(COA001)UI-GS-OPLCP (Onshore Pipeline Impressed Current CP

1.0 SCOPE

This specification shall govern the design, materials procurement, installation and inspection requirements of Cathodic protection system for the steel pipe used as onshore pipelines. The Work includes the furnishing all labor, materials, tools and equipment and the performance of all operations, and incidentals necessary for the design and installation of the system. As used in this specification, the following definitions shall apply : COMPANY - UNOCAL INDONESIA COMPANY CONTRACTOR - Cathodic Protection System Designer/Installer CONTRACTOR shall obtain COMPANY written approval for any deviations from the requirements of this specification, applicable standards and referenced drawings. This document is not intended to be all inclusive, and the use of the guidelines set forth does not relieve the CONTRACTOR of his responsibility to complete the WORK.

2.0 CODES AND STANDARD The latest issue of the following Codes and Standards referenced shall be applicable :

2.1 National Association of Corrosion Engineers (NACE).

RP 0169-83 Control of External Corrosion on Underground or Submerged Metallic Piping Systems

RP 0572-85 Design, Installation, Operation And Maintenance Of Impressed

Current Deep Ground beds.

2.2 National Electrical Code (NEC)

3.0 DESIGN OF CATHODIC PROTECTION SYSTEM

3.1 Introduction The Cathodic Protection System shall be impressed current system with deep ground

bed anode. The CONTRACTOR shall carry out a corrosion site survey and design a Cathodic protection system to protect the onshore pipeline.

3.2 Design Criteria

(a) The proposed of the Cathodic protection system is to protect the steel pipe from external corrosion due to electrolyte and oxygen present surrounding the pipe for a period of not less than 30 years.

UI-GS-OPLCP 1 of 5 Rev. B September 2002

(b) The Cathodic protection system for this steel pipe shall be an impressed current type with a deep ground bed anode which should be compatible with existing C.P systems and with existing buried structures along the pipe route.

(c) The impressed current shall capable to supply current and DC Voltage

required by the pipe to maintain the potential of the pipe to the soil more negative than - 850 mV versus copper/copper sulphate (Cu/Cu SO4) reference cell.

(d) Facilities shall be included to monitor the effective operation of the system.

3.3 Impressed Current Cathodic Protection System (a) Pipeline to be protected :

Total length : Refer to the drawing attached in the bid document/contract

Material : API5L-X52 Coating : Hot applied coal tar enamel or equal. Burial : 4 feet depth min.

(b) Impressed Current Anodes : Type : Tubular Titanium Anode with mixed metal oxide

coating , pre packaged with petroleum grade coke breeze in steel canister or pre packaged graphite anode with coke breeze

Design Life : Each Anode shall have a minimum DC rating of 5 Amperes over 30 year design life.

Bed Design : Deep well , Steel Casing with Depth 60 to 100 mtrs underground (See Attachment 1)

Extension Wire : 8 AWG ( or 10 sqmm ) , 1 core stranded , tinned , copper conductor with HMWPE (High Molecular Weight PE) insulation or N2XY_CV_XLPE/PVC or equal.

Location : Within Company area (c) Anode ( + ) Junction Box : Enclosure : Cast Aluminum enclosure , with IP 55 minimum rating. Common DC Bus : Shall be designed to carry 100 Amperes of DC current continuous , material Copper with Insulation post that may withstand 2 KV DC test for 2 minutes. The Terminal lug shall be minimum No: 50 sqmm Branch Circuits : shall be designed to accommodate 10 circuits maximum , complete with 50mV/50A DC Shunt for each circuit and No: 8AWG ( or 10 sqmm ) terminal Lugs or equal.


(d) Cathode ( Negative ) Junction Box : Enclosure : Cast Aluminum enclosure , with IP 55 minimum rating.

Common DC Bus : Shall be designed to carry 100 Amperes of DC current continuous , material Copper with Insulation post that may withstand 2 KV DC test for 2 minutes. The Terminal lug shall be minimum No: 50 sqmm Branch Circuits : shall be designed to accommodate maximum 5 circuits complete with 50mV/50A DC Shunt for each circuit and No: 1/0AWG ( or 50 sqmm ) terminal

Lugs or equal. (e) DC Cable :

minimum 50 sqmm armored , single core , copper conductor with N2Xb(Al)Y 1/C or equal insulation shall be used to connect the output of the Transformer Rectifier to the Ground Bed system , to the Negative Junction Box and to the pipeline being protected.

(f) AC Cable :

size of AC cable shall be calculated , based on the maximum rated capacity of the Transformer Rectifier and also the maximum allowable Voltage Drop ( 5 % ) between the AC Source to the Transformer Rectifier unit , however it shall not be less than 10 sqmm copper cable.

Type of Construction shall be Direct Burial , Armored NYFGbY or equal .

(g) Transformer Rectifier Type : Outdoor Type , oil filled with Shell Diala B

transformer Oil , Caltex BSI or equal. Input voltage : 240 VAC/50 Hz , single phase or otherwise stated in

the detailed Engineering Drawing. Output voltage : DC , adjustable voltage (coarse and fine) Current interuptor : Adjustable time set-up Metering : Analog Ampere meter and Analog DC Voltmeter

Lightning Protection : Both the DC side and the AC side of the Transformer Rectifier shall be equipped with Surge / Lighting Protection Overvoltage with minimum capacity as follows : - DC side : 100 KA - AC side : 25 KA.

(h) Current Span Test Station :


Type : Four (4) wires per pipeline (see Attachment 2) Minimum span : 200 feet Requirement : Two (at both side of rectifier connection) Wire size : 12 AWG ( or 4 sqmm minimal , single conductor,

copper conductor , color coded insulation with HMWPE , N2XY_CV_XLPE/PVC or equal insulation.

(i) Test Point Station : Type : One (1) Wire minimal per Station (see Attachment 3) Distance : Every 1 Kilometer Wire size : 6 AWG ( or 25 sqmm ) , single conductor copper

conductor with N2XY_CV_XLPE/PVC or equal insulation.

4.0 INSTALLATION OF THE IMPRESSED CURRENT CATHODIC PROTECTION SYSTEM

4.1 Installation Impressed Current Cathodic Protection System shall be installed so as to minimize

adverse affects on existing metallic structures. Anodes shall be installed at the location within COMPANY’s area.

Procedures for installation of all cathodic protection equipment shall follow the

requirements of the relevant electrical code and/or NACE. The installation shall be in accordance with the detail shown on the Attachment 1 , 2 , 3 , 4 and 5 .

4.2 Inspection and Approval During installation of the system, all aspects of the installation process shall be made

available for inspection by COMPANY or its Representative. Any equipment assembly not meeting the requirements of a this specification or referenced documents may be rejected. Rejected assemblies are to be dismantled and reassembled in compliance with the requirements of this specification at CONTRACTOR expense.


5.0 INSTALLATION OF THE ELECTRICAL CONNECTIONS AND MONITORING POINTS

5.1 Test Point Station : One (1) electrical lead wire minimum shall be used for testing , and shall be installed

at every 1 km of pipeline. The size of the lead shall be at least 6 AWG or 25 sqmm ( single standed copper wire with HMWPE , N2XY_CV_XLPE/PVC insulation or equal The installation is to be typically as is shown at Attachment 3.

5.2 Current Span Test Station : Four (4) electrical lead wires used for corrosion control or current span measurement

shall be installed at each section of the pipeline at the location within COMPANY’s Right of Way ( ROW ) area. The size of lead wire shall be at least 12 AWG or 4 sqmm single stranded copper wire with HMWPE , N2XY_CV_XLPE/PVC or equal insulation. The installation is to be typically as is shown at Attachment 2.

5.3 Electrical Lead Installation at Pipeline : Prior to installation of the wire, a small area of the pipe corrosion coating shall be

removed to bare metal of the pipe joint. The wire which will be connected to the pipe shall be sleeved by correct size copper sleeve prior to thermit welding. The wire shall be one length from the pipe connection to the test box and shall not be spliced in anyway to meet the length required. Electrical leads shall be attached directly on the pipe by the thermit welding process, using copper oxide and aluminium powder. The size of the thermit welding charge shall not exceed a 15 g cartridge.

The Connection to the Pipeline shall use an approved CADWELD product for CP services ( such as CA-15 charge and CAHAA-H moulding for connecting 6 AWG ( or 25 sqmm ) copper cable to 10 " above pipeline.

Special attention shall be given to the manner of installation of these electrical leads

to avoid harmful stress concentration at the point of attachment to the pipe. The connection shall be secure and no loose connection in any way.

All joints which are to be buried underground shall be sealed using a 3M , Roystone Cap Brand or equal epoxy encapsulation kit.

5.4 Corrosion Coat Repair After the leads have been installed, the weld area shall be thoroughly cleaned with a

wire brush. All steel surfaces, including the pipe, bonding plates, etc., exposed for welding purposes shall be repaired in accordance with General Specification for Pipeline Corrosion Coating. Damage to the pipe corrosion coat for any reason shall be repaired in accordance with COMPANY General Specification for Pipeline Corrosion Coating.


5.5 Inspection and Approval

During installation of the current span and test point leads, all aspects of the

installation process shall be made available for inspection by COMPANY or its Representative. Any lead assembly not meeting the requirements of this specification or referenced documents may be rejected. Rejected assemblies are to be dismantled and reassembled in compliance with the requirements of this specification at CONTRACTOR expense.

6.0 INSPECTION OF THE CATHODIC PROTECTION SYSTEM

Upon completion of the pipelaying, the cathodic protection system shall be inspected and a CP survey shall be performed to assure the system provides good protection. The CP survey shall be performed by CONTRACTOR and witnessed by COMPANY’s Representative. The log of the survey shall be approved by COMPANY prior to commissioning. The Type of the inspection shall consist of the minimum works as following :

1. Pipe Soil Potential Measurement 2. ON and Instant OFF Computerized Close Interval Potential Survey 3. DCVG ( direct current voltage gradient ) Survey

7.0 ATTACHMENTS

1 Deep Well Anode Groundbed Installation Detail 2 Above Ground Current Span Installation Detail 3 Above Ground Test Point Installation Detail 4. Tansformer Rectifier Installation Detail 5. Cabling and Thermit Weld Installation Detail


UI-GS-OPLCP 2 of 5 Rev. B

September 2002


September 2002

(COA001)UI-GS-OPLCP (Onshore Pipeline Impressed Current CP

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Transcript of (COA001)UI-GS-OPLCP (Onshore Pipeline Impressed Current CP