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نویسندگان
IPS-M-TP-750
This Standard is the property of Iranian Ministry of Petroleum. All rights are reserved to the owner.
Neither whole nor any part of this document may be disclosed to any third party, reproduced, stored in
any retrieval system or transmitted in any form or by any means without the prior written consent of
the Iranian Ministry of Petroleum.
MATERIAL AND EQUIPMENT STANDARD
FOR
CATHODIC PROTECTION
ORIGINAL EDITION
DEC. 1997
This standard specification is reviewed and updated by the relevant technical committee on March 2006. The approved modifications are included in the present issue of IPS.
Dec. 1997 IPS-M-TP-750
1
0. INTRODUCTION
This Standard consists of fourteen parts, as listed hereunder:
Part 1 : Impressed Current Anodes
Part 2 : Carbonaceous Backfill for Impressed Current Anodes
Part 3 : Galvanic Anodes for Underground Applications (Magnesium and Zinc)
Part 4 : Galvanic Anodes for Submerged Applications (Magnesium and Zinc)
Part 5 : Bracelet Type Galvanic Anodes for Submarine Pipelines (Aluminum and Zinc)
Part 6 : Cast Galvanic Anodes for Fixed Offshore Installations (Aluminum)
Part 7 : Cathodic Protection Cables
Part 8 : Insulating Joint
Part 9 : Flange Insulation Kit
Part 10: Polypropylene Rope
Part 11: Splicing Kit
Part 12: Split Bolt Connector (Line Tap)
Part 13: Splice Coating Materials
Part 14: Thermit Weld (CAD Weld) Powder
Dec. 1997 IPS-M-TP-750/1
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PART 1
IMPRESSED CURRENT ANODES
Dec. 1997 IPS-M-TP-750/1
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CONTENTS : PAGE No.
1. SCOPE...........................................................................................................................................4
2. REFERENCES...............................................................................................................................4
3. UNITS.............................................................................................................................................5
4. TECHNICAL DOCUMENTS...........................................................................................................5
5. MATERIALS AND MANUFACTURE..............................................................................................6
6. ANODE CASTING.........................................................................................................................6
7. LEAD WIRE-TO-ANODE CONNECTION.......................................................................................7
8. ANODE LEAD WIRE......................................................................................................................8
9. PROPERTIES................................................................................................................................9
10. DIMENSIONS AND WEIGHTS...................................................................................................10
11. SAMPLING.................................................................................................................................12
12. REJECTION...............................................................................................................................12
13. INSPECTION..............................................................................................................................12
14. CERTIFICATION........................................................................................................................12
15. PACKAGING AND SHIPMENT..................................................................................................13
16. LABELING.................................................................................................................................13
APPENDICES:
APPENDIX A DATA SHEET FOR HIGH-SILICON-IRON ANODES...............................................15
APPENDIX B DATA SHEET FOR GRAPHITE ANODES................................................................16
APPENDIX C DATA SHEET FOR MAGNETITE ANODES.............................................................17
Dec. 1997 IPS-M-TP-750/1
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1. SCOPE
This Part of IPS-M-TP-750 covers the minimum requirements for anodes (High-Silicon-Iron, Graphite, Magnetite) for use in impressed current cathodic protection systems. It specifies the composition, materials, manufacture, properties, inspection and testing for High-Silicon-Iron, Graphite and Magnetite anodes. The specification covers only general requirements for the anodes, the specific requirements will be given in pertinent ordering documents by the Purchaser (see Appendices A, B and C).
Note:
This standard specification is reviewed and updated by the relevant technical committee on March 2006. The approved modifications by T.C. were sent to IPS users as amendment No. 1 by circular No. 310 on March 2006. These modifications are included in the present issue of IPS.
2. REFERENCES
Throughout this Standard the following dated and undated standards/codes are referred to. These referenced documents shall, to the extent specified herein, form a part of this standard. For dated references, the edition cited applies. The applicability of changes in dated references that occur after the cited date shall be mutually agreed upon by the Company and the Vendor. For undated references, the latest edition of the referenced documents (including any supplements and amendments) applies.
ASTM (AMERICAN SOCIETY FOR TESTING AND MATERIALS)
A 256 Standard Method of
"Compression Testing of Cast Iron"
A 327 Standard Method of
"Impact Testing of Cast Iron"
A 518M Standard Specification for
"Corrosion-Resistant High-Silicon Iron Casting"
B 8 Standard Specification for
"Concentric-Lay-Stranded Copper Conductors, Hard, Medium-Hard, or Soft"
B 193 Standard Test Method for
"Resistivity of Electrical Conductor Materials"
B 539 Standard Test Method for
"Measuring Contact Resistance of Electrical Connections (Static Contact)"
D 1047 Standard Specification for
"Poly (Vinyl Chloride) Jacket for Wire and Cable"
D 1248 Standard Specification for
"Polyethylene Plastics Molding and Extrusion Materials"
D 2308 Standard Specification for
"Polyethylene Jacket for Electrical Insulated Wire and Cable"
D 2655 Standard Specification for
"Crosslinked Polyethylene Insulation for Wire and Cable Rated 0 to
Dec. 1997 IPS-M-TP-750/1
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2000 V"
D 3032 Standard Test Methods for
"Hookup Wire Insulation"
E 10 Standard Test Method for
"Brinell Hardness of Metallic Materials"
E 94 Standard Guide for
"Radiographic Testing"
E 802 Standard Reference Radiographs for
"Gray Iron Casting up to 114 mm (4½ in.) in Thickness"
IEC (INTERNATIONAL ELECTROTECHNICAL COMMISSION)
228 "Conductors of Insulated Cables"
ISO (INTERNATIONAL ORGANIZATION FOR STANDARDIZATION)
2859 "Sampling Procedures for Inspection by Attributes"
Part 1: Sampling Plans Indexed by Acceptable Quality Level (AQL) for Lot-by-Lot Inspection
3. UNITS
This Standard is based on International System of Units (SI), except where otherwise specified.
4. TECHNICAL DOCUMENTS
The technical bid shall include the following with reference to data sheet (see Appendices).
4.1 Catalogue (including technical data of the offered anodes).
4.2 Production procedures that cover all stages of the manufacturing process, from receipt of raw materials to finishing and packing for shipment, including:
- chemical analysis;
- measurements of weight, dimensions, etc.;
- inspection and testing procedures and frequencies;
- anode manufacture;
- anode connections.
4.3 Anodes consumption rates at maximum applicable current density in different environments (e.g., sea water, fresh water, soil, etc.).
4.4 Full information about anode lead wire indicating product identification number, construction details, voltage rating of primary insulation, physical properties of the primary insulation and jacket material including tensile strength and ultimate elongation of finished wire, insulation resistance of primary insulation, notch propagation of the finished wire, abrasion resistance of the finished wire, concentricity tolerance of the finished wire, and continuous service temperature limits of the finished product.
4.5 Preservation, packing and shipping procedures, such that anodes are not damaged or deformed and do not deteriorate during handling, delivery to the fabrication yard, storage: including methods, materials and any requirement for periodic inspections.
Dec. 1997 IPS-M-TP-750/1
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5. MATERIALS AND MANUFACTURE
5.1 Manufacturing of anodes shall be carried out using approved production procedures covering each stage of the process from supply of raw materials to finishing and packing for shipment. The procedures shall be fully referenced in an inspection and test plan which shall also refer to requirements of this Standard specification, as applicable.
5.2 The manufacturer shall ensure that full traceability of all the materials is maintained throughout manufacturing process.
5.3 The quality control at the anode manufacturing plant shall include control systems on the following:
- Raw materials, i.e. checking of documentation.
- Production equipment and process.
- Testing during and after production.
- Identification of anodes.
- Chemical analysis.
- Weight and dimensional tolerances.
- Surface condition of produced anodes.
- Documentation (material certificates).
5.4 The manufacturer shall submit to the Purchaser his quality assurance and control plan.
6. ANODE CASTING
6.1 Casting of High-Silicon-Chromium-Iron Anode
6.1.1 Anodes shall be made from High-Silicon-Chromium-Iron casting conforming to the ASTM A 518M-86 (Grade 3) and shall have either a solid or "rod type" configuration with the anode lead attached at one end of the anode or a "tubular type" configuration with the anode lead attached at the center of the anode.
6.1.2 The casting may be produced by any process at the option of the manufacturer, capable of meeting the chemical composition and physical properties specified.
6.1.3 Where solid or "rod type" anodes are required, the anode shall be single end with enlarged head. The anode’s enlarged head shall be cored to provide cavities for lead wire connection.
6.1.4 Where "tubular type" anodes are required, the anode shall be hollow, straight-walled tubular anode having walls of uniform thickness and having an open cylindrical interior for lead wire connection.
6.1.5 The casting shall be dense and homogeneous ensuring that the anode properties are uniform throughout their length.
6.1.6 The chemical composition of the anode alloy content shall conform to the limits prescribed in Table 1.
6.2 Casting of Graphite Anode
6.2.1 Anodes shall be of the plain graphite type extruded in circular or square shapes. They shall be of the "treated type", having been impregnated with linseed oil by a vacuum-pressure autoclave process.
Dec. 1997 IPS-M-TP-750/1
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6.2.2 The graphitizing ovens shall be so designed to ensure that a uniform internal graphite structure is obtained as well as an overall consistency from one anode to another.
Note:
If great care is not taken during the manufacturing process, internal cracks and flaws may develop in the graphite. It is therefore necessary that the manufacturer takes the necessary steps to maintain a consistent material free from internal and external flaws.
6.2.3 The aggregate and grain shall be small and shall have similar physical, chemical and electrical properties. The material shall be free of voids and impurities.
6.2.4 The anodes shall be sufficiently resistant to permit firm tamping of backfill around them and immune to chemical attack.
6.2.5 Anodes shall have one end drilled for cable connection.
6.3 Casting of Magnetite Anode
6.3.1 Anodes shall be made by casting the magnetite (Fe3O4) with the melting point of about 1540°C, plus an addition of small quantities of alloying elements, into a hollow cylinder closed at one end. The whole inside surface of the anode shall be coated with a plated thin copper layer. 100 mm below the anode top a copper tag shall be fixed to the inside copper layer for cable attachment.
The anode body shall be filled with a soft plastic core (e.g., polystyrene or polyurethane) to absorb the differential rates of expansion of the resin and the magnetite.
6.3.2 Casting may be produced by any process at the option of the manufacturer, capable of meeting the requirements specified herein.
6.3.3 The casting shall be dense, and homogeneous ensuring that the anode properties are uniform throughout their length.
7. LEAD WIRE-TO-ANODE CONNECTION
7.1 The anodes shall be supplied complete with lead wires (see 8) connected to the casting.
7.2 For "rod type" High-Silicon-Iron anodes, the method of connecting the lead wire to the anode shall either be by leading and tamping (caulked lead connection), or by the use of a tapered pin connection.
7.3 For Graphite anodes, the method of connecting the lead wire to the anode shall either be by a brass soldered, or by the use of a compression connection.
7.4 For Magnetite anodes, the method of connecting the lead wire to the anode copper conducting layer shall be by the use of a brazed connection.
7.5 The anode lead to anode connection shall be fully sealed to prevent water intrusion by application of an epoxy compound. Finally an internally mastic lined heat shrink cap which covers the anode head 75 mm minimum and the lead wire 50 mm minimum, shall be applied and shrunk into place to provide a complete water-tight and leak-free seal capable of withstanding sever service conditions.
7.6 Heat shrink anode cap used for sealing the anode lead connection, as will be specified by the Purchaser, shall be either standard or chlorine resistant type in accordance with following:
Standard Type: Heat-shrinkable polyethylene
Dec. 1997 IPS-M-TP-750/1
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Chlorine Resistant Type: Heat-shrinkable polyvinylidene fluoride
7.7 For "tubular type" High-Silicon-Iron anodes, the type and method of connecting and sealing the lead wire to the anode shall be approved by the anode manufacturer.
Note:
The internal moisture seal must withstand the hydrostatic pressure and resist degradation from oxidizing gases released at the anode.
8. ANODE LEAD WIRE
8.1 Conductor
The copper conductors shall be single core stranded, compressed, soft annealed, uncoated copper in accordance with ASTM specification B8 Class B or IEC Publication 228 Class 2.
Unless otherwise specified by the Purchaser, the lead wire size shall be 10 mm².
Unless otherwise specified by the Purchaser, the lead wire length shall be 3 meters.
8.2 Lead Wire Insulation
The lead wire insulation, as will be specified by the Purchaser (see Appendices A, B and C), shall be either standard or chlorine resistant type and shall conform to one of the following types:
8.2.1 Standard type insulation
The insulation shall be in accordance with one of the following alternatives:
8.2.1.1 A single jacket of High Molecular Weight Polyethylene insulation complying with the physical and electrical requirements of ASTM Specification D 1248, Type I, Class C, Category 5, Grade J3, having an average insulation thickness of 2.8 mm.
8.2.1.2 A double jacket of High Molecular Weight Polyethylene primary insulation complying with the physical and electrical requirements of ASTM Specification D 1248, Type 3, Class C, Category 5, Grade J3; sheathed with a chemical and abrasion resistant Polyvinyl Chloride (PVC) extruded jacket conforming to ASTM specification D 1047. The average thickness shall be 2.8 mm.
8.2.1.3 A double jacket of chemically Cross-Linked Polyethylene (XLPE) primary insulation conforming to ASTM specification D 2655, sheathed with a chemical and abrasion resistant Polyvinyl Chloride (PVC) extruded jacket conforming to ASTM specification D 1047. The average thickness shall be 2.8 mm.
Note:
In the case of local purchasing which the anode lead wire with the above insulation material may not be available, a double jacket PVC/PVC insulation are also acceptable, subject to Company approval.
8.2.2 Chlorine resistant type insulation
The insulation shall be in accordance with one of the following alternatives:
8.2.2.1 A single jacket of modified Polyvinylidene Fluoride (PVDF), double extruded insulation, having a minimum insulation thickness of 0.75 mm.
Dec. 1997 IPS-M-TP-750/1
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8.2.2.2 A double jacket of a radiation Cross-Linked Polyvinylidene Fluoride (XLPVDF), primary insulation, sheathed with a chemical and abrasion resistant High Molecular Weight Polyethylene extruded jacket conforming to ASTM specification D 2308. The minimum thickness shall be 0.5 + 1.7 = 2.2 mm.
8.3 Lead wire insulation shall have a minimum of 600 Volt rating.
8.4 The minimum thickness at any point shall not be less than 90% of the specified average thickness.
8.5 The insulation shall provide continuous coverage, adequate dielectric properties, and have a high resistant to abrasion, stress cracking, notch propagation*, and notch sensitivity.
8.6 Unless otherwise specified by the Purchaser, the color of anode lead wire insulation shall be fade-resistant black for standard type and fade-resistant red for chlorine-resistant type.
9. PROPERTIES
The finished product shall meet the following requirements:
9.1 Workmanship, Finish, and Appearance.
9.1.1 Anodes shall be free from defects which may impair the performance of the finished component. Anodes shall be free of flaws, slags, cracks, blow holes, and excessive porosity consistent with good commercial practice.
9.1.2 The lead wire insulation shall be continuous having a thickness as uniform as possible and shall be completely free of nicks, scratches, or other discontinuities.
* Notch propagation: The tendency of a cut, nick, or scratch in a material to increase in depth and/or length when the material is stressed.
9.2 Mechanical Resistance Test
When an uniaxial force equivalent to 100 kg, or five times the mass of the anode metal, whichever is the greater, is applied to a cast anode, it shall not result in damage to the cable or its connections.
9.2.2 The Silicone –iron alloy shall meet transverse bond test results (according to test method A518/A518 M and acceptance test criteria)
9.3 Electrical Resistance Test
The electrical resistance at the connection of a completely assembled anode, shall not exceed 0.03 ohms, when tested in accordance with ASTM test method B 539.
Note:
Connection resistance is defined as total resistance minus resistance of the anode cable.
9.4 Temperature Dependence
Anodes shall not have a tendency of cracking when affected by alternating high and low temperatures.
9.5 Fluoropolymer Insulated Anode Lead Wire Test
The Fluoropolymer insulation used on anode lead wire must pass the impulse dielectric test** performed in accordance with ASTM D 3032, Section 12, at 600 Volts (peak) per 0.025 mm or a
Dec. 1997 IPS-M-TP-750/1
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maximum of 18 kilovolts (peak).
If an outer jacket of fluoropolymer or other material is applied, all finished wire must pass the impulse dielectric test at a voltage equal to 600 Volts (peak) per 0.025 mm of primary insulation plus 100 Volts (peak) per 0.025 mm of the jacket thickness or a maximum of 18 kilovolts (peak).
9.6 Radiographic Test
The anode shall show no internal defects when tested by means of X-ray in accordance with ASTM Guide E94. Types and degrees of discontinuities considered shall be judged by reference radiographs ASTM E 802.
9.7 In addition the "rod type" High-Silicon-Iron anodes shall conform to the requirements for physical properties prescribed in Table 2.
TABLE 1 - CHEMICAL COMPOSITION LIMITS FOR HIGH-SILICON-IRON ANODES
ELEMENT
COMPOSITION,
wt%
METHOD OF
ANALYSIS
Carbon
Manganese
Silicon
Chromium
Molybdenum
Copper
Iron
0.9-1.0
1.5 max.
14.25 - 14.75
4.3 - 5.00
0.2 max.
0.50 max.
Remaindera)
ASTM A 518M
a) Determined arithmetically by difference.
** Impulse dielectric test: A method of applying voltage to an insulated wire through the use of electric pulses (usually 170 to 250 pulses per second) to determine the integrity of the wire’s insulation.
TABLE 2 - PHYSICAL PROPERTIES OF "ROD TYPE" HIGH-SILICON-IRON ANODES
PROPERTY
UNIT
REQUIREMENT
TEST METHOD
ASTM
Density
Hardness, Brinell (min)
Compressive strength (min)
Electrical resistivity (max)
Impact resistance (min)
g/cm³
---
MPa
μΩ . cm
J
7 – 7.05
500
650
72
0.1
Approved method
E 10
A 256
B 193
A 327
(Charpy Type)
10. DIMENSIONS AND WEIGHTS
10.1 The dimensions and weights of High-Silicon-Iron "rod type" anode; as will be specified by the Purchaser, shall be in accordance with Table 3.
Dec. 1997 IPS-M-TP-750/1
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TABLE 3 - DIMENSIONS OF HIGH-SILICON-IRON ANODES ("ROD TYPE")
DIAMETER
(NOMINAL)
mm
HEAD DIAMETER
(NOMINAL)
mm
LENGTH
(NOMINAL)
mm
WEIGHT
(NOMINAL)
kg
51
51
51
76
76
76
76
76
76
102
102
102
915
1220
1525
915
1220
1525
14.5
19
22.5
29
38
49
10.2 The dimensions and weights of High-Silicon-Iron "tubular type" anode, as will be specified by the Purchaser, shall be in accordance with Table 4.
TABLE 4 - DIMENSIONS OF HIGH-SILICON-IRON ANODES ("TUBULAR TYPE")
OUTSIDE
DIAMETER
mm
INSIDE
DIAMETER
mm
WALL
THICKNESS
mm
LENGTH
(NOMINAL)
mm
WEIGHT
(NOMINAL)
kg
67
56
67
95
121
121
47
36
47
75
100
86
10
10
10
10
10
17
1067
2134
2134
2134
2134
2134
14
21
29
39
50
79
10.3 The dimensions and weights of Graphite anode, as will be specified by the Purchaser, shall be in accordance with Table 5.
TABLE 5 - DIMENSIONS OF GRAPHITE ANODES
DIAMETER
(NOMINAL)
mm
LENGTH
(NOMINAL)
mm
WEIGHT
(NOMINAL)
kg
76
102
152
1525
2032
1830
11
28
53
10.4 The dimensions and weight of Magnetite anode shall be as follows:
Overall length : 800 mm
Effective length : 740 mm
Outside diameter : 60 mm
Inside diameter : 40 mm
Total weight : 6.0 kg
Magnetite weight : 4.7 kg
10.5 The actual dimensions shall conform to the following:
10.5.1 Anode mean length shall be ±3% of nominal length or ±25 mm, whichever is smaller.
10.5.2 The diameter of anode shall be ±5% of nominal diameter.
10.5.3 The permissible variation in weight of each finished anode shall be ±5% of the nominal weight.
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11. SAMPLING
11.1 Lot
Unless otherwise specified by the Purchaser, a lot shall consist of all anodes made from the same production run offered for inspection at one time.
11.2 Sampling for Inspection
Sample anodes shall be selected from each lot in accordance with inspection Level II of ISO 2859 (Part 1). The acceptable quality level shall be 4 percent for all visual, dimensional and weight defects combined and 2.5 percent for all other type of defects with reference to this Part of Standard specification. The single sampling plans for normal inspection (Table II A of ISO 2859 Part 1) shall be used.
12. REJECTION
Where the numbers of anodes that do not conform to this Part of Standard specification exceed the acceptance numbers specified in 11.2, this shall be cause for rejection of entire lot.
13. INSPECTION
13.1 The manufacturer and/or supplier shall be responsible for carrying out all the tests and inspections required by this Part of Standard specification, using his own or other reliable facilities, and he shall maintain complete records of all such tests and inspections. Such records shall be available for review by the Purchaser.
13.2 The manufacturer and/or supplier shall afford the purchaser’s inspector all reasonable facilities necessary to satisfy him that the material is being produced and furnished in accordance with this Part of Standard specification. Such inspections in no way relieve the manufacturer and/or supplier of his responsibilities under the terms of this Standard specification.
13.3 The Purchaser reserves the right to perform any inspections set forth in this Part of Standard specification where such inspections are deemed necessary to assure that supplies and services conform to the prescribed requirements.
13.4 The Purchaser’s inspector shall have access to the material subject to inspection for the purpose of witnessing the selection of the samples, the preparation of the test samples, and the performance of the tests. For such tests, the inspector shall have the right to indicate the pieces from which the samples will be taken in accordance with the provisions of this Part of Standard specification.
14. CERTIFICATION
14.1 The manufacturer shall provide the Purchaser with a certification stating that the anodes meet the specified requirements of this Part of Standard specification.
14.2 The test report shall contain results of tests required by this Part of Standard specification and other tests specified by the Purchaser.
14.3 Each test report shall be signed by an authorized agent of the seller and/or manufacturer.
14.4 Certified test reports furnished by the manufacturer shall be properly identified with each lot (batch) of products.
Dec. 1997 IPS-M-TP-750/1
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15. PACKAGING AND SHIPMENT
15.1 Anodes shall be bundled, strapped, placed on pallets or in sturdy crates with supports, pads and binding as necessary to facilitate unloading and minimize damage to anodes during normal handling and transportation.
15.2 Cables shall be carefully coiled and positioned inside the crates or on the pallets so that no cable damage can occur during loading and transportation. Under no circumstances must anodes lay on the cables.
15.3 Cleaning, preservation, and packaging of anodes shall be in accordance with the manufacturer’s commercial practice, provided they are such as to ensure acceptance by common or other carriers for safe transportation to the delivery point.
16. LABELING
16.1 Anode Identification
Each anode casting shall be stamped with the following:
- Name and/or trademark of the manufacturer.
- Batch number.
- Cast number.
- Alloy type (i.e., High-Silicon-Iron, Graphite, or Magnetite).
16.2 Lead Wire Identification
The lead wire shall be marked with the following information:
- Manufacturer’s name.
- Lead wire size.
- Lead wire insulation.
- Specification.
16.3 Marking of Containers
Each crate or pallet shall be plainly marked with the following information:
Name of anode : (i.e., High-Silicon-Iron, Graphite, or Magnetite) anode
Specification : IPS-M-TP-750: Part 1
Order No. : ........................................................................................
M.E.S.C. No. : ........................................................................................
Anode type : ........................................................................................
Anode Dimensions : Length.......... mm, Diameter ...... mm, Weight ............. kg.
Batch No. : ........................................................................................
Stock No. : ........................................................................................
Date of Manufacture : ........................................................................................
Quantity : ........................................................................................
Manufacturer’s name and address : ........................................................................................
Dec. 1997 IPS-M-TP-750/1
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Note:
Each crate or pallet shall be clearly marked "FRAGILE".
Dec. 1997 IPS-M-TP-750/1
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APPENDICES
APPENDIX A
DATA SHEET
(TO BE SUBMITTED BY THE PURCHASER)
FOR
IPS-M-TP-750: Part 1 HIGH-SILICON-IRON ANODES
The anodes shall be in accordance with the latest edition of above Iranian Petroleum Standard with following specific requirements:
- Project title: ................................... - Date:
- Indent No.: ..................................... - Purchaser: ………………...
- M.E.S.C. No.: ................................
- Quantity: ........................................
- Type of anode: b "Rod Type"
b "Tubular Type"
- Anode dimensions: .......................
- Anode cap type: b Standard
b Chlorine resistant
- Lead wire insulation type:
Standard type: b Double Jacket - PVC/PVC (see Note of 8.2.1)
b Single Jacket - HMWPE
b Double Jacket - HMWPE/PVC
b Double Jacket - XLPE/PVC
Chlorine resistant type: b Single Jacket - PVDF
b Double Jacket - XLPVDF/HMWPE
- Lead wire length:
- Lead wire insulation color:
Dec. 1997 IPS-M-TP-750/1
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APPENDIX B
DATA SHEET
(TO BE SUBMITTED BY THE PURCHASER)
FOR
IPS-M-TP-750: Part 1 GRAPHITE ANODES
The anodes shall be in accordance with the latest edition of above Iranian Petroleum Standard with following specific requirements:
- Project title: ................................... - Date:
- Indent No.: ..................................... - Purchaser: ...................
- M.E.S.C. No.: ................................
- Quantity: ........................................
- Anode dimensions: .......................
- Anode cap type: b Standard
b Chlorine resistant
- Lead wire insulation type:
Standard type: b Single Jacket - HMWPE
b Double Jacket - HMWPE/PVC
b Double Jacket - XLPE/PVC
Chlorine resistant type: b Single Jacket - PVDF
b Double Jacket - XLPVDF/HMWPE
- Lead wire length:
- Lead wire insulation color:
Dec. 1997 IPS-M-TP-750/1
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APPENDIX C
DATA SHEET
(TO BE SUBMITTED BY THE PURCHASER)
FOR
IPS-M-TP-750: Part 1 MAGNETITE ANODES
The anodes shall be in accordance with the latest edition of above Iranian Petroleum Standard with the following specific requirements:
- Project title: ................................... - Date:
- Indent No.: ..................................... - Purchaser: .......................
- M.E.S.C. No.: ................................
- Quantity: ........................................
- Anode dimensions: .......................
- Anode cap type: b Standard
b Chlorine resistant
- Lead wire insulation type:
Standard type: b Single Jacket - HMWPE
b Double Jacket - HMWPE/PVC
b Double Jacket - XLPE/PVC
Chlorine resistant type: b Single Jacket - PVDF
b Double Jacket - XLPVDF/HMWPE
- Lead wire length:
- Lead wire insulation color:
Dec. 1997 IPS-M-TP-750/2
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PART 2
CARBONACEOUS BACKFILL
FOR
IMPRESSED CURRENT ANODES
Dec. 1997 IPS-M-TP-750/2
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CONTENTS : PAGE No.
1. SCOPE.........................................................................................................................................20
2. REFERENCES.............................................................................................................................20
3. DEFINITIONS AND TERMINOLOGY...........................................................................................20
4. UNITS...........................................................................................................................................21
5. CLASSIFICATION.......................................................................................................................21
6. REQUIREMENTS.........................................................................................................................22
7. PACKAGING FOR SHIPMENT....................................................................................................23
8. SAMPLING FOR INSPECTION....................................................................................................24
9. INSPECTION AND TESTING.......................................................................................................24
10. LABELING.................................................................................................................................24
Dec. 1997 IPS-M-TP-750/2
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1. SCOPE
This Part of IPS-M-TP-750 covers the minimum requirements for the supply of carbonaceous backfill for use in shallow and deep-well type impressed current ground beds.
Notes:
1) The term "carbonaceous backfill" has been used to describe the conductive backfill materials used to surround ground bed anodes to lower the total resistance of the ground bed, to improve current distribution, to prolong anode life, and to provide a permeable medium for migration of gases.
2) In case of local purchase, the specification can be tolerated to some extent.
2. REFERENCES
Throughout this Standard the following dated and undated standards/codes are referred to. These referenced documents shall, to the extent specified herein, form a part of this standard. For dated references, the edition cited applies. The applicability of changes in dated references that occur after the cited date shall be mutually agreed upon by the Company and the Vendor. For undated references, the latest edition of the referenced documents (including any supplements and amendments) applies.
ISO (INTERNATIONAL ORGANIZATION FOR STANDARDIZATION)
ISO 334 "Coal and Coke-Determination of Total Sulphur-Eschka Method"
ISO 351 "Solid Mineral Fuels-Determination of Total Sulphur-High Temperature Combustion Method"
ISO 562 "Hard Coal and Coke-Determination of Volatile Matter Content"
ISO 567 "Coke-Determination of the Bulk Density in a Small Container"
ISO 609 "Coal and Coke-Determination of Carbon and Hydrogen-High Temperature Combustion Method"
ISO 625 "Coal and Coke-Determination of Carbon and Hydrogen-Liebig Method"
ISO 687 "Coke-Determination of Moisture in the Analysis Sample"
ISO 1013 "Coke-Determination of Bulk Density in a Large Container"
ISO 1171 "Solid Mineral Fuels-Determination of Ash"
ISO 2309 "Coke-Sampling"
ISO 2325 "Coke-Size Analysis (Nominal Top Size 20 mm or Less)"
3. DEFINITIONS AND TERMINOLOGY
Ash
Inorganic residue remaining after ignition of combustible substances, determined by definite prescribed methods.
Note:
Ash may not be identical, in composition or quantity, with the inorganic substances present in the material before ignition.
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Bulk density
The mass in air per unit volume of bulk material, including the voids within and between particles.
Coke
A carbonaceous solid produced from coal, petroleum, or other materials by thermal decomposition with passage through a plastic state.
Coke breeze
The fine screenings from crushed coke or from coke as taken from the ovens, of a size varied in local practice, but usually passing a 12.5 mm screen opening.
Dry screening
The screening of solid materials of different sizes without the aid of water.
Fixed carbon
In the case of coal, coke, and bituminous materials, the solid residue other than ash, obtained by destructive distillation, determined by definite prescribed methods.
Note:
It is made up principally of carbon, but may contain appreciable amounts of sulfur, hydrogen, nitrogen, and oxygen.
Screening
The separation of solid materials of different sizes by causing part to remain on a surface provided with apertures through which the remainder passes.
Sieve analysis
The process or result of the division of a sample into size fractions by the use of test sieves.
Wetting agent
A reagent to reduce the interfacial tension between a solid and a liquid and so to facilitate the spreading of the liquid over the solid surface.
Wet screening
The screening of solid materials of different sizes with the aid of water, normally in the form of a spray.
4. UNITS
This Standard is based on International System of Units (SI), except where otherwise specified.
5. CLASSIFICATION
Carbonaceous backfill material, as will be specified by the Purchaser, shall be one of the following
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types:
Type 1: Coal coke breeze
Type 2: Calcined petroleum coke breeze
Type 3: Special calcined petroleum coke breeze
Note:
Types 1 and 2 coke breeze are to be used for shallow (horizontal or vertical) groundbeds and type 3 coke breeze for deep well groundbeds.
6. REQUIREMENTS
6.1 Composition
6.1.1 Type 1 backfill material
Backfill shall be coal coke breeze of low resistivity and low ash content. The coke breeze may be treated by the addition of 10% (by weight) of commercial grade slaked lime.
The proposed material shall have the properties of Table 1.
TABLE 1 - TYPE 1 BACKFILL MATERIAL (COAL COKE BREEZE)
PROPERTY
UNIT
REQUIREMENT
TEST METHOD
Carbon content (min.)
Moisture content (max.)
Ash content (max.)
Total sulphur content (max.)
Volatile matter content (max.)
wt%
wt%
wt%
wt%
wt%
80
5
15
1
5
ISO 609 or ISO 625
ISO 687
ISO 1171
ISO 351 or ISO 334
ISO 562
6.1.2 Type 2 backfill material
Backfill shall be petroleum coke calcined (heat treated) to remove all other petroleum products, other than carbon, and shall be supplied in granular form. Lime in a proportion of 10% by weight of coke breeze shall be added to the product.
The proposed material shall have the properties of Table 2.
TABLE 2 - TYPE 2 BACKFILL MATERIAL (PETROLEUM COKE BREEZE)
PROPERTY
UNIT
REQUIREMENT
TEST METHOD
Carbon content (min.)
Moisture content (max.)
Ash content (max.)
Total sulphur content (max.)
Volatile matter content (max.)
wt%
wt%
wt%
wt%
wt%
90
5
5
5
5
ISO 609 or ISO 625
ISO 687
ISO 1171
ISO 351 or ISO 334
ISO 562
6.1.3 Type 3 backfill material
Backfill shall be petroleum coke calcined (heat treated) to remove all other petroleum products, other than carbon, specially formulated to facilitate pumping, settling, and compaction of carbon lubricants. The product shall contain 0.1% wetting agent to enhance setting of the granular particles
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and water absorption of the bakfill. It shall have round, uncrushable shape.
The proposed material shall have the properties of Table 3.
TABLE 3 - TYPE 3 BACKFILL MATERIAL (SPECIAL PETROLEUM COKE BREEZE)
PROPERTY
UNIT
REQUIREMENT
TEST METHOD
Carbon content (min.)
Moisture content (max.)
Ash content (max.)
Total sulphur content (max.)
Volatile matter content (max.)
wt%
wt%
wt%
wt%
wt%
95
1
3
1
1
ISO 609 or ISO 625
ISO 687
ISO 1171
ISO 351 or ISO 334
ISO 562
6.2 Bulk Density
The bulk density of backfill materials on dry packed basis shall conform to the following range:
TYPE
BULK DENSITY
(kg/m³)
TEST METHOD
1
2
3
650-800
700 - 1100
1050 – 1200
ISO 1013 or ISO 567
6.3 Resistivity
For Types 1 and 2 backfill material the resistivity shall be less than 100 ohm-cm when dry and lightly tamped and prior to the addition of lime. For Type 3 backfill material the resistivity of the tamped dry backfill shall not exceed 0.1 ohmcm.
6.4 Particle Size
The particle sizes of backfill materials shall conform to the following size distribution:
Type 1: Less than 10 mm 100%
Greater than 1 mm 90%
Type 2: Less than 3 mm 100%
Greater than 0.5 mm 90%
Type 3: Less than 1.0 mm 100%
Less than 0.6 mm 80%
Greater than 0.4 mm 90%
Greater than 0.15 mm 99%
The test method shall be in accordance with ISO 2325.
7. PACKAGING FOR SHIPMENT
The materials purchased according to this Standard specification shall be packaged in suitable containers to ensure acceptance and safe delivery to their destination.
The backfill shall be supplied in 25 kg bags, in 1 tone containers or other suitable containers as specified by the Purchaser.
The method of shipment, as will be specified by the Purchaser, may be either double bagged or bulk in accordance with following:
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Double bagged-packaging shall be double packing in bags, the inner bag being woven polypropylene, the outer bag can be hessian but not polyethylene which is subject to U.V deterioration and temperature distortion.
Bulk-method of shipping shall be agreed upon by the Purchaser and supplier.
8. SAMPLING FOR INSPECTION
Sampling shall be in accordance with ISO 2309.
The numbers and types of test specimens shall be in accordance with the ISO test method for the specific properties to be determined.
9. INSPECTION AND TESTING
9.1 All materials supplied under this Standard specification shall be subject to timely inspection by the Purchaser or his authorized representative. The Purchaser shall have the right to reject any material(s) supplied which is (are) found to be defective under this Part of Standard specification. In case of dispute, the arbitration or settlement procedure, established in the procurement documents shall be followed.
9.2 The supplier shall be responsible for the performance and costs for all laboratory test requirements as specified in this Part of Standard specification. The supplier shall set up and maintain such quality assurance and inspection systems as are necessary to ensure that the materials comply in all respects with the requirements of this Part of Standard specification.
9.3 Purchaser’s inspector(s) shall have free access to the supplier’s work to follow up the progress of the materials covered by this Part of Standard specification and to check the quality of materials. The supplier shall place free of charge at the disposal of the Purchaser’s inspector(s) all means necessary for carrying out their inspection results of tests, checking of conformity of materials to this Part of Standard specification, checking of marking and packing and temporary acceptance of materials.
9.4 The supplier shall furnish the Purchaser with a certified copy of results of tests made by the manufacturer covering physical and performance characteristics of each batch of product to be supplied under this Part of Standard specification. The supplier shall furnish, or allow the Purchaser to collect samples of the material representative of each batch of product. Certified test reports and samples furnished by the supplier shall be properly identified with each batch of product.
9.5 Supplier shall submit to the Purchaser a typical analysis, and the test methods used, of a random sample of backfill material giving following information:
- Moisture content.
- Carbon content.
- Ash content.
- Particle size distribution.
- Bulk density.
- Resistivity.
Supplier shall perform screening tests on samples of the backfill to ensure compliance with the particle size requirements.
10. LABELING
Each package or container of backfill material shall be marked with the following information:
Name: .......................................................................................................
Specification: IPS-M-TP-750: Part 2 ........................................................
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Order No.: ................................................................................................
M.E.S.C No.: ...........................................................................................
Type or trade name of backfill: ...............................................................
Weight (gross and net): ..........................................................................
Batch No.: ..............................................................................................
Stock No.: ...............................................................................................
Date of manufacture: ..............................................................................
Storage conditions: .................................................................................
Trademark of the manufacturer: .............................................................
Manufacturer’s name and address: .......................................................
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PART 3
GALVANIC ANODES
FOR
UNDERGROUND APPLICATIONS
(MAGNESIUM AND ZINC)
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CONTENTS : PAGE No.
1. SCOPE.........................................................................................................................................28
2. REFERENCES.............................................................................................................................28
3. DEFINITIONS AND TERMINOLOGY...........................................................................................29
4. UNITS...........................................................................................................................................32
5. TECHNICAL DOCUMENTS.........................................................................................................32
6. CLASSIFICATION.......................................................................................................................32
7. MATERIALS AND MANUFACTURE............................................................................................32
8. REQUIREMENTS.........................................................................................................................35
9. CHEMICAL BACKFILL FOR GALVANIC ANODES...................................................................39
10. SAMPLING.................................................................................................................................40
11. REJECTION...............................................................................................................................40
12. INSPECTION..............................................................................................................................40
13. SUPPLIED DOCUMENTATION.................................................................................................41
14. PACKAGING AND SHIPMENT..................................................................................................41
15. LABELING.................................................................................................................................42
APPENDICES:
APPENDIX A DATA SHEET FOR MAGNESIUM ANODES............................................................43
APPENDIX B DATA SHEET FOR ZINC ANODES..........................................................................44
APPENDIX C METHOD FOR THE DETERMINATION OF THE ANODE-TO-CORE RESISTANCE OF GALVANIC ANODES.................................................................................................................45
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1. SCOPE
This Part of IPS-M-TP-750 covers the minimum requirements for galvanic (sacrificial) anodes for use in the cathodic protection of buried structures against corrosion. It specifies the compositions, materials, manufacture, properties, inspection and testing for magnesium and zinc anodes. It also includes details of backfill compositions and properties, for magnesium and zinc anodes.
This specification covers only the general requirements for the anodes, the specific requirements will be given in pertinent ordering documents by the Purchaser (see Appendices A and B).
2. REFERENCES
Throughout this Standard the following dated and undated standards/codes are referred to. These referenced documents shall, to the extent specified herein, form a part of this standard. For dated references, the edition cited applies. The applicability of changes in dated references that occur after the cited date shall be mutually agreed upon by the Company and the Vendor. For undated references, the latest edition of the referenced documents (including any supplements and amendments) applies.
ASTM (AMERICAN SOCIETY FOR TESTING AND MATERIALS)
A 36 Standard Specification for
"Structural Steel"
A 283 Standard Specification for
"Low and Intermediate Tensile Strength Carbon Steel Plates"
B 6 Standard Specification for
"Zinc"
B 275 Standard Practice for
"Codification of Certain Nonferrous Metals and Alloys, Cast and Wrought"
B 418 Standard Specification for
"Cast and Wrought Galvanic Zinc Anodes"
D 1047 Standard Specification for
"Poly (Vinyl Chloride) Jacket for Wire and Cable"
D 1351 Standard Specification for
"Polyethylene Insulation for Electrical Wire and Cable"
D 2219 Standard Specification for
"Poly (Vinyl Chloride) Insulation for Wire and Cable"
D 2655 Standard Specification for
"Crosslinked Polyethylene Insulation for Wire and Cable"
G 97 Standard Test Method for
"Laboratory Evaluation of Magnesium Sacrificial Anode Test Specimens for Underground Applications"
IEC (INTERNATIONAL ELECTROTECHNICAL COMMISSION)
IEC 228 "Nominal Cross-Section Areas and Composition of Conductors of Insulated Cables"
Dec. 1997 IPS-M-TP-750/3
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ISO (INTERNATIONAL ORGANIZATION FOR STANDARDIZATION)
2859-1 "Sampling Procedures for Inspection by Attributes
Part 1: Sampling Plans Indexed by Acceptable Quality Level (AQL) for Lot-by-Lot Inspection"
3. DEFINITIONS AND TERMINOLOGY
For the purpose of this Standard, the definitions below apply:
Anode backfill
Material surrounding and in contact with a buried anode to maintain or improve its performance.
Anode consumption rate
The rate of alloy mass consumption for a given current output over a given period; normally stated in kilograms per ampere year.
Anode core
A metal insert (usually steel) either cast into the anode or extruded with the anode to provide mechanical strength and attachment.
Cast sacrificial anode
The negative (reactive) component of a galvanic cell, designed to oxidize sacrificially and produce direct electrical current to protect a more electropositive (noble) metal operating in the same electrolyte and produced to a desired shape by the solidification of a molten alloy in a mold or die.
Cathodic protection
The prevention or reduction of corrosion of metal by making the metal the cathode in a galvanic or electrolytic cell.
Certificate of conformity
A statement made by the producer’s representative (executive) and endorsed by a representative of the Purchaser that the anodes listed comply with the requirements of the order.
Cold lap
Horizontal discontinuity caused by solidification of the meniscus of a partially cast anode as a result of interrupted flow of the casting stream. The solidified meniscus is covered with metal when the flow resumes. Cold laps can occur along the length of an anode.
Cold shut
Horizontal surface discontinuity caused by solidification of a portion of a meniscus during the progressive filling of a mold, which is later covered with more solidifying metal as the molten metal level rises. Cold shuts generally occur at corners remote from the point of pour.
Cracking
Fracture of metal along an irregular path producing a discontinuity similar to a ragged edge. It can
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occur during the solidification of the anode (hot cracking), during the contraction of the anode after solidification, or under externally applied loads. Hot cracking may be associated with the shrinkage depression the can occur in open-topped molds.
Current capacity
The total current flow available from an anode of given mass of alloy; normally expressed as ampere years per kilogram. This is the inverse of the anode consumption rate.
Current density
The average amount of current entering or leaving a given surface area.
Driving potential
The difference between the open circuit potentials of the anode and the structure.
Dulling of zinc
Deterioration in appearance of zinc-coated inserts because of oxidation that produces a white bloom of zinc oxide.
Electrochemical properties
Those properties of potential and current capacity that characterize a sacrificial anode and can be assessed by quantitative tests.
Galvanic anode
An electrode used to protect a structure by galvanic action.
Gas holes
The evidence of bubbles within the metal. The holes can indicate that moisture was on the mold or insert prior to casting, or that the liquid metal contained a high level of hydrogen that had been thrown out of solution to form bubbles during the cooling of the metal.
Gross anode mass
Total mass of an anode, including anode core, and backfill (if a packaged anode).
Heat
Also called a "melt" or "cast", it is the unit that defines molten metal and identifies the anodes cast from it. A heat is the product that is cast to a planned procedure in one melting operation in one furnace, without significant interruption. If the casting sequence is interrupted, the anodes produced before, between and after the interruptions constitute "batches".
Net anode mass
Mass of actual anode alloy.
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Nonmetallic inclusions
Particles of oxides and other refractory materials entrapped in liquid metal during the melting or casting sequences.
Open circuit potential
The potential of an anode when not connected to a structure; normally measured against a reference electrode in a particular environment.
Packaged anode
Either a magnesium or zinc anode placed, with backfill, in a calico bag or other approved container to provide a uniform low resistivity environment for the anode.
Porosity
Generally distributed fine holes caused by gas bubbles, shrinkage (formed by the starvation of eutectic material within the dendrite arms during "unfed" solidification), or a combination of the two mechanisms when hydrogen in solution diffuses into the lower pressure shrinkage voids.
Protrusion
Extraneous material on the anode surface. It may interfere with the anode-to-structure fit, appear unattractive, and be a safety hazard if there are sharp edges. Protrusions can be formed by careless filling of the mold or the flash from imperfect fitting of mold sections.
Reference electrode
An electrode which has a stable potential in one or more electrolytes, thus enabling it to be used for the measurement of other electrode potentials at a given temperature.
Shrinkage depression
The natural concave surface produced when liquid metal is allowed to solidify in a container without the provision of extra liquid metal to compensate for the reduction in volume that occurs during the liquid-solid transformation. The term also applies to the concave surface produced when liquid metal is solidified in a closed mold in such a manner that the area is not "fed" by the liquid metal provided by the casting’s riser.
Test anode
A prepared anode test piece, made from a test specimen by a mechanical operation.
Test sample
A portion of material or a group of items selected from a batch or consignment by a sampling procedure.
Test specimen
A portion of material or a single item taken from the test sample for the purpose of applying a particular test.
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4. UNITS
This Standard is based on International System of Units (SI), except where otherwise specified.
5. TECHNICAL DOCUMENTS
The technical bid shall include the following with reference to data sheet (see Appendices A.3 and B.3).
5.1 Manufacturing drawings or catalogues for anodes: including dimensions, tolerances, steel insert grade, alloy type and weights.
5.2 Production procedures that cover all stages of the manufacturing process, from receipt of raw materials to finishing and packing for shipment, including:
- chemical analysis;
- measurements of weights, dimensions, bowing, twisting, crack size, etc.;
- backfill composition (for Type 1 anodes);
- inspection and testing procedures, and frequencies;
- anode manufacture;
- identification of rejected anodes.
5.3 Insert preparation procedures: including acceptance limits for surface, wall thinning and ovality.
5.4 Electrochemical test procedures, including acceptance criteria, description of test apparatus, measurement methods and preparation and cleaning of samples.
5.5 Preservation, packing and shipping procedures, such that anodes are not damaged or deformed and do not deteriorate during handling, delivery to the fabrication yard, storage: including methods, materials and any requirements for periodic inspections.
6. CLASSIFICATION
The anodes, as will be specified by the Purchaser (see Appendices A and B), shall be one of the following types:
Type I: Cast anodes.
Type II: Extruded rod (or ribbon) anodes.
7. MATERIALS AND MANUFACTURE
7.1 General
7.1.1 Anodes shall be manufactured by any suitable casting or extruding process. The anode material shall be cast or extruded around a steel insert (core) so designed as to retain the anode material even when it is consumed to its design utilization factor.
7.1.2 Manufacturing of anodes shall be carried out using approved production procedures covering each stage of the process from supply of raw materials to finishing and packing for shipment. The procedures shall be fully referenced in an Inspection and Test plan which shall also refer to requirements of this Standard specification, as applicable.
The manufacturer shall ensure that full traceability of all the materials is maintained throughout manufacture and thereafter.
7.1.3 The supplier shall submit to the Purchaser his quality assurance and control plan.
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The quality control at the anode manufacturing plant shall include control systems on the following:
- Raw materials, i.e.,checking of documentation.
- Production equipment and process.
- Testing during and after production.
- Identification of anodes.
- Chemical analysis.
- Weight and dimensional tolerances.
- Surface condition of produced anodes.
- Documentation (material certificates).
7.1.4 The cast anodes may be supplied bare or packaged in a permeable cloth bag containing a rapid wetting and moisture retaining backfill (see 9), which reduces the electrolyte resistivity adjacent to the anode and improves performance, as will be required by the Purchaser (see Appendices A and B).
7.2 Anode Composition
7.2.1 Magnesium anodes
Magnesium anodes shall be manufactured from virgin materials conforming to the chemical composition limits given in Table 1 as determined by approved spectrographic and analytical procedures.
The anode composition in this Standard specification meets the chemical composition requirements of ASTM specification B275 Designation M1C (also called Galvomag).
7.2.2 Zinc anodes
Zinc anodes shall be made from special High Grade Zinc conforming to ASTM specification B 6, with suitable alloying additions, with an iron content well below the 0.003% maximum given in ASTM specification B 6. Composition of the anode alloy content shall conform to the limits given in Table 2.
The anode composition in this Standard specification meets the chemical composition requirements of ASTM specification B 418, Type II.
Notes:
1) The chemical analysis of the anode samples may be carried out either at the time they are cast, or at the finished or semifinished product stage.
2) The electrochemical properties are highly dependent on the content of alloying elements and impurity elements. The anode manufacturer shall thus prove his capability of delivering anodes which satisfy this Standard specification.
3) Small deviations from the specification in the alloy composition may significantly reduce the protective properties. Generally it is of importance that the fabrication procedure ensures that the melt is not polluted by iron or other impurities. Furnaces, pumps, pipes, etc., shall be non-metallic or properly lined.
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TABLE 1 - CHEMICAL COMPOSITION LIMITS FOR MAGNESIUM ALLOY ANODES
ELEMENT COMPOSITION, %
Aluminum, max. 0.01
Manganese 0.9 - 1.2
Copper, max. 0.02
Iron, max. 0.03
Nickel, max. 0.001
Other elements, total, max. 0.3
Magnesium* Remainder
* The magnesium content shall be calculated by subtracting from 100.00%.
TABLE 2 - CHEMICAL COMPOSITION LIMITS FOR ZINC ALLOY ANODES
ELEMENT COMPOSITION, % (max.)
Aluminum 0.005
Cadmium 0.003
Iron 0.0014 a)
Lead 0.003
Copper 0.002
Other elements, total 0.012
Zinc b) Remainder
a) Critical deleterious impurity.
b) The zinc content shall be calculated by subtracting from 100.00%.
7.3 Anode Core
7.3.1 The magnesium anode core shall be made from commercial hot dipped galvanized steel conforming to ASTM specification A 283, Grade C or equivalent standard.
7.3.2 The zinc anodes shall have steel cores conforming to ASTM specification A 36. The steel shall be coated with zinc or cadmium to a minimum thickness of 12.5 microns. Hot-dipped or electro-deposition methods may be used. Either coating shall be adherent and free from flaking. The coating shall adhere tenaciously to the surface of the base metal. When the coating is cut or pried into, such as with a stout knife applied with considerable pressure in a manner tending to remove a portion of the coating, it shall only be possible to remove small particles of the coating by paring or whittling, and it shall not be possible to peel any portion of the coating so as to expose the steel.
7.3.3 The position of the anode core shall be such that the maximum possible mass of anode material is available to provide cathodic protection.
7.3.4 Cores shall be abraded or otherwise treated to ensure that the requirements of 8.5 and 8.6 can be achieved.
7.4 Production Testing
The manufacturer shall carry out the following tests:
a) A full spectrographic analysis, or an approved alternative, of each cast. The results shall meet the requirements of Table 1 (for magnesium anodes) or Table 2 (for zinc anodes).
b) A electrochemical performance test for each cast. The test shall be carried out by the manufacturer in accordance with approved procedures designed to demonstrate batch consistency of the as cast electrochemical properties.
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8. REQUIREMENTS
8.1 Performance Properties of Magnesium and Zinc Anodes
Any anode must be capable of a sufficient driving voltage to provide the necessary design current output. The performance properties of anode alloys shall be in accordance with Table 3.
TABLE 3 - PERFORMANCE PROPERTIES OF GALVANIC ANODE ALLOYS
ANODE
ALLOY
TYPE
OPEN CIRCUIT
POTENTIAL
NEGATIVE VOLTS
(Cu/CuSO4 ELECTRODE)
CURRENT
EFFICIENCY
% (min)
ENERGY
CAPABILITY
amp-hr/kg (min)
CONSUMPTION RATE
kg/amp-YEAR (max)
Zinc
1.1
90
780
11.2
Magnesium
1.7*
50
1200
7.3
* 14 days test, with reference to ASTM test method G 97.
8.2 Workmanship, Finish, and Appearance
8.2.1 The anodes shall be free of flash burrs, cracks, blow holes, and surface slag consistent with good commercial practice. The cast anodes shall be free of shrinkage cavities exceeding 6 mm (¼ inch)in depth, except that anodes 50 mm (2 inch) thick or more shall be free of shrinkage cavities exceeding 9.5 mm (3/8 inch) in depth, when measured from a straight edge placed diagonally across the opposite edges of the anode.
8.2.2 Metal core extensions from the anodes shall be smooth and free of sharp burrs. The cast-in cores shall have metallurgical bonds specified herein free of air pockets and inclusions consistent with good commercial practice.
8.2.3 The anode lead wire insulation shall be continuous having a thickness as uniform as possible and shall be completely free of nicks, scratches, or other discontinuities.
8.3 Mechanical Resistance
When an uniaxial force equivalent to 100 kg, or five times the mass of the anode metal, whichever is the greater, is applied to a cast anode containing a core, no movement of the core or any metal insert shall occur. Where a cable is provided, a uniaxial loading of 100 kg shall not result in damage to the cable or its connections.
8.4 Electrical Resistance
When determined in accordance with the test method in Appendix C, the electrical resistance of the anode to core or, if appropriate, of the anode to the end of the cable, shall be not greater than 0.01 for the life of the anode.
8.5 Anode Dimensions and Weights
8.5.1 Magnesium anodes
8.5.1.1 The cast anode (Type I) dimensions and weights (nominal), as will be specified by the Purchaser (see Appendix A), shall be as follows:
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WEIGH
kg (lbs)
DIMENSIONS
(mm)
A B C
TOTAL PACKAGED
WEIGHT (APPROX.)
Kg
4.1 (9)
7.7 (17)
14.5 (32)
21.8 (48)
90 90 350
90 90 650
140 140 540
140 140 820
10
20
30
45
Core straps shall be 20 gage (8 mm) perforated electroplate galvanize steel with 6 mm. holes on 12.7 mm (½ inch) centers. The core length shall be 75% of anode length.
8.5.1.2 The Type II anodes dimensions and weight (nominal) shall be as follows:
Magnesium weight: 370 g/m
Cross section: 9.5 × 19 mm
Core diameter: 3.2 mm
Coil length: 300 m (unless otherwise specified by the Purchaser),
(see Appendix A).
8.5.2 Zinc anodes
8.5.2.1 The cast anode (Type I) dimensions and weights (nominal), as will be specified by the Purchaser (see Appendix B), shall be as follows:
WEIGH
kg (lbs)
DIMENSIONS
(mm)
W H L
2.3 (5)
5.5 (12)
8.2 (18)
13.6 (30)
20.5 (45)
27.3 (60)
35 35 230
35 35 610
35 35 915
50 50 760
50 50 1140
50 50 1525
The cores shall be made of a 6.35 mm (¼ inch) diameter electrogalvanized mild steel.
8.5.2.2 The Type II anode dimensions and weights (nominal), as will be specified by the Purchaser (see Appendix B), shall be as follows:
WEIGH
kg/m (lb/ft)
CROSS SECTION
(mm)
COIL LENGTH*
(m)
1.8 (1.2)
0.9 (0.6)
0.37 (0.25)
15.8×22.2
12.7 × 14.2
8.7 × 11.9
60
150
300
* Unless otherwise specified by the Purchaser (see Appendix B.3).
8.5.3 Dimensions and weights tolerances shall conform to the following:
8.5.3.1 Anode mean length shall not deviate more than 3% of nominal length.
8.5.3.2 Anode mean width shall not deviate more than 3% of nominal width.
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8.5.3.3 The straightness of the anode shall not deviate more than 2% of the anode nominal length from the longitudinal axis of the anode.
8.5.3.4 The permissible variation in weight of each finished anode will be plus or minus 5% of the nominal weight.
8.5.3.5 The total contract weight shall be no more than 2% above and not below the nominal contract weight.
8.6 Methods of Attachment of Cable for Cast Anodes
8.6.1 The cast anodes shall be supplied complete with cables connected to the anode core. One end of the anode shall be recessed to provide cavity for attachment of the lead wire to the anode core and subsequent sealing of this connection.
The method of connecting the lead wire to anode core shall be either by the use of a brazed connection or silver solder connection or any other approved method. The connection shall be so to bear the weight of the anode.
The lead wire to anode core connection shall be sealed to prevent water intrusion by application of a potting compound (e.g.,epoxy resin) or mastic-lined polyethylene heat-shrink sleeve to completely seal the connection and to protect the joint mechanically.
For Magnesium anodes, typical methods of attachment are shown in Figs. 1 and 2.
For zinc anodes, a typical method of attachment is shown in Fig. 2.
8.6.2 The lead wires shall be 6 sq. mm single core, stranded soft annealed copper conductor conforming to IEC Publication 228, Class 2 or ASTM specification B 8 Class B, and 5 meter in length.
8.6.3 The lead wire insulation, as will be specified by the Purchaser (see Appendices A and B) shall be in accordance with one of the following alternatives:
- A single jacket of High Molecular Weight Polyethylene (HMWPE) insulation conforming to ASTM specification D 1351, having a minimum thickness of 1.5 mm.
- A single jacket of Cross-Linked Polyethylene (XLPE) insulation conforming to ASTM specification D 2655, having a minimum thickness of 1 mm.
- A double jacket of Polyvinyl Chloride (PVC) primary insulation conforming to ASTM specification D 2219, sheathed with a polyvinyl chloride jacket conforming to ASTM specification D 1047. The average insulation (of insulation and sheath), shall be 2 mm with a 10% tolerance.
8.6.4 Lead wire insulation shall have a minimum of 600 Volt rating.
8.6.5 The color of the insulation of anode cables should be red, unless otherwise specified by the Purchaser.
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TYPICAL METHOD OF CABLE ATTACHMENT FOR BURIED MAGNESIUM ANODES
Fig. 1
Dec. 1997 IPS-M-TP-750/3
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TYPICAL METHOD OF CABLE ATTACHMENT FOR BURIED ANODES
Fig. 2
8.7 Identification of Anodes
Each anode shall be clearly marked with the type of material (trade name), the cast number, and a piece serial number. The numbers of any rejected anodes shall not be used again for replacement anodes.
9. CHEMICAL BACKFILL FOR GALVANIC ANODES
9.1 Backfill Composition
When specified by the Purchaser, the cast anodes shall be supplied with backfill. The backfill surrounds, as will be specified by the Purchaser, with reference to notes to Table 4 shall be in accordance with one of the nominal composition of Table 4 (see data sheet).
TABLE 4 - BACKFILL COMPOSITION
GYPSUM (CaSO4)%
Hydrated
Molding Plaster
(Plaster of Paris)
Bentonite
Clay
%
Sodium
Sulfate
%
Approx.
Resistivity in
Ohm-cm
(A) 25
(B) 50
(C) ---
(D) 75
---
---
50
---
75
50
50
20
---
---
---
5
250
250
250
50
Notes:
1) Backfill mix (A), is useful in low soil moisture areas and utilizes the moisture-holding characteristic of the bentonite clay.
2) Backfill mix (B), is commonly used with Zinc anodes.
3) Backfill mix (C), is useful with Zinc or Magnesium in very wet or marshy soils to prevent rapid migration of backfill from anode surface.
4) Backfill mix (D), with low resistivity, is useful in high soil resistivity areas to reduce the anode resistance to earth.
9.2 Particle Size
The Backfill shall have a grain size so that 100% is capable of passing through a 0.84 mm. (20 mesh screen) and 50% shall be retained by a 0.15 mm (100 mesh screen), and shall contain not more than 5% moisture.
9.3 Backfill Analysis
The manufacturer shall submit to the Purchaser a typical analysis of a random sample of backfill material giving the following information:
- Moisture content.
- Gypsum content.
- Bentonite content.
- Sodium sulfate content (if any).
Dec. 1997 IPS-M-TP-750/3
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The manufacturer shall perform screening tests on samples of the backfill to ensure backfill is in the form of a fine powder.
9.4 Anode Packaging
Anodes shall be packed in a calico bag, or in some other type of approved porous container. The diameter of the packaging shall be at least 50 mm greater than the diagonal of the anode. The backfill shall be tightly packed in the bag to prevent movement of the anode and shall achieve the following coverage around the anode:
a) A minimum of 25 mm of cover on corners, measured diagonally.
b) A minimum of 50 mm of cover on the top, bottom and sides.
The backfill shall be firmly held around the anode, the whole shall be vibrated during filling to ensure compaction.
The container shall be sealed to minimize moisture intrusion during storage and shipment and to ensure against loosening or loss of backfill.
10. SAMPLING
10.1 Lot
Unless otherwise specified by the Purchaser, a lot shall consist of all anodes made from the same production run offered for inspection at one time.
10.2 Sampling for Inspection
Sample anodes shall be selected from each lot in accordance with inspection level II of ISO 2859 (Part 1). The Acceptable Quality Level shall be 4 percent for all visual, dimensional and weight defects combined and 2.5 percent for all other type of defects with reference to this Part of Standard specification. The single sampling plans for normal inspection (Table IIA of ISO 2859 (Part 1)) shall be used.
11. REJECTION
Where the numbers of anodes that do not conform to this Part of Standard specification exceed the acceptance numbers specified in 10.2, this shall be cause for rejection of entire lot.
12. INSPECTION
12.1 Responsibility for Inspection
12.1.1 The manufacturer and/or supplier shall be responsible for carrying out all the tests and inspections (during and after fabrication) required by this Part of Standard specification, using his own or other reliable facilities, and he shall maintain complete records of all such tests and inspections. Such records shall be available for review by the Purchaser.
12.1.2 The manufacturer and/or supplier shall afford the purchaser’s inspector all reasonable facilities necessary to satisfy him that the material is being produced and furnished in accordance with this Part of Standard specification. Such inspections in no way relieve the manufacturer and/or supplier of his responsibility under the terms of this Standard specification.
12.1.3 The Purchaser reserves the right to perform any inspections set forth in this Part of Standard specification where such inspections are deemed necessary to assure that supplies and services
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conform to the prescribed requirements.
12.1.4 The purchaser’s inspector shall have access to the material subject to inspection for the purpose of witnessing the selection of the samples, the preparation of the test samples, and the performance of the tests. For such tests, the inspector shall have the right to indicate the pieces from which the samples will be taken in accordance with the provisions of this Part of Standard specification.
12.2 Inspection
Inspection shall cover the following as a minimum:
a) Dimensional checking, identification, weight, and quality of casting on at least 5% of the number of anodes from each cast.
b) Quality of steel inserts (cores) before casting on at least 5% of inserts for the batch of anodes from each cast. Any reject inserts shall be isolated and returned to the fabricator or the electroplater for correction.
c) Quality of insulation of the anode lead wire and each anode lead to anode seal connection to ensure absence of holes or nicks or other faults.
d) Compliance of prepackaged anodes with Clause 9.4 particularly with respect to centering of the anode in the backfill.
e) Inspection of results of spectro analysis, electrochemical tests, and other tests required by this Part of Standard specification.
13. SUPPLIED DOCUMENTATION
The following documentation shall be supplied with each anode batch:
- Certificate No. and date.
- The anode type, batch, cast and heat numbers.
- Details of anode casting, weights (net and gross) and numbers.
- Results of any destructive testing.
- Results of any non-destructive testing.
- Electrochemical test results.
- Anode alloy chemical analysis methods and results.
- Backfill composition analysis results (if any).
- Material specification and trade name.
- The anode manufacturer.
- The company’s order No.
- The date of manufacture.
- Certificate of conformity with this Part of Standard specification.
14. PACKAGING AND SHIPMENT
14.1 Anodes shall be bundled, strapped, placed on pallets, or in sturdy crates with supports, pads, and binding as necessary to facilitate unloading and minimize damage to anodes during shipment, multiple rough handling, and intransit storage.
14.2 Leads shall be carefully coiled and positioned inside the crate or on the pallet as necessary to minimize damage during loading and transportation.
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14.3 Cleaning, preservation, and packaging of anodes shall be in accordance with the manufacturer’s commercial practice, provided they are such as to ensure acceptance by common or other carriers for safe transportation to the delivery point.
14.4 The prepackaged anodes shall be contained in a waterproof bag clearly marked "outer bag to be removed before installation".
Note:
For backfill-surrounded anodes, the total contents are normally contained within the packaging, should the Purchaser require special packaging or limitations on the mass of such packages, such requirements shall be specified.
15. LABELING
15.1 Marking of Anodes
The following information shall be legibly and durably marked on each anode or group of anodes supplied, or on a label securely fixed to each anode:
a) The name or registered mark of the manufacturer or supplier.
b) The alloy designation.
c) Nominal net mass of the anode and, in the case of a packaged anode, the gross mass of the anode and the backfill.
Note:
Gross mass also includes the mass of the cable attached to the anode.
d) If appropriate, the instruction "remove plastic bag prior to installation of the anode".
e) The backfill composition (if any).
f) Batch number.
g) Cast number.
The anode lead wire shall be identified by surface marking indicating manufacturer’s identification, conductor size, voltage rating and insulation type.
15.2 Marking of Container
Each pallet shall be plainly marked with the following information:
Name: .............……………………………………………………………………………………
Specification: IPS-M-TP-750: Part 3 ......................................……………………………
Order No.: ......…………………………………………………….……………………………
M.E.S.C No.: ...…………………………………………………………………………………
Anode type: .....…………………………………………………………………………………
Anode weight (net and gross): ...............................................……………………………
Anode dimensions: ................................................................……………………………
Batch No.: ......…………………………………………………………………………………
Stock No.: .......…………………………………………………..……………………………
Date of manufacture: ...........................................................……………………………
Quantity: .........…………………………………………………………………………………
Manufacturer’s name and address: .......................................……………………………
Note:
Each pallet shall be clearly marked "FRAGILE".
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APPENDICES
APPENDIX A
DATA SHEET
(TO BE SUBMITTED BY THE PURCHASER)
FOR
IPS-M-TP-750: Part 3 MAGNESIUM ANODES
The anodes shall be in accordance with the latest edition of above Iranian Petroleum Standard with following specific requirements:
- Project title: ................................... - Date: .........................................
- Indent No.: ..................................... - Purchaser: .................................
- M.E.S.C. No.: ................................
Type I Anodes:
- Quantity: ....................................... Nos.
- Weight of Magnesium: .................kg
- Lead wire insulation type:
b Single Jacket - HMWPE
b Single Jacket - XLPE
b Double Jacket - PVC/PVC
- Backfill mixture: ..........................
Type II Anodes:
- Quantity (Coil length): .................m
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APPENDIX B
DATA SHEET
(TO BE SUBMITTED BY THE PURCHASER)
FOR
IPS-M-TP-750: Part 3 ZINC ANODES
The anodes shall be in accordance with the latest edition of above Iranian Petroleum Standard with following specific requirements:
- Project title: ................................... - Date: .........................................
- Indent No.: ..................................... - Purchaser: .................................
- M.E.S.C. No.: ................................
Type I Anodes:
- Quantity: ....................................... Nos.
- Weight of Anode (Net): ................ kg
- Lead wire insulation:
b Single Jacket - HMWPE
b Single Jacket - XLPE
b Double Jacket - PVC/PVC
- Anode Packaging:
b Packaged with backfill in Calico bag
b Bare anode (No backfill)
- Backfill mixture: ..........................
Type II Anodes:
- Zinc Weight (kg/m): ......................
- Quantity: ........................................ m
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APPENDIX C
METHOD FOR THE DETERMINATION OF THE ANODE-TO-CORE
RESISTANCE OF GALVANIC ANODES
C.1 General
This Appendix describes the method for the determination of the anode-to-core resistance of galvanic (sacrificial) anodes used for cathodic protection.
C.2 Principle
The voltage across the anode metal and anode core is measured when a known current is passed between them. The anode-to-core resistance is then computed by dividing the measured voltage by the known current.
C.3 Apparatus
The following apparatus is required:
a) A d.c. supply of 5 A capacity, with an adjustable current control capable of smooth variation from 5 A to near zero. It shall be capable of generating an on-load-voltage sufficient to pass a current of 5 A through a resistance of not less than 1 Ω.
b) An ammeter capable of reading to at least 5A d.c. with a maximum error of ±1% at full scale deflection. This ammeter may be integral with the d.c. supply (see Item (a)).
c) A millivoltmeter of the electrically protected type capable or reading to 50 mV d.c., with a maximum error of ±1%.
d) Suitable test leads and clamps or clips to connect Items (a), (b) and (c) to the anode and the core. The clamp system shall be of such quality to ensure that the connection resistance to each point is less than 0.05 Ω.
C.4 Circuit
The circuit shall be arranged as shown in Fig. C.1 (a) or (b), as applicable. The leads connecting the millivoltmeter to the anode and the anode core (or cable), shall be independent of the leads from the power supply. All connections shall be properly made to minimize contact resistance.
If the millivoltmeter is connected across the anode metal and the terminal of the cable attached to the anode core, the anode-to-core resistance is obtained by subtracting the cable resistance from the total resistance. The total resistance is computed by dividing the measured potential by the known current.
C.5 Procedure
The procedure shall be as follows:
a) Before connecting the power supply, set the variable current control to ensure a minimum current flow when the circuit is switched on.
b) Connect the power supply. Adjust the variable current control until approximately 5 A is registered on the ammeter.
c) Read the voltage difference as indicated by the millivoltmeter.
(to be continued)
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APPENDIX C (continued)
d) Calculate the anode-to-core resistance (R), in ohms, using the following equation:
R = amperes)(in readingammeter (in volts) readingeter millivoltm
e) Reverse both ammeter supply leads and also the millivoltmeter supply leads, and repeat Steps (a) to (d) above. The results of this second calculation of R should be the same as the initial result.
C.6 Report
The test report shall contain the following information:
a) Name of test laboratory.
b) Identification of the equipment used to carry out the test.
c) Identification of the galvanic anode tested
d) The date on which the test was carried out.
e) The results of the anode-to-core resistance test calculations.
f) Reference to this test method.
(to be continued)
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APPENDIX C (continued)
b) With cable attached
SCHEMATIC CIRCUITS FOR MEASUREMENT OF ANODE-TO-CORE RESISTANCE
Fig. C.1
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PART 4
GALVANIC ANODES
FOR
SUBMERGED APPLICATIONS
(MAGNESIUM AND ZINC)
Dec. 1997 IPS-M-TP-750/4
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CONTENTS : PAGE No.
1. SCOPE.........................................................................................................................................50
2. REFERENCES.............................................................................................................................50
3. UNITS...........................................................................................................................................50
4. TECHNICAL DOCUMENTS.........................................................................................................50
5. MATERIALS AND MANUFACTURE............................................................................................51
6. REQUIREMENTS.........................................................................................................................52
7. INSPECTION................................................................................................................................52
8. ACCEPTANCE/REJECTION........................................................................................................52
9. ORDERING INFORMATION.........................................................................................................53
10. SUPPLIED DOCUMENTATION.................................................................................................53
11. MARKING OF CONTAINERS....................................................................................................53
APPENDICES:
APPENDIX A DATA SHEET FOR ZINC ALLOY ANODES.............................................................54
APPENDIX B DATA SHEET FOR MAGNESIUM ALLOY ANODES..............................................55
APPENDIX C METHOD FOR THE DETERMINATION OF THE ANODE-TO-CORE RESISTANCE OF GALVANIC ANODES.................................................................................................................56
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