking nuts shall be fitted to all bolts, other than high strength friction grip bolts, undereach of the following conditions:- the bolt carries a tension lead- the bolt is connected to vibrating equipment- the bolt is connected to crane beams, lifting beams or trolley hoists- the bolt is used on the jacket- called for on the design drawings

High strength friction grip bolt holes shall be drilled, and shall be free from burrs.Punching is not permitted.

At the time of assembly, the contact surfaces of a high strength friction grip bolt connectionshall be clean and free from paint, scale, loose rust, burrs, dirt, oil, grease and all defects thatmight impair a good solid sealing and friction between the surfaces.All high strength friction grip bolt connections shall be assembled and tightened by a methodto be approved by Company.

Anchor bolts will be specified on drawings or by Company.

5.4 Bolt Coating

For use on structural items all threaded fasteners shall be cadmium plated. Hot-dip orelectrical galvanized bolts/nuts are not acceptable.For small bore fasteners SS A4 bolts/units can be used (≤ M12); for strength bearingconnections a calculation is required.


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6.0 CATHODIC PROTECTION

6.1 General

The Cathodic Protection System for any under water (or in seabed) structure shall be sacrificialsystem consisting of aluminum alloy anodes (unless indicated otherwise).

6.2 Design criteria

Cathodic protection design (if in scope contractor) according to latest recommendationsS.M.O.Z. for applicable location (North Sea or otherwise, all subject to approval etc.).Net weight of anodic material in each anode shall be within the weight range applicable toa twenty year life.

6.3 Anodes

Anode construction shall be in accordance with relevant drawings. Anode material shall bealuminum alloy of electrochemical value of no less than 1240 ampere hours per pound. Theindividual anode ampere rating shall correspond to that calculated for a water resistance ofno less than 30 ohm.cm at 50 % of the anode cross-sectional area consumed.

7.0 ADDITIONS/AMENDMENTS

7.1 General

Depending on the nature and use of the structure to be fabricated additional requirementscan be required. The additional requirements indicated in this chapter are only applicable forthe indicated type of structure.

7.2 Pipe-sections to be assembled

Additional requirements for pipe sections which will be delivered without over-length andwith bevels. The following requirements are applicable in addition to the API Spec. 2B(Section 4.0).

7.2.1 Material length

The length of each pipe shall not vary more than –10 mm or +20 mm total for each item notbeveled or beveled on one side and -0 mm to +3 mm for items beveled on both sides.

7.2.2 Out-of-Roundness

The difference between the major and minor outside diameters shall not exceed 5 mm.

7.2.3 Bevels

All pipes shall be beveled for welding with an angle as indicated. Tolerances for bevel angleand root face shall be respectively -0° +2.5° (measured from a line perpendicular to the surfaceof the pipe) and +0 mm - 2 mm unless otherwise specified. The root face shall beperpendicular to the longitudinal axis of the pipe within 1 mm per 200 mm diameter, witha maximum allowable deviation of 4 mm, measured with a square and straight edge acrossthe end of the pipe.

7.2.4 Straightness


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The maximum allowable straightness deviation in any 3 m length shall be 3 mm. For lengthover 3 m, the maximum deviation of the entire length may be computed by the followingformula, not to exceed 9.5 mm in any 12 m length.

3 mm x (total length m. )

3 m

For special items such as jacket legs and piles other more stringent requirements forstraightness and roundness will be applicable (see relevant construction drawings).

7.2.5 Weld inspection

All longitudinal welds shall be 100% U.S. tested. All circumferential welds 100% X-ray.Longitudinal welds at weld crossing and weld ends shall also be X-ray tested.

7.2.6 Material toughness

Charpy V-notch values as per subject chapter (Materials, Chapter 2) of this specification.

7.3 Main pad-eyes

In addition to other requirements specified either in documents, on drawings or in generalcodes, the following will be applicable for main pad-eyes.

7.3.1 Design

The pad-eye design is always subject to check and approval of the installation contractor andthe classifying authority. The design of a pad-eye is amongst others based on weight andC.O.G. of the item involved. Therefore it can be necessary to leave at least some aspects ofthe pad-eye design relatively long on hold, at least until above mentioned aspects arereasonably known to be accurate.

7.3.2 Material

Selection of material will be a part of the pad-eye design. In general the pad-eye material willbe type I. This includes the main-structure the pad-eye is welded to. For pad-eye componentsthe charge number(s) must be hard stamped on each individual part, on such a location thatthe numbers can be found after assembly of the pad-eye.

7.3.3 Fabrication

The pad-eye main-plate will be taken from the rolled plate such, that the rolling direction ofthe plate is the same as the pulling direction for the pad-eye. Assembly/welding shall beplanned and organized such that:- remaining weld tension is minimal,- pre-heating shall be done electrically, temperature controlled and recorded,- once pre-heating has started, fabrication shall be continued till subject part/ beam / area is finished- cool-down shall be slow and controlled.Above shall be controlled full time by a qualified and dedicated quality-inspector.

7.3.4 Non-Destructive Testing

Components of pad-eyes and adjacent main-structure shall be checked for doubling/material


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imperfections. All welding to pad-eyes shall be checked MPI (all welds) and UT (full Pennwelds) at least 48 hours after cool-down. After each use of pad-eyes this NDT-check shall berepeated (note therefore weld-seams on pad-eyes not to be painted).

8.0 REFERENCES

In this list the reference codes as used in this specification (latest revision to be used) arelinked to the publications they are taken from in alphabetic order:

[1] AISC Specification for Structural Steel Buildings, Manual of SteelConstruction (including supplements and commentary) (Publishedby American Institute of Steel Construction).

[2] API RP 2A Recommended Practice for Planning, Designing and ConstructingFixed Offshore Platforms. (Published by American PetroleumInstitute).

[3] API Spec. 2B Fabrication of Structural Steel Pipe.[4] API Spec. 5L Specification for Line Pipe.[5] ASME BPV V Nondestructive Examination.[6] ASME BPV VIII Pressure Vessels.[7] ASME BPV IX Qualification Standard for Welding and Brazing Procedures, Welders,

Brazers and Welding and Brazing Operators.[8] ASTM A6 Standard Specification for Delivery of Rolled Steel Plates, Shapes,

Sheet Piling and Bars for Structural Use.[9] ASTM A123 Spec. for Zinc (Hot-dip Galvanized) Coatings on iron and steel

products.[10] ANSI/AWS D1.1 Structural Welding Code - Steel, Latest Edition.[11] BS 7191 Weldable structural steels for fixed offshore structures[12] DIN 1543 Stahlbleche über 4.75 mm (Grobbleche), Maß- und Gewichts

abweichungen.[13] DIN 1626 Geschweißte kreisformige Rohre aus unlegierten Stahlen für

besondere Anforderungen; Technische Lieferbedingungen. [14] DIN 1629 Nahtlose kreisformige Rohre aus unlegierten Stahlen für besondere

Anforderungen; Technische Lieferbedingungen.[15] DIN 17100 Allgemeine Baustähle; Gütevorschriften - Steels for general structural

purposes.[16] DIN 17200 Vergütungsstähle; Gütevorschriften - Quenched and tempered steels.[17] DIN 17210 Einsatzstähle; Gütevorschriften - Case hardened steels.[18] DIN 2448 Seamless Steel Pipes.[19] DIN 59410 Hollow Square and Rectangular Sections for Steel Structures.[20] DIN 50049 Bescheinigungen über Werkstoff prüfungen - Certificates on material

tests.[21] DNV Recommended Practice for Testing of Steel Subject to Appreciable

'Z' Direction Loading, Det Norske Veritas, Engineering Service.[22] Euronorm 19 Beam Section IPE.[23] Euronorm 53 Wide Flange Sections.[24] Euronorm 54 Hot Rolled I-Sections.[25] Euronorm 55 Hot Rolled Equal T-Sections.[26] Euronorm 56 Hot Rolled Equal L-Sections.[27] Euronorm 57 Hot Rolled Unequal L-Sections.[28] Euronorm 58 Hot Rolled Flat Steel[29] Euronorm 59 Hot Rolled Square Bar Sections.[30] Euronorm 60 Hot Rolled Round Bars.[31] EN 10204 Metallic Products, Types of Inspection Documents.[32] EN 16085 Ultrasonic testing.

[33] GDF Specification 525, General Painting and Coating Specification.[34] NEN 81-I/II Metric Screw Thread (ISO).[35] NEN 1275 Testing Demands and Methods for Zinc Coated (Galvanizing) Layers

of Steel.


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[36] NPR 1800 Nederlandse Praktijk richtlijn 1800, superseeds: NEN 914, 1555, 1560,5511, 5512, 5513, 5514, 5515.

[37] NEN 1275 Testing Demands and Methods for Zinc Coated (Galvanizing) Layersof Steel.

[38] NEN-EN 10025 Hot-rolled products of non-alloy structural steels (Euronorm 25).[39] NEN-EN 10045 Metallic Materials - Charpy impact test.[40] NEN-EN 10225 Weldable structural steels for fixed offshore structures- Technical

delivery conditions[41] SEL 072 STAHL-EISEN-Lieferbedingungen 072 (SEL 072) des Vereins Deutscher

Eisenhüttenleute, Ultraschallgeprüftes Grobblech.[42] Thyssen Steels for Offshore Requirements.


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ATTACHMENT 1

MATERIAL GRADES

Type Min.Yield[N/mm2]

Material reference standard CertificateEN 10204

Application Typical Usage

I 355 EN 10025 S355J4G3/Z35+USEN 10225 S355G7+N/Z35+US

3.1.C Special TTP quality material,loaded in thickness direction

• Jacket leg joints• Padeyes• Deck leg cans• Where indicated on drawings

I+TMCP 355 EN 10025 S355J4G3/Z35+US+TMCPEN 10225 S355G8+M/Z35+US

3.1.C Special TTP quality material,loaded in thickness directionwith increased weldabilityTermo-mechanically rolled

• Where specifically indicated ondrawings

I I 355 EN 10025 S355J4G3EN 10225 S355G7+N

3.1.C Primary high strength steel • Substructure and topside tubulars• Piles• Deck legs• Plate > 25mm• Beams with flanges > 25mm thick• Where indicated on drawings

II+TMCP 355 EN 10025 S355J4G3+TMCPEN 10225 S355G8+M

3.1.C Primary high strength steelwith increased weldabilityTermo-mechanically rolled

• Where specifically indicated ondrawings

I I I 355 EN 10025 S355J2EN 10225 S355G2+N

3.1.C Secondary high strength steel • Plate < 25mm• Beams with flanges < 25mm thick• Where indicated on drawings

IV 235 EN 10025 S235J0 3.1.B Mild Steel • All secondary steel• Deck plating• Where indicated on drawings

Charpy-V notch requirements

Type Charpy-V testtemperature[°C]

Average / Minimum Individual Value[Joules]

I -40 27 / 21I+TMCP -40 50I I -40 27 / 21II+TMCP -40 50I I I -20 27 / 21IV 0 27 / 21