AS 2832.2-1991

1 - AS 2832.2-1991 CATHODIC PROTECTION OF METALS - COMPACT BURIED STRUCTURES
4 - PREFACE
5 - CONTENTS
7 - FOREWORD
8 - SECTION 1 SCOPE AND GENERAL
8 - 1.1 SCOPE
8 - 1.2 REFERENCED DOCUMENTS
9 - 1.3 DEFINITIONS
10 - SECTION 2 DESIGN OF STRUCTURES FOR CATHODIC PROTECTION
10 - 2.1 GENERAL
10 - 2.2 STRUCTURE COATING
10 - 2.3 STRAY CURRENTS
10 - 2.4 TEST POINTS
10 - 2.4.1 General
11 - 2.4.2 Location
11 - 2.4.3 In-situ reference electrodes
11 - 2.5 INSULATING JOINTS
12 - 2.6 ROAD AND RAIL CROSSINGS
12 - 2.7 ELECTRICAL ISOLATION
12 - 2.8 EARTH POTENTIAL RISE CAUSED BY HIGH VOLTAGE POWER SYSTEM FAULTS
13 - 2.9 ELECTRICAL CONTINUITY
13 - 2.10 GRAPHICAL SYMBOLS
14 - SECTION 3 COATINGS FOR USE WITH CATHODIC PROTECTION
14 - 3.1 GENERAL
14 - 3.2 COATING PROPERTIES
14 - 3.3 COATING CHOICE
16 - SECTION 4 CRITERIA FOR CATHODIC PROTECTION
16 - 4.1 GENERAL
16 - 4.2 FERROUS STRUCTURES
16 - 4.2.1 Buried structures
16 - 4.2.2 Alternative protection criteria
16 - 4.3 COPPER/COPPER ALLOY STRUCTURES
16 - 4.4 LEAD STRUCTURES
16 - 4.5 MIXED METALLIC STRUCTURES
16 - 4.6 STRUCTURES SUBJECT TO STRAY DIRECT CURRENT
16 - 4.7 MEASUREMENT OF POTENTIAL
16 - 4.7.1 Polarized potential measurement
17 - 4.8 OVERPROTECTION
18 - SECTION 5 DESIGN OF CATHODIC PROTECTION SYSTEMS
18 - 5.1 GENERAL
18 - 5.2 SAFETY PRECAUTIONS
18 - 5.3 CHOICE OF SYSTEM-IMPRESSED CURRENT OR GALVANIC ANODES
19 - 5.4 CONTROL OF INTERFERENCE CURRENTS
19 - 5.5 CABLES
19 - 5.5.1 Cable joints and protection
19 - 5.5.2 Types of cables
19 - 5.5.3 Test cables
20 - 5.5.4 Impressed current anode cables
20 - 5.5.5 Galvanic anode cables
20 - 5.6 CHECK LIST FOR INITIAL SURVEYS
20 - 5.7 DETERMINATION OF CATHODIC PROTECTION CURRENT REQUIREMENTS
20 - 5.7.1 General
20 - 5.7.2 Prediction of current requirement from design parameters
21 - 5.7.3 Determination of current requirement by field testing of existing structures
21 - 5.8 ANODE ARRANGEMENTS
21 - 5.8.1 General
21 - 5.8.2 Calculation of appropriate anode/structure separation
22 - 5.8.3 Anode positioning and burial
23 - 5.9 ANODE MATERIALS, APPLICATIONS AND OPERATING CHARACTERISTICS
23 - 5.10 CALCULATION OF GALVANIC ANODE MASS
24 - 5.11 CALCULATION OF GALVANIC ANODE OUTPUT CURRENT
24 - 5.12 POWER SUPPLY FOR IMPRESSED CURRENT SYSTEMS
24 - 5.12.1 Sources of direct current
25 - 5.12.2 Equipment
25 - 5.12.3 Calculation of voltage requirements
25 - 5.13 BACKFILL
25 - 5.14 PROVISION FOR STRAY CURRENTS
25 - 5.15 SYSTEM DESIGN DOCUMENTATION
27 - SECTION 6 INSTALLATION OF CATHODIC PROTECTION SYSTEMS
27 - 6.1 GENERAL
27 - 6.2 MATERIALS AND EQUIPMENT ACCEPTANCE TESTS
27 - 6.2.1 General
27 - 6.2.2 Anodes
27 - 6.2.3 Cables
27 - 6.2.4 Transformer-rectifier equipment
28 - 6.2.5 Prefabricated insulating joints
28 - 6.3 INSTALLATION OF GALVANIC ANODE SYSTEMS
28 - 6.4 INSTALLATION OF IMPRESSED CURRENT ANODE SYSTEMS
28 - 6.4.1 Cabling
28 - 6.4.2 Groundbed
28 - 6.5 INSTALLATION OF REFERENCE ELECTRODES
29 - 6.6 INSTALLATION OF INSULATING FLANGES, JOINTS AND COUPLINGS
29 - 6.6.1 Test for insulation integrity
30 - SECTION 7 CONTROL OF INTERFERENCE CURRENTS FROM CATHODIC PROTECTION SYSTEMS TO MINIMIZE THEIR EFFECT ON FOREIGN STRUCTURES
30 - 7.1 GENERAL
30 - 7.2 REGULATORY REQUIREMENTS
30 - 7.3 MINIMIZATION OF INTERFERENCE CURRENT
30 - 7.3.1 Design of the system
31 - 7.3.2 Actions for minimizing interference currents
31 - 7.3.3 Detection of interference levels
31 - 7.3.4 Control of interference
33 - SECTION 8 CATHODIC PROTECTION OF STRUCTURES SUBJECT TO STRAY DIRECT CURRENT
33 - 8.1 GENERAL
33 - 8.2 MINIMIZATION OF STRAY CURRENT EFFECTS
33 - 8.2.1 General
33 - 8.2.2 Minimization of track leakage current
33 - 8.2.3 Mitigation of stray current pick-up and discharge
34 - SECTION 9 OPERATION AND MAINTENANCE OF CATHODIC PROTECTION SYSTEMS
34 - 9.1 GENERAL
34 - 9.2 MEASURING TECHNIQUES
35 - 9.3 COMMISSIONING SURVEY
35 - 9.4 CATHODIC PROTECTION POTENTIAL SURVEYS
35 - 9.5 EQUIPMENT MAINTENANCE CHECKS
35 - 9.5.1 For impressed current systems
35 - 9.5.2 For galvanic anode installations
35 - 9.6 STRUCTURE INSPECTIONS
35 - 9.7 RECORDS
37 - APPENDIX A - GUIDANCE ON THE GENERAL USE OF CATHODIC PROTECTION
37 - A1 SCOPE
37 - A2 GENERAL COMPONENTS OF CATHODIC PROTECTION INSTALLATIONS
37 - A3 FACTORS AFFECTING THE CORROSION OF BURIED OR PARTIALLY BURIED METALLIC STRUCTURES
40 - APPENDIX B - LIST OF DEFINITIONS
42 - APPENDIX C - CONTROL OF INTERFERENCE CURRENTS-LIST OF ELECTROLYSIS COMMITTEES

Provides guidelines for the cathodic protection of external surfaces of compact buried structures and gives information on the design, installation, operation and maintenance of cathodic protection systems.

This Standard provides guidelines for the cathodic protection of external surfaces of compact buried structures, including tank farms, service station tanks, tower footings, steel pilings (in soil), short well casings, compressor and pump stations and associated pipework. The Standard specifically covers the following subjects which relate to cathodic protection:(a) The design of structures requiring cathodic protection.(b) Coatings for use on buried metal structures.(c) Criteria for choice of cathodic protection potential.(d) The design of cathodic protection systems.(e) The installation of cathodic protection systems.(f) The control of interference currents on foreign structures.(g) The cathodic protection of structures subject to stray direct current.(h) The operation and maintenance of cathodic protection systems.NOTES:1 A different approach is required to achieve satisfactory protection of mounded installations to that for installations buried below ground.2 Guidance on the general use and design of cathodic protection systems, and factors affecting the corrosion of buried metallic structures, are given in Appendix A.3 This Standard employs positive current flow, and uses the potential sign conventions specified in AS 1852.

First published as AS 2832.2-1991.