Methodic Statement for CP KNPC

KNPC CFP - MAB2 Project P6022MAB.000.51H.014 Rev.: F2, 07 July, 2015

KNPC CFP Project MAB2 Package REVIEW

BY:

1

CODE:

DISCPLINE:

R A Growcott

Gen Supt

DATE:

21-Jul-15

7668

REVIEW CODE: 1%Approved\No Comments; 2% Minor Comments; 3%Comments as Noted; 4%Rejected

METHOD STATEMENT FOR CATHODIC PROTECTION SYSTEM P6022MAB.000.51H.014_F2 IFF ‐ Issued Final By Sang An Chu on July 07, 2015

Unpublished Copyright Fluor Daewoo Hyundai All Rights Reserved This document was prepared for the KNPC CFP by Fluor, Daewoo Engineering and Construction Co and Hyundai Heavy Industries Co. It is not to be disclosed, reproduced or in any other manner made available to any third party without our prior, written permission except as authorized by FDH JV for the performance of the Order. Please destroy any previous issues Rev

Date

O1

22-Apr-15

F1 F2

Revision Description

Made

Checked

Approved

Issued for Comment

Rey Sadioa

Y. H. Lee

S. A. Chu

03-June-15

Issued Final

Rey Sadioa

S. H. Park

S. A. Chu

07-Jul-15

Issued Final

Rey Sadioa

S. H. Park

S. A. Chu

Project number

Document number

Revision number

P6022MAB

P6022MAB.000.51H.014

F2

P6022MAB.000.51H.014_F2

Page 1 of 62


CONTENTS 1.0 INTRODUCTION ......................................................................................................... 4 2.0 TERMINOLOGY .......................................................................................................... 4 2.1.

DEFINITIONS .......................................................................................................................4

2.2.

ABBREVIATIONS .................................................................................................................4

3.0 REFERENCES ............................................................................................................ 5 4.0 HANDLING PROCEDURES FOR EQUIPMENT&MATERIALS .................................. 5 4.1

STORING ............................................................................................................................5

4.2

SITE TRANSPORT................................................................................................................5

5.0 INSTALLATION FOR TANK EXTERNAL.................................................................... 6 5.1

INSTALLATION OF GRID (RIBBON, CONDUCTOR BAR & POWER CABLE) .................................6

5.2

INSTALLATION OF PERMANENT REFERENCE ELECTRODE ......................................................7

5.3

INSTALLATION OF SLOTTED PIPE .........................................................................................7

5.4

CABLE TO TANK CONNECTION ..............................................................................................7

5.5

BACKFILLING......................................................................................................................8

6.0 INSTALLATION FOR TANK INTERNAL-IMPRESSED CURRENT CATHODIC PROTECTION ................................................................................................................... 8 6.1

SUSPENDED ANODE INSTALLATION ......................................................................................8

6.2

REFERENCE ELECTRODE INSTALLATION ...............................................................................8

6.3

INTERFACE JUNCTION BOX..................................................................................................8

6.4

CONDUIT PIPE ....................................................................................................................8

6.5

CABLE TRAY INSTALLATION .................................................................................................8

7.0 INSTALLATION FOR TANK INTERNAL-SACRIFICIAL ANODE CATHODIC PROTECTION ................................................................................................................... 9 7.1

INSTALLATION OF ZN ANODE ...............................................................................................9

8.0 INSTALLATION FOR U/G PIPING .............................................................................. 9 8.1

INSTALLATION OF M.M.O TI TUBULAR ANODE ......................................................................9

8.2

INSTALLATION OF REFERENCE ELECTRODE ..........................................................................9

8.3

CABLE TO PIPE CONNECTION ...............................................................................................9

8.4

CABLES ...........................................................................................................................10

8.5

BACKFILLING....................................................................................................................10

8.6

INSTALLATION & TESTING OF INSULATION FLANGES ...........................................................10

8.7

INSTALLATION OF MG ANODE(FOR SHORT BURIED PIPING & TEMPORARY) .......................... 11

9.0 INSTALLATION FOR REBAR IN CONCRETE .......................................................... 11 9.1

INSTALLATION OF M.M.O TI RIBBON MESH ANODE BEFORE POURING CONCRETE ................ 11

9.2

CONNECTION OF CABLE ....................................................................................................13

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9.3

TACK WELDING PROCEDURE OF NEGATIVE CONNECTION .....................................................14

9.4

INSTALLATION OF REFERENCE ELECTRODE ........................................................................14

10.0

INSTALLATION FOR COMMON EQUIPMENT ................................................... 15

10.1 INSTALLATION OF TR/RECTIFIER ........................................................................................15 10.2 INSTALLATION OF BOXES ..................................................................................................15

11.0

PRE-COMMISSIONING ...................................................................................... 16

11.1 ADJUSTMENT OF TR/RECTIFIER ........................................................................................16 11.2 POTENTIAL TEST ..............................................................................................................16 11.3 JUNCTION BOX .................................................................................................................17

12.0

COMMISSIONING ............................................................................................... 17

ATTACHMENT -I SPOT WELDING PROCEDURE ...............................................................................19 ATTACHMENT - II TECHNICAL INSTRUCTION FOR SPOT WELDING BY MANUFACTURE ........................21 ATTACHMENT - III INSPECTION CHECKLIST AND TEST REPORTS ....................................................37

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1.0

INTRODUCTION The purpose of this document is to define the minimum requirement for method statement of cathodic protection system for Clean Fuels Project.

2.0

TERMINOLOGY

2.1.

Definitions

2.1.1

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

2.1.2

Bond Cable A cable providing electrical continuity specifically for the purpose of cathodic protection between protected structures.

2.1.3

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

2.1.4

Galvanic Anode A metal that is consumed to provide corrosion protection to another metal when they are electrically connected in the environment / electrolyte.

2.1.5

Impressed Current Direct current supplied to a CP system by an external AC power source converted to DC by a transformer / rectifier, batteries or electric power generators.

2.1.6

Reference Electrode An electrode that open-circuit potential is constant under similar conditions of measurement. It is used for measuring the relative potentials of other electrodes.

2.1.7

Voltage An electromotive force or a difference in electrode potentials expressed in volts.

2.2.

Abbreviations AJB

Anode Junction Box

ASTM

American Society for Testing and Materials

BJB

Bonding Junction Box

CP

Cathodic Protection

FR

Flame Resistance

GRP

Glass Reinforced Plastic

HMWPE

High Molecular Weight Poly Ethylene

ICCP

Impressed Current Cathodic Protection

IEC

International Electro technical Commission

JB

Junction Box

MMO

Mixed Metal Oxide

NACE

National Association of Corrosion Engineers

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3.0

NJB

Negative Junction Box

PVC

Poly Vinyl Chloride

TB

Test Box

TS

Test Station

UG

Underground

XLPE

Cross Linking-Polyethylene

REFERENCES This cathodic protection design and the equipment specified shall be in accordance with; but not be limited by the following codes and standards:

4.0



P600CFP.000.10.64.014 Project Specification Cathodic Protection Design Basis for Clean Fuels Project.



P600CFP.000.10.64.015 Project Specification Cathodic Protection Transformer Rectifier.



IEC 529 Degrees of Protection Provided by Enclosures.(IP Code)



NACE SP 0169 Control of External Corrosion on Underground or Submerged Metallic Piping Systems.



NACE SP 0187 Design Considerations for corrosion control of reinforcing steel in concrete.



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



NACE TM 0101 Measurement Techniques Related to Criteria for Cathodic Protection.



NACE TM 0497 Measurement Techniques Related to Criteria for Cathodic Protection on Underground or Submerged Metallic Piping Systems.



API 651 Cathodic Protection for above ground petroleum storage tank

HANDLING PROCEDURES FOR EQUIPMENT&MATERIALS All handling, storage and maintenance shall be performed in a safe manner as to avoid mechanical damage and corrosion.

4.1

Storing When storing, it is important to avoid exposure to moisture, dust, oil, and lubricant in order to prevent rust. Store in a dry and well ventilated place preferably in the original package covering.

4.2

Site Transport When transporting, rubber or wood support/underpinning should be used to avoid surface scratching.

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Gloves should be worn to avoid smudges from fingerprints.

5.0

INSTALLATION FOR TANK EXTERNAL

5.1

Installation of Grid (Ribbon, Conductor Bar & Power Cable)

5.1.1

Rolling of MMO ribbon anode from coils and positioning at the spacing required on approved drawing. Note: The ribbon anode shall be confirm that ASTM B 265 Grade 1 and 6mm (0.25") in width by 0.6mm(0.025") thick. Ribbon anode spacing shall be one(1) m separation between adjacent ribbon anodes and 450 from the tank wall. MMO Ribbon anode shall be uncoiled and straightened prior to installation. The total installed ribbon anode length shall not be less than the total length on approved drawing. Conductor bar from coils shall be uncoiled and positioned at the spacing required. Spot welding at each MMO ribbon anode and conductor bar, according to vendor procedure Refer to attachment - I & II Connect the conductor bar and the power feeder cable according to the approved drawing. Titanium rod to power feeder cable will be compression crimped to the positive cable and the connection will be insulated with adhesive heat shrink sleeve prior to using splice kit and sealed with an approved splice kit and filled with epoxy resin. Ensure sufficient time (More than 2 hour) is allowed for the resin to set.

5.1.2 5.1.3 5.1.4 5.1.5 5.1.6 5.1.7

5.1.8

The spot welding for joint between MMO Ribbon and conduct bar shall be as below;: AC Voltage : AC 200~240V Power source : 200~240VA Output current : Max.28,000A Note : Refer to attached appendix-II

5.1.9

The following inspection and tests shall be performed for the anode grid system and related accessories on approved drawing: ① Depth of the polyethylene membrane liner with respect to the Tank Bottom (within ±5%). ② Anode spacing (within ±5%). ③ Anode depth with respect to the tank bottom (within ±5%).

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KNPC CFP - MAB2 Project P6022MAB.000.51H.014 Rev.: F2, 07 July, 2015 ④ Anode quantity (Not less than approved total length. Refer to approved drawing)). ⑤ Conductor bare spacing (within ±5%). ⑥ Anode/conductor bar welding. Spot weld is by making a cross and rubber hammering (1kg) one arm to shear the weld if a nugget pulls out of one of the sections- the weld is acceptable (Test sample). ⑦ Prior to tank installation, to be performed by using a ohm meter with TR/Rectifier switched off. Resistance measurement (up to 1 ohm) Before backfilling, to be performed by using a multi-meter with TR/Rectifier switched off. Resistance measurement (up to 1 ohm) After backfilling, to be performed by using a multi-meter with TR/Rectifier switched off. ⑧ Resistance measurement between power feeder cables after installation and after backfilling ⑨ Visual and dimension (Typ.±10%) check of grid system accessories 5.1.10 The inspection result shall be recorded on form No.51Q-EL-0001 & 0002.

5.2

Installation of Permanent Reference Electrode

5.2.1

5.2.6

Installation of permanent reference electrode at location required on approved drawings (prior to installation, reference electrodes to be soaked in a water container for 10 minutes minimum). Installation of permanent reference electrode at location required on approved drawings Termination to the test box and junction box will be as per the approved drawing,. The following inspection and tests shall be performed for the installation of permanent reference electrode. ① Electrodes installed in the sand bed of tank foundations shall be inspected to ensure the functional capability, their location and level is as per the detail drawing. ② The measured potential of the electrodes to standard electrode (Potable Cu/CuSo4 Referen ce Electrode) shall be as follow: * Cu/CuSo4 Reference electrode: 0 ± 50mV ③ Check the reference cell soaked in water. The chloride level for sand and water of above ground storage tank shall be tested as per P6000CFP.000.10.64.014 by others. * Chloride level : < 10 ppm The inspection result shall be recorded on form No.51Q-EL-0010

5.3

Installation of Slotted Pipe

5.2.2 5.2.3 5.2.4

5.2.5

5.3.1 5.3.2

Installation of slotted section of monitoring pipe at location on approved drawing. The slotted U-PVC pipe shall be penetrated through HDPE or approved in the concrete foundation ring. 5.3.3 Attention to be paid to avoid sand ingress inside the pipe. 5.3.4 Any sand which can obstruct the passage of the potable electrode should be removed. 5.3.5 U-Pipe connection point of monitoring pipe to be sealed by means of PVC bond. Insure that retractable reference electrode passes through the monitoring pipe. 5.3.6 Provision of geotextile cloth on the perforated PVC tube will be provided by vendor. 5.3.7 Verification of installed depth of U-PVC tube. 5.3.8 PVC cap shall be installed at both sides of tubes. 5.3.9 SS “U” clamps shall be provided on the PVC cap to secure pulling rope. Insure that retractable reference electrode passes through the monitoring pipe. 5.3.10 Installation polypropylene rope inside monitoring pipe for connection to retractable electrode, in case of future measurement. The polypropylene rope should be provided by contractor. 5.3.11 Visual and dimension check (within ±10%). 5.3.12 Check the smooth operation of passage through the monitoring pipe with temporary electrode instead of retractable reference electrode.

5.4

Cable to tank connection

5.4.1

Above ground cable to tank connections shall be carried out by lugging the cable on same tank material. The plate shall be touch-up painted after cable connection is made.

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5.4.2 5.4.3 5.4.4

Cable connections to tanks shall be via steel studs and bosses welded to tank chime by using a lug, nut and washers.. Steel plate for negative and test lead cable of reference electrode are welded by tank fabricator Cable lug shall be suitably sized to fit the cable cross-section and M18 threaded stud bolt.

5.5

Backfilling

5.5.1 5.5.2

Backfilling within the concrete ring foundation by means of clean sand, attention to be paid to avoid damages to MMO anode, cables, permanent reference electrodes and monitoring pipes. If any damage to C.P materials is detected (cable cutting, welding damage etc), backfill shall be interrupted and prompt repair actions shall undertake. If any damage for repair activity shall be submit the procedure for approval

6.0

INSTALLATION FOR TANK INTERNAL - Impressed Current Cathodic Protection

6.1

Suspended Anode Installation

6.1.1 6.1.2 6.1.3

6.1.7 6.1.8

Anode suspender shall be installed correctly as per approved drawing. Quantity of anode shall as per approved drawing. Sufficient length of anode cable shall be lopped inside and outside anode nozzles to allow removal of anode nozzle cap. Anodes shall be suspended from the anode nozzle by rope. Anode cables shall be tied to polypropylene support rope at max. 600mm intervals by cable ties. This rope shall be tensioned by using a hook. The anode installation will be checked to ensure the fixing by hook is secure and there is no interference or contact with the tank internal surfaces. Anode cable shall be connected to tank top mounted interface junction box. The inspection result shall be recorded on form No. 51Q-EL-0005 or 0007.

6.2

Reference Electrode Installation

6.2.1 6.2.2 6.2.3

6.2.7

Reference electrode shall be installed correctly as per approved drawing. Quantity of reference electrode shall as per approved drawing. Sufficient length of reference electrode cable shall be lopped inside and outside electrode nozzles to allow removal of electrode nozzle cap. Reference electrode shall be suspended from the electrode nozzle by rope. Reference electrode cables shall be tied to polypropylene support rope at max 600mm intervals by cable ties. This rope shall be tensioned by using a hook. The reference electrode installation will be checked to ensure the fixing by hook is secured and there is no interference or contact with the tank internal surfaces. Reference electrode cable shall be connected to tank top mounted interface junction box.

6.3

Interface Junction Box

6.3.1 6.3.2 6.3.3

Interface Junction Box (IJB) shall be installed on pre-welded C-channel (by tank fabricator). IJB and nozzle shall be connected with flexible conduit. IJB shall be installed according to approved drawing.

6.4

Conduit Pipe

6.4.1

Galvanized conduit pipe and support shall be installed as per site condition in order to achieve the shortest cable length and to avoid obstruction from other facilities on top of the tank. Conduit support (Unistrut Channel) shall be welded roof as per approved drawing (by tank fabricator).

6.1.4 6.1.5 6.1.6

6.2.4 6.2.5 6.2.6

6.4.2

6.5

Cable Tray Installation Cable tray shall be installed on pre-welded C-channel (by tank fabricator) on tank wall according to approved drawing for tank internal CP with ICCP system.

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7.0

INSTALLATION FOR TANK INTERNAL - Sacrificial Anode Cathodic Protection

7.1 7.1.1 7.1.2 7.1.3 7.1.4 7.1.5 7.1.6

Installation of Zn Anode

7.1.7

Anodes shall be installed correctly as per approved drawing. Quantity of anode shall as per approved drawing. During the installation work of the anodes, interference and contact with tank internal Surface shall be avoided strictly. Remove the paint of steel plate for anode or structure The following inspection shall be performed for sacrificial anode system and related accessories on approved drawing: ① Zn Anode quantity ② Interference & contact with internal surface. ③ Location of fixed anode. The inspection result shall be recorded on form No. 51Q-EL-006 or 007.

8.0

INSTALLATION FOR U/G PIPING

8.1

Installation of M.M.O Ti Tubular Anode

8.1.1 8.1.2

8.1.6

Check anode locations and identifications as per approved drawing. The excavation of anode hole should be witnessed to ensure the correct depth with respect to approved drawings. All welding works should be carried out before the installation of the anodes to avoid any damages to the anodes or the cables. Install anode to positive distribution box and terminate each anode cable ensuring that each cable is correctly labelled The following inspections and tests should be performed for anode bed as per approved drawings : ① Location of anode bed (Visual). ② Depth of excavation to the required depth (within ±5%). The inspection result shall be recorded on form No. 51Q-EL-008..

8.2

Installation of Reference Electrode

8.2.1

8.2.6 8.2.7

Installation of permanent reference electrode at location required on approved drawings (prior to installation, reference electrodes to be soaked in a water container for 30 minutes minimum). Installation of permanent reference electrode at location required on approved drawings. Reference electrodes shall be placed approximately 15cm from the pipeline with the lower edge of the electrode on a level with the centerline of pipeline. Termination to the test box will be as per the approved drawing, The following inspection and tests shall be performed for the installation of permanent reference electrode. ① Electrodes installed in the sand bed of pipeline shall be inspected to ensure the functional capability, their location and level is as per the detail drawing. ② The measured potential of the electrodes to standard electrode (Potable Cu/CuSO4 Refere nce Electrode) shall be as follow: * Cu/CuSO4 Reference electrode : ± 50mV Check the reference cell soaked in water. The inspection result shall be recorded on form No. 51Q-EL-0010.

8.3

Cable to pipe connection

8.1.3 8.1.4 8.1.5

8.2.2 8.2.3 8.2.4 8.2.5

8.3.1 8.3.2 8.3.3 8.3.4 8.3.5 8.3.6

Cable to pipe connections shall be by the cad welding, the connection shall be made directly to the pipe as detailed below: The coating of pipe shall be removed over an area of approximately 50 x 50 mm either using a scraper or hot knife. The exposed area shall be thoroughly cleaned to bright metal using a coarse file. The exposed area is then pre-heated using a flame torch to relieve area of moisture. Remove cable sheath for a length of approximately 50mm and thoroughly clean the conductors. Ensure mould is thoroughly dry by pre heating, if necessary. Insert bared end of cable into slot in carbon mould ensuring cable end is centered in crucible. Keep carbon mould firmly into cleaned area of pipe and insert metal disc in bottom of crucible. Pour powder into crucible on top of disc ensuring that a small amount is spread on the mould edge.

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8.3.7 8.3.8

Ensure mould is held upright and firmly against the pipe surface. Once the exothermic reaction has taken place, the mould shall be carefully removed and cleaned using a scraper and brush ready for the next cable connection. 8.3.9 The completed welding shall be checked visually and mechanically tested with a small headed hammer. 8.3.10 The completed connection and the surrounding pipe shall be washed clean. The cable connection and the exposed pipe shall then be coated with approved coating material. The repair material shall overlap existing coating at least by 20mm. 8.3.11 If flanges are used for pipe connections, electrical continuous of pipe should be ensured by bolt and nut of flanges or cable lug and jumper cable to each flange side. And the electrical continuous must be checked before backfilling work. 8.3.12 The inspection result shall be recorded on form No. 51Q-EL-0008.

8.4

Cables

8.4.1

8.4.4

Buried main cables should lie at a depth that will protect them from disturbance by other excavations. Cable tiles or cable warning tape should be used to warn of the presence of the cable during any subsequent excavation. The main cable shall then immediately be tagged with its unique ID as per approved drawing. The cable lengths shall be checked against the cable schedule lengths or approved drawing in order that wastage is minimized. The inspection result for main CP cable shall be recorded on form No. 51Q-EL-0014.

8.5

Backfilling

8.5.1

Before Backfilling, attention to be paid to avoid damages to anode, cables, permanent reference electrodes etc. If any damage to C.P. materials is detected (cable cutting, welding damage etc.), backfill shall be interrupted and prompt repair actions shall undertake

8.4.2 8.4.3

8.5.2

8.6

Installation & Testing of Insulation Flanges

8.6.1

An “isolation checker” is an instrument specifically built to check both below grade as well as above grade isolation devices (See figure 1). For above grade isolation devices, the isolation checker probes are placed in contact with each side of the flange or union. A functioning electrical isolation device will show a full-scale deflection while an electrically shorted device will show a deflection toward zero on the scale.

Figure1. Isolation Checker If the electrical isolating device is buried and test wires exist on both sides of it, an underground “isolation checker” may be used. This instrument is similar to the above grade isolation checker but is designed to be used only with an underground isolating fitting. It can be used P6022MAB.000.51H.014_F2

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8.6.3

to test for a shorted isolating bolt of stud if it has double isolating washers. The value of insulating resistance by 500-Volt megger shall not be less than 1MΩ at flange to each bolts. The megger test should be done by contractor or piping. The following inspection and test shall be performed for the installation of insulation flange test point ① Location of IFTP as per approved drawing. ② Identified pipeline ID ③ Spark gap installation ④ Foundation location and details correct ⑤ Installation as details drawing ⑥ Cable connections as per connection diagram. ⑦ Cables installed & termination complete. ⑧ All cable clearly identified with tags The inspection result shall be recorded on form No. 51Q-EL-0015.

8.7

Installation of Mg Anode(for Short Buried Piping or Temporary)

8.7.1

Prior to installation, Mg anodes and cable tails shall be inspected for damages and defects. Proper care and attention to avoid damages on anodes during handling and installation. The location of magnesium anode shall be marked out on site and the installation depth of the anode shall be in accordance with approved drawing.

8.6.2

8.7.2 8.7.3

Anode lead shall have 100mm slacks as a minimum.

8.7.4

8.7.9 8.7.10 8.7.11 8.7.12 8.7.13

Before installation, the anode shall be soaked in water about 1 hour. The soaked pre-packaged anodes shall be installed in excavation and pouring down water. Before backfilling, proper attention shall be observed to avoid damages on anode, cables and installed cathodic protection facilities. If any damages of cathodic protection materials are detected (cable cutting, welding damage etc), prompt repair and appropriate actions shall be undertaken. After installation, the anode shall be backfilled with native soil and wetted with potable water to provide better soil contact and compaction. Anode leads shall be terminated into a test station. The test box shall be located such that anode cables are kept as short as possible. Following points shall be inspected during or after installation work Mg anodes. Location of anode as per approved drawing. Anode lead cable termination as per approved drawing. Cable tags. The inspection result shall be recorded on form No. 51Q-EL-0008

9.0

INSTALLATION FOR REBAR IN CONCRETE

8.7.5 8.7.6 8.7.7 8.7.8

9.1 Installation of M.M.O Ti Ribbon Mesh Anode before Pouring Concrete 9.1.1 Rebar clips shall be pushed onto the reinforcement at designated point and tied securely with two (2)

9.1.2 9.1.3 9.1.4 9.1.5 9.1.6 9.1.7 9.1.8

cable ties. Note :Contractor to instruct civil people using the concrete vibrators - To keep the vibrators away from this cage section to avoid spot weld ,anode damage. The mesh anode shall run along a line of rebar clip as per approved drawing. The spacing between the anodes and reinforcing steel in the structure shall be a minimum of 10 mm. The mesh anode shall be fixed to each rebar clip with two (2) cable ties and tensioned over its full length. The end of the mesh anode should be looped and weld each other, and then the mesh anode can be stretched by cable ties and rebar clip. The conductor bar shall be positioned along a line of rebar clip that cross the mesh anode as per approved drawing. The conductor bar shall be fixed to rebar clip with cable tie as for mesh anode. The mesh anode shall be spot welded to the conductor bar at every crossing point. The installation procedures for spot welding machine is as follows: ① Make sure the mesh anode and the conductor bars are clean and free of dust. ② Place the conductor bar underneath the section of the mesh anode.

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KNPC CFP - MAB2 Project P6022MAB.000.51H.014 Rev.: F2, 07 July, 2015 ③ Welding gun insert between mesh anode and conductor bar ④ Press the trigger to weld. ⑤ The welding shall be done instantly when the trigger is pressed

Note : Max 400 mm of MMO mesh anode interval is average interval in the each zone.

9.1.9 To reduce the possibility of mesh anode displacement during the concrete pour, the mesh anode must be installed tightly to the rebar cage to avoid electrical shorts. In particular, to avoid anode movement during the concrete pour, it is important for the anode to be stretched tightly. P6022MAB.000.51H.014_F2

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9.1.10 A discontinuity check between the anode system and the rebar shall be carried out by measuring the resistance between the anode lead cable and negative cables. Discontinuity is proven by failure of this test. If there is continuity between anode and cathode then the short-circuit should be traced and eliminated before work proceeds. The successful elimination of the short circuit shall be demonstrated by re-measuring the continuity between anode and cathode. Note : Resistance measurements will be taken between the anode cables and the system negative cables within each anode zone at the T/R. Open circuit or large different forward and reverse resistances (greater than 100 ohm) will indicate discontinuity between anode and cathode

9.1.11 All cable tie tails shall be removed. 9.1.12 The following inspection and tests shall be performed for the anode system and related accessories on approved drawing: ① Anode spacing ② Location of anode ③ Anode quantity (Not less than approved total length - refer to approved drawing) ④ Conductor bar quantity (Not less than approved total length - refer to approved drawing) ⑤ Anode/Conductor bar welding spot weld is by making a cross and rubber hammering (1kg) one arm to shear the weld if a nugget pulls out of one of the sections - the weld is acceptable (Test sample) ⑥ Resistance measurement (up to 1 ohm) Before the concrete pour, to be performed by using a multi-meter. ⑦ Resistance measurement (up to 1 ohm) After the concrete pour, to be performed by using a multi-meter. ⑧ Visual and dimension (Typ.±10% ) check of anode system accessories 9.1.13 The inspection result shall be recorded on form No. 51Q-EL-0009, 0011 & 0012.

9.2 Connection of cable 9.2.1 Anode lead cable of the specified rating, size shall be prepared in sufficient length to run from the anode lead connection to the appropriate junction box by the specified route without a cable splice.

9.2.2 The pre-stripped copper core of the anode lead cable shall be compression crimped to a titanium rod 9.2.3 The assembly shall be encapsulated with company approved, mechanically strong adhesive lined 9.2.4 9.2.5 9.2.6 9.2.7

heat shrink type, which extends 50mm either side of the crimp. Care shall be taken during the application of heat shrink to ensure no damage results to the cable insulation. The Titanium wire shall be positioned in the correct orientation and secured to the conductor bar. The cable leading from the anode lead connection shall be securely fastened to the conductor bar. A connection between the titanium wire and conductor bar shall be made by metallurgical welding, taking care to ensure that the process in no way damages conductor bar or the cable connection system. The negative cable to connection rebar is below:

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The negative cable shall be cad welding or approved drawing to steel plate assembly (steel plate min.15mm x 80 mm 2mm thick and steel rod is steel rebar size ) Steel rod shall be tack welding to steel rebar as per approved WPS/PQR No. SM-P1.1-103S or relevant approved document. The assembly shall be encapsulated with a suitable, mechanically strong adhesive lined heat shrink tube, which extends 30mm side of the cable joint. Care shall be taken during the application of heat shrink to ensure no damage results to the cable insulation.

9.2.8 The installation procedure for spot welding the MMO Ti anode lead connection to the Ti conductor bar is as follows: ① Make sure the anode lead connection and the conductor bar are clean and free of dust. ② Firmly fix the positive connection to the top of the conductor bar. ③ Anode lead connection shall be placed onto the conductor bar to make a direct connection. ④ Press the trigger to weld 9.2.9 The following inspection should be performed as per approved drawings : ① Check the connection of cables to boxes. ② Cable identification. 9.2.10 The inspection result shall be recorded on form No. 51Q-EL-0009..

9.3

Tack Welding procedure of negative connection A tack welding is a kind of welding that describes how welding is to be carried out in production. Welding usually is recommended for all welding strict application operations and approved document make them mandatory. But this tack welding is considered only physical connection to void electrical isolation between the rebar and negative connector or anode ribbon mesh and anode conductor. That is why this tack welding is simple and different with strict SMAW because the tack welding is no need free of leakage, force of tension and other strict requirement. Tack welding generally is doing like arc welding procedure without strict test and qualification. Worker must be skilled and qualified by DEC’s welding quality control department.

Note : The negative cable shall be cad welding as per approved drawing to steel plate assembly (steel plate min.15mm x 80 mm 2mm thick and steel rod is steel rebar size ) Steel rod shall be tack welding to steel rebar as per approved WPS/PQR No. SM-P1.1103S

9.4 Installation of Reference Electrode 9.4.1 Installation of reference electrode at location required on approved drawings. 9.4.2 In case of malfunction of reference electrode, pseudo reference electrode which is kind of M.M.O mesh anode shall be installed additionally near the location of reference electrode.

9.4.3 At a given location, the reference electrodes shall be placed at the level of and parallel to the reinforcing steel.

9.4.4 All cables shall be secured to the reinforcement with cable ties, and routed to the location of the P6022MAB.000.51H.014_F2

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appropriate junction box as shown on the design drawing.

9.4.5 The installation procedure for pseudo reference electrode is as follows:

9.4.6

9.4.7

□ Weld 200mm Long M.M.O mesh to 150mm Long conductor bar by spot welding. □ Weld conductor bar to titanium wire by spot welding. □ Connect pseudo reference electrode lead cable to titanium wire by compression sleeve and heat shrinkable tube. The fabrication method of encapsulation reference electrode is as follows: □ Divide the PVC pipe(Φ75mm x 200mm Long) along with centerline into two equal parts or as per drawing □ Tie up the divided PVC pipe by cable tie like original shape. □ Insert the reference electrode to middle of PVC pipe. □ Pour the concrete into PVC pipe. □ After concrete curing, remove PVC pipe from concrete. □ Check whether the surface of concrete is smooth or is not cracked. The following inspection and tests shall be performed for the installation of permanent reference electrode. ① Electrodes installed in the sand bed of pipeline shall be inspected to ensure the functional capability, their location and level is as per the detail drawing. ② The measured potential of the electrodes to standard electrode (Potable Ag/AgCl Reference Electrode) shall be as follow: * Ag/AgCl Reference electrode : ± 50mV

9.4.8

For a reference electrode to be acceptable it’s measured potential at high and low impedance should not differ more than 5mV after encapsulation Note: 1.Prior to en-capsulation, each RE shall be subject to a calibration test. All reference electrodes shall be immersed in 3% sodium chloride solution and the potential of each reference shall be measured against a potable Ag/AgCl reference electrode. 2. Criteria of potential difference between 100Mohm (High) and 10Mohm (Low) range is △V = 2mV [Max] after encapsulation The inspection result shall be recorded on form No. 51Q-EL-0016 & 0017.

10.0

INSTALLATION FOR COMMON EQUIPMENT

10.1

Installation of TR/Rectifier

10.1.1 Prior to installation, the foundations will be checked for level and civil clearance will be obtained. 10.1.2 Fix transformer rectifier to base utilizing anchors and the fixing holes provided. Great care to be taken in identification of polarity of all cables ensuring they match the polarity of the marked terminals. 10.1.3 The installation of unit will be witnessed to ensure correct orientation alignment for cabling. 10.1.4 The following inspection and tests shall be performed for the installation of TR/Rectifier. ① Prior to installation the TR/Rectifier at site, it will be inspected for mechanical damage at enclosure of TR/Rectifier. ② Particular attention will be paid to control panel measuring instruments and control devices. ③ Where oil immersed unit has been supplied oil filled, the oil level will be checked to ensure no leakage. ④ Prior to installation, the foundations will be checked for level and civil clearance will be obtained. ⑤ The installation of the unit will be witnessed to ensure correct orientation and alignment for cabling. 10.1.5 The inspection result shall be recorded on form No. 51Q-EL-0004

10.2

Installation of Boxes (PJB, NJB, BJB, ATB, TS)

10.2.1 Install Boxes at location on approved drawing. 10.2.2 Anode lead cables to be terminated to positive junction box, while test lead cable & reference electrode cables to be terminated to test box. 10.2.3 A minimum suitable length of slack cable shall be left in the trench at points of termination/connection to above ground apparatus. P6022MAB.000.51H.014_F2

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10.2.4 The following inspection and tests shall be performed for the installation of boxes. ① Equipment supports will be inspected to ensure they are fabricated as per the approved detail drawing. ② Base plates, fixings, concrete foundations etc. will be checked for locations and level and the fixings. ③ Cables to boxes will be checked against the approved drawing for correct routing and termination 10.2.5 Check the connection. 10.2.6 The inspection result shall be recorded on form No. 51Q-EL-0003

11.0

PRE-COMMISSIONING

11.1

Adjustment of TR/Rectifier

11.1.1 Check the polarity at output terminal by multi-tester ① The cable to positive junction box shall be connected on positive (+)terminal ② The cable to structure shall be connected on negative (-) terminal 11.1.2 Check the input/output switch (MCCB) position. It should be in "Off" position. 11.1.3 Check the input voltage. It should be fit to rating of rectifier. 11.1.4 Check the fine and coarse volume, it is recommended set to low position. 11.1.5 Before energizing the TR/rectifier, check the potential at test box (Natural potential). 11.1.6 Energizing the rectifier step by step as follows ① Input MCCB “ON” ② Output MCCB “ON” 11.1.7 Check the value of DC ampere, DC voltage and protective potential. 11.1.8 Control the DC output current by adjust the volume as follow. ① If the value of potential at test box is lower than the criteria of clause 8.2, increase the DC current by adjust the volume to clock-wise. 11.1.9 The inspection result shall be recorded on form No. 51Q-EL-0020 & 0021

11.2

Potential Test

11.2.1 Check the natural potential before rectifier energizing. 11.2.2 Check the protective potential after rectifier energizing. 11.2.3 At test box, the protective potentials of structure to electrolyte should be recorded with respect to a Cu/CuSO4 reference electrode or Ag/AgCl reference electrode. 11.2.4 This shall be achieved by connecting the structure under test to the (+) terminal of a multi-meter set to D.C. Volts. 11.2.5 The reference electrode lead wire shall be connected to the (-) terminal of the multi-meter and the electrode placed upon moist soil immediately above the structure. 11.2.6 Potential measurements with current applied (on) and interrupted (instant off). Use an interruption cycle of 4 seconds "on" and 1 second "off" normally excepted decay potential test for steel rebar 11.2.7 The potential criteria is below: ① U/G pipeline An instant off potential more negative than -850mV and less negative than -1200mV with respect to a Cu/CuSO4 reference electrode as per DEP 30.10.73.33 71.1.3 Para 8. ② Metallic reinforced concrete structures: The cathodic protection of metallic reinforcement inside concrete shall comply with one of the following potential criteria. i) 100mV decay or more measured up to 24 hours from instantaneous off ii) 150mV decay or more measured up to 168 hours from instantaneous off iii)The instantaneous off potentials are between the ranges of -0.78 volt to -1.1 volt with reference to a silver/silver chloride reference electrode. If the sensing of Ag/AgCl reference electrode can be impacted dry or not by concrete if found the system shall be deemed as successfully commissioned if the following results are observed after conducting the Performance Verification Test (1 month after energization) - 50% of all REs within a zone achieve either criteria 1, 2 or 3. If the above criteria is met then the system shall be deemed commissioned and the 1 month P6022MAB.000.51H.014_F2

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monitoring period shall commence. ③ PIV over Short Pipe  Test Station with Mg Anode Test box where testing facilities are going to be provided along with the magnesium anodes installation: An instant off potential more negative than -850mV and less negative than -1200mV with respect to a Cu/CuSO4 reference electrode  Mg Anode without Test Station. For the remaining PIV’s where the magnesium anode cables are going to be connected directly to the PIV’s, the following criteria only applies when the surface above the PIV is not paved and allows the porous plug of the electrode to be placed in contact with the soil: • An “On” potential more negative than -850 mV and less negative than -2,500 mV with respect to a saturated copper/copper sulfate (Cu/CuSO4) reference electrode 11.2.8 The inspection result shall be recorded on form No. 51Q-EL-0018, 0019,0025 & 0026

11.3

Junction Box

11.3.1 Check the internal connection with approved drawing (All Boxes). 11.3.2 Check the anode current of feeder cable(PJB). ① To be performed by using shunts foreseen in the distribution box or positive junction box, with TR/Rectifier switched on 11.3.3 The inspection result shall be recorded on form No. 51Q-EL-0003

12.0

COMMISSIONING  The commissioning are required approved installed cathodic protection system in accordance with the design. the system shall be considered satisfactory when the cathodic protection criteria are met. On completion of remedial action, the commissioning shall be carry out the testing as minimum; -

Natural potential measurement  Verify that the temporary cathodic protection has been disconnected for at least 24 Hr.  Measure potential at all test locations prior to energizing the CP TR/Rectifiers.  Measure and record on form No. 51Q-EL-0018, 0025 & 0027.

-

On and Instant Off potential measurement  Insert current interrupter into TR/Rectifier or using the function of TR/Rectifier.  Measure and record the structure to soil potential reference to potable or permanent reference electrode.  Measure and record on form No. 51Q-EL-0019,0025,0026,0027

-

Out put current measurement of Anode at AJB and TR/Rectifier  Open the TR cabinet or Box.  Measure and record readings on volts and amps panel meters and anode feeder inside AJB Box  Measure and record on form No. 51Q-EL-0020,0021 & 0022

 Protection Potential range  Metallic reinforced concrete structures The cathodic protection of metallic reinforcement inside concrete shall comply with one of the following potential criteria. i) 100mV decay or more measured up to 24 hours from instantaneous off ii) 150mV decay or more measured up to 168 hours from instantaneous off iii)The instantaneous off potentials are between the ranges of -0.78 volt to -1.1 volt with reference to a silver/silver chloride reference electrode.  For Tank External and Internal with ICCP An instant off potential more negative than -850mV and less negative than -1200mV with respect to a Cu/CuSO4 reference electrode as per DEP 30.10.73.33 71.1.3 Para 8. but tank internal CP with sacrificial anode system is ON potential more negative than -950mV and less negative than -1200mV With respect to a Cu/CuSO4 reference electrode P6022MAB.000.51H.014_F2

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12.0.1 Commissioning shall consist of: ① Measuring structure to soil potential at all measuring points. ② Measuring the total current output from box and from each anode. ③ Measure the status of TR/Rectifier ④ The inspection result shall be recorded on form No.51Q-EL-0018 ~ 0027.

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Attachment - I Spot welding procedure 1) General

Spot welding will be used for connection of ribbon mesh and anode conductor which is very thin metallic as shown the below. Spot welding is a resistance welding process for joining metal sheets by directly applying opposing forces with electrodes with pointed tips. By one or two electrode The current and the heat generation are localized by the form of the electrodes. The weld nugget size is usually defined by the electrode tip contact area. Spot welding for CP work also used to connect electrical conductivity without force of tension and other reason. Worker for spot welder must be trained and qualified by DYCE. Spot welding is simple and different with strict SMAW because the spot welding is no need free of leakage, force of tension and other strict requirement. Spot welding generally is doing like resistance spot welding procedure without strict test and special qualification. But have to training the person for spot welding- Refer to below clause 2). Training and quality testing. The following inspection should be performed. ① Completeness. ② Free of harmful defect and visual inspection .

The inspection result shall be recorded on form No.1.

Note: Spot welding shall be carry out opposed welding or series welding to met quality testing acceptable.

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2) Training and quality testing Spot welder and related electronic assemblies shall be performed by a welding operator qualified and certified by training. For each unique type of weld to be produced, a minimum of 5 sample welded connections shall be produced for an initial procedure qualification A NACE certified Technician of level II or equivalent shall present at site to training the spot welding to make the sample, The qualification sample set shall be acceptable to all of the following 3 levels of quality control as applicable, for successful qualification: 1) visual inspection, 2) conductivity (resistivity) testing, 3) destructive testing. A) Visual Inspection and Electrical Conductivity Testing All weld specimens shall be visually inspected and tested for electrical conductivity (resistivity). The resistivity of each connection shall meet the drawing requirements or if not specified by the drawing, shall measure less than 1.0Ω. B) Destructive Testing Five (5) weld samples shall be tested prior to start. Anode/Conductor bar welding spot weld is by making a cross and rubber hammering (1kg) one arm to shear the weld and a nugget pulls out of one of the sections-the weld is acceptable

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Attachment - II Technical Instruction for spot welding by manufacture

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Methodic Statement for CP KNPC

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