---

A 30.01.2012 ISSUED FOR INFORMATION O.Y O.Y E.D

Rev.No. Date Description

Prepared Checked Contr. By Approved ------------

ORIGINATOR Published by

EDOPEC ENERJİ PETROL MÜHENDİSLİK SANAYİİ VE TİCARET LİMİTED ŞİRKETİ

Contractor

Document Title

Corrosion Management and Cathodic ProtectionOffice :

Palmiye Mah. Adnan menderes Bulv. Oktay SitesiNo: 9/8 PK = 33100 Yenişehir /Mersin –TURKEYP:+90 324 3260595 F:+90 324 3260596Ankara Office :UĞUR MUMCU CAD(köroğlu cad) ERDİL APT 87/13 Gop-Çankaya -Ankara-TURKİYEP: +90 312 447 17 18 / 20F:+90 312 447 17 21İstanbul Office: Burhanıye Mahallesı Çamlıca Caddesi İhlamur villaları no 28 / 6^ŞRD3K Villa ̂ Beylerbeyi –Üsküdar İstanbul / TURKEYP : +90 216 4220414 PBXF: +90 216 4220415www.edopec.com. info@edopec.com

Document No.

EDO PPP COE COR INT XXX 013 051 052 Rev ACo. Org.

CodDoc Type

Disc. Code

Unit Code

Prj. type

Prj.NO

Prıj.Year

Pro.Doc.Seq.No

DCC Seq.NoPage Scale

53

Head Office : Palmiye Mah. Adnan menderes Bulv. Oktay Sitesi No: 9/8 PK = 33100 Yenişehir /Mersin –TURKEYP:+90 324 3260595 F:+90 324 3260596Ankara Office : UĞUR MUMCU CAD(Köroğlu cad) ERDİL APT 87/13 Gop-Çankaya -Ankara-TURKİYEP: +90 312 447 17 18 / 20 F:+90 312 447 17 21İstanbul Office: BURHANIYE MAHALLESI ÇAMLICA CADDESİ İHLAMUR VİLLALARI NO 28 / 6 ^^ŞRD 3K VİLLA ^^ Beylerbeyi –Üsküdar İSTANBUL / TURKEY P : +90 216 4220414 PBX F: +90 216 4220415

EDOPEC ENERJİ PETROL MÜHENDİSLİK SANAYİİ VE TİCARET LİMİTED ŞİRKETİ

www.edopec.com. info@edopec.com

Corrosion Management and Cathodic Protection

Edopec Corrosion divisions

is organized with a vision of providing engineering services and manufacturingfor Authorities and Clients located in Turkey , Iran , irak Syria and Middle-east.Libya ,Our focus is on complete Cathodic Protection services including all of theConsultation, Survey, Design, production and installation related work for On-shore & Off-shore facilities, Off-shore & Marine inspection and IndustrialAutomation for:

•Oil and Gas Industries (offshore & onshore)•Petrochemical industry•Energy•Cement industry

Edopec Co. carries out its business under five separate functionaldivisions as follows;

• Engineering Design and R&D• Manufacturing and Fabrication• Installation, Commissioning and Maintenance• Strategic Planning and Project Control• Financial and Commercial

Edopec. is a Company having a powerful blend of managementexperience, young and dynamics and technical expertise. Each Purchase orderor Work order is considered as a separated project and required team isorganized to undertake assigned Project manager to conduct the relevantsteps of Procurements, Quality Control, fabrication/erection/commissioningalong logistics and documents.

We continuously strive to perform all of our projects with the best quality tosatisfy clients' needs, using the qualified engineers and specialists. We realizedthat our success is largely dependent upon customer satisfactions witch isdirectly involved within each member products and managed projects.

Project Manger

Procurementbody

QC and Test body

Logistic coordinator

Technical Support

Erection GroupDocumentation

GroupElectrical Group

•PROJECT ACTİVİTİES

ACTIVITY DETAILS

ENGINEERING & DESIGN

Direct Assessments Services;Soil Resistivity Survey, CAT (Current Attenuation Test) Survey, DCVG (Direct Current Voltage/Gradient) Survey, CurrentRequirement/Drainage Survey, CIPS (Close Interval Potential) Survey, Stray Current Interference Survey, Polarization and On/Off PotentialSurvey, Coating Resistance Survey, Anode bed Resistance Survey, Buried Structures Natural Potential Survey, Overhead line Effect onBuried Structures Survey, (SRB) Sulphur Reduced Bacteria Survey, pH Survey, Carbonate And Sulphate Ions Survey, Grounding SystemResistance Survey, Internal Cathodic Protection and microbial corrosion monitoring and inspections.Engineering Design;Basic & Detailed Design of Cathodic Protection systems for Pipelines, Tank Forms, Petro-Chemical Plates, Power Plants, vessels, harbors,Jetties, offshore and marine structures by both means of SACP and ICCP system (where applicable) Design of SCADA based ICCP systems, Design of Stray Current and AC mitigation Systems.Materials/Equipment Design;Design and development of various types of CP Trans/rectifier Units, Design and development of Special Power Supply units, Design anddevelopment of RRU systems ( Remote Rectifier Units), Design and development of RMU systems ( Remote Monitoring Units), Design anddevelopment CP Remote Monitoring and Control systems. Design and development of GPS synchronized On/Off control of T/R units,Design and Development of Current Control boxes, Sacrificial anode design.

PROJECT MANAGEMENT Project management of SCADA based ICCP systems, Project management of ICCP and SACP systems, Project management of LocalCathodic Protection of Oil and Gas and Energy Facilities.

COMMISSIONING & START UP

Deepwell and shallow groundbed installations, ICCP systems for Pipelines and Storage Tanks, ICCP systems for Congested area andTank Farms, SACP installation for interior surfaces of storage tanks, SCADA based Cathodic Protection systems, CP Remote monitoring andControl systems, Galvanic CP and ICCP systems for Pipelines, Storage Tanks and Tank Farms, CP systems for Marine Structures andOffshore Pipelines, Galvanic CP and ICCP systems for Ships, Vessel, Jetties and Piers, Internal Galvanic CP and ICCP systems for WaterTanks and Boilers, Galvanic CP and ICCP systems for Reinforcing steel in Concrete Structures, SCADA communication systems (Wireless,Satellite, GSM, Fiber Optics) , Installation and replace of permanent reference electrodes under the tank bottom plate for further potentialmonitoring proposes via. horizontal drilling technology.

EQUIPMENT MANUFACTURE Fabrication and production of TR units ICCP anodes, Sacrificial anodes, current control and junction boxes, Coupons and referenceelectrodes.

•PRODUCTION and SUPPLY

Item Product1 Transformer Rectifier Units

2 Test, Junction, Bond Boxes

3 Current Control and Compensation Boxes

4 Reference electrodes and coupons

5 Cables and connections

6 Remote Monitoring System& Software

7 MMO coated Ti anodes

8 Silicon Iron Chromium Anodes

9 Magnesium anodes

10 Zn Anodes

11 Al Anodes

12 Backfill Materials

13 Miscellaneous

14 Cathodic Protection Software

•CATHODIC PROTECTION SYSTEMSCADA SOFTWARE

•CATHODIC PROTECTION SYSTEMSCADA SOFTWARE

•CATHODIC PROTECTION RECTIFIERUNIT

•PRODUCTION and SUPPLY

•MAJOR CP SERVICES OFEDOPEC

•SITE SURVEYS & INSPECTIONSSERVICES•ENGINEERING DESIGN, PLANNINGAND R&D SERVICES•INSTALLATION AND COMISSIONINGSERVICES•BACK-UP SERVICES•TRAINING

SITE SURVEYS & INSPECTIONS SERVICESSite surveys are undertaken to evaluate the corrosion behaviour of different environments, Cathodic Protection monitoring, underwater inspection of structures, anodes, and coatings , Earthing and lightning activities by means of soil, water, location, stray current and so on testing. EDOPEC , undertakes the following surveys and inspections

•Soil Resistivity Survey•CAT (Current Attenuation Test) Survey•DCVG (Direct Current Voltage/Gradient) Survey•Current Requirement/Drainage Survey•CIPS (Close Interval Potential) Survey•Stray Current Interference Survey•Polarization and On/Off Potential Survey•Coating Resistance Survey•Anode bed Resistance Survey•Buried Structures Natural Potential Survey•Overhead line Effect on Buried Structures Survey•(SRB) Sulphur Reduced Bacteria Survey•pH Survey•Carbonate And Sulphate Ions Survey •Grounding System Resistance Survey•Contact Voltage (Touch and Step Voltages) Survey•Lightning Protection Installation Survey•Lightning Protection Level Survey •Internal Cathodic Protection and microbial corrosion monitoring and inspections.•Potential Profile, Current Distribution Survey of Power Plants, Take-off yards and substations

•Sub-sea Platform inspection for maximum deep of 40 meters including repair, wet welding, cutting, anode• inspection ( Cleaning, montage, re-montage, photography)and NDT tests (MPI, FMD, Thickness testes)

•BACK-UP SERVICES

EDOPEC . maintains close contact with the market so that it cantailor its product offering to the needs of the clients. Theconsiderable experience has ensured that the Company canprovide complete back-up services from initial design to finalcommissioning and maintenance. The aim is to give customers anefficient, professional service of the highest quality. Comprehensiverange of maintenance and support services provides a further levelof back up, as appropriate.

ENGINEERING DESIGN, PLANNING AND R&D SERVICES

The engineering and design phase is one of the key processes during the project execution stage. EDOPEC.Currently has a core staff of several engineers. All of these have been selected because of their unique alternativeexperience.We are more than able to provide our clients with the project teams to meet the challenges presented bymature fields.Advantages have been successfully involved in almost every advanced engineering project carried out in EDOPEC..Clients have recognised, through the provision of project services, EDOPEC’s ability to efficiently provide theirrequirements.

•Basic & Detailed Design of Cathodic Protection systems for Pipelines, Tank Forms, Petro-Chemical Plates, Power Plants,vessels, harbours, Jetties, offshore and marine structures by both means of Galvanic and ICCP system (where applicable).•Design and development of various types of CP Trans/rectifier Units•Design and development of Special Power Supply units•Design and development of RRU systems ( Remote Rectifier Units)•Design and development of RMU systems ( Remote Monitoring Units)•Design and development CP Remote Monitoring and Control Systems•Design and development of GPS synchronized On/Off control of T/R units•Project Design of SCADA based ICCP systems•Project Management of ICCP Galvanic CP systems•Project Design of Local Cathodic Protection of Oil and Gas and Energy Facilities•Design and Planning of CP installation of special ICCP anodes•Design and Planning of Subsea and Offshore Structure CP systems•Design and Planning of Ships and Vessels ICCP systems•Design and Planning SCADA communication systems•Design and Planning of ICCP Systems for Internal Cathodic Protection•R & D of CP systems of Reinforcing steel in Concrete Structures•R & D on AC interference analysis and mitigation system design•R & D on Projects Safety and Economics

•INSTALLATION AND COMISSIONING SERVICES

Edopec Co. have ability to provide installation and commissioning services for the following projects and systems relevant toOil & Gas and Energy Industries.

• Deepwell and shallow groundbed installations• ICCP systems for Pipelines and Storage Tanks• ICCP systems for Congested area and Tank Farms• Galvanic CP installation for interior surfaces of storage tanks• SCADA based Cathodic Protection systems• CP Remote monitoring and Control systems• Galvanic CP and ICCP systems for Pipelines, Storage Tanks and Tank Farms• CP systems for Marine Structures and Offshore Pipelines• Galvanic CP and ICCP systems for Ships, Vessel, Jetties and Piers• Internal Galvanic CP and ICCP systems for Water Tanks and Boilers• Galvanic CP and ICCP systems for Reinforcing steel in Concrete Structures• Ribbon anode installation for new constructed storage tanks• ICCP system for existing tanks using horizontal drilling technology.• Installation and replace of permanent reference electrodes under the tank bottom plate

for further potential monitoring proposes via. horizontal drilling technology.

Fundamentals of Corrosion Corrosion Cell:

Conditions required for corrosion Corrosion Rate Corrosion Types Commonly Affected Structures

Corrosion Control Materials Selection Inhibitors/Altering the environment Coatings Cathodic Protection

Measuring potentials Criteria

Fundamentals of Corrosion Corrosion Cell:

Conditions required for corrosion Corrosion Rate Corrosion Types Commonly Affected Structures

Corrosion Control Materials Selection Inhibitors/Altering the environment Coatings Cathodic Protection

Measuring potentials Criteria

Introduction to Corrosion

Corrosion can be defined as the deterioration of metal due to its interaction with the environment. Corrosion is a natural phenomenon, which should not surprise one, but rather should be expected to occur. Metals are high energy materials, which exist because heat energy was added to natural iron ores during the smelting process. Nature, by environmental contact, constantly attacks these high energy materials and breaks them down to the natural elements from which they were derived.

Conditions Required for Corrosion

Corrosion is an electrochemical process occurring at the interface between metal and environment. Three conditions must be present for this to occur.

1. Two areas on a structure or two structures must differ in electrical potential.

2. Those areas, called anodes and cathodes, must be electrically interconnected.

3. Those areas must be exposed to a common electrolyte (soil or water).

Two areas or two structures that differ in electrical potential (different amounts of stored energy)

The two areas, called the “Anode” and “Cathode”, must be electrically connected (conductive path)

Those areas must be exposed to a common electrolyte

CURRENTFLOW

CURRENT FLOWIONIZED ELECTROLYTE

WIRE

ANODE(IRON)

CATHODE(COPPER)

CURRENT FLOW(- TO + IN ELECTROLYTE)

Those areas must be exposed to a common electrolyte

CURRENTFLOW

CURRENT FLOWIONIZED ELECTROLYTE

WIRE

ANODE(IRON)

CATHODE(COPPER)

CURRENT FLOW(- TO + IN ELECTROLYTE)

Corrosion Cell – Dissimilar Metalsi.e. steel pipe connected to copper ground rod

CURRENTFLOW

CURRENT FLOWIONIZED ELECTROLYTE

WIRE

ANODE(IRON)

CATHODE(COPPER)

CURRENT FLOW(- TO + IN ELECTROLYTE)

24

Corrosion Rate

As a result of this process, electric current flows through the interconnection between cathode and anode. The cathodic area is protected from corrosion damage at the expense of the metal, which is consumed at the anode. The amount of metal lost is directly proportional to the current flow. Mild steel is lost at approximately 20 pounds for each ampere flowing for a year.

25

Factors Affecting Corrosion Rate

Potential Difference Between Anode and Cathode (Galvanic Series)

Circuit resistance – Resistivity of the Electrolyte Chemical Activity Stray Currents

26

Potential Difference

Interconnecting two dissimilar metals in an electrolyte will create a corrosion cell. The strength of this cell increases as the distance within the galvanic series increases.

27

Galvanic Series

METAL VOLTS (CSE) Commercially Pure Magnesium -1.75 Magnesium Alloy -1.60 Zinc -1.10 Aluminum Alloy -1.05 Commercially Pure Aluminum -0.80 Mild Steel (clean & shiny) -0.50 to -0.80 Mild Steel (rusted) -0.20 to -0.50 Cast Iron (not graphitized) -0.50 Lead -0.50 Mild Steel in Concrete -0.20 Copper, Brass, Bronze -0.20 High Silicon Cast Iron -0.20 Carbon, Graphite, Coke +0.30

Example: connecting magnesium to copper will produce a corrosion cell with a potential of about 1.5 volts.

28

Circuit ResistanceCircuit resistance includes the following: Resistance of the anode Resistance of the cathode Resistance of the electrolyte Resistance of the metallic path

Increasing the resistance will reduce the corrosion rate.

29

Resistance of Common Electrolytes

Soils – High resistivity water reduces the corrosion rate, while low resistivity water increases the corrosion rate.

CLASSIFICATION

ELECTROLYTERESISTIVITY

(ohm-cm)

ANTICIPATEDCORROSIVITY

Low Resistance 0 to 2,000 Severe

Medium 2,000 to 10,000 Moderate

High 10,000 to 30,000 Mild

Very High Above 30,000 Increasingly Less

30

Resistance of Common Electrolytes

Water – Approximate resistivity valuesWater resistivity Ohms-cmopen sea 20-25 seawater (coastal) 30-40river water 500-10,000tap water 1,000-10,000 rain water 20,000distilled water 500,000pure water 20,000,000

31

Chemical Activity

Passive (less corrosive) Environment High pH (neutral or basic) Low Moisture Content Lack of Salts High Resistivity Low Temperature Homogenous Environment

32

Chemical Activity

Active (more corrosive) Environment Low pH (acidic) High Moisture Content Salts Low Resistivity Moderate to High Temperature Heterogeneous Environment

Stray current corrosion

Boat 1

Boat 2

Boat 3

Ground

wire

34

Corrosion Type

Uniform or near uniform - Corrosion attacks all areas of the metal at the same or similar rate.

Localized - Some areas of the metal corrode at different rates due to heterogeneities in the metal or environment. This type of attack can approach pitting.

Pitting - Very highly localized attack resulting in small pits that may penetrate to perforation.

35

36

Commonly Affected Structures

Buried Piping Steel Piles

Storage Tanks - Above Ground / Underground Reinforcing Steel in Concrete Ships/Boats

37

38

39

Methods to Control Corrosion

Use of Corrosion resistant materials (plastic, stainless alloys, fiberglass).

Use of the same or similar metals per the galvanic series.

Altering the environment (utilizing homogeneous high resistivity backfill or inhibitors).

Utilize coatings and linings that electrically insulate the structure from the electrolyte (paints, plastic films, etc).

Use of Cathodic Protection.

40

Fundamentals of Cathodic Protection

Cathodic Protection (CP) Defined - Minimize corrosion by utilizing an external source of electrical current which forces the entire structure to become a cathode.

41

1824: Earliest practical use of cathodic protection

Sir Humphrey Davy’s work on protecting the copper sheathing on wooden hulls in the British Navy by sacrificial zinc or iron anodes is generally considered to be the earliest example of practical cathodic protection.

42

Galvanic CP

When metals such as magnesium or zinc are placed in the environment in contact with a more noble metal such as steel, a current flows from the more active anode to the noble cathode (corrosion cell).

43

Anodes Used for Galvanic CP

Magnesium – Magnesium is often used in soil to protect small electrically isolated structures, such as underground storage tanks, and well coated pipelines.

Zinc – Zinc is often used in marine environments. They are commonly found on boats.

Aluminum – Aluminum can be used for a variety of marine applications.

Anodes Used for Galvanic CP

44

Keys to obtaining enough cathodic protection

Determine amount of current requiredTheoretical calculations based on coating quality and environmentOr, perform current requirement testing Calculate output expected from anode and determine number of anodes required.

45

Galvanic CP

Pros of Galvanic CP Inexpensive Little Maintenance cost No external Power source A variety of install methods can be used. For

example, many UST’s are shipped with anodes attached.

46

Galvanic CP

Cons of Galvanic CP Typically work best with electrically isolated structures. No external power source, limited driving potential

(driving potential based on the galvanic series) Limited output makes it ineffective when trying to

protect large uncoated surfaces. Require a low resistivity electrolyte to function well.

47

Impressed Current CP

Utilize an external power source to develop a high potential difference between the surface to be protected and an anode.

Impressed Current CP

Anode Groundbed

Rectifier

Negative Cable

Positive Cable

AC Power Supply

Pipeline

IMPRESSED CURRENT SYSTEM

49

Impressed Current CP

Pros of Impressed Current CP Unlimited driving potential. Capable of protecting large steel structures

when designed properly. Requires less anodes then a galvanic system. Output can be controlled using a permanent

reference electrode, desirable when the electrolyte resistivity is known to change.

50

Impressed Current CP

Cons of Impressed Current CP Initial costs can be more expensive. Requires an external DC power source along

with an AC supply. System requires routine maintenance and

monitoring. Anode wires can be susceptible to damage.

51

Impressed Current CP Rectifier

A rectifier converts available AC power to low voltage DC power. Most cathodic protection rectifiers are provided with a means to vary the DC output voltage in small increments, or in some cases offer complete control from zero to 100% of rated DC output.

Impressed Current CP Rectifier

52

CP System Testing

A CP system can be evaluated by obtaining a reference cell potential. This potential determines the amount of cathodic polarization the structure is receiving.

Adequate protection is indicated by obtaining a value more negative then the established criteria.

This criteria is specific to the reference cell used to obtain potentials.