koc-l-018_cp for internal steel tanks

UMI @ hrij a+ KUWAIT OIL COMPANY (K.S.C.)

STANDARDS PUBLICATION

KOC STANDARD

FOR

CATHODIC PROTECTION OF INTERNAL SURFACES OF STEEL TANKS & VESSELS

STANDARDS TEAM

DOC. NO. KOC-L-018

KUWAIT OIL COMPANY (K.S.C.)

STANDARDS PUBLICATION

KOC STANDARD

FOR

CATHODIC PROTECTION OF INTERNAL

SURFACES OF STEEL TANKS & VESSELS

STANDARDS TEAM

TABLE OF CONTENTS

FOREWORD

APPLICATION

TERMINOLOGY 3.1 Definitions 3.2 Abbreviations

REFERENCE STANDARDS AND CODES 4.1 Conflicts 4.2 List of Standards and Codes

5.0 ENVIRONMENTAL CONDITIONS

6.0 HEALTH, SAFETY AND ENVIRONMENT

7.0 CATHODIC PROTECTION SYSTEM DESIGN 7.1 Design Considerations 7.2 Potential Range 7.3 lmpressed Current Cathodic Protection (ICCP) 7.4 Galvanic Anode Cathodic Protection Systems 7.5 Current Requirement and Density 7.6 Electrical Continuity

8.0 CATHODIC PROTECTION DESIGNER & INSTALLER

9.0 MATERIALS & EQUIPMENT REQUIREMENTS 9.1 Selection of Equipment and Materials 9.2 lmpressed Current CP Anodes 9.3 Galvanic I Sacrificial Anodes 9.4 Cables 9.5 Transformer Rectifier (TIR) 9.6 Junction Boxes

10.0 INSTALLATION OF ANODES 10.1 lmpressed Current Anodes Installations 10.2 Galvanic I Sacrificial Anode Installations

Page No.

IMPRESSED CURRENT SYSTEM - PRE-COMMISSIONING & FINAL COMMISSIONING 11.1 General 11.2 Preliminary Adjustment 11.3 Potential Measurement 11.4 Final Commissioning

GALVANIC 1 SACRIFICIAL ANODE SYSTEM - PRE-COMMISSIONING & FINAL COMMISSIONING

QUALITY ASSURANCE I QUALITY CONTROL

PACKING & MARKING

DOCUMENTATION 15.1 General 15.2 Deliverables

16.0 AS BUILT DRAWINGS 24

17.0 APPENDICES 24-37 APPENDIX- A: INSPECTION AND TEST PLAN 25-27 APPENDIX- B: CHECK LISTS (1-7) 28-34 APPENDIX- C: CATHODIC PROTECTION N P . DRAWINGS 35-37

(Appendix - I : Typ. Single & Double TIR Unit Compound Earthing Layout, Drg. No. CP-004 Rev.0 36 Appendix-ll : Typ. Cathodic Protection Details for Tank lntemals Using Impressed Current System, Drg. No. CP-005 Rev.0) 37

ACKNOWLEDGEMENT 38

This document "KOC Standard for Cathodic Protection of Internal Surfaces of Steel Tanks & Vessels (Rev.1)" has been approved by Standards Team in consultation with Standards Technical Committee (STC) for consistent use throughout the corporate engineering and operational functions of Kuwait Oil Company (K.S.C).

This Standard sets out to achieve the following objectives:

a. To describe current technical practices in industry and general procedures for establishing cathodic protection system to minimize and control corrosion of the internal surfaces of steel tanks & vessels.

b. To provide general technical inputs and guidance for developing project specifications in order to ensure quality, safety and reliability.

c. To cover technical requirements and guidelines for KOC Teams and Contractors during the maintenance and upgrading programs of the existing Cathodic Protection systems.

d. To set out minimum basic requirements and guidlines for monitoring compliance of materials and testing with a Contract.

e. To act as a tool for internal communication from which future safety, environmental and technological changes can be measured.

Feedback as well as any comments or suggestions from the application of this Standard derived at any stage of design, construction, maintenance and field experiences are encouraged and should be directed to:

The Team Leader Standards (Chairman, Standards Technical Committee) P.O. Box-9758, Ahmadi 61 008 State of Kuwait

Task Force Responsible for this Standard

The Preparation of this Standard has been entrusted by the Standards Technical Committee (STC) of the Task Force No. (TF-CPl02) Comprising of the following Members:

Mr. Abdul R. Al-Shamari Insp. & Corr. (N&WK) TF Leader Tel. No. 61426 Mr. Hasan Sabri Insp. & Corr (S&EK) Member Tel. No. 67489 Mr. Govinda Mishra Design Team Member Tel. No. 61 097 Mr. Liakat Ali Maintenance Team (WK) Member Tel. No. 20061 Mr. Uppara Saibaba HSE Systems Member Tel. No. 71837 Mr. Narayan Ramanathan Major Projects (EFP) Member Tel. No. 66960

This Standard covers the minimum technical requirements for system design, selection of equipment and material, installation, inspection & testing and commissioning of permanent cathodic protection systems that provide adequate internal corrosion control / prevention to the internal surfaces of the following Tanks / Vessels within KOC Facilities, which are in contact with the environment

a) New and existing tanks:

Fresh Potable water tanks. ii. Brackish & Fire fighting water tanks. iii. Effluent water tanks. iv. Wet Crude oil tanks.

b) New and existing process vessels:

I. Wet Hydrocarbon Pressure vessels. ii. Wet Crude Oil separators. iii. Desalter vessels. iv. Water filters. v. Heaters (using water as heat transfer medium). vi. Degassing Boots.

1 -2 The Cathodic System Designer / Contractor shall perform all the necessary investigation of system requirements and other pre-design requisites such as electrolyte properties, tank or vessel design, lining materials, tank or vessel size, etc.

1.3 The application of this Standard shall be undertaken only by qualified personnel, who have the necessary experience, knowledge and qualification in the field of corrosion prevention as per clause 8.0 of this Standard.

2.0 APPLICATION

2.1 The materials, equipment, system design, installation, inspection / testing and commissioning of cathodic protection (CP) system for tanks & vessels shall conform to the requirement of this Standard and the reference standards / codes mentioned herein.

2.2 Any exceptions or deviations from this Standard, along with their merits and justifications, shall be brought to the attention of KOC Controlling Team for their review, consideration and amendment by Standards Team (if required).

2.3 Compliance with this KOC Standard does not of itself confer immunity from legal or statutory obligations.

TERMINOLOGY

For the purpose of this Standard, the following definitions shall apply.

The electrode of an electrochemical cell at which oxidation occurs. Electrons flow away from the anode in the external circuit. Corrosion usually occurs and metal ions enter the solution at the anode.

The electrode of an electrochemical cell at which reduction occurs.

Cathodic Disbondment

The disturbance of adhesion between coating and metal surface due to the cathode reaction.

3.1.4 Cathodic Protection

A technique to reduce the corrosion of a metal surface by making that surface the cathode of an electrochemical cell.

3.1.5 Coating

A liquid, liquefiable, or mastic composition that, after application to a surface, is converted into a solid protective, decorative, or functional adherent film.

3.1.6 Coating Disbondment

The loss of adhesion between the coating and the metal surface.

3.1.7 Corrosion

The deterioration of a material, usually a metal, that results from a reaction with its environment. It is an electrochemical process.

3.1.8 Corrosion Rate

The rate that corrosion proceeds.

3.1.9 Current Density

The current flowing to or from a unit area of an electrode surface.

3.1.10 Electrolyte

An environment containing ions that migrate in an electrical field.

3.1.1 1 Electrical Isolation

The condition that a metal structure is being electrically separated from other metallic structures or the environment.

3.1.12 Foreign Structure

Any metallic structure that is not intended as part of cathodic protection system.

3.1 .I 3 Galvanic Anode

A metal that provides sacrificial protection to another metal that is nobler when electrically coupled in an electrolyte. This type of anode is the electron source in one type of cathodic protection.

3.1.14 Holiday

A discontinuity in a protective coating that exposes an unprotected surface to the environment.

3.1.15 Impressed Current

Direct current supplied to a CP system by an external power source such as rectified commercial AC, batteries or electric generators.

3.1 . I 6 Instant-off Measurement

Potential measurement taken with the current interrupted to determine the polarized potential that is free of IR drop.

3.1.17 IRDrop

The voltage across a resistance in accordance with Ohm's Law.

3.1 .I 8 Polarization

The change from the open-circuit potential as a result of current across the electrode 1 electrolyte interface.

3.1.19 Resistivity

A measure of the specific resistance of a material to the passage of electric current. It is usually expressed in ohm-centimeters (ohm-cm) and is the reciprocal of conductivity.

3.1.20 Reference Electrode

An electrode whose open-circuit potential is constant under similar conditions of measurement, which is used for measuring the relative potentials of other electrodes.

3.1.21 Structure-to-Electrolyte Potential

The potential difference between a steel surface and a reference electrode immersed in the electrolyte with which the steel surface is in contact.

Abbreviations

Anode Junction Box American National Standard Institution American Petroleum Institute American Water Works Association

CP Cathodic Protection DIN Deutsches lnstitut For Normung DNV Det Norske Veritas HSE Health, Safety and Environment ICCP Impressed Current Cathodic Protection ITP Inspection and Test Plan JB Junction Box KOC Kuwait Oil Company (K.S.C.) MMO Metal Mixed Oxide NACE lnternational National Association of Corrosion Engineers International NSF National Sanitation Foundation TIR Transformer Rectifier

4.0 REFERENCE STANDARDS AND CODES

4.1 Conflicts

In the event of conflicts between this Standard and the standards I codes referenced herein, or other contractual requirements, the most stringent requirement shall apply. In case further clarifications are required, the subject shall be brought to the attention of KOC Controlling Team.

4.1 .I In general, the sequence of precedence shall be followed as:

a) Kuwait Governmental Rules and Regulations b) KOC Technical Specifications c) This KOC Standard (KOC-L-018) d) lnternational codes and standards e) Contractor's standards and specifications

List of Standards and Codes

The latest edition of the following standards, codes and specifications shall

International / National Standards

Cathodic Protection of Above Ground Petroleum Storage Tanks

AWWA D l 04 Automatically Controlled, Impressed-Current Cathodic Protection for the Interior of Steel Water Tanks

BS 7361 Part 1 Cathodic Protection, Code of Practice for Land and Marine Applications

DNV RP 9401 Recommended Practice - Cathodic Protection Design

NACE RP 0196 Galvanic Anode Cathodic Protection of Internal Submerged Surfaces of Steel Water Storage Tanks

NACE SP 0387 Metallurgical and lnspection Requirements for Cast Galvanic Anodes for Offshore Applications

NACE RP 0388 lmpressed Current Cathodic Protection of Internal Submerged Surfaces of Carbon Steel Water Storage Tanks

NACE RP 0575 Internal Cathodic Protection Systems in Oil-Treating Vessels

NACE SP 0492 Metallurgical and lnspection Requirements for Offshore Pipeline Bracelet Anodes

NACE TM 01 01 Measurement Techniques Related to Criteria for Cathodic Protection on Underground or Submerged Metallic Tank Systems

NACE TM 01 90 lmpressed Current Laboratory Testing of Aluminum Alloy Anodes

ANSIINSF-61 Drinking Water System Components - Health Effects

4.2.2 KOC Standards and Specifications

KOC-E-004 KOC Recommended Practice for Selection, Installation and (Parts 1 to 6) Maintenance of Electrical Equipment in Hazardous Areas.

KOC-E-008 KOC Recommended Practice for Design, Selection and Installation of Electric Cables, Cable Systems and Wiring

KOC-E-023 KOC Standard for Electrical Power Cables and Wiring

KOC-E-024 KOC Recommended Practice for Earthing and Bonding

KOC-G-002 KOC Standard for Hazardous Area Classification

KOC-G-004 KOC Standard for Packing, Marking and Documentation

KOC-G-007 KOC Standard for Basic Design Data

KOC-G-009 KOC Standard for Spare Parts and Maintenance Data

KOC-L-0 1 2 KOC Standard for Cathodic Protection Material Specification

KOC-L-026 KOC Recommended Practice for External Cathodic Protection of On-Grade New Steel Tank Bottom

KOC-P-001 KOC Standard for Painting / Coating of Metal Surfaces - New Construction

KOC Fire & Safety Regulations (Latest)

KOC HSE Management System Procedures (Latest)

01 5-PH-1910 Cathodic Protection (CP) Transformer Rectifier Units

4.2.3 KOC Drawings

CP-004 Rev. 0 Cathodic Protection Typical Single and Double T.R. Unit Compound Earthing Layout

CP-005 Rev. 0 Typical Cathodic Protection Details for Tank Internal Using Impressed Current System

5.0 ENVIRONMENTAL CONDITIONS

5.1 The environment of Kuwait is severe, and must be considered carefully for selection and before procurement of plant and equipment.

5.2 For environmental conditions in Kuwait, refer to KOC Standard for Basic Design Data, (KOC-G-007), which provides the detailed design information regarding the environmental, site and utility supply conditions prevailing throughout the KOC facilities.

6.0 HEALTH, SAFETY AND ENVIRONMENT

6.1 The Designer / Contractor shall assure the compliance of necessary HSE design requirements to minimize the consequences and impacts of hazards on the personnel and the surrounding environment and adjoining facilities.

All relevant safety requirements of the KOC Fire & Safety Regulations, KOC Health, Safety and Environment Management System (HSE MS) procedures and the KOC Health, Safety and Environment (HSE) policy shall be adhered to by the Contractor, while performing the project work within KOC operational and non-operational areas.

The Cathodic Protection Systems shall be installed and continuously operated under safe conditions.

CATHODIC PROTECTION SYSTEM DESIGN

Desiqn Considerations

7.1.1 The design of tanks and vessels shall be made to allow the installation of cathodic protection system.

7.1.2 The design for cathodic protection system shall be based on the corrosion historical data, corrosion rate, cathode area and coating / lining type and condition along with the operational parameters as well as the surrounding environment.

7.1.3 All internal piping systems, supports and connections shall be included to be protected within the tank / vessel CP system.

7.1.4 Special consideration shall be given in the CP design and selection of anode material for the electrolyte resistivity, presence of sulfides, bacteria, disbonded coatings, thermal applied coatings, elevated temperatures, flow condition, acid environments, amount of oxygen, dissimilar metals, shielding and stray current caused by other systems.

7.1.5 The cathodic protection shall be installed in the areas of water phase (submerged), as it will not be effective in the crude or gas phases due to lack of electrolyte.

7.1.6 The design for tank cathodic protection system (impressed and sacrificial) shall allow to take IR free potential reading, which can be achieved by installing a cathodic protection coupon near the reference electrode.

7.2 Potential Rancle

7.2.1 The internal surface of tank potential shall be measured by using Silver / Silver Chloride (Ag / AgCI) saturated reference electrode.

7.2.2 The minimum negative accepted value at any point of the protection potential for steel (IR corrected, instant off) shall be -0.800 V (AgIAgCI).

7.2.3 The maximum negative potential value permissible (IR corrected, instant off) shall not exceed -1.05 V (Ag I AgCI).

7.2.4 Copper / Copper Sulfide reference electrodes are preferred to be used for fresh water applications. Adjustments to the above potential values shall be considered.

7.2.5 The design shall consider the maximum negative potential value that will not lead to the coating disbonding.

Impressed Current Cathodic Protection (ICCPL

7.3.1 Basic Design Requirements

a) lmpressed Current Cathodic Protection (ICCP) shall be used to protect the Fresh potable water, Brackish and Fire fighting water tanks.

b) The minimum design life of the lmpressed Current Cathodic Protection (ICCP) system for water tanks is 35 years. Additional increase in current requirement with time shall be considered within the

c) Each steel tank protected by impressed current CP system shall be provided with a minimum of one (1) separate individual system.

d) The actual number and weight of anodes and anodes distribution shall be considered in order to control the current flow and to provide uniformly protected potentials over the entire cathode facility.

e) The anodes shall be placed hanged from the top / roof of the tank for better current distribution and easy maintenance. The anode shall be properly isolated to prevent grounding of the lead wire to the tank.

f) Locations of placing anode, cables, junction boxes, rectifier and test stations shall be considered, where the possibility of physical damage is minimal.

g) Adequate monitoring of the tank internal surface shall be provided to ensure proper corrosion protection.

h) The design of ICCP of the tank shall consider that all electrical connections (splices) are located outside the perimeter of the tank.

i) The Cathodic Protection System shall be continuously operated to maintain polarization.

j) All impressed current CP system positive cables shall be electrically isolated from the tank structure in conduit.

k) The potential range shall be as per clause 7.2 of this Standard.

Permanent Reference Electrode

a) Sufficient number of permanent reference electrodes shall be installed inside the tanks.

b) The lead wire of the reference electrode shall be brought to the transformer1 rectifier location.

c) The reference electrodes wiring shall not be routed through the same conduit used for the CP system wiring.

7.3.3 Automatic Impressed Current System

a) Automatic impressed current system shall be used to control the required structure-to-electrolyte potential for effective corrosion control for tanks.

b) Current control limiting devices shall be installed to prevent damages to coating due to cathodic disbondment.

c) The transformer I rectifier properties are as below:

I. It shall be provided with either silicon or selenium rectifying element.

ii. It shall be capable of varying the current output from 0 to 100% of its rated capacity.

iii. It shall be automatically controlled and capable of varying the current output in order to maintain the structure-to-electrolyte potential as per clause 7.2.of this Standard.

iv. It shall be provided with protection and monitoring devices including disconnect switches, circuit breakers, output voltmeter, ammeters, potential meter, surge, lightning and overload protection.

v. It shall have control circuit to limit the maximum current output to avoid coating damage.

d) One or more long life reference electrode 1 electrodes shall be installed in a proper place inside the tank to control the required structure-to- electrolyte potential as per clause 7.2 of this Standard. The IR drop must be eliminated to determine the actual voltage between the tank surface and the reference electrode.

e) The reference electrode shall be continuously immersed and when it is calibrated with new reference electrode, it shall have a potential difference of less than +I- 10 mV. When the potential difference exceeds +I- 20 mV, the electrode shall be replaced.

Electrical Connections

Cable connections of impressed current cathodic protection shall be provided as

a) Positive cable connected to the anodes' lead wires via waterproof junction box shall be used. Connections shall be mechanically secured and electrically conductive and sealed from moisture.

b) Negative cable shall be electrically connected to the outer surface of the tank by using electrical lugs.

c) All cable connections shall be water-proof.

d) All cables shall be protected from damage caused by abrasion or sharp

e) No underwater splices are allowed.

Galvanic Anode Cathodic Protection Svstems

7.4.1 Basic Design Requirements

a) Galvanic Anode Cathodic Protection systems shall be used to protect effluent water tanks, wet crude tanks and process vessels.

b) The minimum design life of the Galvanic Anode Cathodic Protection system shall comply with the run time interval (minimum 10 years) of each tank or vessel in order to allow replacement of anodes during the shut-down period.

c) The number, weight and shape of anodes shall depend on the area of the cathode, required current density, and current output of anodes, tank I vessel configuration and the desired lifetime of CP system.

d) In order to avoid passivation or reverse effect, the environment temperature shall be considered when selecting the type of anode and calculating the required anode weight.

e) Adequate monitoring of the tank internal surface shall be provided to ensure proper corrosion protection.

9 Sufficient number of permanent reference electrodes shall be installed inside the tanks.

g) The galvanic I sacrificial anodes shall be mounted on the tank 1 vessel surface by bolting the anode core to welded brackets permanently attached to the shell surface.

h) The potential range shall be as per clause 7.2 of this Standard.

Current Requirement and Density

7.5.1 For design purpose, the minimum bare metal protective current density shall be

a) 15 mAlm2 for fresh water associated tanks.

b) 100 mAlm2 for water associated with other tanks and process vessels.

7.5.2 Consideration shall be given to the presence of depolarizers such as H2S, oxygen, or operating at high temperatures and 1 or high flow rates that could require higher current densities.

7.5.3 Coating efficiency shall be considered initially with an estimate of 80% for applied coating systems.

7.5.4 The design of all CP systems shall include a minimum 30% excess current capacity over the design life to compensate for coating degradation and possible current drainage to other structures.

7.6 Electrical Continuity

7.6.1 The tank / vessel shall be electrically continuous over the total surface.

7.6.2 Where contact between dissimilar metals exists, no isolating device shall be installed. The design shall consider the current required to protect against galvanic corrosion.

7.6.3 Electrical continuity shall be insured for bolted and riveted tanks by joining components.

8.0 CATHODIC PROTECTION DESIGNER & INSTALLER

8.1 The design and installation of the Cathodic Protection systems shall be carried out by a cathodic protection specialized Contractor subject to approval by KOC.

8.2 The design and commissioning of cathodic protection systems shall be carried out by a Cathodic Protection Specialist Engineer (NACE certified as CP- Specialist or equivalent).

8.3 Construction work shall be carried out in accordance with project specifications and drawings. Any deviations shall be brought forward to the Company's approval.

8.4 A NACE certified Technician of Level II or equivalent shall be present at all times at site to inspect the cathodic protection materials and equipment prior to installation and to supervise the installation of the work activity.

I DOC. NO. KOC-L-018

9.0 MATERIALS & EQUIPMENT REQUIREMENTS

9.1 Selection of Equipment and Materials

All cathodic protection materials shall be as per "KOC Standard for Cathodic Protection Material Specification" (KOC-L-012).

9.2 Impressed Current CP Anodes

9.2.1 The anode material shall be Titanium with a mixed metal oxide (MMO) coated with Electro catalytic mixed metal oxide. The substrate material shall be Grade I Titanium according to ASTM B388.

Vendor shall provide technical data sheet of the proposed MMO anode clearly mentioning the oxides, MMO application method, and thickness of the MMO, breakdown voltage across the substrate oxide and maximum voltage across the MMO film.

9.2.2 The MMO coating shall be dimensionally stable and shall have a proven track record showing that their resistances to electrolyte do not increase with time. The Manufacturer's test certificate shall provide all the above information including a test for each of the anode under various charge densities.

9.2.3 Anode construction shall be tubular and the number, size and weight shall depend on the design life, required current, current density and cathode surface area.

9.2.4 MMO anode shall be corrosion, acid and high abrasion resistant.

9.2.5 A common header cable shall be routed through each anode.

9.2.6 The connection between the cable and the anode shall be as normally recommended by the Manufacturer and shall be sealed watertight and finished with an epoxy end seal.

9.2.7 The anode lead cable shall be single core, stranded, copper with KYNAR I HMWPE 25 mm2.

9.2.8 Anodes and associated cables installed for fresh water tanks shall be environmentally friendly and not harmful to human beings and shall comply with KOC HSE and government regulations for drinking water. Manufacturer test certificate shall be provided including all required information as per ANSI 1 NSF- 61.

Page 17 of 39 REV. 1

Galvanic 1 Sacrificial Anodes

9.3.1 Anode material shall be aluminum, magnesium or zinc alloys.

9.3.2 The selection of anode material, number, shape, size and weight shall depend on the electrolyte I water chemical composition, resistivity, temperature and operating parameters. The anode selection and calculations shall be as per DNV RP B401 and shall be approved by KOC.

9.3.3 The sacrificial anodes shall be procured from KOC approved vendor.

9.3.4 The anode shall have a steel core centered and extended through the entire length of the anode. The steel core shall be used for mounting the anode to the cathode surface.

9.3.5 The anodes' inserts shall be designed to enable their mounting to the structure.

9.3.6 The anode insert shall be core centered and extended through the entire length of the anode.

9.3.7 The anode insert shall be structurally suitable for the anode weight and shall be capable of withstanding all forces caused by fluid waves. The insert material shall maintain electrical contact with the anode body for the full lifetime of the anode.

9.3.8 The anode packing shall be stored in a clean environment and shall be made secured to avoid any damages to the anodes during shipping and transportations.

9.3.9 The Contractor shall submit the characteristics of the anode alloy including the chemical composition, electrochemical properties, and material specifications. In addition, the Contractor shall submit the manufacturing processes and the anode characteristics.

9.4 Cables

9.4.1 Cables shall be designed, supplied and installed in accordance with KOC Standards KOC-E-008 & KOC-E-023.

9.4.2 Anode tails shall be of PVDF I HMWPE (KYNAR@ I FLUOROPOLYMER + HMWPE) suitable to resist chlorine. Cables from junction box shall be of PVDF, HMWPE or approved equivalent

9.4.3 Cable sizes shall be determined to suit the current rating and voltage drop requirements of the CP design. However, the following types with minimum sizes shall be used:

a) Anode main cables - 50 mm2 b) Anode string cables - 25 mm2 c) Cathode main cables - 50 mm2 d) Test cables - 10 mm2

9.4.4 Positive and negative cables shall be of RED and BLACK color respectively. Reference electrode cable shall be of different color.

9.4.5 All cables shall be clearly identified and numbered and tagging shall be provided such that no confusion exists as to their purpose or point of origin or termination.

9.4.6 The cable and all connections are critical. Complete electrical isolation between the cable / splice / connection and the environment is essential. Water ingress or soil contact must not occur.

9.4.7 All cables shall be laid in single runs. No cable to cable splicing shall be made.

9.4.8 AC supply cable shall be armored direct burial type of suitable size. Contractor shall provide voltage drop calculations to substantiate cable sizing.

Transformer Rectifier (TIR)

9.5.1 The T/R unit output ratings for CP systems shall satisfy the following requirements:

a) A/C input 440V, 3 Phase, 50 Hz.

b) Minimum Output voltage 25V DC, or as specified by design if higher rate is required.

c) Minimum output current rating : 10A DC, or as specified by design if higher rate is required.

9.5.2 All T/R units shall comply with the requirements of 015-PH-1910.

9.6 Junction Boxes

9.6.1 Junction boxes shall be certified for use in respective classified area with minimum degree of protection as IP55. The system design shall have the following types of junction boxes:

a) AJB: Anode junction boxes.

b) TJB: Test junction boxes.

c) NJB: Negative junction boxes.

9.6.2 Inside the AJB, TJB & NJB, a layout drawing with a glass cover shall be fixed to show the arrangement of permanent reference electrodes & power feed cables.

INSTALLATION OF ANODES

Impressed Current Anodes Installations

10.1 . I Prior to installation, all materials including transformer 1 rectifiers, cables, anodes, and junction boxes shall be inspected to ensure that they are in good condition and comply with project specifications.

10.1.2 All electrical connections shall be made safe, secured and waterproof.

10.1.3 The transformer 1 rectifier shall be installed in secured, fenced and accessible area as per KOC Drg. No. CP-004. External AC cut-off switch shall be connected. The transformer I rectifier body shall be grounded.

10.1.4 The anodes lead wires shall be connected to a distribution box installed on the top of the tank.

10.1.5 The anode main cable shall be connected to the positive terminal of the transformer I rectifier and installed in a conduit to the top of the tank, where it is connected to the distribution anode junction box (AJB).

The negative terminal of the transformer I rectifier shall be connected to the structure to be protected. These installations have to be confirmed after energizing the CP system by suitable measurements.

10.1.6 All electrical connections shall be as per clause 7.3.4 of this Standard.

10.1.7 The negative and positive CP cables shall be laid at 750 mm depth. After installation the cables shall be covered with tiles and warning tapes followed by backfilled with soil to the original condition.

10.1.8 Aboveground cable markers shall be installed to show the cable routes.

10.2 Galvanic 1 Sacrificial Anode Installations

10.2.1 The Contractor shall submit a procedure for the anodes' installation for KOC review and approval.

10.2.2 Prior to installation, the following shall be inspected:

a) All materials shall be verified with Manufacturer's test certificate(s) and project specifications.

b) The dimensions, weight and the material of the anodes to confirm compliance with specifications.

c) Any crack shall be made sure that it is within the acceptable limits as per NACE RP 0387 and NACE RP 0492.

d) Any damage during handling.

10.2.3 Anodes shall be distributed in a way that provides uniform current to the entire cathode surface.

10.2.4 Samples of installation check lists are attached in Appendix B of this Standard. The Contractor shall make suitable amendments for a specific type of work.

10.2.5 After installations, anodes shall be checked for electrical continuity.

IMPRESSED CURRENT SYSTEM - PRE-COMMISSIONING & FINAL COMMISSIONING

1 1.1.1 Pre-commissioning shall be carried out by CP I Corrosion Engineer to ensure high quality performance.

11 .I .2 All terminations inside the junction boxes, test boxes and TIR shall be checked.

I 1 .I .3 Calibrated instruments shall be used for taking all measurements.

11.2 Preliminarv Adjustment

Before energizing, the TIR output shall be kept at 10% of design current output. After 48 hours, potential shall be measured and the transformer 1 rectifier output shall be increased, if required, in order to meet the protection criteria indicated in clause 7.2 of this Standard.

11.3 Potential Measurement

Following the adjustment of cathodic protection outputs to meet the structure-to- electrolyte potentials, a complete set of potentials shall be recorded at all the measuring points.

11.4 Final Commissioning

Final commissioning shall consist of the following:

a) Measuring structure-to-electrolyte potentials at all measuring points by an approved method.

b) Measuring total current and voltage output of the transformerlrectifier.

c) Recording the settings of the transformer1 rectifiers.

12.0 GALVANIC 1 SACRIFICIAL ANODE SYSTEM - PRE-COMMISSIONING & FINAL COMMISSIONING

The number and location of the welded anodes shall be verified, if they are as per drawing. In addition for tanks, the reference cells number and locations shall be verified if they are conforming to drawing. After tank commissioning, the potential readings shall be verified.

QUALITY ASSURANCE / QUALITY CONTROL

The Manufacturer I Contractor shall operate a quality system to ensure that the requirements of this Standard are achieved. The quality system shall be preferably based on IS0 9000 series of standards and the Manufacturer 1 Contractor shall demonstrate compliance by providing a copy of the accredited certificate or the Manufacture's I Contractor's quality manual.

Verification of the Manufacturer's / Contractor's quality system is normally part of the pre-qualification procedure, and it is therefore not detailed in the core text of this Standard.

The Contractor shall submit their Quality System Manual & Quality Assurance Plan that includes all the activities in chronological order with responsibilities. Inspection & Test Plan (ITP) for CP system installation and commissioning shall be submitted for KOC approval. Columns shall be provided so that KOC can mark up its 'Review' (R) points, 'Surveillance' (S) points, 'Witness' ON) points and 'Hold' (H) points.

13.4 Samples of ITP and check lists are given in Appendixes A & B of this Standard, which are only typical and the Contractor shall make suitable additions or changes for the particular job.

13.5 The Contractor shall submit the HSE plan and safety procedures for the installation and commissioning of CP system for KOC approval as per HSEMS procedure for the preparation of project HSE plan (GE.KOC.048)

14.0 PACKING & MARKING

Regarding packing and marking refer to "KOC Standard for Packing, Marking & Documentation" (KOC-G-004) for all relevant details and requirements.

15.0 DOCUMENTATION

15.1 General

15.1.1 All correspondences, drawings, instructions, data sheets, design calculations, or any other written information shall be in English Language. In the case of dual languages, one language shall be English.

15.1.2 All dimensions, units or measurements, physical constant, etc. shall be in SI units, unless otherwise specified.

Deliverables

15.2.1 The following documentation, drawings, inspection & test plans and check lists shall be submitted for approval:

a) Schematic of the entire tank / vessel and the CP systems and date of

b) Coating material; c) Maintenance historical data of old tanklvessel; d) Anode configuration detail drawings; e) TIR unit electrical schematic diagrams; 9 TIR unit general arrangement and mounting detail drawings; g) Anode material and testing certifications; h) Anode layout drawing, type weight and spacing;

CP cable layout drawing & sizing, color schedule; Test facility detail drawings;

k) Junction boxes and support stands construction drawings; Junction boxes termination drawings;

m) Tank cable connection detail drawings; n) CP electrical installation specification; o) Pre-commissioning procedures; p) Operation and Maintenance procedures; q) Measuring techniques; r) Inspection & Test Plan; s) Post Installation survey procedure; t ) Post Construction survey results.

15.2.2 CP calculations shall include the following:

a) Protected structure surface area; b) Protected structure CP current demand; c) Coating breakdown factor; d) Electrolyte resistivity test; e) Anode material, electrochemical capacity, closed potential, resistance to

electrolyte, remaining net mass, and utilization factor; 9 Anode surface area, dimensions, and weight; g) Foreign structure CP drain current; h) System design life including current demand and estimated CP drain

current demand to foreign structures; i) Anode total current output anode current capacity, deterioration rate,

resistance, life time, mass and number; j) CP TIR unit voltage including both the anode and cathode circuit; k) CP TIR unit current rating.

AS BUILT DRAWINGS

Construction I design drawings shall be updated to reflect field modifications to the original design to show the as-built cathodic protection system.

The as-built drawings shall establish the coordinate (Geographic Information System- GIs) locations of the following:

a) The tank I vessel location; b) Test posts; c) Electrical bonding; d) Electrical isolation locations;

The Contractor shall also update the existing CP drawings of the particular facility I area incorporating the new system.

17.0 APPENDICES

APPENDIX A: INSPECTION AND TEST PLAN

1.0 ITP for Tank Internal for Impressed Current Cathodic Protection System

2.0 ITP for Sacrificial Anodes at the Manufacturer's works.

3.0 ITP for Sacrificial Anodes Installation

Activity Description

APPENDIX A:

1.0 : ITP for Tank Internal (Impressed Current Cathodic Protection System)

Note : Additional items may be added by KOC at any stage of the work and shall be implemented by the Contractor.

R : Review S : Surveillance W : Witness H: Hold

2.0 : ITP for Sacrificial Anodes at the Manufacturer's Works


APPENDIX A (contd.):


R : Review S : Surveillance W : Witness H: Hold


I 11 1 Commissioning I I I W ]

APPENDIX A (contd.):

3.0 : ITP for Sacrificial Anodes Installation


R : Review S : Surveillance W : Witness

APPENDIX B: CHECK LISTS

1.0 Check List of Tank Internal CP System for Suspended Anode System 2.0 Check List of Sacrificial Anode System 3.0 Check List of Reference Electrode Function Test 4.0 Check List of Boxes (J.B and Test Box) 5.0 Check List of TR 1 Rectifier 6.0 Check List of Pre-commissioning for Impressed Current Cathodic Protection

7.0 Check List of Pre-commissioning for Sacrificial Anode Cathodic Protection

APPENDIX B (contd.):

1.0 : Check List of Tank Internal CP Svstem for Suspended Anode Svstem

Date:

Comments:


Name

Signature

Date

KOC sub-contractor Contractor

Results Inspection

Acc, Rej, SI. No. Description. NIA Vendor Contractor KOC

1 Anode quantity ( EA )

2 Anode Installations

3 Anode continuity check Number of permanent reference cell (EA) (for

4 Tanks)

5 Reference electrode Function test ) (for Tanks)


2.0 : Check List of Sacrificial Anode Svstem

Tan Wessel No: Date:

Comments:


\

Name

Signature

Date

sub-Contractor Contractor KOC


3.0 : Check List of Reference Electrode Function Test

Date:

Comments.

KOC Contractor

Name

Signature

Date

sub-contractor


4.0 : Check List of Boxes (J.B and Test Box)

Date:

Comments:


Results Inspection

Vendor Contractor SI. No. Description. Acc, Rej, NIA KOC

I Support as per detail drawings

2 Foundation location and details correct

3 Installation as details drawing

4

5

6

Cable connections as per termination Diagram.

Cables installed & termination Complete.

All cable clearly identified with tags.

Name

Signature

Date

Contractor sub-Contactor KOC


5.0 : Check List of TR I Rectifier

Comments:

Note : Addit ional items may be added b y KOC at a n y stage of the work and shall be implemented b y the Contractor.

13

14

15

DC output current

Negative cable connection

Positive cable connection

Name

Signature

Date

Contractor sub-contractor KOC

DOC. NO. KOC-L-018 Page 34 of 39


6.0 : Check List of Pre-commissioninq for Impressed Current Cathodic Protection System

(Internal)

Description.. .................................................................................................

Notes:. ................................................................................................................................. ..........................................................................................................................................

Reviewed By.. ............................... Approved by ...................... (Snr Engr)

7.0 : Check List of Pre-Commissioninq for Sacrificial Anode Cathodic Protection Svstem

(Tank 1 Vessels Internal)

Description. ....................................................................................................

Notes:. ........................................................................................................................... .......................................................................................................................................

...................... Reviewed By.. ............................... Approved by (Snr Engr)

SI. No. 1.0

1.1

1.2

1.3

1.4 1.5 1.6

1.7

1.8 1.9

1 . I0

2.0

2.1

2.2

2.3

Pre-Commissioning

Check if number and location of the anodes are as per drawing.

Check if all anodes cable are terminated and labeled in the anode Junction Box (JIB).

Check if the negative cable (from structure) is terminated in a Junction box.

Check if all JIBS and test posts are marked and labeled inside and outside. Check if all JIBS shunt and resistor rating as per specifications. Check if all TIRs capacity, location, labeling, oil level, silica gel are as per specification. Check if the TIR positive cable is connected to anode JIB and negative cable is connected to Structure JIB. Check if all reference cells and coupons are installed as per drawings. Check If all temporary cathodic protection system is disconnected. Wfiness potential natural reading for all test posts before energizing the TIRs.

After energizing the TIRs.

Verify if TIRs meters are functioning.

Witness if potential "OnIOfF readings are meeting the protection criterion for all test posts Check for any interference.

1.0

1.1

1.2

1.3

Inspector

Precommissioning (Tank I Vessels Internal)

Check if number and location of the welded anodes are as per drawing.

Check if all reference cells are installed as per drawings. (Tanks only)

Witness if potential readings are meeting the protection criterion. (Tanks only)

Remarks lnspector

Date

Date

Remarks

APPENDIX C: CATHODIC PROTECTION TYPICAL DRAWINGS

CP-004 Rev.0 : Cathodic Protection Typical Single and Double T.R. Unit Compound Earthing Layout

CP-005 Rev.0 : Typical Cathodic Protection Details for Tank Internal Using Impressed Current System

I DOC. NO. KOC-L-018 Page 38 of 39

ACKNOWLEDGEMENT

This Standard has been approved by the Standards Technical Committee (STC) consisting of the following:

Mr. AIRedha Al-Haddad Standards Team Chairman Mr. Mohammad Emam Insp. & Corr. Team (WE) Deputy Chairman Mr. S. Kumar Standards Team Secretary1 Member Mr. A. Unnikrishnan Standards Team Member Mr. Khalaf Hamada Design Team Member Mr. N. Ramanathan Export Facilities Team Member Mr. Ali Hassan Al-Failakawi HSE System Team Member Mr. Daniel Pino Utilities Team Member Mr. Abdul R. Al-Shamari Insp. & Corr. Team (N&WK) Member Mr. Khalid Al-Ahmad Gen. Project Team Member Mr. Abdul Aziz Akbar Project Mgmt. Team (NK) Member Mr. Moataz Khalaf Information System Team Member

The draft of this Standard had been circulated to the KOC User Teams for review and the responses were received from the following:

ENGINEERING GROUP TECHNICAL SERVICES DIRECTORATE

Team Leader Design Team Leader HSE (TS)

MAJOR PROJECTS GROUP (I) MAJOR PROJECTS GROUP (11)

Team Leader Export Fac. Projects Team Leader Project Support

AHMADI SERVICES GROUP GAS MGMT GROUP (SEK)

Team Leader Utilities Team Leader Gas Opns.

Team Leader Project Design Team Leader Consumer Networks

INDUSTRIAL SVCS. GROUP OPERATIONS GROUP (SK)

Team Leader Insp. & Corr. (S&EK) Team Leader Opns. Tech. Svcs

Team Leader Insp. & Corr. (N&WK) Team Leader Maintenance

OPERATIONS GROUP (EK) EXPORT & MARINE OPNS GROUP

Team Leader Maintenance Team Leader Export Svcs.

SECURITY & FIRE GROUP DRILLING OPNS GROUP

Team Leader Fire Team Leader Drlg. & WIO Svcs.

DOC. NO. KOC-L-018 Page 39 of 39 REV. I

SOUTH & EAST DIRECTORATE WEST KUWAIT DIRECTORATE

Team Leader HSE (SEK) Team Leader HSE (WK)

HSE GROUP NORTH KUWAIT DIRECTORATE

Team Leader HSE Systems Team Leader HSE (NK)

Team Leader H&E

Team Leader Safety

Task Force Responsible for this Stqndard

The preparation of this Standard has been entrusted by the Standards Technical Committee (STC) of the Task Force No. (TF-CPl02) comprising of the following members:

Mr. Abdul R. Al Shamari Insp. & Corr. (N&WK) TF Leader Tel No. 61426 Mr. Hasan Sabri Insp. & Corr. (S&EK) Member Tel No. 67489 Mr. Govinda Mishra Design Team Member Tel No. 61 097 Mr. Liakat Ali Maintenance (WK) Member Tel No. 20061 Mr. Uppara Saibaba HSE Systems Member Tel No. 71837 Mr. Narayan Ramanathan Major Projects (EFP) Member Tel.No. 66960

koc-l-018_cp for internal steel tanks

Documents

cathodic protection

cathodic protection

impressed current system

list of standards

lmpressed current cp

final commissioning

current requirement

current technical practices