CP_MANUAL

CORROSION MATTERS

Page 1 of 48

DESIGN , ENGINEERING AND INSTALLATION MANUAL

FOR

PERMANENT CATHODIC PROTECTION SYSTEM

FOR

UNDERGROUND PIPELINE.

CORROSION MATTERS

6-3-899/2, 2ND FLOOR , SWATHI PLAZA

RAJBHAVAN ROAD, SOMAJIGAUDA, HYDERABAD – 500082

PHONE NO : +91 40 3240 4595

TELEFAX : +91 40 2341 8786

EMAIL: [email protected]

WEBSITE : www.corrmatt.com

CORROSION MATTERS

Page 2 of 48

COMPANY OVERVIEW

Corrosion Matters , this company has been founded by Corrosion and Electrochemical

Engineers in 2005 to cater to projects, related to corrosion prevention systems

For prevention of corrosion , our team of engineers , are having hands on experience in

handling time bound and critical projects of importance.

The company is actively engaged in Cathodic Protection related comprehensive design

and project management services for projects that are typically , cross country pipelines,

complex plant Underground piping, Onshore and Offshore facilities , City Gas and Water

mains, above ground storage tanks , concrete steel structures etc.

The company has been chosen to foresee and supervise construction projects and key

assets of National and International Importance in Oil and Gas sectors.

The Objective of the company is to provide services to the industry to the minute detail

and innovate user friendly methods of Cathodic Protection Applications which shall help

the industries world over in a long way.

REGARDS,

CORROSION MATTERS

CORROSION MATTERS

Page 3 of 48

CATHODIC PROTECTION SYSTEM FOR U/G PIPING ( CROSS-COUNTRY)

1. SCOPE OF WORK :

The scope of work covers the Design, Engineering, Supply of Materials, Installation, Testing &

Commissioning of Permanent cathodic protection system for external surface of under ground

pipeline including post commissioning surveys such as Coating Conductance Measurements ,CIPL

survey, Pearson detection followed by DCVG [for defect classification] at defect locations evinced.

Also getting specific approval for major activities like

• Soil Resistivity survey & site data generation/collection.

• CP Design & Detailed Engineering

• Field Testing & Commissioning

• Procedures for interference testing & mitigation

• All major installation Procedures

• Coating conductance, CPIL & PEARSON Survey.

• Post Commissioning, Monitoring methodology & frequency formats

CORROSION MATTERS

Page 4 of 48

1.1 SOIL RESISTIVITY SURVEY

Soil resistivity survey should be carried out at at minimum two plots for each proposed CP station

as option for selecting best location for construction. Soil resistivity will be carried out at different

depth and at all anode bed locations.

The locations of anode ground bed plot will be selected based on the land availability to avoid

problems during construction & keeping maintenance in view. However from the resistance

calculations it can be decided type of anode bed.

Land selection for anode ground bed has been taken base on following broad guidelines, however

final decision to be taken at site based on land availability.

1. site for shallow ground bed should have minimum 100 mtr perpendicular distance from

the pipeline.

2. Location shall be remote (anode remoteness requirement to be calculated based on design

current rating with local resistivity & criteria)

3. Accessibility of location and route for laying of anode header cable shall be checked and

marked on plot plan drawing.

4. Anode bed shall not be situated below HT line and near electrical earthing.

5. Lowest resistivity location shall be considered over options available, for better anode

ground bed resistance option.

CORROSION MATTERS

CP_MANUAL.doc Page 5 of 48

1.2 DESIGN BASIS & CRITERIA

The intent of this section is to propose design data and criteria for the Permanent Cathodic Protection

System.

1.2.1 Cathodic Protection Design Life & Current Density

In accordance with the project specification, the Cathodic Protection system will be designed to have a

desired design life in years.

For Example :

The Pipeline external surface is coated with 3 Layer Polyethylene (3LPE) coating and the current density

considered for the design is as follows:

i) For Polyethylene coated Pipeline (Normal Soil) : 25µµµµA/m2

ii) For Polyethylene coated Pipeline (Salt pan Area) : 125 µµµµA/m2

A safety margin of 1.3 i.e. 30% has been provided for the current calculations over and above the

specified protective current density.

1.2.2 Philosophy of Cathodic Protection System for Permanent CP

The Cathodic protection systems shall be a MMO Lida anodes systems and shall be designed for Deepwell

and Horizontal type anode bed.

1.2.3 Codes & Standards

Latest revision of following standards shall be considered

BS7361-Cathodic Protection-Part 1 Cathodic Protection –code of Practice for Land and Marine

Applications

BS: CP:2008 Protection of Iron & Steel Structures From Corrosion.

NACE RP 0177-2000 Mitigation of alternating current and Lightning Effects on

Metallic structures and corrosion control systems

NACE RP 0286-2002 Electrical Isolation of Cathodically protected pipelines

NACE RP 0169-2002 Control of external corrosion on underground or

submerged metallic piping system.

CORROSION MATTERS


NACE TM 0497-2002 Measurement techniques related to criteria for cathodic

protection of underground-submerged metallic piping

system.

NACE Publication No 54276 Cathodic protection monitoring for buried pipelines.

NACE RPO. For Deep well CP

1.2.4 Cathodic Protection Design Criteria for Permanent CP

Cathodic Protection system shall be designed to meet the following criteria:

1. The pipe to Soil Potential measurements shall be in between (-) 0. 95V “Off ” and (-) 1.1.7V “Off ”

as measured between the pipe surface and a copper – copper sulphate reference electrode.

2. In rare circumstances a minimum polarization shift of (-) 100mV shall indicate adequate levels of

cathodic protection for the pipeline with the written permission from owner.

3. A positive potential swing of >20mV shall be considered as the criteria for presence of an

interaction situation requiring investigation and incorporation of mitigation measures.

CORROSION MATTERS


1.3 Cathodic Protection Stations

In line with the project specifications and design calculations, location and No. of CP Station shall be

proposed as under:-

S.N. CP St’n. Location CP Station No. Chainage (Km) Type Rating

1 (SV#1) CP#1

2 (SV#2) CP#2

3 (SV#3) CP#3

4 (SV#5) CP#4

1.4 DESIGN CALCULATION

The following Calculation shall be used for design the permanent cathodic protection system

1.4.1 Total Cathodic Protection Current Requirement

i. Surface Area

Sa = ΠΠΠΠ x D x L

Where :

Sa = Surface area of Pipeline m2

D = Diameter of pipeline m

L = length of pipeline m

ii. Current Requirement

It = Sa x Cd x 1.3/1000 Amps.

Where

It = C.P. current requirement (Amp)

Sa = Surface area of Pipeline m2

Id = C.P. protective current density mA/m2

1.3 = Safety Margin

CORROSION MATTERS


The current requirement calculations shall be tabulated as under:

Protection span

(Km)

CP station Area Classification Chainage

(Km)

Dia.

(mm)

From TO

Total Km Surface

Area (m2)

Protective

Current

Density (µA)

Current

Required

(Amp.)

CP#1 (SV#

1)

CP#2 (SV#

2)

CP#3 (SV#

3)

CP#4 (SV#

5)

CORROSION MATTERS


1.4.2 Anode Requirement

Current

NA = It /Ia.

Where

NA = Total Anode Weight (Kg.)

It = C.P. current requirement

Ia = Out put current of Anode (4Amps)

Weight

W = It x Ct x L/Uf

Where

W = Total Anode weight (Kg)

Ct = Consumption Rate of anode (1 mg/Amp-year)

It = C.P. current requirement

Uf = Anode utilization factor

Location

Total current

requirement as per

design (Amps)

Out put current

of individual

anode (Amps)

Type of

Anode

Anode required

as per current

(Nos)

Anode

required as

per Weight

(Nos.)

Number of

Anode

proposed

(Nos)

CP#1 (SV#1)

CP#2 (SV#2)

CP#3 (SV#3)

CP#4 (SV#5)

CORROSION MATTERS


1.4.3 Ground bed Resistance calculation

i) Horizontal Grounded Resistance Calculation

The resistance of horizontal anode to electrolyte is calculated by the following formula :

Rs = 0.159Ps [ Ln ( 4L2 + 4L ( S2 + L2 ) 0.5) + S – (S2 + L2)0.5 – 1 ) ]

L DS L L

Where

Rs = Resistance to earth in ohms of the horizontal anode (Ω)

Ps = Soil Resistivity in Ω - m

L = Length of Active Anode in Mtr

D = Diameter of Active Anode in Mtr

S = Twice the depth of Anode (M)

ii) DEEP ANODE BED RESISTANCE CALCULATION

The resistance of deep anode to electrolyte is calculated by the following formula :

Rdb = 0.159 Ps [[[[ Ln ( 8 L / d)-1 ]]]]

L

Where Rdb = Resistance to earth in ohms of the Deep anode (Ω)

Ps = Soil Resistivity in Ω – m

L = Length of Active Anode in Mtr

D = Diameter of Active Anode in Mtr

iii) INDIVIDUAL ANODE TO BACKFILL RESISTANCE

Rbs = 0.159 P [[[[ Ln ( 8 L / d)-1 ]]]]

L

where

Rbs = Individual Anode to backfill resistance in Ω

Ps = Back fill Resistivity for calcined petroleum coke breeze ( 50 Ω-cm )

L = Length of Anode in mtr.

d = Diameter of Anode in mtr.

CORROSION MATTERS


TOTAL ANODE TO BACKFILL RESISTANCE

Rtbs = Rbs/N

where

Rtbs = Total Anode to Backfill Resistance in Ω

Rbs = Individual Anode to backfill resistance in Ω

N = Number of Anodes

iv) TOTAL GROUND BED RESISTANCE OF THE BED

Rgb = Rs + Rtbs

Rgb = Total Ground bed resistance

Rs = Resistance of vertical /Horizontal Anode to earth in (Ω)

Rtbs = Total Anode to Backfill Resistance in Ω

v) TOTAL CABLE RESISTANCE

ANODE TAIL CABLE RESISTANCE OF SHALLOW GROUNDBED

Single core copper conductor Armoured cable of 10 sq.mm is selected as Anode Tail Cable as per tender

specification.

Ri = Li x R10

Where

Ri = Individual Anode lead Cable resistance in Ω ( i = 01 to 10 )

Li = Length of Anode cable in meters

R10 = Resistance of 10 sq.mm cable = 1.83 Ω / km

1

Rta = ( 1/R1 + 1/R2 + 1/R3 ........+R/n)

CORROSION MATTERS


HEADER CABLE RESISTANCE FOR CP SYSTEM

Single core copper conductor cable of 35 sq.mm is selected as Anode and Cathode Header cable .

Rac = R35 ( Lac + L cc )

Where

Rac = Resistance of Header Cable

Lac = Length of Anode Header Cable

Lcc = Length of Cathode Cable

R35 = Resistance of 35 sq.mm cable = 0.529 Ω / km

TOTAL RESISTANCE OFFERED BY ALL CABLES

Rtc = Rta + Rac

Rtc = Total cable resistance

Rta = Total anode tail cable resistance

Rac = Total Header Cable Resistance

vi) TOTAL CIRCUIT RESISTANCE

Rtcr = Rgb + Rtotal

Rtcr = Total circuit resistance in Ω

Rtotal = Total cable resistance in Ω

Rgb = Total Ground bed resistance in Ω

vii) OUTPUT OF SYSTEM

It = current required for CP Station in amps

Rtcr = Total Circuit resistance in Ω

Back Voltage : 2Volts

Additional Voltage to drive the required current (V) = It x Rtcr

Total Output Voltage (Vt) = V + 2

CORROSION MATTERS


viii) REMOTE EARTH CALCULATIONS

Following Formulae is used to calculate the distance to remote earth

VE = ρ x A / 2 x π x d

Where

ρ = Resistivity in Ohm- mtr

A = Current in Amps

D = Distance between pipeline & Anodebed in mtr

VE = Voltage at Pipeline

Remote earth voltage shall be less than the Natural PSP i.e. -0.45V

CORROSION MATTERS


1.4 Summary of Design Calculation

Proposed No. of Anodes Size of Anode bed. Total out put

required

CP

St’n.

Locati

on (1)

Average Soil

Resistivity (ΩΩΩΩ -

mtr

Considered (2)

Type

(3)

No

(4) Rating

(Amps)

(5)

Installed

Anode

current

(Amps) (6)

Type of

Anode Bed

(7) Depth

(mtr)

(8)

Active

Length

(mtr) (9)

Dia / Width

(mm) (10)

Distance

between

Anode

(11)

Total

Ground

bed

R’tance -

Rab (ΩΩΩΩ)

(12)

Total

cable

R’tance

(Rtc) (13)

Total

circuit

R’tance

(Rtcr)

(14)

Amps

(It)

(15)

Volts

(Vt)

(16)

Remote

earth

Voltage

(Volts)

(17)

Distance

between

Anode bed to

Pipeline

proposed

(mtr) (1.7)

SV-1

SV-2

SV-3

SV-5

Note: If column (17) is less than pipeline Natural PSP , the distance of remoteness is sufficient.

CORROSION MATTERS

CP DESIGN / PERM / CORRMATT Page 15 of 48

1.5 Length Of Pipeline Protected From Drain Point

i) CROSS SECTION AREA OF PIPELINE

Ap = ΠΠΠΠ x t x ( D-t ) in m2

where

A = Cross section area of Pipe

D = Diameter of Pipe

T = Thickness of pipe

ii) LINEAR RESISTANCE OF PIPE

Rs = ρρρρs x l / A in Ω / km

where

ρs = Resistivity of steel pipe (2.2 x 10-7) ohm meter

A = Cross section area of pipe

l = Unit length of pipe

iii) COATING LEAKAGE RESISTANCE PER KM FOR 3LPE COATING

Rl = Rp/Sak in Ω per km

where

Rp = Coating resistance in

Sak = Surface area of pipe per Km

iv) ATTENUATION CONSTANT - αααα

αααα = ( Rs/Rl )0.5

Where

Rs = Linear Resistance of pipe

Rl = Coating leakage resistance

v) MINIMUM POTENTIAL SHIFT AT END POINT

CORROSION MATTERS


Edp = P/s min - P/s nat in Volts

where

P/s min = Least negative PSP at end point

P/s nat = Natural PSP of pipeline

vi) LENGTH OF PIPELINE PROTECTED FROM DRAIN POINT

Lp = (1/αααα) x Cosh-1(Edp/ Ed)

Summary of current Attenuation calculation

01 Dia (mtr)

02 Thickness (mm)

03 Surface Area of 1 Km Pipe (m2)

04 Resistivity of steel pipe (ohm-m)

05 Coating Resistance of Pipe (ohm/ m2)

06 Linear Resistance of pipeline (ohm/km)

07 Coating Leakage resistance of Pipe (ohm/km)

08 Attenuation constant α

09 Least negative PSP at end point

10 Natural PSP of pipeline

11 Minimum potential shift at end point

12 Max. PSP at drain point

13 Length of pipeline protected from drain point

CORROSION MATTERS


1.6 Sample Design Calculation for CP Station for Span Length from 0 to 28.9 Km

Equation Description Value unit

Sa Surface area 41165 m2

d Dia 0.4534 m

1.6.1

Sa = P x d x l

l Length 28900 m

It Total Current requirement 1.33 Amps

Sa Surface area 41165 m2

1.6.2

It = Sa x Id x 1.3/1000

Id Current density 0.025 mA/mt2

W Total Anode Weight 0.062 grams

It Total Current 1.33 Amps

Ct Consumption Rate 0.001 gm/A-Y

L Life 40 Years

1.6.3

W = It x Ct x L / Uf

Uf Anode Utilization factor 0.85

Nw No of Anode required by weight 0.25 Nos

W Total Anode Weight 0.062 grams

Wa Weight of Anode 0.240 grams

1.6.4

Nw = W/ Wa

(Thickness of MMO Coating 6gm/m2)

CORROSION MATTERS


Nt No of Anode required by current 0.44 Nos

It Total current 1.33 Amps

1.6.5

Nt = It/ Ia

Ia Anode output current 3 Amps

GROUND BED RESISTANCE CALCULATION FOR SHALLOW HORIZONTAL ANODE BED

RS Individual anode to backfill resistance 0.806 Ohms

PS Soil Resistivity 36

ohm-

mtr

N No of Anodes 8 Nos

L Active length of anode 51 mtr

D Active diameter of Pre-packed anode bed 0.4 mtr

1.6.6

Rs = 0.159Ps/L Ln(4L2 + 4L (S2+L2) 0.5)/DS)+( S/L) – (S2+L2)0.5/L –1)

S Twice the depth of Anode 6 mtr

Rbs Individual anode to backfill resistance 0.38 Ohms

Pb Backfill Resistivity for Calcined Coke 0.5

ohm-

mtr

L Length of anode 1 mtr

1.6.7

Rbs = 0.159 Pb/L Ln ( 8 L / d)-1

d Diameter of anode 0.025 mtr

Rtbs Total Anode to Backfill Resistance 0.047 Ohms

Rbs Individual anode to backfill resistance 0.38 ohms

1.6.8

Rtbs = Rbs/N

N Number of Anodes 8 Nos

CORROSION MATTERS


Rgb Total Ground bed Resistance 0.853 Ohms

Rs Resistance of vertical Anode to earth 0.806 Ohms

1.6.9 Rgb = Rs + Rtbs

Rtbs Total Anode to Backfill Resistance 0.047 Ohms

Rta Resistance of Anode Tail Cable 0.0552 Ohms

Li Length of Anode cable mtr

1.6.10

Rta = 1/(1/R1)+(1/R2)……..+1/R6

Ri = Li x R10

R1 & R5 = 8 x 0.001.73 = 0.015ohms

R2 & R6 = 15x0.001.73 = 0.028 ohms

R3 & R7 = 22x0.001.73 = 0.040 ohms

R4 & R8 = 29x0.001.73 = 0.053 ohms R25 Resistance of 10 mm2 cable 0.00115 Ohm/Mtr

Rac Resistance of Header cable 0.14 Ohms

R35 Resistance of 35 mm2 cable 0.00056 Ohm/mtr

Lac Length of Cathode cable 75 mtr

1.6.11

Rac = R35 ( Lac + L cc )

lcc Length of Anode cable 175 mtr

Rtc Total Reisistance offered by All cables 0.143 Ohms

Rac Resistance of Header cable 0.14 Ohms

1.6.12

Rtc = Rta + Rac

Rta Resistance of Anode tail cable 0.00342 Ohms

Rtotal Total Circuit Resistance 0.997 Ohms

Rgb Total Ground bed Resistance 0.853 Ohms

1.6.13

Rtotal = Rgb + Rtc

Rtc Total Reisistance offered by All cables 0.143 Ohms

CORROSION MATTERS


Vt Total Output Voltage 3.32 Volts

Rtotal Total Circuit Resistance 0.997 Ohms

It Total Current 1.33 Amps

1.6.14

Vt = (Rtotal x It)+ 2Volts

Back Voltage 2 Volts

Vx

Voltage rise in earth with respect to remote

earth 0.401 Volts

Soil Resistivity 36 Ohms

L Distance between P/L and Anode bed 100 Mtr

1.6.15

Vx = I /2 L

I Maximum current output 7 Amps

From above electrically remoteness calculations for Anode bed, it can observed that Voltage raise in earth with respect to remote earth at a distance 100 is

less than to pipeline Voltage to earth (ie 0.45V) & Remoteness of anode ground bed can be achieved

Ap Cross section area of Pipe 0.0123 Mtr

D Diameter of Pipe (m) 0.4534 Mtr

t Thickness of pipe 0.0087 Mtr

1.6.16

Ap = P x t x ( D-t )

P

Rs Linear Resistance of pipeline 0.01.70

ohm/K

m

s Resistivity of steel pipe

0.0000

0022 ohm-mtr

I unit length of pipe 1000 mtr

1.6.17

Rs = s x l / Ap

Ap Cross section area of Pipe 0.0123 mtr

CORROSION MATTERS


Rl Coating Leakage Resistance for 3LPE 10.45

ohm/K

m

Rp Coating Resistance 15000

ohm-

mtr2

1.6.1.7

Rl = Rp/Sa

Sa Surface area per Km

1435.7

1 mtr2

attenuation Constant 0.0415

Rs Linear Resistance of pipeline 0.01.70 ohm/Km

1.6.1.7

=( Rs/Rl )0.5

Rl Coating Leakage Resistance for 3LPE 10.45 ohm/Km

Edp Maximum potential shift at drain point -1.05 V

P/s

max Least negative PSP at drain point -1.5 V

1.6.20

Edp =P/s max - P/s nat

P/s

nat Natural PSP of pipeline -0.45 V

Ed Maximum potential shift at end point -0.5 V

P/s

min Least negative PSP at end point -0.95 V

1.6.21

Ed =P/s min - P/s nat

P/s

nat Natural PSP of pipeline -0.45 V

Lp Length of P/L protected from drain point 33.12 Km

Edp Maximum potential shift at drain point -1.05 V

Ed Maximum potential shift at end point -0.5 V

1.6.22

Lp=(1/) x Cosh-1(Edp/ Ed)

attenuation Constant 0.0415

CORROSION MATTERS


1.7 INSTALLATION PROCEDURES

1.7.1 TEST STATION / JUNCTION BOX INSTALLATION

Purpose :

Test stations/ Junction box shall be provided along the pipeline ROW for monitoring the

performance of the Cathodic Protection system

Materials Required :

Shuttering Plates, Reinforcement, Concrete Mix, CableLugs , Ferrules

Detailed Procedure:

• The location of the test stations/junction box shall be marked on row as per

approved design with their connection scheme and other related information on

alignment sheet.

• The test stations/junction box shall be installed with the front of the test station

facing the pipeline.

• The overall dimensions of foundations shall be 600 mm(W) x 700 mm (H) X 500

mm (D).

• Excavate 1m x 1 m x 1 m where the foundation is to cast.

• Place reinforcement properly and take TLP bend and place it properly in the

reinforcement.

• Take MS shuttering and place it in right position.

• Fill annular space with RCC Mix. The mixture shall be constantly rammed for

proper compaction.

• Remove the shuttering after 24 hrs.

• The foundation shall be cured properly or it shall be coated with curing

compound.

• Place the TLP boxes/Junction boxes on the studs of the bend cast in concrete

foundation and tighten the bolts.

• The bolts shall then be distorted by hitting with a heavy hammer to make the

installation vandal/theft proof

CORROSION MATTERS


Precautions:

• All the connections should be checked for proper tightening.

• Cable core ferrules are to be provided at end before final termination

• Door of the TLP/Junction box should face Pipeline

• Cable should be neatly dressed inside the trench and to be terminated inside test

station.

• In case of location, where sacrificial anode is to be installed, the same should be

taken parallel and the anode cable to be terminated at test station.

Documentation:

Inspection Reports shall be furnished as per the report formats attached below:

CORROSION MATTERS


INSPECTION AND TEST PLAN FOR TEST STATION / J.B INSTALLATION

PROJECT

OWNER

CONTRACTOR

CP CONTRACTOR

REFERENCE DOCUMENT

PERSONAL RESPONSIBLE

SR NO ACTIVITY CPC CONTRACTOR OWNER

1 APPROVAL OF TEST STATION INSTALLATION

PROCEDURE P W A

2 CHECK LOCATION P W RM

3 CONCRETE FOUNDATION SIZE, RCC MIXTURE,

REINFORCEMENT & CURING P W RM

4 INSTALLATION TEST POST MOUNTING ABOVE

FONDATION P

W RM

5 TERMINATION OF CABLES IN THE TEST STATION P W

RM

LEGEND

A - APPROVAL / ACCEPTANCE; R - REVIEW OF RECORD; RM - RANDOM CHECK

W - WITNESS ALL; P- PERFORM

CORROSION MATTERS


SITE INSPECTION REPORT FOR TEST STATION/

JUNCTION BOX INSTALLATION

PROJECT

OWNER

CONTRACTOR

CP CONTRACTOR

REF. DOC UMENT

Test station Location ( Chainage in Km)

Test Station Type

Distance from Pipeline

Foundation Acceptable /Not Acceptable

Test Station Mounting Acceptable /Not Acceptable

Cable Termination Acceptable /Not Acceptable

Final Restoration Acceptable /Not Acceptable

Notes :

CPC CONTRACTOR OWNER

Name

Signature

Date

CORROSION MATTERS


1.7.2 ANODEBED INSTALLATION

PROCEDURE FOR ANODE BED INSTALLATION

SCOPE

This procedure covers installation of Deep ground bed as per standard drawing & design document.

MATERIALS REQUIRED

Sr.No Material/Tool Make Application/Purpose

01 Crimping Tool Standard For crimping cable with lug

02 Excavation tools & Auggers Standard For Excavation

03 Measuring Tape Standard Measurement

04 Petroleum coke breeze Goa Carbons Backfill material

05 Canister Standard Sheet steed for Backfilling

06 Tubular anode Lida® / SME /

other

approved

Anodes for Anode bed

07 Anode Tail cable Netco/Suyog Connection to pipe

08 Cu Sleeves/ Cable Lug/D

clamps/Ferrules, PVC pipe & Warning

mat etc.

Standard

09 Electrical Tool Box Standard

10 Casing Pipe for Deep anode bed Standard Casing Pipe for Deep anode bed

11 PVC Shrouding Pipe Standard For Deep anode ground bed

13 PVC Vent Pipe Standard For Deep Well

PROCEDURE FOR DEEP WELL ANODE INSTALLATION

• Locate the Drilling Rig at approved deep well ground bed location.

• Start the drilling of borehole with suitable diameter drilling bit and drill a borehole of

suitable depth as per approved document.

• Lower the casing pipe (3mm) one length at a time and coupling various lengths with couplers

one after the other.

• After lowering MS casing pipe, a PVC shrouding pipe equal to the inactive length of the deep well

ground bed shall be lowered along the casing pipe from the top.

• Mark length equal to the required depth on the tail cables of anodes to avoid excessive lowering.

CORROSION MATTERS


• Tie all MMO anodes with vent pipe and cables to gather, and also install the centralizers for each

anodes and End weight to last anode as per design approval.

• Anodes shall be lowered with suitable nylon rope. Nylon rope shall be binded with end weight.

• Mix the coke breeze with water to form slurry.

• Fill the slurry coke breeze inside the bore well up to the active length and rest backfill with metal

gravel, this is to ensure proper filling of entire borehole.

• Backfilling to be done till overflowing from top of the pit, and than allow it to settle, fill the top of

pit as per approved drawing, with metal gravel after settling time of two-three days.

• Clamp / Tie the anode tail cable and lay up to anode junction box

• All the tail cables and Header cable shall be laid and terminated in anode junction box.

• Prepare Anode pit and cover as per approved drawing.

FOR HORIZONTAL BED INSTALLATION

• Length of the ground bed shall be according to the approved design package.

• Total depth of excavation in horizontal ground bed shall be as per design document.

• Cross section of bottom of the trench should be as per approved design document, as the same is

only considered for anode bed resistance calculation. The shape of excavated trench from top to

bottom need not be precise. Moreover, it shall depend on nature of soil at the site.

• Pour backRill into the trench and tamp it to a level corresponding to 0.150 m from bottom of

trench. Pour sufficient water on coke breeze and mix with wooden plank to prepare slurry.

• Mark the locations of individual canister anodes alongside the trench as spacing indicated in the

approved design package and place the individual anode horizontally within the trench on the

bed of the backfill prepared.

• Anode tail cables of individual anodes should be coiled and kept on ground adjoining the trench.

• Pour backfill into the trench and tamp it to a level corresponding to design requirement. (Take

care while tamping the coke breeze so that the anode connection or cable is not damaged). Again

pore sufficient water on top of the spread up coke breeze all over the anode so that slurry can be

achieved.

• Lay Tail cable & header cables and bring them up to proposed anode junction box location as per

standard drawing.

• PVC sleeve to be provided on all anode tail cables up to entry of anode junction box, for

mechanical protection.

CORROSION MATTERS


• At 1.0 m depth all anode tail cable and anode header cable to be laid as per cable laying

procedure.

• Earth restoration work with proper compaction to be carried out at cable laying and anode bed

location.

• Layout of anode installation in anode bed shall be as detailed out in the drawing showing anode

installation.

PRECAUTIONS

• Lower anode carefully to avoid damage to tail cable, Canister anodes should never be handled by

cables, but rope to be used for the same.

• After lowering clamp/Tie the cable to avoid further slide

• Tail cables and PVC conduits shall be of sufficient length so as to reach Anode Junction Box

without any joint and providing sufficient slack for future maintenance purpose.

• Each shallow anode bed shall contain anodes with canisters positioned in the soil with suitable

backfill at appropriate depth with due regards to type of configuration.

• Keep tail cable lengths sufficient so as to reach anode junction box without any joint and

providing sufficient slack for future maintenance purpose

• All cables are to be appropriately tagged before lowering cables in to trench/well.

• Provide cable core ferrules at end before final termination.

HEALTH, SAFETY & ENVIRONMENT

Hazard Identification and risk assessment will be carried out and Operational Control measures shall be

adopted for Anode Installation Activities.

i. Necessary PPE to be utilized

ii. Only trained personnel to be deployed for this activity.

QUALITY ASSURANCE & QUALITY CONTROL

Quality Assurance shall be maintained by ensuring the systematic implementation of this Procedure and

ensure that necessary quality records are generated as per ITP.

CORROSION MATTERS


INSPECTION AND TEST PLAN FOR DEEPWELL /

SHALLOW HORIZONTAL ANODEBED INSTALLATION

PROJECT

OWNER

CONTRACTOR

CP CONTRACTOR

CPC : SITE ENGINEER / SUPERVISOR PERSONAL RESPONSIBLE

CONTRACTOR/ OWNER : INSPECTOR

SR NO ACTIVITY CPC

CONTRACTO

R

OWNER

1 APPROVAL OF DEEP GROUND BED PROCEDURE P R A

2 CHECK LOCATION P W A

3 CHECK DEPTH P W R

4 CHECK CASING PIPE LOWERING P W R

5 CHECK ANODE LOWERING P W RM

6 FILLING OF COKE BREEZE P W R

LEGEND

A - APPROVAL / ACCEPTANCE; R - REVIEW OF RECORD; RM - RANDOM CHECK

W - WITNESS ALL; P- PERFORM

CORROSION MATTERS


SITE INSPECTION REPORT FOR DEEPWELL ANODE INSTALLATION

PROJECT

OWNER

CONTRACTOR

CP CONTRACTOR

REFERENCE DOC.

LOCATION

DISTANCE OF ANODE BED FROM PIPELINE

DIA OF CASING PIPE

LENGTH & DIAMETER OF BORE HOLE

NO OF ANODES IN THE STRING

ANODE RATING

ANODE LOWERING OK / NOT OK

COKE BREEZE FILLING OK / NOT OK

Notes:


Name

Signature

Date

CORROSION MATTERS


1.7.3 PIPE TO CABLE CONNECTION

Pipe To Cable Connection By Thermit Welding

Scope

This procedure covers Thermit Weld for cable connection to pipeline for all type of cables related to

Cathodic Protection System.

Cable to Pipe connection during construction shall be done by Thermit welding method.

Materials Required

Sr.No Material/Tool Make Application/Purpose

01 Crimping Tool Standard For crimping cable with

lug/ferrule

02 Thermit Mould & Sparking Gun Erico, USA Thermit welding & Igniting

03 Cad Weld Powder, CA15 & CA32 Erico, USA Welding

03 Cables Netco Connection to pipe

04 Hammer & Chisel Standard Hammering test for Thermit

& Coating cutting

05 Epoxy Dobefil-60 Doctor Beck

06 Hardner-758 Doctor Beck

For sealing of Cable to pipe

joints

07 PVC Funnel Local Coating Repair Filing.

08 M seal / Mastic Mahindra / CPC Sealing for PVC funnel

09 Cu Sleeves Standard For Cable Connections

10 Fine File Local Surface Cleaning

11 Sand Paper Local Surface cleaning

12 Holiday Detector Caltech For coating check

Procedure

• Excavate (wherever pipeline backfilled with soil) a pit over the pipeline to expose the pipeline

top surface at location of Thermit weld where cable to pipe connection is to be carry out as per

design document. Care should be taken not to damage the coating of buried pipeline. Only

manual excavation shall be carried out over pipeline.

• Mark where connection is to be carried out. If there are more than one connection as per design

document, consecutive marking shall be minimum 300 mm apart. Connection location shall be

minimum 300mm apart from other connection and Welding joint, Seam or Circumferential Weld

CORROSION MATTERS


Joint of the pipeline. The location for cable to pipe connection shall be selected such that the pipe

joints and field-coated areas are avoided.

• Cut open the coating on the pipeline with care and without damaging the pipe for a size of

approximately 50 mm x 50 mm (suitable for thermit weld mould).

• Clean the surface of the pipeline to white metal finish using sand paper and cleaning with fine file

as required.

• Depending on the size of cable select the model of cad weld material i.e. CA-15 or CA-32 and

mould.

• Copper sleeve of suitable size shall be double Crimped on the cable (up to 10 sqmm cable).

• Place the mould on the exposed area and pour the cad weld material. Ignite using the gun and

wait for 2 minutes cool down period.The resistance of Cable to pipe at thermite connection point

shall not exceed 0.1Ω

• Test the connection by striking 0.5 Kg hammer directly over the connection. And if connection

fails, the above procedure shall be repeated after waiting time of approx.10min.to cool the

pipeline surface.

• Place a plastic funnel around the exposed area such that about 15mm wide coating remains in

side the plastic funnel. Apply mastic/Mseal around the plastic funnel to prevent leakage of

encapsulation materials.

• Mix proper quantity of epoxy-hardner and keep mixing with wooden rod till it gets heated, Fill up

the conical funnel from the top by pouring mix of Epoxy – Dobofil – 60 and hardener – 758 at

1:10 ratio. 3/4th of the cone to be Rilled with mix and remaining plastic cone to cut after setting of

the hardener.

• Allow the epoxy-hardener to set ensuring every metallic part of joint is completely insulated and

test the insulation level by a holiday detector at 25 KV.

• Cable shall be laid in accordance with approval cable laying drawings. Cable route shall be

carefully measured and cable cut to be required length from test station to pipe. A loop of approx

0.5mtr.of cable shall be kept at both pipe and Test Station end.

Precautions

a. Only Manual excavation to be done without damaging the coating.

b. All cables are to be appropriately tagged.

c. Location of cable to pipe connection shall be minimum 300mm apart from other connection

and from Pipe weld joint, Seam or Circumferential Weld Joint

CORROSION MATTERS


d. Check hardness of encapsulation before holiday test by applying pressure with

thumb/Wooden Stick.

e. Coating repair and holiday test should be completed before backfilling.

f. Maximum 15 grams Ignition powder shall be used for each connection. If one connection

fails, wait of approx 10 min for pipeline cooling and then repeat the procedure for

connection.

Health,Safety & Environment

Hazard Identification and risk assessment will be carried out and Operational Control measures shall be

adopted for Anode Installation Activities.

• Necessary PPE to be utilized

• Only trained personnel to be deployed for this activity.

CORROSION MATTERS


SITE INSPECTION REPORT FOR THERMIT WELD CONNECTION

PROJECT

OWNER

CONTRACTOR

CP CONTRACTOR

REFERENCE DOC.

Test Station Type Chainage

Type of Cable to Pipe Connection Thermit welding

Cable Size Length No. of Pipe to Cable Connection

1C x 6 SQMM Cable

1C x 10 SQMM Cable

1C x 25 SQMM Cable

Resistance of cable to pipe at thermit connection point

Hammer Test

Acceptable / Not Accebtable

Holiday Test OK / NOT OK

Pipe to soil potential (Natural) w.r.t. Zinc Reference Half cell

1C x 6 SQMM Cable

1C x 10 SQMM Cable

1C x 25 SQMM Cable

Sealing of exposed area of pipe with Epoxy Sealing material


Signature

Name

Date

CORROSION MATTERS


1.8 PROCEDURE FOR COMMISSIONING OF PCP SYSTEM

Purpose

To describe the procedure for commissioning of Permanent cathodic protection system and provide

adequate quality assurance / control of workmanship and inspection at site.

Scope

This procedure will cover commissioning of the Impressed Current C.P system installed to protect under

ground pipeline from external corrosion.

Equipments

- Soil resistivity meter

- Digital multimeters

- Portable reference electrodes

- Megger

Commissioning Procedure

• On completion of installation of anode beds and other systems as envisaged in the specification,

they shall be individually checked, tested and compared against the agreed specifications and

procedure.

• The CP commissioning shall be carried out with current interrupter provided in the output of the

CPPSM unit to measure CP “ON” & “OFF” potentials.

• Current dissipated by each anode shall be corrected through anode lead junction box.

• Electrical continuity of the entire pipeline shall be verified in conformity with design.

• Input resistance of the pipeline at all the drainage points shall be checked and recorded.

• All current measuring test stations shall be calibrated and recorded.

• Temporary protection facilities provided (if any) which do not form part of permanent CP shall

be disconnected from the sytem & removed unless agreed otherwise.

• The pipeline shall be allowed to depolarize for atleast 72 hours after switching ‘off’ the protection

(if any) of all other pipelines in the common R.O.W.

• Before the pipeline is put on charge by switching ‘on’ CP station, natural structure –to-electrolyte

potential values at all the test stations of the system shall be measured with respect to zinc

reference cell.

CORROSION MATTERS


• CP station shall be energized so as to achieve a maximum pipe soil potential (PSP) as specified at

the test station nearest to the drainage point, and observations on either spread of protected

portion of pipeline under this CP station shall be taken for PSP values pipeline current values

across the cross section of the pipeline shall also be determined at all the intended test stations

influenced by this CP station.

• Another complete set of PSP observations shall be taken after lines have stayed on charge for

24/48 hours. If there are appreciable differences in these observations as compared to those of

earlier set, a third set of observations shall be taken after 72 hrs. Maximum drainage point

protective potentials shall not be allowed to go beyond the maximum PSP values as specified, in

any case.

• The output of CP Station shall then be so adjusted that the sites of occurrence of least negative

protective potentials are increased to (-) 1.00 V. A full set of observations shall again be taken 72

hrs. after the adjustment of potentials and the protection system shall be left in this state of

operation.

• Care shall be exercised to ensure that power supply remains uninterrupted during the period of

commissioning. In case of an interruption, the test in progress shall be repeated after allowing

time for polarization. More sets of observations may be advised to be taken by the

owner/owner’s representative in any of the above-mentioned steps.

• PSP values at each of the test stations of the existing pipelines shall be measured and plotted

where existing pipelines run in parallel to the new pipeline and mutual interference situations

between the pipelines shall be identified and necessary mitigation shall be carried out.

• Interference situations shall also be identified and mitigated by comparing different sets of

readings taken at same test stations at different intervals of time under identical conditions

where positive potential swing exceed 50 MV.

• Final records of testing and commissioning including graphical representation of final structure

to electrolyte potential readings shall be complied with interpretation in consolation with

owner/owner’s representative and submitted.

• If it is found during commissioning that the sites of occurrence of least negative or most negative

protective potentials are less negative than (-) 1.00V even after 72 hrs of operation, then the

drainage point potentials shall be adjusted depending upon anode ground bed currents in

consultation with Owner/Owner’s representative. In any case, the drainage point protective ‘ON’

potential values shall not exceed the PSP values as per specification and the pipe to soil ‘OFF’

potential shall not exceed a value more negative than (-) 1.20 V at any location on the pipeline.

• The current dissipated by the indiviual anodes shall be measured from the anode lead junction

box and corrected for equal dissipation to the extent possible keeping the total ground bed

current same.

CORROSION MATTERS


INSPECTION AND TEST PLAN FOR PCP COMMISSIONING

PROJECT

OWNER

CONTRACTOR

CP CONTRACTOR

REFERENCE DOC


CONTRACTOR / OWNER : INSPECTOR

SR NO ACTIVITY CPC CONTRACTOR OWNER

1 Pre commissioning Tests At Anode Bed And TR Unit S W A

2 Disconnection Of Sacrificial Anode On Entire Spread And

Allow For Depolarization

P W RM

3 After 72 Hrs. Of Depolarization Collect Natural Potentials At

All Test Stations

P W RM

4 Energize The Cp Unit And Record The Reading To Find

Attenuation

P W RM

5 Submission Of Records P W A

LEGEND

A - APPROVAL / ACCEPTANCE W - WITNESS ALL

R - REVIEW OF RECORD P- Performed by

RM - RANDOM CHECK S – Submitted by

CORROSION MATTERS


PRE-COMMISIONING CHECKS REPORT

PROJECT

OWNER

CONTRACTOR

CP CONTRACTOR

REFERENCE DOC.

LOCATION

DATE

SR NO ACTIVITY OBSERVATION

1 Anode Bed Installation Termination Etc. OK/NOT OK

2

CP unit Installation & Earthing , cable

termination and tagging etc & No Load

operational checks.

OK/NOT OK

3 CP system cable termination & taging OK/NOT OK

4 CP unit working condition (No load) OK/NOT OK

5 Surge Diverter Installation OK/NOT OK

6 Reference cell Calibration (mv) RE-1

RE-2

REMARKS


Name:

Sign:

Date:

CORROSION MATTERS


INSPECTION REPORT FOR PCP COMMISSIONING (ANODE BED)

PROJECT

OWNER

CONTRACTOR

CP CONTRACTOR

REFERENCE DOC.

Date

CP Station No Location

GROUND BED DETAILS

1.0 Groundbed Configuration & Type

2.0 Groundbed Rating Anode Quantity

3.0 Voltage between Pipe and Anode (Back EMF):

4.0 TR Unit Output Voltage Current

5.0 Total Anode bed Resistance (3 Pin) Ohms

6.0 Total Anode To Cathode Circuit Resistance (DC O/P Volts/Current) Ohms

7.0 Individual Anode current at Anode Junction Box

Anode No Potential Across the

shunt (mV)

Current (amps) Anode No

Potential Across the shunt

(mV)

Current (amps)

A1 A6

A2 A7

A3 A8

A4 A9

A5 A10

REMARKS Total Current:


Name:

Sign:

Date:

CORROSION MATTERS


INSPECTION REPORT FOR PCP COMMISSIONING (CP Unit)

PROJECT

OWNER

CONTRACTOR

CP CONTRACTOR

REFERENCE DOC.

Report.No. Date:

CP Station No: Chainage & Location :

TR Unit Parameters

Hour Meter Reading :

Input Voltage (Volts) DC Input Current (Amp) DC

DC output Voltage (Volts) DC output Current (Amps)

Anode bed Loop Resistance Calculated V/I from above _______________________Ohm

Mode Auto/AVCC/Manual

Coarse Control Switch Fine Control Switch

Pipe to Soil Potential W.r.to Permanent Reference cell (Cu-CuSO4)

Reference 1 (-V) Reference 2 (-V) Reference 3 (-V)

Set PSP in TR unit (-V)

PSP at nearest TS (Drainage) -V

REMARKS


Name:

Sign:

Date:

CORROSION MATTERS


INSPECTION REPORT FOR PCPCOMMISSIONING (PSP Natural PSP)

(Format 1 of 3)

PROJECT VCM PIPELINE PROJECT

OWNER CHEMPLAST SANMAR LIMITED

CONTRACTOR CONTRACTOR INFRASTRUCTURE LIMITED

CP ONTRACTOR CPCRPG LIMITED

REFERENCE DOC. CPC-CONTRACTOR-VCM-DD-001

Report.No. Date:

Readings From _______ km to _______km

Test station PSP (-V) Remarks

No Type Chainage

(Km) Natural PSP AC PSP

Casing

PSP

REMARKS :- PSP after 48 hrs of disconnection of sacriRicial anode connections to pipeline.


Name:

Sign:

Date:

CORROSION MATTERS


NSPECTION REPORT

FOR PCPCOMMISSIONING (PSP reading First Set ) Format 2 of 3

PROJECT

OWNER

CONTRACTOR

CP ONTRACTOR

REFERENCE DOC.

Report.No. Date:

CP Unit On : Chainage & Location __________________________

Readings From _______ km to _______km

Test station PSP (-V) Remarks

No Type Chainage

(Km) `ON` PSP AC PSP

Casing

PSP

REMARKS : Setting of TR unit to be recorded in TR format with note for commissioning first set of readings

purpose.


Name:

Sign:

Date:

CORROSION MATTERS


INSPECTION REPORT

FOR PCPCOMMISSIONING (PSP reading ) Format 3 of 3

PROJECT

OWNER

CONTRACTOR

CP ONTRACTOR

REFERENCE DOC.

Report.No. CP section (IJ to IJ) From _________ to __________km Date:

Test station PSP Initial (-V) PSP 48 Hrs (-V) PSP After 72 Hrs (-V). Remarks

No Type Chainage Km ON PSP ON PSP ON PSP AC PSP CASING

REMARKS


Name:

Sign:

Date:

CORROSION MATTERS


1.9 POST COMMISSIONING SURVEY

CIPL SURVEY

Purpose

To define the procedure for the conduction of CIPL Survey on the commissioned Pipeline to evaluate the

CP system and to provide adequate quality assurance / control.

Equipment / Accessories Required

• Pipeline locators (if required)

• Data collector-Sincoder along with the reference cell Sticks.

• Current interrupts with synchronized timer circuits and adjustable time settings

• Rodometer

• Flexible cable/wire of required length.

Procedure

• Before commencing the survey, confirm that the cathodic protection system is operating

normally by checking the DC feeders, drain points, insulating joints with commissioning

results.

• Check the cathodic protection commissioning result to identify the area requiring special

attention during the CIPL survey.

• Locate the route of the pipeline using the pipeline locator and provide temporary markers

(Marking powder) on the route to enable the survey to walk-on the route of the pipeline for

carrying out the CIPL survey.

• Install current interrupter with synchronized timer in the DC negative output of the DC

power source (CP System) at the CP station of the section in which the survey is being

carried out.

• Set the interrupter switching cycle at a ratio of 4:1 ON:OFF.

• With the equipment connected and the pipeline located, move along the pipeline carrying the

mobile data collector and Zinc reference cell and measure and store the pipe to soil

potentials.

• Check reference electrodes regularly for its operation.

• Record distance traversed and physical features such as roads, as descriptors to assist

locating specific areas after processing the data.

CORROSION MATTERS


• As each section between TLP connections is completed, real the fine wire for further use and

shift continuous chart records to the next section.

• Transfer the data from the simcorder to a computer for producing the data print outs and

plot of the PSP potential profiles.

• The data collected during the survey shall include

i. Monitoring results of the sectional T/R Units

ii. Data (PSP Values) – ON and Instant OFF

Distance location details as a descriptors.

• After completing the survey based on the above procedure, the readings in numeric and

graphical manner shall be submitted after detailed interpretation.

CORROSION MATTERS


SITE INSPECTION PLAN FOR CIPL SURVEY

PROJECT

OWNER

CONTRACTOR

CP

ONTRACTOR

REFERENCE DOCUMENT


CONTRACTOR/OWNER: INSPECTOR

S.NO ACTIVITY Performed By

CPC

Verification

By

CONTRACTOR

Verification By

OWNER

Records

submission

by CPC

1 Submission & Obtaining approval of

Procedure

P R A

2 TR Interrupter Setting P

R RM

3 Conduction of Survey P W RM

5 Entering of Readings P R RM

5 Entering of Location Description P R RM

6 Final Report

P R R

LEGEND

A - APPROVAL / ACCEPTANCE

R - REVIEW

RM - RANDOM CHECK

W - WITNESS

CORROSION MATTERS


**********************

Inspection Report for CIPL Survey

PROJECT

OWNER

CONTRACTOR

CP ONTRACTOR

REF. DOC : CPC-CONTRACTOR-VCM-DD-001 DATE

Interrupter Setting OK / NOT OK

Staring Location , Chainage

Ending Location , Chainage

TRU Section

Conduction of Survey OK / NOT OK

Entering of Datas / Locations OK / NOT OK

Remarks


Signature

Name

Date

CP_MANUAL

Documents

cathodic protection

s cathodic protection

cathodic protection

corrosion matters page

corrosion matters design

cpcathodic protection

prevention of corrosion

corrosion prevention