BGA ENG MATL TS 0006 Cathodic Protection Rev 02a

BG Standard Materials Engineering

Cathodic Protection BGA-ENG-MATL-TS-0006

Value Assurance Framework (VAF)

Value Assurance Framework (VAF)

BG Standard Cathodic Protection

DOCUMENT INFORMATION SHEET TITLE: Materials Technical Standard – Cathodic Protection PURPOSE AND SCOPE: This Standard sets out Company requirements for developing and implementing the cathodic protection strategy when selected in accordance with BGA-ENG-MATL-TS-0001.

Document No: BGA-ENG-MATL-TS-0006

Issue No: 02a

Issue Date: 12/11/08

FOR ISSUE: Signature:

Position: Group Technical Authority Materials / Welding / Corrosion and document custodian

Name:

Email address: [email protected]

Richard Carroll

CHECKED AND ENDORSED BY: Dept.

(NR – Check not required)

Signature

Name

Position

Engineering

M. Freeman

Head of Engineering

Safety

M Nishapati

Environment

D.Ord

Head of Environment

Operations

R.Murray

Head of Asset Integrity

Others

L.Guthrie

Head of Projects

Head of Safety engineering

Well Engineering

FINAL APPROVAL: Signature:

Position:

Name:

Date:

APPROVAL AND ISSUE RECORD: Issue No.

Date

Description

01

Oct 2006

Issued for Use

02

02/04/08

Revised and re-issued

02a

12/11/08

Approvers changed

BGA-ENG-MATL-TS-0006 Issue 02a 12/11/08

Author (name) R Carroll

Approved (name) M. Freeman

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BG Standard Cathodic Protection

REVISION RECORD: Issue No.

Description of Revision

02

Introduction revised to match updated standard template

02a

Mark Nishapati added to approvers replacing Michael Tousignant

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BG Standard Cathodic Protection

Contents INTRODUCTION 1.0 1.1 Purpose and Scope 1.2 Definitions 1.3 Abbreviations 1.4 Units 1.5 Referenced/Associated Documents 2.0 BASIS FOR CATHODIC PROTECTION 2.1 General 2.2 Health, Safety & Environment 2.3 Design Life 2.4 Existing Facilities 2.5 Environmental Survey 2.6 Electrical Isolation 2.7 Electrical Interference Effects 2.8 Current Density and Protection Criteria 3.0 MATERIALS AND EQUIPMENT 3.1 General 3.2 Anodes 3.3 Rectifiers 3.4 Cables 4.0 SPECIFIC DESIGN REQUIREMENTS 4.1 Marine Structures 4.2 Submerged Pipelines 4.3 On-shore Well Casings 4.4 Land Based Pipelines 4.5 In-plant Buried Piping, Vessels and Structures 4.6 Above Ground Storage Tank Base Plates 4.7 Process Vessels, Storage Tanks and Piping Internal Surfaces 5.0 INSTALLATION, COMMISSIONING AND MONITORING 5.1 Installation 5.2 Commissioning 5.3 Monitoring 6.0 QUALITY CONTROL 6.1 General 6.2 Documentation 7.0 FEEDBACK APPENDIX A - LIST OF REFERENCED / ASSOCIATED DOCUMENTS APPENDIX B - FEEDBACK FORM

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1.0

BG Standard Cathodic Protection

INTRODUCTION This Standard should be read in conjunction with the Purpose, Development and Application of BG Standards and Guidelines Standard (BGA-BGA-GEN-OS-0001). It is essential that everyone is aware that compliance with this, or any other Company Standard, is mandatory and failure to comply may constitute serious misconduct and disciplinary action may be taken against the employee(s). Failure to comply with the Standard by a secondee or contractor may result in the termination of their secondment or engagement and or any other appropriate action being taken. Although BG Standards are mandatory, dispensations may be granted in exceptional cases by the relevant GTA/Head of Function. The Dispensations against BG Standards (BGA-BGA-GEN-OS-004) sets out the procedure in full. Please note that dispensations need to be granted before any BG Standard is deviated from. In all instances, legally required National codes and standards of the country where the equipment is to be operated shall be complied with, together with any other applicable legal requirements. Where BG Standards are more stringent, then the BG requirements shall take precedence. Where a BG Standard appears to be less stringent, then the applicable legal requirements shall be followed and it shall be brought to the attention of the appropriate BG Group Technical Authority. All applicable International Codes and Standards shall be complied with. If you are reading a hard copy of this Standard, you should consider it out of date and refer instead to the version currently on the Portal.

1.1

Purpose and Scope This Standard sets out Company requirements for developing and implementing the cathodic protection strategy when selected in accordance with BGA-ENG-MATL-TS-0001 and is applicable to the following items: • Submerged zones of marine structures Commentary:

This will include all inshore and offshore structures exposed to seabed or seawater environments and in-land lake and water courses e.g. jacket structures (including pile areas, well casings, conductor guide frames and J-tubes), jetties, trestles, harbour facilities etc., sub-sea manifolds, sub-sea christmas trees and associated well casings

• External surface of submerged steel pipe lines Commentary:

This will include risers (if electrically isolated from jacket), jumpers, pipe lines & inter-field flow lines

• External surfaces of on-shore well casings • External surfaces of direct buried, land based steel pipe lines (including flow lines, trunk lines and distribution piping) • Internal surfaces of steel process vessels, piping and above ground storage tanks in contact with an electrolyte Commentary:

This will include oil treating equipment such as desalters and dehydrators, storage tanks for potable water, fire water etc.

• Soil-side surfaces of above ground steel storage tank base plates • External surfaces of direct buried, steel process vessels, storage tanks and mounded storage bullets • External surfaces of direct buried, in-plant, steel piping Commentary:

This will include pressure retaining hydrocarbon and safety-critical piping and non-pressure retaining piping containing products that may pose a safety or environmental threat if leakage occurs e.g. atmospheric drain lines handling H2S. It will also include short sections of normally above ground piping at road, rail crossings etc. or at connections to existing buried piping

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BG Standard Cathodic Protection

• External surfaces of steel casings at road, rail, camel crossings etc. • External surfaces of direct buried, steel components of non-metallic piping or pipe line systems Commentary:

This will include valves, fire hydrant risers etc.

• Steel reinforcement in submerged or buried concrete structures • External surfaces of direct buried portions of steel support piles. Excluded from the scope of this document is retrofitting of cathodic protection systems to existing facilities or components. Commentary:

For cathodic protection of these, contact the Technical Authority in the first instance

The range of business segments and development lifecycle stages to which this Standard applies are identified below: All developments/projects, world-wide Business Segment:

Upstream X

Creat e

Developme nt Stage:

T& D X

Selec t X

Commentary:

1.2

Power

LNG

X

X

Execute X

Decom mission

It is expected that this Standard will be more applicable from the ‘Select’ stage onwards for new ‘green field’ developments but its applicability at earlier stages should be assessed for ‘brown field incremental’ developments

Definitions

Company

BG Group or a wholly owned subsidiary company or other client organisation;

Contractor

The person, firm or company undertaking to supply services plant, or equipment to which this document applies;

Vendor

The main supplier or manufacturer of the items of plant or equipment to which this document applies, including items that may be designed and/or manufactured by others

Shall

A mandatory term - no dispensation is permitted without written approval using the formal dispensation procedure;

Should

A recommended term applied to this Standard, indicating a certain course of action is preferred but not necessarily required

Group Technical Authority

The manager or principal discipline engineer responsible for producing and maintaining a given Standard / Guideline; Review and either approve or reject Dispensation Requests made against BG Standards by Asset / Project.

Safety-critical

Any structure, plant or equipment, or component part whose failure could cause or contribute substantially to a major accident or which is intended to prevent or limit the effect of a major accident

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1.3

Abbreviations API

American Petroleum Institute

BS

British Standard

CFC

Chlorofluorocarbons

CIPS

Close Interval Potential Survey

CRA

1.4

BG Standard Cathodic Protection

ion Resistant Alloy

DCVG

Direct Current Voltage Gradient

ESD

Emergency Shutdown

FRP

Fibre Reinforced Plastic

FWPH

Flowing Wellhead Pressure

HISC

Hydrogen Induced Stress Cracking

HSCI

High Silicon Cast Iron

ISO

International Standards Organisation

MIC

Microbial Induced Corrosion

MMO/Ti

Mixed Metal Oxide/Titanium

PCB

Polychlorobiphenyls

ROV

Remote Operated Vehicle

ROW

Right of Way

RTR

Reinforced Thermosetting Resin (synonymous with FRP)

SI

Système International d’Unités

T&I

Turnaround and inspection interval between planned shutdown (turnaround) activities as defined by the Company or RBA process

VOC

Volatile Organic Compounds

Units Company requirements are that metric SI units shall be used throughout. If an asset requires Imperial units to be used for clarity, then SI units shall be stated, followed by the local requirement in brackets. The following exceptions shall apply: • • •

Pressure shall be expressed as either gauge pressure in barg or absolute pressure in bara, gauge pressure being referenced to Standard Atmospheric pressure of 1.01325 bara. Temperature shall be expressed as degrees Celsius (oC) Dynamic viscosity shall be expressed as centipoise (cP)

In addition, the following common industry units shall also be used (applying dual units where appropriate): • • •

Volume gas flow in million standard cubic feet per day (MMscfd) Volume liquid flow in barrels per day (bpd) or US gallons per minute (gpm) as appropriate Stock tank oil/condensate flow shall be expressed in stock tank barrels per day (stbpd) and reflect the oil/condensate volumetric flow after flashing to stock tank conditions of 1.01325 bara and 15.5556 oC.

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BG Standard Cathodic Protection

The definition of Standard Conditions for pressure and temperature that shall be applied is 1 atmosphere pressure (or 1.01325 bara) and 15.5556 oC (rather than 1 atmosphere and 273.15 degrees Kelvin (0 oC).).

Any deviations to this definition to be consistent with local standards shall be discussed and agreed with BG Advance Engineering but shall, as a minimum, be fully defined in the project Basis of Design.

1.5

Referenced/Associated Documents Appendix A contains a list of referenced and associated documents related to this BG standard.

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2.0

BG Standard Cathodic Protection

BASIS FOR CATHODIC PROTECTION 2.1

General

2.1.1 Contractor shall select internationally recognised codes of practice and standards for the design, manufacture, inspection, installation and commissioning of cathodic protection systems within the scope of this Standard, using the following list in the first instance: Marine structures

DNV-RP-B401, EN 12495, EN 13174, EEMUA 194, NACE RP0176

Submerged steel pipe lines

ISO 15589-2, DNV-RP-F103, EN 12474, NACE RP0169,

Buried on-land based steel pipe lines

ISO 15589-1, EN 12954, NACE RP0169

In-plant steel piping including steel components of non-metallic piping systems, steel piles

EN 12954, NACE RP0169,

Internal surfaces of steel vessels, storage tanks and piping

NACE RP0196, NACE RP 0388, NACE RP0575

Soil-side surfaces of above ground storage tanks

NACE RP0193, API RP651

Direct buried steel vessels, storage tanks and mounded storage bullets

EEMUA 190, NACE RP0285

Steel reinforcement in concrete structures

NACE RP0290

Well casings

NACE RP0186

Commentary:

Alternative codes may be proposed where it can be demonstrated they will achieve an equivalent technical result

2.1.2 Contractor shall determine the requirement for cathodic protection based on the corrosion risk assessment required by BGA-ENG-MATL-TS-001 but unless otherwise agreed with Company the following items shall always be protected by a suitable cathodic protection system: •

Submerged pipe lines, manifolds and associated equipment

•

Buried, on-land pipe lines covered by ISO 13623/EN 14161

•

Offshore jacket structures

•

Mounded storage bullets.

Commentary:

Company and industry experience is that these are safety-critical items and require additional protection to that provided by coatings. Other items within the scope of this Standard should be evaluated to determine whether the installation of additional cathodic protection is feasible and economically justified in lowering the likelihood of corrosion and subsequent impact on safety, asset integrity, production, operability and the environment

2.1.3 In defining the appropriate cathodic protection strategy Contractor shall evaluate all applicable parameters that will influence the design and operation of the system, including but not limited to: •

Environmental conditions

Commentary:

•

This will include conditions such as electrolyte resistivity at applicable depths and locations, soil pH, presence of anaerobic conditions and bacterial activity, dissolved oxygen levels, temperature, salinity, fouling tendency, flow rates/turbulence, calcareous deposit formation

Details of media to be stored or processed

Commentary:

This will include details of media such as produced or connate water in oil treating equipment, cooling or fire water for storage tanks etc., sludge in storage tanks – in general, water or sludge with a resistivity of 2000 Ohm-cm or less is considered corrosive

•

Experience of similar structures in the same environment

•

Type of shop and field coatings

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BG Standard Cathodic Protection

•

Composition of backfill materials

•

Presence of earthing systems

•

Presence of high voltage overhead lines, AC or DC traction or power systems, other sources of interference or stray currents

•

Presence of existing cathodic protection systems

•

Presence of existing buried structures, pipe lines etc.

2.1.4 In addition to the parameters referenced in paragraph 2.1.1, Contractor shall evaluate the ease of installation, market availability, local content and satisfactory, documented service experience of the selected systems in developing the cathodic protection strategy. 2.1.5 Contractor shall develop detailed specifications for the design, purchase, inspection, installation and commissioning of the cathodic protection system. 2.1.6 Unless otherwise stated in this Standard, cathodically protected structures shall be protected with a high integrity coating system to reduce current demand. The selection of suitable coating systems shall be subject to review and agreement by Company. 2.1.7 Once the cathodic protection strategy has been reviewed and agreed with Company, no changes are permitted without Company agreement. 2.2

Health, Safety & Environment

2.2.1 Contractor shall ensure that all activities involved in the development, installation and operation of the cathodic protection strategy reduce the occurrence of hazardous events to ‘as low as reasonably practicable’ (ALARP) including but not limited to: •

Implementation of safety measures for protecting workers in accordance with all local and national regulations including provision of suitable protective equipment and training in its use, regular safety briefings/tool-box talks etc.

•

Provision of adequate ventilation and extraction facilities in confined spaces to prevent the build-up of toxic or flammable atmospheres

Commentary:

This requirement is principally aimed at minimising the likelihood of toxic chlorine gas or flammable hydrogen-air mixtures occurring in confined spaces as part of the cathodic protection reaction (H2S can also be an issue in confined spaces as a result of MIC)

•

Provision of adequate access and secure, temporary formwork to ensure safe working environments below grade

•

Provision of adequate safety systems to prevent electric shock either from impressed current systems or from lightning strikes

•

Adherence to existing asset permit-to-work systems including adequate training of personnel in their use.

2.2.2 Contractor shall ensure that manufacturing and installation processes, and any associated materials and substances, do not constitute a toxic, microbiological or organoleptic hazard. Materials and substances shall not contain asbestos, PCBs, CFCs and Halon refrigerants, or VOCs in excess of local, national and international legal limits. 2.3

Design Life

2.3.1 The design of the cathodic protection system shall ensure that the facilities are adequately protected for a minimum of 20 years unless otherwise specified by Company. For the following systems a shorter design life is permitted: •

Cathodic protection systems for on-shore well casings shall ensure a design life equivalent to the anticipated life expectancy of the well

•

Internal cathodic protection systems for process vessels and storage tanks shall ensure a design life of 5 years or one full T & I interval, whichever is greater

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• 2.4

BG Standard Cathodic Protection

Temporary cathodic protection systems shall be capable of protecting structures for a minimum of 2 years.

Existing Facilities

2.4.1 Where cathodic protection is specified for ‘brown field’ incremental projects at existing facilities or for new pipe lines in an existing corridor/ROW, Contractor shall ensure that the new cathodic protection system does not interfere with the performance of any existing cathodic protection system(s). 2.4.2 In developing the cathodic protection strategy Contractor shall evaluate the following as a minimum: •

Existing protection levels

•

Existing electrical isolation of system

•

Coating quality of existing buried components

•

Potential interference effects from existing systems on new systems

•

Output levels and capacity of the existing system

•

Accessibility for installing new systems.

2.4.3 Where feasible and economically justified, either any surplus capacity in the existing cathodic protection system should be used to protect the new structure(s) or the existing system should be upgraded in which case Contractor shall submit detailed design calculations to confirm no loss of protection to existing systems and remedial work required to upgrade system (e.g. increased capacity of rectifier, number of additional anodes, additional drain cables etc.). 2.4.4 Where it is not feasible or economically justified to use an existing cathodic protection system Contractor shall ensure that any new cathodic protection system is electrically isolated from, and does not interfere with, the existing system. Where complete electrical isolation is not feasible, Contractor shall design the new system to minimise current loss to foreign structures e.g. using hot-spot or localised systems. 2.5

Environmental Survey

2.5.1 In evaluating the requirement for cathodic protection systems Contractor shall undertake a survey to confirm the nature of the environment to which the structure is exposed including, but limited to: •

For marine structures, the water temperature, salinity, dissolved oxygen content, resistivity, suspended solids, sea currents, tidal movements and any potential for marine growth or calcareous deposits shall be confirmed at the relevant depths associated with the structure Where this survey is not feasible or no reliable empirical data exists, Contractor shall undertake suitable testing to confirm appropriate parameters for use in the design

•

For direct buried steel components, the soil resistivity and composition shall be confirmed as follows: o From a representative sample of the proposed installation locations for localised galvanic anode or impressed current distributed anode beds, measurements o At 10m intervals over the entire length of the proposed installation location for impressed current remote surface anode beds o During drilling of the anode hole for impressed current deep anode beds, measurements

Commentary:

If imported materials are used for backfill, mounding or foundations, the results from any initial measurements of the native soil shall be re-confirmed after completion of all ground engineering work

•

For above ground storage tank base plates, the foundation fill resistivity and composition shall be confirmed sufficiently well in advance of the installation to permit design of the cathodic protection system and shall be re-confirmed once the system is installed and the foundation backfilled but prior to installation of the tank base plates

•

For internal surfaces of above ground storage tanks and process vessels, the media’s resistivity and dissolved oxygen content shall be confirmed at the normal operating temperature.

2.5.2 Soil resistivity measurements should be made using either a non-contact electromagnetic instrument (e.g. Geonics, Syscal) to a depth commensurate with the burial depth or the Wenner 4-pin method. BGA-ENG-MATL-TS-0006 Issue 02a 12/11/08

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Commentary:

2.6

BG Standard Cathodic Protection

Electromagnetic instruments will normally be used for soil resistivities in excess of 1000 Ohm.cm

Electrical Isolation

2.6.1 Contractor shall evaluate the need for electrical isolation of each cathodic protection system including but not limited, to: •

Marine structures should be electrically continuous and isolating devices should not be used other than where the design requires isolation of pipe lines or risers from the structure

•

Submerged pipe lines shall be electrically isolated in accordance with the recommendations in the design codes and the following: o Change of ownership o Offshore-to-onshore landfall transitions o Pipe line-jacket structure transition unless the design of both systems ensure compatibility without impairing the performance of either system o Flexible pipe-to-fixed pipe transitions.

•

Land-based pipe lines shall be electrically isolated in accordance with the recommendations in design codes and the following: o Offshore-to-onshore landfall transitions o Connections to unprotected structures such as in-line inspection tool launcher/receiver, valve stations etc. o Above ground cross-over and by-pass piping supports, buried steel anchors and supports o Pipe line to in-plant piping transitions o Transmission pipe lines to distribution/service piping.

Commentary:

•

Contractor should evaluate whether additional cathodic protection may be more effective than electrical isolation in some of the above cases

For individual or multiple well casings, Contractor shall evaluate the need for electrical isolation between the well head and associated pipe line/flow line based on the layout of the well site and overall system design

Commentary:

In principle the cathodic protection system for the pipe line and well casing should be operated as an integrated system unless distance or proximity to other buried structures or plant facilities makes this approach unfeasible and/or costly

•

For new, above ground storage tanks with cathodic protection systems installed between the base plates and membrane, Contractor shall evaluate the need for electrical isolation of the piping entering and exiting the tank based on the positioning and proximity of the anode grids relative to the tank base

•

Buried in-plant piping, equipment and structures shall be electrically continuous and isolating devices shall not used other than to limit flow of current from the in-plant cathodic protection system to off-plot pipe lines or to above grade steel structures or buildings.

Commentary:

If the buried components are not electrically continuous as a result of welding Contractor shall install continuity bonds between affected components, terminating cable connections in above grade electrical enclosures

2.6.2 Where electrical isolation is required the design, installation and testing of isolating joints shall comply with NACE RP0286 and the following: •

The isolating device shall be installed at an easily accessible location to enable easy maintenance and inspection

•

Isolating devices shall not be installed in submerged or buried sections of pipe lines or in locations classified as potentially flammable unless otherwise agreed with Company.

Commentary:

•

Even with the installation of protective devices to minimise the likelihood of arcing from high voltage surges, there is an increased ‘risk’ from installing isolating devices in flammable areas and they should not be used unless absolutely necessary

Electrical continuity shall be confirmed at all flanged or clamp-type joints.

Commentary:

Bolting between flanges or clamp sections does not necessarily guarantee electrical continuity across the joint

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2.7

BG Standard Cathodic Protection

Electrical Interference Effects

2.7.1 Contractor shall ensure that the impact of any electrical grounding system is included in the design of the cathodic protection system including, but not limited to: •

Isolation of cathodically protected structures from the plant grounding system to avoid loss of protection current

•

Positioning of electrical ground rods and conductors in the immediate vicinity of a cathodically protected structure should be avoided but should not be installed closer than 3m. Where this is not feasible all ground conductors within 3m of, or electrically continuous with, a cathodically protected structure shall be insulated

•

Where grounding is required for the cathodically protected structure for safety reasons, it shall be separate from the rest of the electrical grounding system. Ground rods should be galvanised carbon steel or other suitable corrosion resistant alloy.

2.7.2 Contractor shall evaluate the likelihood of electrical interference on cathodic protected components including, but limited, to: •

Stray currents from other cathodic protection systems

•

Stray currents from DC traction systems or power sources

•

Stray currents from AC traction systems or power sources or lightning

•

Telluric currents.

2.7.3 Where such interference effects are anticipated or detected during commissioning and testing, Contractor shall specify appropriate mitigation measures including, but not limited, to: •

Design and install electrical bonds with suitable resistance between the affected structures

•

Installation of additional, localised cathodic protection in the area(s) at which the current is being discharged at the affected component

•

Installation of dielectric shields

•

Relocation of ground beds

•

Relocation of the affected component

•

Installation of suitable located isolating joints in the affected component

•

Application of coatings at the area(s) at which the current is being picked up on the affected component

•

Installation of grounding mats.

Commentary:

The requirements of NACE RP0177 should be included in the design of components subject to AC current and lightning effects

2.7.4 On completion of the remedial mitigation measures Contractor shall re-test the soil-to-component potential and dynamic interference current of the affected component to confirm that the remedial measures are effective. Commentary:

2.8

Further details of dynamic interference testing is contained in NACE RP0177

Current Density and Protection Criteria

2.8.1 Contractor shall ensure that the design of the cathodic protection system delivers an adequate current density to polarise the whole of the item under protection to the minimum required level for full protection. 2.8.2 In determining the minimum required current densities for the item under protection, Contractor shall evaluate the following parameters as a minimum: •

Material of construction

•

Coating system applied to the item, coating breakdown factor over the design life

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•

BG Standard Cathodic Protection

Water temperature, depth, oxygen content, tidal velocity, calcareous deposit formation, marine growth fouling.

2.8.3 The level of polarisation shall be in accordance with the relevant design codes but shall recognise the following requirements: •

The design shall avoid over-polarisation due to the potential for HISC and/or coating disbondment

Commentary:

•

The materials of construction

Commentary:

•

HISC has been experienced with high strength ferritic steels and CRAs such as duplex and martensitic stainless steels. Experience with titanium is limited but in principle it may also be susceptible and precautions should be taken if its use is proposed

CRAs generally require less negative potentials for full protection – where they are connected to ferritic steels the more negative potential criteria is normally applied but over-polarisation shall be avoided

The presence of anaerobic conditions or high temperature environments

Commentary:

These conditions will normally require a more negative potential for full protection but over-polarisation shall be avoided

2.8.4 Where CRAs are proposed for use in sub-sea equipment (e.g. manifolds, christmas trees, umbilical end terminations, pipe lines etc.) Contractor shall ensure that the basic design, material specification, coating selection and cathodic protection system design minimise the likelihood of HISC including but not limited to, the following: •

Adherence to the design guidelines in M-WA-01 and EEMUA 194 (as applicable to the material selection)

•

Provision of a high integrity coating system, qualified for resistance to cathodic disbonding at the maximum operating temperature

•

Specifying maximum hardness limits in accordance with NACE MR0175/ISO 15156 (as applicable to the material selection)

Commentary:

•

Avoiding attachment of anodes directly to CRA components – anode pads shall be used, designed to minimise local plastic strain

Commentary:

Short anode pipe spools may be used as an alternative to attaching anodes directly to the CRA

•

Avoiding designs with complex geometries that make it difficult to achieve uniform current distribution

•

Avoiding interaction with other cathodic protection systems to prevent overprotection of the CRA

Commentary:

3.0

These hardness limits shall be applied even where the process environment is not sour – the intention is to minimise hard microstructures that may be more susceptible to HISC

Low voltage cathodic protection may be considered as an alternative to conventional systems but should not be used if carbon steel is present as the carbon steel may not become sufficiently polarised

MATERIALS AND EQUIPMENT 3.1

General

3.1.1 Contractor shall develop detailed material specifications and purchase orders (as appropriate to its scope of supply) for all anode materials and associated equipment such as rectifiers, cables, reference electrodes etc. 3.2

Anodes

3.2.1 Anodes shall be manufactured in accordance with the requirements of the relevant design code and the following: •

Only anodes that have been pre-qualified by a procedure approved by Contractor are acceptable. The manufacturing procedure shall include method of casting, minimum and maximum chemical composition ranges, guaranteed consumption rates and electrochemical characteristics, anode-to-

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BG Standard Cathodic Protection

cable resistance, extent of destructive and non-destructive testing, weight and dimensional tolerances as a minimum •

Sacrificial anodes shall be manufactured from high purity alloys. Low purity anodes or anodes activated with mercury or cadmium are not permitted

•

Contractor shall confirm that anodes are suitable for the specified application and the complete range of anticipated environmental conditions including temperature and environment resistivity

•

Steel cores for sacrificial anodes shall be manufactured from killed or semi-killed weldable steel where welding is proposed for attaching anode to the structure.

3.2.2 Cables shall be securely attached to the anode and covered with an insulating sheath or sleeve. Cable pull-out tests shall form part of the inspection and testing requirements. Damaged or repaired cables or sheaths/sleeves are not permitted. 3.2.3 Pre-packaged sacrificial anodes shall be contained in a water absorbent material and its output certified for the material and fill. 3.2.4 Contractor shall ensure that representative inspection and testing of each type of anode is performed by the manufacturer and witnessed by Contractor. 3.2.5 Each anode shall be labelled with all relevant information, including type, dimensions, unique identification number for traceability and the manufacturer, in an indelible manner. The anodes shall be transported and stored in a manner that prevents damage to the anodes or cables and enables individual anodes to be removed without effecting the remaining anodes or anode cables. 3.3

Rectifiers

3.3.1 Rectifiers shall be shall be manufactured in accordance with the requirements of the relevant design code and the following:

3.4

•

Rectifiers shall comply with the appropriate electrical and hazardous area regulations for the site and shall be suitable for both indoor and outdoor use

•

Rectifiers shall be suitable for the prevailing atmospheric conditions at site and shall be guaranteed for the design life of the cathodic protection system.

Cables

3.4.1 All cables shall be manufactured from single core stranded copper with double insulation and sheathed to prevent damage form the buried or immersed environment. Where third party damage may occur armoured cables should be used. Commentary:

The selection of protective sheathing shall take into account potential for chlorine production or high acidity in deep ground beds or marine organisms in sub-sea applications

3.4.2 All cables shall be sized to ensure no excessive voltage drops occur that could reduce the capacity of the system. 3.4.3 Cable splices shall not be made at underground or undersea locations unless agreed with Company.

4.0

SPECIFIC DESIGN REQUIREMENTS 4.1

Marine Structures

4.1.1 Contractor shall ensure that the cathodic protection system provides uniform current distribution, and the required structure-to-electrolyte potential is met, over the entire surface area of the structure including, but not limited to, the following: •

The recommendations in the design codes shall be mandatory unless otherwise agreed with Company

•

The design prevents ‘over-polarisation’ of high strength carbon steels or CRAs and does not impair the corrosion-fatigue performance of the structure or exacerbate the likelihood of galvanic corrosion between dissimilar metals.

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BG Standard Cathodic Protection

4.1.2 The requirement for coating of submerged zones shall be subject to an economic and current demand evaluation and shall be subject to Company review. Commentary:

The submerged zone of fixed offshore structures is normally not coated unless very high current demand or required weight of anodes would result in an ineffective cathodic protection design. Other marine structures such as in-shore and in-land jetties, trestles, piles etc. should be coated to reduce current demand unless the evaluation indicates it is not feasible or uneconomic

4.1.3 Contractor shall include an allowance for current drain to well casings (whether jacket or sub-sea), mud mats, piles and mooring chains. 4.1.4 Where the use of CRAs is proposed, the requirements in paragraph 2.8.4 shall be met to minimise the likelihood of HISC. 4.1.5 Monitoring of marine structures shall be in accordance with the design codes, and the following:

4.2

•

Permanent reference electrodes and anode output/current density monitors shall be installed on offshore jacket structures at locations representing key features and zones. The extent and location shall be agreed with Company

•

A permanent test station shall be installed on each sub-sea manifold and christmas tree, suitable for interrogation by diver and/or ROV

•

A sufficient number of permanent test stations shall be installed on jetties, trestles or other in-shore structures to demonstrate that the submerged structure is fully protected across its entire area. The extent and location shall be agreed with Company.

Submerged Pipelines

4.2.1 Contractor shall ensure that the cathodic protection system provides uniform current distribution, and the required structure-to-electrolyte potential is met, over the entire surface area of the structure including, but not limited to, the following: •

The recommendations in the design codes shall be mandatory unless otherwise agreed with Company

•

The design prevents ‘over-polarisation’ of high strength carbon steels or CRAs and does not exacerbate the likelihood of galvanic corrosion between dissimilar metals.

4.2.2 All surfaces shall be protected with a high integrity coating system, qualified for resistance to cathodic disbanding at the maximum operating temperature. 4.2.3 Submerged pipe lines shall normally be protected by a sacrificial anode system. An impressed current system may be proposed for the following situations: •

On short sections of pipe line that terminate at a structure with an impressed current system

•

On short sections of in-shore pipe line where an impressed current system can be operated from the shore.

4.2.4 Where the use of CRAs is proposed the requirements in paragraph 2.8.4 shall be met to minimise the likelihood of HISC. 4.2.5 Contractor shall assess the impact of weight coatings or thermal insulation on the requirements for, and effectiveness of, cathodic protection systems. 4.2.6 Monitoring of the pipe line shall be in accordance with the design codes, with permanent test stations provided at each end of the pipe line. Contractor shall define the limitations on accuracy associated with this requirement and incorporate in its corrosion management guidelines (as required by BGAENG-MATL-TS-001) Commentary:

4.3

Company recognises that potential measurements at these points may not be representative of the whole pipe line therefore an understanding of the inherent limitations on the accuracy is required in developing the corrosion management strategy

On-shore Well Casings

4.3.1 Contractor shall ensure that the cathodic protection system provides uniform current distribution, and the required structure-to-electrolyte potential is met, over the entire external surface area of the well casing including, but not limited to, the following: BGA-ENG-MATL-TS-0006 Issue 02a 12/11/08

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•

The recommendations in the design codes shall be mandatory unless otherwise agreed with Company

•

The design prevents ‘over-polarisation’ of high strength carbon and low alloy steels and does not exacerbate the likelihood of galvanic corrosion between dissimilar metals.

4.3.2 Contractor shall evaluate the most cost effective design based on the well site layout, proximity of well sites and to other plant facilities including but not limited to: •

Each well casing shall have a dedicated cathodic protection system unless the distance between well sites is such that a common system can provide the required current density and polarisation at each well casing

Commentary:

The maximum distance between well sites protected by a common system should not normally exceed 2km

•

Where a common cathodic protection system is acceptable each well casing shall have a dedicated negative cable

•

All buried metallic structures associated with the well casing shall be integrated with the cathodic protection system

Commentary:

The requirements for electrical isolation between the well casing and the pip line/flow line are addressed in Section 2.6

4.3.3 Contractor shall evaluate whether coating of the casing is economically justified based on the design life, depth of casing, the design of the cathodic protection system and extent and quality of cementing. Commentary:

Coating will generally be more economic at remote well sites where provision of power and regular inspection is difficult, long design life or critical production wells, or in aggressive soils

4.3.4 Monitoring of well casings shall be in accordance with the design codes, with sufficient test stations installed to demonstrate that each well casing is fully protected at the surface. Contractor shall define the limitations on accuracy associated with this requirement and incorporate in its corrosion management guidelines (as required by BGA-ENG-MATL-TS-001) Commentary:

4.4

Company recognises that potential measurements at the surface may not be representative of the whole depth of well casing therefore an understanding of the inherent limitations on the accuracy is required in developing the corrosion management strategy. Where feasible, appropriate surveys will be performed during well work-over operations

Land Based Pipelines

4.4.1 Contractor shall ensure that the cathodic protection system provides uniform current distribution, and the required structure-to-electrolyte potential is met, over the entire surface area of the pipe line including, but not limited to, the following: •

The recommendations in the design codes shall be mandatory unless otherwise agreed with Company

•

The design prevents ‘over-polarisation’ of high strength carbon steels or CRAs and does not exacerbate the likelihood of galvanic corrosion between dissimilar metals.

4.4.2 Pipe lines shall normally be protected by an impressed current system. Sacrificial anode systems may be proposed for the following situations: •

Buried sections of above ground pipe lines e.g. road, camel crossings

•

Electrically isolated pipe line sleeves or casings

•

If no power for an impressed current system is available

•

Localised ‘hot-spot’ protection to supplement the impressed current system e.g. at pipe line terminations adjacent to plant facilities to compensate for current drain to underground metallic structures

•

Short sections of pipe line where installation of an impressed current system cannot be economically justified.

4.4.3 All surfaces shall be protected with a high integrity coating system, qualified for resistance to cathodic disbanding at the maximum operating temperature.

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4.4.4 Where it Is not feasible to transport suitable backfill materials or these are not readily available locally, Contractor shall assess the impact on the effectiveness of the cathodic protection system of applying alternative or additional coating systems to protect the pipe line in rocky terrain. 4.4.5 Where the use of CRAs is proposed the requirements in paragraph 2.8.4 shall be met to minimise the likelihood of HISC. 4.4.6 Monitoring of the pipe line shall be in accordance with the design codes, with sufficient test stations installed to demonstrate that it is fully protected along its entire length. As a minimum, test stations shall be installed at each marker post and at other features such as paved road, casing or other crossing, isolating joints, drain points. Contractor, in conjunction with Company, shall identify certain representative test stations to act as ‘key performance indicators’ for the whole pipe line system. 4.5

In-plant Buried Piping, Vessels and Structures

4.5.1 Where specified, Contractor shall ensure that the cathodic protection system provides uniform current distribution, and the required structure-to-electrolyte potential is met, for all structures under protection including, but not limited to, the following: •

The recommendations in the design codes shall be mandatory unless otherwise agreed with Company

•

The design prevents ‘over-polarisation’ of high strength carbon steels or CRAs and does not exacerbate the likelihood of galvanic corrosion between dissimilar metals.

4.5.2 All surfaces shall be protected with a high integrity coating system, qualified for resistance to cathodic disbonding at the maximum operating temperature. 4.5.3 All buried metallic components in RTR or thermoplastic systems, such as valves, hydrant risers shall be cathodically protected. 4.5.4 The ’earth potential rise’ method may be proposed where the facilities layout includes extensive quantities of metallic structures that do not require protection (e.g. copper ground beds, reinforcing steel in concrete) or electrical shielding precludes the use of remote anode beds. In this case the size and shape of the anodes, their spacing and location relative to the structure under protection and the local soil conditions to define the native earth potential shall be determined by Contractor and agreed with Company. 4.5.5 Monitoring of the system shall be in accordance with the design codes with sufficient test stations installed to demonstrate that all protected structures are fully protected. 4.6

Above Ground Storage Tank Base Plates

4.6.1 Where specified, Contractor shall ensure that the cathodic protection system provides uniform current distribution, and the required structure-to-electrolyte potential is met, over the entire surface area of the soil-side of the tank base plates including, but not limited to, the following: •

The recommendations in design codes shall be mandatory unless otherwise agreed with Company

•

Installation of a flexible, impermeable (dielectric) membrane for under-tank leak detection and subgrade protection as required by API 650

•

An impressed current MMO/Ti gird system or continuous, polymeric ribbon distributed anode system placed between the membrane and tank base plates, sized and spaced to ensure uniform current distribution, and structure-to-soil potential

Commentary:

•

If alternative under-tank leak detection systems are proposed due to local regulations or operating practices (e.g. clay) these shall maintain a resistance low enough to permit cathodic protection current from remote anodes to reach the tank base plates

For small tanks (below approximately 10m diameter) , a galvanic anode system using conventional pre-packaged anodes or a continuous galvanic anode may be proposed as an acceptable alternative to an impressed current system, subject to an economic analysis to justify the most costeffective, as-installed system

4.6.2 The base plates shall be protected by a coating system on the soil-side to reduce current demand with an allowance of 10% of the base plate area considered to have no external coating to allow for coating

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BG Standard Cathodic Protection

damage during base plate installation and welding. The operating temperature of the tank shall determine the appropriate current density to be used 4.6.3 Tank foundation fill should be either clean, dry sand or sand and cement mixture with low levels of chlorides and sulphates 4.6.4 The impact of draw-off sumps below the level of the tank base on current demand and anode layout/spacing shall be addressed in the cathodic protection design 4.6.5 Connections between the cables and the central conductor bar shall be factory made, tested and epoxy encapsulated for water tightness. No field joints/splices shall be permitted below the base plates. 4.6.6 Monitoring of the system shall be in accordance with the design codes and the following: •

A sufficient number of slotted, non-metallic tubes (50mm diameter) shall be installed through access points in the ring wall and positioned across the diameter of the tank foundation to demonstrate that the entire surface area of the base plates are fully protected

•

The slotted tube material shall be suitable for the normal operational temperature of the tank and each tube shall be wrapped with a low weight, water permeable textile to prevent sand entering the pipe during compaction

•

Additional access point shall be provided in the ring wall to permit installation of temporary portable reference electrodes beneath the tank periphery

•

Permanent reference electrodes should be copper/copper sulphate with an additional zinc reference electrode for back-up and calibration purposes

Commentary:

4.7

The slotted pipes and access tubes required above will be installed during the ring wall construction and their layout shall ensure they do not clash or interfere with other structures, pipes etc. and that adequate access is provided for insertion/pulling of the reference electrodes during monitoring activities

Process Vessels, Storage Tanks and Piping Internal Surfaces

4.7.1 Where specified, Contractor shall ensure that the cathodic protection system provides uniform current distribution, and the required structure-to-electrolyte potential is met, over the entire surface area of the soil-side of the tank base plates including, but not limited to, the following: •

The recommendations in the design codes shall be mandatory unless otherwise agreed with Company

•

The design prevents ‘over-polarisation’ of high strength carbon steels and does not exacerbate the likelihood of galvanic corrosion between dissimilar metals

•

A sacrificial anode system using aluminium, magnesium or zinc anodes is preferred unless the operating temperature, process environment of contamination of the environment precludes their use

Commentary:

•

Mercury activated aluminium anodes or zinc anodes shall not be used for potable water applications. Zinc anode consumption rates for use above 50ºC shall be certified by the manufacturer for the maximum expected operating temperature

Where a sacrificial anode system is precluded, an impressed current system using MMO, polymeric, platinum or HSCI anodes.

Commentary:

Only inert anodes shall be used where product contamination could occur

4.7.2 The number and location of anodes shall be assessed based on the accessibility of components, configuration of the internals and whether shielding can occur, the weight requirement to achieve the design life and the current requirement (i.e. the current demand necessary to achieve and maintain protection). Contractor shall submit detailed calculations and drawings to substantiate the final design. Commentary:

The placement of anodes shall ensure there is no (or minimal) disruption to the fluid flow

4.7.3 Monitoring of the system shall be in accordance with the design codes and the following: •

A sufficient number of permanent reference electrodes shall be installed through access holes in the tank roof, spaced equidistant between anode strings, to demonstrate that the relevant surface area of the tank is fully protected

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•

A sufficient number of permanent reference electrodes shall be installed through a nozzle or branch connection in the vessel or piping to demonstrate that the relevant surface area of the vessel or pipe is fully protected.

Commentary:

5.0

BG Standard Cathodic Protection

Where a nozzle or branch connection is used to mount a reference electrode, the blind flange to which the electrode is attached shall be electrically isolated from the main vessel or pipe wall by means of an insulating gasket set

INSTALLATION, COMMISSIONING AND MONITORING 5.1

Installation

5.1.1 Contractor shall ensure that the installation of the cathodic protection system is undertaken in accordance with the recommendations of the design codes under the supervision of the Contractor and the party responsible for the system design (if applicable). 5.1.2 Contractor shall develop specific procedures to control the installation activities including, but not limited to: •

Verify resistivity of environment where anodes are to be installed is in accordance with design assumptions

Commentary:

•

Inspection of all components prior to and after installation to ensure no damage has occurred during transport, storage or installation

•

Location, depth and orientation of anodes, including use of correct back fill materials and venting (where applicable), is in accordance with the design

•

Coating removal and re-instatement at anode or cable connections

Commentary:

A minimum of coating should be removed and the area re-instated by an approved system with an equivalent life as the main coating system

•

Location, protection and routing of cables, rectifiers etc. is in accordance with the design

•

Anodes, ground beds, cables, rectifiers etc. are individually identified to permit correct connection and future maintenance and warning signs/markers are installed

•

Attachment of anodes or cables to structures and pipe lines including use of qualified welding/joining procedures and welders/operators

Commentary:

5.2

Where any differences are noted that may require modification to the design Contractor shall notify Company and undertake all necessary remedial action to ensure the design is acceptable for the actual environmental conditions

This will include all acceptable methods of joining anodes or cables to the structure e.g. fusion welding, pin brazing, adhesive bonding. Thermite welding should not be used on CRA materials or high strength ferritic steels

•

Location of monitoring test points is in accordance with the design

•

Adequate access is provided for future maintenance/retrofit activities

•

Activation and monitoring of any temporary cathodic protection systems.

Commissioning

5.2.1 Contractor shall ensure that the commissioning of cathodic protection systems is undertaken in accordance with the recommendations of the design codes under the supervision of the Contractor and the party responsible for the system design (if applicable). 5.2.2 Contractor shall develop specific procedures to control the pre-commissioning and commissioning activities including, but not limited to: •

Verify electrical continuity of system

•

Verify anode ground bed resistance

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•

BG Standard Cathodic Protection

For impressed current systems: o Verify rectifier output in accordance with manufacturer’s recommendations o Verify all temporary cathodic protection systems, bonds to foreign structures or earthing systems are disconnected o Verify and record individual anode outputs and native electrolyte-to-structure potentials prior to energising system and polarised potentials 24-48 hours after energising at key monitoring points on structure to confirm full polarisation of the complete structure is achieved. Where multiple structures are protected by one system the potential at each structure shall be measured

Commentary:

Full polarisation may take several days but shall be achieved no later than 30 days after the start of commissioning

o Verify and record electrolyte-to-structure ON-OFF potentials (as applicable) after steady polarisation potentials achieved o Verify and record electrical isolation of system and effectiveness of electrical interference mitigation measures •

For sacrificial anode systems: o Verify and record native electrolyte-to-structure potential and the open circuit potential of the sacrificial anode prior to connection o Verify and record the electrolyte-to-structure potential and current at each anode 24-48 hours after connection to confirm full polarisation of the complete structure is achieved o Verify and record electrical isolation of system

5.2.3 Commissioning of the cathodic protection system for storage tank base plates shall only be performed once a sufficient content level is present in the tank to ensure intimate contact between the base plates and the foundation. 5.2.4 Where full potential cannot be achieved during commissioning, Contractor shall notify Company and undertake all necessary remedial action to ensure full protection is achieved. 5.3

Monitoring

5.3.1 In addition to measuring electrolyte-to-structure potentials as part of the commissioning activities, Contractor shall specify all necessary monitoring activities required to ensure the cathodic protection system is functioning correctly and will deliver full protection across all structures under protection for the specified design life including but not limited to: •

Extent, type and frequency of functional checks of equipment outputs, cable connections, battery charge, calibration of instruments etc monitoring

•

Frequency of electrolyte-to-structure potential measurements, particularly during the initial period after commissioning

•

Recommendations for regular surveys of the structures under protection e.g. CIPS, DCVG, Pearson

5.3.2 Contractor shall include the results of all environmental surveys and monitoring activities undertaken during the design, installation and commissioning of the cathodic protection system within the corrosion management database required by BGA-ENG-MATL-TS-001.

6.0

QUALITY CONTROL 6.1

General

6.1.1 Contractor shall ensure that suitable quality assurance systems are in place to ensure that all activities that affect the performance and quality of the cathodic protection system are adequately controlled including but not limited to: •

Validation of the design, including review of any third party design

•

Review of purchase orders/sub-contract requisitions to ensure correct specification of materials and services

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•

Inspection of materials and their certification to ensure requirement of the design codes, Company standards and project specifications and have been met

•

Witness of material testing, installation and commissioning activities etc.

•

Development of inspection and test plans detailing all the principal stages of design, manufacture, inspection and testing, installation and commissioning.

6.1.2 The detailed design, installation and commissioning of the cathodic protection system shall be undertaken by, or under the supervision of, an experienced cathodic protection specialist, certified in accordance with an internationally recognised scheme (e.g. NACE International). Evidence of the specialist’s current certification shall be submitted for Company review. Commentary:

Original “wet copy” certificates attesting to personnel certification shall be made available for review by Company photocopies of certificates are not acceptable as proof of personal certification

6.1.3 Company reserves the right to inspect all phases of fabrication and testing to verify that Contractor/Purchaser/Vendor procedures and systems are working effectively and that the requirements of Company standards and project specifications are being met. Commentary: This inspection shall not be used as a substitute for adequate Contractor/Purchaser/Vendor supervision and inspection

6.2

Documentation

6.2.1 Contractor shall develop all necessary documentation to ensure that the requirements of the design code, Company standards and Basis of Design are met during all stages of design, manufacture, installation and commissioning including but not limited to: •

Detailed specifications for the design, materials, installation and commissioning

•

Detailed drawings of the system indicating each cathodic protection item and associated cables and junction boxes, cable routing, existing cathodic protection systems that may affect the new system

•

Detailed calculations to support the design

•

Installation and commissioning procedures

•

Records of all surveys, material inspections

•

Personnel certification

•

Material certification

•

Maintenance and operating manuals.

6.2.2 All relevant documentation shall be included in the equipment data books or piping isometric test packs

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7.0

BG Standard Cathodic Protection

FEEDBACK Where inaccuracies, errors, omissions or other general areas for quality or performance improvement are identified in this document the Feedback Form, provided in Appendix B shall be completed and returned to the Group Technical Authority (Document Custodian) identified in the Document Information Sheet.

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APPENDIX A - LIST OF REFERENCED / ASSOCIATED DOCUMENTS BG Standards BGA-ENG-MATL-TS-001

Material Selection & Corrosion Control

BGA-ENG-SYS-OS-001

Management of Change

BGA-ENG-SYS-OS-002

Dispensation from Mandatory Requirements

International Standards Organisation (ISO) ISO 13623

Petroleum and Natural Gas Industries – Cathodic Protection of Pipeline Transportation Systems

ISO 15156

Petroleum and Natural Gas Industries - Materials for use in H2SContaining Environments in Oil and Gas Production

ISO 15589-1

Petroleum and Natural Gas Industries – Cathodic Protection of Pipeline Transportation Systems – Part 1 On-land Pipelines

ISO 15589-2

Petroleum and Natural Gas Industries – Cathodic Protection of Pipeline Transportation Systems – Part 2 Offshore Pipelines

ISO 9001

Quality Management Systems - Requirements

NACE International MR0175

Petroleum and Natural Gas Industries - Materials for use in H2SContaining Environments in Oil and Gas Production

RP0169

Control of External Corrosion on Underground or Submerged metallic Piping Systems

RP0176

Corrosion Control of Steel Fixed Offshore Structures Associated with Petroleum Production

RP0177

Mitigation of Alternating Current and Lightning Effects on Metallic Structures and Corrosion

RP0186

Application of Cathodic Protection for External Surfaces of Steel Well Casings

RP0193

External Cathodic Protection of On-Grade Carbon Steel Storage Tank Bottoms

RP0196

Galvanic Anode Cathodic Protection of Internal Submerged Surfaces of Steel Water Storage

RP0285

Corrosion Control of Underground Storage Tank Systems by Cathodic Protection

RP0286

Electrical Isolation of Cathodically Protected Pipelines

RP0290

Impressed Current Cathodic Protection of Reinforcing Steel in Atmospherically Exposed Concrete

RP0388

Impressed Current Cathodic Protection of Internal Submerged Surfaces of Carbon Steel Water Tanks

RP0575

Internal Cathodic Protection Systems in Oil-Treating Vessels

American Petroleum Institute (API) RP 651

dic Protection of Above Ground Storage Tanks

Std 650

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Welded Steel Tanks for Oil Storage

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European Norms (EN) EN 12474

Cathodic Protection of Submarine Pipelines

EN 12495

Cathodic Protection of Fixed Steel offshore Structures

EN 12954

Cathodic Protection of Buried or Immersed Structures – General Principles and Application for Pipelines

EN 13174

Cathodic Protection for Harbour Installations

EN 14161

Petroleum and Natural Gas Industries – Cathodic Protection of Pipeline Transportation Systems

Det Norske Veritas (DNV) RP-B401

Cathodic Protection Design

RP-F103

Cathodic Protection of Submarine Pipelines by Galvanic Anodes

Norsok M-WA-01

Design Guideline to Avoid Hydrogen Induced Stress Cracking in Sub-sea Duplex Stainless Steels

Engineering Equipment Manufacturers & Users Association (EEMUA) Publication 190

Guide for the Design, Construction and Use of Mounded Horizontal Cylindrical Steel Vessels for Pressurised Storage of LPG at Ambient Temperatures

Publication 194

Guidelines for Materials Selection and Corrosion Control for Subsea Oil and Gas Production Equipment

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APPENDIX B - FEEDBACK FORM

FEEDBACK FORM This form should be used to notify comment or suggestions for improvement, relating to any aspect of the document identified below. Please return the completed form by Email, to the Technical Authority identified in the associated Document Information Sheet. Document title:

Document No: BGA-ENG-MATL-TS-003

TAS Engineering Technical Standard – Cathodic Protection Issue No: 02

Issue Date: 02/04/08 Comments by:

Date: …………………………

Name: ………………………………………………..

Email address / Contact Tel.No: …………………………

Position: …………………………………………..

Project / Business Unit: …………………………..

Page/Section No:

BGA-ENG-MATL-TS-0006 Issue 02a 12/11/08

Comment

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