Dep 34.28.00.31 Steel Structures

TECHNICAL SPECIFICATION

STEEL STRUCTURES

DEP 34.28.00.31-Gen.

January 2009

DESIGN AND ENGINEERING PRACTICE

This document is restricted. Neither the whole nor any part of this document may be disclosed to any third party without the prior written consent of Shell Global Solutions International B.V., The Netherlands. The copyright of this document is vested in this company. All rights reserved. Neither the whole nor any part of this

document may be reproduced, stored in any retrieval system or transmitted in any form or by any means (electronic, mechanical, reprographic, recording or otherwise) without the prior written consent of the copyright owner.

PREFACE

DEPs (Design and Engineering Practice) publications reflect the views, at the time of publication, of:

Shell Global Solutions International B.V. (Shell GSI)

and/or

Shell International Exploration and Production B.V. (SIEP)

and/or

other Shell Service Companies.

They are based on the experience acquired during their involvement with the design, construction, operation and maintenance of processing units and facilities, and they are supplemented with the experience of Shell Operating Units. Where appropriate they are based on, or reference is made to, international, regional, national and industry standards.

The objective is to set the recommended standard for good design and engineering practice applied by Shell companies operating an oil refinery, gas handling installation, chemical plant, oil and gas production facility, or any other such facility, and thereby to achieve maximum technical and economic benefit from standardization.

The information set forth in these publications is provided to Shell companies for their consideration and decision to implement. This is of particular importance where DEPs may not cover every requirement or diversity of condition at each locality. The system of DEPs is expected to be sufficiently flexible to allow individual Operating Units to adapt the information set forth in DEPs to their own environment and requirements.

When Contractors or Manufacturers/Suppliers use DEPs they shall be solely responsible for the quality of work and the attainment of the required design and engineering standards. In particular, for those requirements not specifically covered, the Principal will expect them to follow those design and engineering practices which will achieve the same level of integrity as reflected in the DEPs. If in doubt, the Contractor or Manufacturer/Supplier shall, without detracting from his own responsibility, consult the Principal or its technical advisor.

The right to use DEPs is granted by Shell GSI, in most cases under Service Agreements primarily with Shell companies and other companies receiving technical advice and services from Shell GSI or another Shell Service Company. Consequently, three categories of users of DEPs can be distinguished:

1) Operating Units having a Service Agreement with Shell GSI or other Shell Service Company. The use of DEPs by these Operating Units is subject in all respects to the terms and conditions of the relevant Service Agreement.

2) Other parties who are authorized to use DEPs subject to appropriate contractual arrangements (whether as part of a Service Agreement or otherwise).

3) Contractors/subcontractors and Manufacturers/Suppliers under a contract with users referred to under 1) or 2) which requires that tenders for projects, materials supplied or - generally - work performed on behalf of the said users comply with the relevant standards.

Subject to any particular terms and conditions as may be set forth in specific agreements with users, Shell GSI disclaims any liability of whatsoever nature for any damage (including injury or death) suffered by any company or person whomsoever as a result of or in connection with the use, application or implementation of any DEP, combination of DEPs or any part thereof, even if it is wholly or partly caused by negligence on the part of Shell GSI or other Shell Service Company. The benefit of this disclaimer shall inure in all respects to Shell GSI and/or any Shell Service Company, or companies affiliated to these companies, that may issue DEPs or require the use of DEPs.

Without prejudice to any specific terms in respect of confidentiality under relevant contractual arrangements, DEPs shall not, without the prior written consent of Shell GSI, be disclosed by users to any company or person whomsoever and the DEPs shall be used exclusively for the purpose for which they have been provided to the user. They shall be returned after use, including any copies which shall only be made by users with the express prior written consent of Shell GSI. The copyright of DEPs vests in Shell GSI. Users shall arrange for DEPs to be held in safe custody and Shell GSI may at any time require information satisfactory to them in order to ascertain how users implement this requirement.

All administrative queries should be directed to the DEP Administrator in Shell GSI.

DEP 34.28.00.31-Gen.January 2009Page 2

TABLE OF CONTENTS

1. INTRODUCTION................................................................................................41.1 SCOPE...............................................................................................................41.2 DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS. .41.3 DEFINITIONS....................................................................................................41.4 CROSS-REFERENCES.....................................................................................41.5 CHANGES SINCE PREVIOUS EDITION...........................................................51.6 COMMENTS ON THIS DEP..............................................................................6

2. DESIGN AND ENGINEERING...........................................................................72.1 GENERAL..........................................................................................................72.2 DESIGN REQUIREMENTS................................................................................72.3 CONSTRUCTION MATERIALS.........................................................................92.4 CONSTRUCTION DETAILS..............................................................................92.5 ACCESSORIES...............................................................................................112.6 FIREPROOFING OF STEEL STRUCTURES..................................................11

3. FABRICATION................................................................................................123.1 GENERAL........................................................................................................123.2 MATERIAL.......................................................................................................123.3 WELDING AND WELD INSPECTION..............................................................12

4. PROTECTION AGAINST CORROSION..........................................................134.1 GENERAL........................................................................................................134.2 PAINTING........................................................................................................134.3 HOT-DIP GALVANISATION.............................................................................134.4 THERMAL SPRAYED SYSTEMS....................................................................13

5. ERECTION.......................................................................................................145.1 GENERAL........................................................................................................145.2 SAFETY...........................................................................................................145.3 ERECTION BY SUPPLIER OF THE STRUCTURE.........................................145.4 ERECTION BY OTHERS.................................................................................145.5 SETTING OUT.................................................................................................145.6 DOCUMENTS TO BE PROVIDED TO THE PRINCIPAL.................................145.7 FIELD WELDING.............................................................................................14

6. QUALITY CONTROL DURING FABRICATION AND ERECTION..................15

7. INSPECTION AND MAINTENANCE (AFTER ERECTION)............................16

8. REFERENCES.................................................................................................17


1. INTRODUCTION

1.1 SCOPE

This DEP specifies requirements and gives recommendations for the design, fabrication and erection of onshore steel structures.

This DEP shall be used in conjunction with DEP 34.00.01.30-Gen.

Steel stacks are outside the scope of this DEP and shall be in accordance with DEP 34.24.26.31-Gen.

This DEP is a revision of the DEP with the same number dated July 1996; see (1.5) regarding the changes.

1.2 DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS

Unless otherwise authorised by Shell GSI, the distribution of this DEP is confined to Shell companies and, where necessary, to Contractors and Manufacturers/Suppliers nominated by them.

This DEP is intended for use in oil refineries, chemical plants, gas plants, exploration and production facilities and supply/distribution installations.

When DEPs are applied, a Management of Change (MOC) process should be implemented; this is of particular importance when existing facilities are to be modified.

If national and/or local regulations exist in which some of the requirements may be more stringent than in this DEP, the Contractor shall determine by careful scrutiny which of the requirements are the more stringent and which combination of requirements will be acceptable with regard to the safety, environmental, economic and legal aspects. In all cases the Contractor shall inform the Principal of any deviation from the requirements of this DEP which is considered to be necessary in order to comply with national and/or local regulations. The Principal may then negotiate with the Authorities concerned, the objective being to obtain agreement to follow this DEP as closely as possible.

1.3 DEFINITIONS

The Contractor is the party, which carries out all or part of the design, procurement, construction, commissioning or management of a project or operation of a facility. The Principal may undertake all or part of the duties of the Contractor.

The Manufacturer/Supplier is the party, which manufactures or supplies equipment and services to perform the duties supplied by the Contractor.

The Principal is the party, which initiates the project and ultimately pays for its design and construction. The Principal will generally specify the technical requirements. The Principal may include an agent or consultant authorised to act for and on behalf of the Principal.

The word shall indicate a requirement.

The word should indicate a recommendation.

1.4 CROSS-REFERENCES

Where cross-references are made, the number of the section or sub-section referred to is shown in brackets. Other documents referenced by this DEP are listed in (8.)


1.5 CHANGES SINCE PREVIOUS EDITION

The previous edition of this DEP was dated July 1996. The following are the main, non-editorial changes.

Old section

New section

Change

1.1 1.1 Added: Reference to DEP for design of steel stacks

2.2.1 2.2.1 Changed: British Standards changed to Eurocodes

Added: Reference to International Building Code (IBC)

Changed: Reference to AISC

2.2.2 2.2.2 Deleted: Section regarding steel exposed to high temperatures (now refers to 2.2.8

2.2.5 2.2.5 Changed: Deflections of beams supporting equipment equipment and cantilevered beams.

2.2.7 2.2.8 Added: Reduction in allowable design stresses in case of continuous heat exposure.Added: Requirements for structural steel applied at high and low temperatures and wide temperature ranges.

2.3 2.3 Added: Reference to Eurocode 3.

2.4.1 2.4.1 Added: Member selection in case of corrosive environment.

2.4.3 2.4.3 Added: Special requirements for bolt connections.

2.4.4 2.4.4 Added: Reference to approved manufacturers standards equivalent to Shell standard drawings.

2.4.5 2.4.5 Added: GRP and GRE grating in highly corrosive environments as an alternative to galvanized steel grating.

2.4.6 2.4.6 Added: Anchor bolts of main structures shall be galvanised

- 3.1 Added: General

3.1 3.2. Added: Requirements for workmanship during fabrication in accordance with AISC or ISO 10721-2.Added: Approval of shop drawings by Principal.

3.2 3.3 Approval of welding test procedures and test criteria by Principal.

4 4 Added: Special protective measures in the event of severe corrosion or wear.Added: Investigation of preferred protective coating system to take into account maintenance opportunities during normal operation and be based on total lifecycle cost. Added: Section 4.1 GeneralAdded: Section 4.2 PaintingAdded: Section 4.3 GalvanizationAdded: Section 4.4 Thermal sprayed systems

5 5.1 Added: Workmanship during erection in accordance with AISC or ISO 10721-2

- 5.2 Added: Safety related to design,erection, inspection and maintenance.

- 5.5 Added: Setting out.

- 5.6 Changed: Documents to be provided to Principal prior to construction/erection.

6 6 Added: Quality control during fabrication and erection.


1.6 COMMENTS ON THIS DEP

Comments on this DEP may be sent to the DEP Administrator at [email protected]. Shell staff may also post comments on this DEP on the Surface Global Network (SGN) under the Standards folder.


mailto:[email protected]

2. DESIGN AND ENGINEERING

2.1 GENERAL

The design of a steel structure shall take into account not only the properties of the materials of construction and the calculated stresses for the members, but also the prevailing conditions of the local environment and the requirements at site, the details of construction, methods of erection and fabrication and their effect on cost, in order to achieve a safe and economic design.

2.2 DESIGN REQUIREMENTS

2.2.1 General

The design of steel structures shall comply with DEP 34.00.01.30-Gen. and one of the following codes:

1) Eurocodes:

EN 1990 Eurocode: Basic of Structural Design

EN 1991 Eurocode 1: Actions on Structures

EN 1993 Eurocode 3: Design of Steel Structures

EN 1994 Eurocode 4: Design of composite steel and concrete structures

EN 1998 Eurocode 8: Design of Structures for Earthquake Resistance

Including National annexes, amendments, corrigendums and references to other codes

2) American Institute of Steel Construction (AISC)

3) International Building Code (IBC)

If local codes are more stringent, they shall be adopted

For the design and engineering of buildings see DEP 34.17.00.32-Gen.

Plastic design methods shall not be applied for steel structures, only if required and with the approval of the Principal.

The design shall take into account special erection loads and forces and indicate temporary measures such as for instance the application of temporary bracings and/or guy wires to cater for these loads and forces.

2.2.2 Derrick structures for flares

The Shell standard design of flare structures with retractable flares is based upon a structure consisting of 4 legs and a rectangular cross section, built up from hot rolled steel sections.

A structural concept based on a three-leg derrick with a triangular cross section may be used if the Contractor can clearly demonstrate (for the approval of the Principal) the structural integrity of both piping and structure. This demonstration shall include the following factors:

- Impact of dynamic wind loading (vortex shedding);- Torsion effects due to asymmetrical wind loading;- Fatigue;- Allowance for spare flare positions in case of future extension. This shall also include

maintenance during operation and flare lifting activities.

Reference is made to (2.2.8) for steel exposed to high temperatures and/or low temperatures.

If tubular members are used, they shall be designed to prevent ingress of rainwater and shall have adequate provisions for drainage of water condensate.

Tubular members shall be protected against internal and external corrosion.


2.2.3 Fatigue due to vortex shedding or other cyclic loads

For structures sensitive to the effects of vibration, calculations shall be made for vortex shedding and/or cyclic loads from other sources. The effects of fatigue shall be verified in compliance with EN 1993-1-9 or AWS D1.1. The Palmgren-Miner's rule shall be applied to judge the combined effect of various types of cyclic loading; see ISO 19902. The design shall ensure adequate safety against damage within the planned life of the structure under the applicable loading.

The method of analysis shall be agreed with the Principal. A detailed fatigue analysis may not be necessary if the design is based on previous and satisfactory experience that is strictly comparable.

As most of the wind loads which contribute to fatigue, are of a random nature, statistical consideration will normally be required for determining the long-term distribution of fatigue loading effects. See EN 1991-1-4.

2.2.4 Maximum allowable stresses on foundations

The maximum allowable stress on foundations for steel structures shall not exceed the following values:

Maximum allowable stress (N/mm2)

on concrete: sand cement groutnon-shrink ready mixed grout

4.08.0

on masonry: 1.0

2.2.5 Deflection and displacement

Unless otherwise specified, the following criteria for deflection shall apply for the load combinations "A" and "C" of DEP 34.00.01.30-Gen.:

Item Maximum deflection

Wall stanchions 1/300th of the height

Purlins 1/250th of the span

Supporting beams without equipment 1/400th of the span

Beams supporting equipment 1/500th of the span

Cantilever beams 1/400th of the span

Lifting applications

Crane gantry girders 1/600th of the span

Overhead runway beams 1/500th of the span

Cantilevered runway beams 1/250th of the overhang

Maximum total horizontal displacement of portal frames in general shall not exceed 1/150th of the height. However, frames supporting equipment or frames with bridge cranes shall not exceed 1/200th of the height.

2.2.6 Camber

A positive camber of 10 mm for every 5m span shall be applied if the total span of a structure or frame exceeds 20 m.

2.2.7 Slenderness

Unless otherwise specified, the ratio of effective length to the appropriate radius of gyration shall not exceed 180.


2.2.8 Temperature range, high and low temperatures

Additional consideration will be necessary for structures in special conditions and at locations where very high or low temperatures occur.

High temperatures:

The allowable design stresses of structural steel elements that are continuously exposed to a temperature above 260 °C shall be reduced in proportion to reductions in yield strength of the steel at the design temperatures. The expected temperature of the steel components shall not exceed 480 °C.

Low temperatures:

Structural steel applied under cold climate (e.g. arctic) conditions shall comply with API RP 2N.

The steel to be selected for cold climate (e.g. arctic) applications shall satisfy the fracture toughness requirements (Charpy V-test) at temperatures between –40 °C and –60 C.

Careful attention shall be paid to dimensioning in view of fatigue of structures and to stresses caused by combined effects of snow and wind loads as well as large temperature variations. High quality corrosion protection is of prime importance in most arctic environments.

2.3 CONSTRUCTION MATERIALS

Materials shall be selected in accordance with EN 10025 and/or DEP 30.10.02.11-Gen., taking weldability and the required finished weldment mechanical properties into consideration.

In locations where the lowest service temperature is 0 °C or below, materials of construction shall also comply with EN 1993-1-10. Reference is also made to (2.2) for materials subjected to low temperatures.

2.4 CONSTRUCTION DETAILS

2.4.1 General

Structures shall be designed and constructed such that the joints/nodes are accessible for proper inspection, cleaning and painting.

Pockets or depressions, which could collect and hold water, shall have drain holes or shall be otherwise protected.

Member selection shall take into account long-term corrosion aspects. Hollow sections either square or tubular shall be used in corrosive environments.

2.4.2 Structural members

For open steel structures higher than 20 m, the thickness of any parts of structural members shall not be less than 6 mm.

Gusset plates shall not be thinner than the members to be connected, and shall have a thickness of at least 6 mm.

For overhead runway beams with underhung cranes, joists with inside tapered flanges are preferred. If only broad flange beams are available, the bottom flange shall be checked separately for distortion, and reinforced if required (See EN 1993-6).

The flange width of purlins supporting lightweight concrete slabs shall be not less than 80 mm. For supporting roof sheeting and wall cladding, the flange width shall be not less than 50 mm.

Purlins shall be fixed to the roof beams or trusses by means of angle cleats.


2.4.3 Connections

Shop connections may be welded or bolted. Field connections shall be bolted. No field welding shall be permitted for structural steel work, unless approved by Principal. This includes approval of welding procedure specifications and welder qualification test certificates See (3.3) for welding and weld inspection.

Bolts, nuts and threads shall comply with ISO 4014, ISO 4032 and ISO 888, respectively. The use of other threads requires prior approval of the Principal.

Unless otherwise specified by the Principal, all bolts shall be grade 8.8 or equivalent in accordance with ISO 898-1 and ISO 898-2.

High-strength friction-grip connections, grade 10.9 or equivalent, may be used for e.g. transport and/or lifting applications or other special applications if approved by the Principal.

High-strength friction-grip (pretension bolts) shall not be used for load cases after installation, because of their loss of pre-tension in a fire.

All bolted connections shall be provided with washers and nuts.

All bolted connections exposed to dynamic loads and vibrations (supporting e.g. machinery, crane beams, flare stacks, masts, etc.) shall be provided with lock nuts.

2.4.4 Walkways, platforms, staircases, ladders and handrailing

The minimum width of walkways, platforms and staircases shall be 750 mm.

The minimum headroom for platforms and walkways shall be 2100 mm.

Theminimum width of walkways over ground level pipe tracks shall be 600 mm and the walkways and steps shall be fitted with handrails on one side only.

For design criteria and details of staircases, see Standard Drawing S 28 001.

Stair treads shall be made of hot-dip galvanized grating (see 4.).

GRP or aluminium stair treads, grating, including support structure and handrailing may be used for specific applications approved by the Principal. The final material selection shall take into account the possible effects of a hydrocarbon fire. It is not recommended to apply these materials for personnel access facilities in Fireproofing zones of hydrocarbon processing plants. Use at locations with a high corrosion rate may be considered such as for instance at water intake or outfall stations, water treatment plants, catwalks between a jette trestle or loading platform and dolphins.

Ladders may be installed instead of staircases if the ladders are only required for occasional use and escape routes.

Ladders shall be made with side steps.

For details of ladders, see Standard Drawing S 28.011.

Where hand railing is installed, floors, platforms and walkways shall be provided with toe plates 100 mm 6 mm.

On platforms, the distance to a stair or ladder shall not exceed 25 m.

For standard details, reference is made to the following Standard Drawings:

S 28.001, S 28.002, S 28.003, S 28.004, S 28.005, S 28.006, S 28.007, S 28.008, S 28.009, S 28.010, S 28.012, S 28.013, S 28.014 and S 28.023.

However, the above standard drawings may be replaced by equivalent manufacturers standards, approved by the Principal, providing that main dimensions are similar and allowable loads are as per the standards specified in this DEP.

2.4.5 Flooring and grating

Open flooring shall be used, using grating in accordance with S 28.022 or approved equivalent.


Solid flooring shall not be used unless approved by the Principal. If used it shall be made out of 6 mm or 8 mm checkered floor plate.

Grating and fixing material shall be hot-dip galvanized steel (see 4.), unless the Principal has approved GRP or aluminium grating. (Ref also 2.4.4. above)

2.4.6 Anchor bolts

If anchor bolts are included in the supply of the steel structure they shall be fabricated and despatched to the construction site in advance for timely installation prior to concreting the foundations.

For standard details of anchor bolts, see S 28.020.

Bolts and nuts used for anchoring main steel structures to foundations shall be galvanised unless the Principal approves the use of black bolts.

2.5 ACCESSORIES

2.5.1 Rain water down pipes and roof gutters

Rain water down pipes and roof gutters shall be made either of 1.5 mm thick steel sheet and hot dip galvanized, or of rigid UPVC or equivalent. The bottom 2 m of exposed down pipe shall be of galvanized steel.

2.5.2 Roof and wall sheets

If the supply of roof and wall sheets is included in the order for the steel structure, the type required shall be stated on the instruction drawing(s) or requisition. Only galvanized corrugated steel sheets shall be used. They shall be provided with a protective coating giving maximum protection against the local climate and other environmental factors unless otherwise approved by the Principal. The type and colour of the coating shall be selected in consultation with the Principal. Other type of sheeting, e.g. composite sheeting, shall have the approval of the Principal.

The corrugated sheets shall be fixed in accordance with the sheet manufacturer's standards. Minimum steel thickness shall be 0.6 mm for industrial applications.

2.5.3 Translucent sheets

Translucent sheeting shall be of corrugated the same size and profile as the adjacent wall cladding and/or roof sheeting.

The translucent sheets shall be of glass fibre reinforced polyester resin of self extinguishing quality, with a resin rich external surface to prevent aging (see DEP 34.17.00.32 Gen.). The translucent sheets shall be incorporated in a sash and/or fitting the steel sheets including the corrugations.

Translucent sheets shall not be used for horizontal or sloping roofs, suitable for personnel (maintenance) access.

2.6 FIREPROOFING OF STEEL STRUCTURES

The method and extent of fireproofing of the steel structure and parts thereof shall be in accordance with DEP 34.19.20.11-Gen.

Cover plates for the protection of fireproofing for stanchions and beams shall be included in the supply of the steel structures.


3. FABRICATION

3.1 GENERAL

Workmanship applied during fabrication of structural steel shall comply with ISO 10721-2 or AISC.

The fabricator shall be responsible for the correct interpretation of design drawings when preparing shop drawings. Shop drawings shall take into account required measures for transport of shop-assembled parts to the construction site. The fabricator shall not deviate from design drawings without the approval of the Principal.

3.2 MATERIAL

Only new material shall be used, which shall be thoroughly straightened in the shop by methods that will not cause damage before it is laid aside or worked in any way.

Any re -use or re-cycling of previously used material requires prior approval of the Principal

Fabrication is only allowed to start after approval of the shop drawings by Principal.

All bolting material, including washers and nuts, required for erection (plus 5 % for spares) shall be furnished by the supplier of the steel structure.

3.3 WELDING AND WELD INSPECTION

AWS D1.1 shall apply.

Prior to the commencement of fabrication activities the contractor shall submit weld procedure qualifications and associated weld procedure specifications, covering all joint configurations, to the Principal for approval.

Each contractor shall maintain a suite of relevant weld procedure qualifications, and have sufficient welders qualified to weld in accordance with these. Prior to the commencement of welding activities, the contractor shall submit all welder qualification records and work histories to the Principal for approval.

Records of all data, tests and examinations relating to all welding procedures used during construction and erection shall be made available to the Principal.

Testing procedures and test acceptance criteria shall be subject to the approval of the Principal before fabrication begins. Field welding shall not be performed unless approved by the Principal.


4. PROTECTION AGAINST CORROSION

4.1 GENERAL

The most commonly used protection against corrosion is painting or coating after a surface preparation has been applied. However, the service life of most coating systems are limited and other protective systems such as galvanisation or thermal sprayed coatings are therefore sometimes applied.

Special protective measures and/or material thickness allowance shall be used for structural elements exposed to severe corrosion of wear conditions.

Reference is also made to (2.4.1), especially with regards to the long-term corrosion aspects in relation to member selection.

4.2 PAINTING

Surface preparation and painting shall be in accordance with DEP 30.48.00.31-Gen.

4.3 HOT-DIP GALVANISATION

Hot-dip galvanizing shall be in accordance with ISO 1461. The application of hot-dip galvanization on flare structures, pipe racks and other steel structures, which are difficult to maintain during normal operation, shall be investigated taking into account the required life cycle, maintenance opportunities during operation and based on total life cycle costs. Galvanisation offers in most cases a longer lasting protection with lower maintenance and total lifecycle cost in comparison with conventional paint systems applied on structural steel. However, availability of size and capacity of galvanisation facilities shall be taken into account. All joints and connections of hot dip galvanised structures shall be provided with hotdip galvanised or zinc nickel coated (by electro deposition process) bolts, nuts and washers.

All fabrication activities shall be completed prior to items being hot-dip galvanised unless otherwise approved by the Principal.

Structural steelwork, platform flooring and handrailing located above austenitic stainless steel, duplex stainless steel, nickel alloy or 9 % nickel steel piping or equipment shall not be galvanized or coated with zinc-containing paint unless precautions are taken to prevent zinc contamination of the piping or equipment when hot-working on the galvanised material or applying the zinc-containing paint. A suitable measure is the application of temporary shielding, e.g. fire blankets (for components which are insulated, the cladding is considered to be sufficient protection.).

4.4 THERMAL SPRAYED SYSTEMS

Parts of structures or total structures which are exposed to a corrosive atmosphere and are difficult to maintain shall be provided with a thermally sprayed coating. Thermally sprayed coatings shall be in accordance with DEP 30.48.40.31-Gen.


5. ERECTION

5.1 GENERAL

Workmanship applied during erection of structural steel shall comply with ISO 10721-2 or AISC.

The method used to erect a steel structure depends upon the type of structure, the size of the structure, the risk involved, whether the structure is to be erected without interfering with other work or operations, the lifting gear available and the local conditions.

All tools, equipment and ropes used for erection shall comply with national and/or local regulations and shall be certified for the purpose intended.

5.2 SAFETY

Safety shall be specificly addressed in design, erection, inspection and maintenance. A safety execution plan for erection shall be provided.

5.3 ERECTION BY SUPPLIER OF THE STRUCTURE

If specified on the requisition, e.g. for complicated structures, the Supplier shall submit to the Principal an erection plan complete with data on heavy lifts, shipping weights and the calculations involved.

5.4 ERECTION BY OTHERS

If the erection of the steel structure is not to be carried out by the Supplier, the Supplier shall provide the Principal with all information needed for erection of the structure. Reference is also made to (5.6) below.

5.5 SETTING OUT

The erection contractor shall also be responsible for setting out of the works and for accurately positioning, plumbing, lining and levelling of all steelwork in accordance with the drawing. Unless otherwise specified, tolerances for erection of structural steelwork shall be:

- Levelling +/- 3 mm

- Alignment and plumb +/- 3 mm.

5.6 DOCUMENTS TO BE PROVIDED TO THE PRINCIPAL

The following documents shall be reviewed and approved by Principal prior to the start of any construction activities:

– Inspection and Test Plan (ITP)

– Quality control procedures, including Quality Control Records (QCR’s)

– Erection plan, including method statements covering erection and construction methods, including temporary facilities (incl.scaffolding) and Health Safety Environment (HSE)

– Materials and workmanship specifications

All QCRs shall be handed over to the Principal before acceptance of the work.

5.7 FIELD WELDING

Refer to (3.3).


6. QUALITY CONTROL DURING FABRICATION AND ERECTION

The fabricator and the erection contractor shall establish an inspection system to perform inspections and tests required to assure compliance with the requirements. The following checks and inspections shall be performed.

Item/activity Fabricator/Supplier

Contractor Principal

Shop drawings (with calculations)

Fabrication

Material

Cutting and drilling

Base metal

Assembly

Weld profiles

Final inspection

Straightness, length, shapes and others

Field check

Dimensional check

High strength bolting

Tightening method /procedure

Tightening of bolts

Welding

Welding procedures and specifications

Welders qualification test certificate

Assembly weld profiles

Visual check for ladders, handrail and steel floor

Hotdip galvanising

Blasting and painting

D

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R

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D

SC

R

SC

R

SC

SC

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SC

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W

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SC

SC

R

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SC

SC

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SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

SCA

Abbreviations:D Drawings to be checkedI Inspection to be performedR Review of inspection reports/records/certificatesW 100 % witnessed inspectionSC Spot checkSCA Spotcheck during audit or site visit


7. INSPECTION AND MAINTENANCE (AFTER ERECTION)

Inspection and maintenance of newly erected steel structures shall be in accordance with ISO 10721-2


8. REFERENCES

In this DEP, reference is made to the following publications:

NOTE Unless specifically designated by date, the latest edition of each publication shall be used, together with any amendments/supplements/revisions thereto.

SHELL STANDARDS

Metallic materials – Selected standards DEP 30.10.02.11-Gen.

Painting and coating of new equipment DEP 30.48.00.31-Gen.

Thermal spray coatings of aluminium and 85/15 zinc/aluminium alloy

DEP 30.48.40.31-Gen.

Structural design and engineering DEP 34.00.01.30-Gen.

Design and engineering of buildings DEP 34.17.00.32-Gen.

Fireproofing of steel structures DEP 34.19.20.11-Gen.

STANDARD DRAWINGS

Stairways: general arrangement S 28.001

Stairways: base of stringers S 28.002

Stairways: railing connections S 28.003

Stairways: intermediate platform S 28.004

Stairways: to connections of stringers S 28.005

Handrailing: Type 'A' S 28.006

Handrailing: Type 'B' S 28.007

Handrailing: Type 'C' S 28.008

Handrailing: connection to concrete Type 'A' S 28.009

Handrailing: connection to concrete Type 'B' and 'C' S 28.010

Ladder: general arrangement to columns S 28.011

Ladder: sliding/fixed connections S 28.012

Column platforms: cleats and brackets for design load 300 kg max

S 28.013

Column platforms: cleats and brackets for design load over 300 kg

S 28.014

Anchor bolts S 28.020

Grating S 28.022

Fastening of apparatus to fireproofed beam S 28.023

AMERICAN STANDARDS

Structural Welding Code - Steel AWS D1.1

Issued by: American Welding Society 550 North LeJeune RoadPO Box 351040, Miami, FL 33136USA


Steel Construction Manual AISC

Issued by American Institute of Steel Construction, Inc. 400 North Michigan Avenue Chicago, Illinois 60611, USA

International Building Code IBC

Issued by:International Code Council,500 New Jersey Avenue, NW 6th floor,Washington DC 20001-2070, USA

Recommended practice for planning, designing, and constructing structures and pipelines for arctic conditions

API RP 2N

Issued by:American Petroleum InstitutePublications and Distribution Section1220 L Street NorthwestWashington, DC 20005USA

EUROPEAN STANDARDS

Eurocode: Basic of Structural Design EN 1990

Eurocode 1 – Actions on structures EN 1991

Part 1-4: General actions - Wind actions EN 1991-1-4

Eurocode 3 – Design of steel structures EN 1993

Part 1-9: Fatigue EN 1993-1-9

Part 1-10: Material toughness and throughthicknessproperties

EN 1993-1-10

Part 6: Crane supporting structures EN 1993-6

Eurocode 4 – Design of composite steel and concrete structures

EN 1994

Eurocode 8 – Design of structures for earthquake resistance

EN 1998

Hot rolled products of non-alloy structural steel EN 10025

Issued by:CENRue de Stassart 36 B-1050 Brussels, Belgium

Copies can also be obtained from national standards organizations.

INTERNATIONAL STANDARDS

Bolts, screws and studs; nominal lengths, and thread lengths for general purpose bolts

ISO 888

Mechanical properties of fasteners –

Part 1: Bolts, screws and studs

Part 2: Nuts with specified proof load values – Coarse thread

ISO 898-1

ISO 898-2

Metallic coatings; hot-dip galvanized coatings on fabricated ferrous products; Requirements

ISO 1461


Hexagon head bolts; product grades A and B ISO 4014

Hexagon nuts, style 1; product grades A and B ISO 4032

Steel structures – Part 2: Fabrication and erection ISO 10721-2

Petroleum and natural gas industries – Fixed offshore steel structures

ISO 19902

Issued by:ISO Central Secretariat 1, ch. de la Voie-Creuse Case postale 56 CH-1211 Genève 20, Switzerland

Copies can also be obtained from national standards organizations.
