1、GEOP Gas Engineering and Operating Practices A Series by the Operating Section The American Gas Association Volume VI TECHNICAL SERVICES Book TS1 Corrosion Control/System Protection The American Gas Association Arlington, Virginia Legal Notice The Gas Engineering and Operating Practices Series was p
2、repared by the American Gas Association (A.G.A.), its member companies and other individuals and groups with an interest in the natural gas industry. Neither A.G.A., its member companies, employees, nor any person acting on their behalf: a. Makes any warranty or representation, express or implied, w
3、ith respect to the accuracy, completeness, or usefulness of the information contained in this series, or that the use of any apparatus, method or process disclosed in this series may not infringe privately owned rights; or b. Assumes any liability with respect to the use of, or for damages or person
4、al injuries resulting from the use of any information apparatus, method, or process disclosed in this series, or for violation of any federal, state or municipal regulation with which it may conflict. c. Reference to trade names or specific commercial products, methods, commodities or services in th
5、is series does not represent or constitute an endorsement, recommendation or favoring by A.G.A. or any other person of the specific commercial product, commodity or service. d. Nothing contained in this series is to be construed as granting any right, by implication or otherwise, for the manufacture
6、, sale, or use in connection with any method, apparatus, or product covered by letters patent, nor as insuring anyone against liability for infringement of letters patent. Copyright 1986 by the American Gas Association, A.G.A. All rights reserved. Library of Congress Catalog Card Number: 8570460 ISB
7、N 0872570010 A.G.A. Catalog Number XY0186 2M02.863025 Printed in the United States of America CONTENTS PREFACE xi ACKNOWLEDGEMENTS . xiv PART 1. CORROSION CONTROL CHAPTER 1. INTRODUCTION . 3 Why Corrosion Control is Necessary . 3 Public Safety and System Reliability 4 CHAPTER 2. FUNDAMENTALS 5 Cause
8、s of Corrosion 5 Galvanic Corrosion 7 Interference Corrosion 9 Biological Corrosion 14 Other Causes of Corrosion 14 Electrical Measurements for Corrosion Control . 18 DC Voltage . 18 DC Current 20 Resistance Measurements 20 Other Measurements 21 CHAPTER 3. CORROSION CONTROL METHODS 23 Coating Materi
9、al Selection and Application . 23 Underground/Submerged Structures 23 Aboveground Structures . 31 Internal Surfaces 35 Use of Alloys . 36 iii iv CORROSION CONTROL / SYSTEM PROTECTION Insulation (Electrical Isolation) . 36 Cathodic Protection 38 Criteria 38 Design Surveys 40 Devices . 43 Control of I
10、nterference Currents . 57 Bonds . 59 Reverse Current Switches 61 Cathodic Protection . 61 Insulation 63 Internal Corrosion 63 Control Methods 64 Safety Considerations 68 Voltage Gradient Problems 68 HVAC Effects 69 HVDC Effects 70 Impressed Current Cathodic Protection Systems . 70 Stray Current 70 O
11、verload Devices . 70 Grounding 71 Fault Protection 71 Hazards 72 CHAPTER 4. MEASUREMENTS . 73 Types . 73 Electrical Measurements 73 Chemical Measurements 80 Visual Examination 80 Nondestructive Testing 80 Analysis . 81 Surveys 81 Underground Structures 81 Offshore Structures . 97 CHAPTER 5. PROGRAMS
12、 105 Training . 105 Records . 106 Construction and Maintenance 106 Monitoring . 107 CONTENTS v Economic Evaluation . 108 The Accounting System . 108 Cost Measurement . 108 Variance Analysis 109 Evaluating Alternatives 109 Comparison of Different Type Costs . 110 APPENDIX ACORROSION CONTROL CODES AND
13、 STANDARDS 111 APPENDIX BCORROSION CONTROL TRAINING . 117 APPENDIX CTRAINING AIDS 119 GLOSSARY . 121 BIBLIOGRAPHY 131 INDEX . 135 PART 2. SYSTEM PROTECTION CHAPTER 1. INTRODUCTION 141 Scope . 141 The Need for System Protection . 142 Transmission Lines 142 Distribution Lines 143 One-Call Notification
14、 143 Joint Trenching 143 Government Involvement 144 A.G.A. Action 144 CHAPTER 2. DAMAGE PREVENTION LEGISLATION AND REGULATIONS . 147 ANSI/ASME Standard Code B 31.8 . 149 State Legislation and Regulations . 149 Massachusetts 150 Georgia 150 Maryland 150 Michigan . 150 vi CORROSION CONTROL / SYSTEM PR
15、OTECTION Wyoming . 150 California 151 Federal Regulations 151 Part 192 151 Additional Regulations . 154 Objectives . 155 Penalties . 155 Exemptions 155 Facilities Protected 155 Sample Legislation 155 CHAPTER 3. SYSTEM PROTECTION PROGRAMS 157 Operator Oriented . 157 Program Outline 157 Communicating
16、the Problem 158 Targeting Programs for Maximum Effect 158 Communication Methods . 159 Company Vigilance 162 Response to Requests for Line Locations and Markings . 162 Operators Awareness Program 163 Notification Methods . 165 One-Call Systems . 165 Direct Notification . 167 Handling of Requests . 16
17、7 Pre-Construction Meetings 168 Employee Observation . 168 CHAPTER 4. MEANS OF LOCATING UNDERGROUND FACILITIES 169 Pipeline Records 169 Records 170 Maps 171 Pipeline Markers 171 Locating Devices 173 Metallic Pipeline Detection . 173 Nonmetallic Pipeline Detection 178 Automatic Shutdown Devices for E
18、xcavating Equipment 180 CONTENTS vii Marking for Outside Construction . 180 Uniform Color Code and Symbol Identification 181 Mandatory Requirements 182 Recommended Procedure for Placement of Stakes or Markers . 182 Temporary Marking Instructional Pamphlet . 184 CHAPTER 5 SYSTEM PROTECTION THROUGH DE
19、SIGN . 185 Remaining Aware of Outside Activity 185 Value of Precise Locating 186 Verification of Locations/Dimensions . 186 Evaluating Effect on the System 186 Temporary Removal . 187 Damage Potential Assessment 187 Pre-Construction Design Meetings 188 CHAPTER 6. BLASTING EFFECTS 189 Operators Respo
20、nsibilities . 189 General Guidelines 189 CHAPTER 7. DAMAGE MITIGATION PLAN . 193 Plan Ahead . 193 Planning Considerations . 193 Incident Follow-Up 196 Notice to Affected Parties 197 Damage Records . 197 Summarizing Damages . 199 Report Contents . 199 APPENDIX A. SYSTEM PROTECTION NATIONAL CODES AND
21、STANDARDS . 201 BIBLIOGRAPHY 205 INDEX . 207 FIGURES AND TABLES PART 1. CORROSION CONTROL FIGURES 1. Typical pipeline corrosion cell 6 2. Typical measurement of pipe-to-soil potential . 19 3. Typical two-wire test point to measure line current 21 4. Mill coating process 24 5. Field coating process 2
22、5 6. Rock shield application 26 7. Electrical Grounding Cell . 37 8. Anode resistance calculations 53 9. Anode resistance calculations 53 10. Stray current from electrified railway 58 11. Stray current form coal mine . 58 12. Cathodic protection interference . 59 13. Drainage bond with diode assembl
23、y switch 60 14. Interference drainage bond 60 15. Anodes to overcome interference effect of foreign line . 62 16. High-temperature, high-pressure wheel test apparatus . 66 17. Assorted corrosion monitoring probes . 67 18. Method used to measure pipe-to-soil potential . 75 19. Typical test lead insta
24、llation . 76 20. Soil resistivity (four electrode method) . 79 21. Potential profile showing electrolytic corrosion activity 86 22. Potential profile showing galvanic corrosion activity 87 23. Line current analysis . 90 24. Coating resistance survey 92 25. E Log I test 96 26. Surface vessel techniqu
25、e 98 27. Remotely operated vehicle technique 99 28. Manned submarine technique 100 viii FIGURES AND TABLES ix TABLES 1. Practical galvanic series 8, 44 2. Typical galvanic anode material alloys . 45 3. Galvanic anode applications 46 4. Typical galvanic anode characteristics 49 5. Carbonaceous backfi
26、ll . 51 6. Single vertical anode resistance (1 000 ohm-cm soil) . 55 7. Single horizontal anode resistance (1 000 ohm-cm soil at 5foot depth) . 55 8. Multiple anode adjusting factors . 56 9. Impressed anode material consumption . 56 10. Copper conductor resistance 57 11. Reference electrodes (half c
27、ells) . 75 12. Soil corrosivity 79 PART 2. SYSTEM PROTECTION FIGURES 1. Example of System Protection Committee Report 145 2. Pipeline Safety Regulations as excerpted from Code of Federal Regulations (CFR) 152 3. One-call system in operation 166 4. Checking drawings in conjunction with one-call syste
28、m 170 5. A.G.A. booklet on temporary stake and marking procedures . 172 6. Electronic signal generating magnetic field around buried facility . 174 7. Correlation of signal intensity and distance from pipe . 174 8. Depth determination by means of electronic probe . 175 9. Depth determination by mean
29、s of triangulation . 176 10. Depth determination by means of ultrasonic reflection . 176 11. Pipe location and depth can be determined by use of vibratory sensor 177 12. Hammer blows to ground enable seismic instruments to locate buried facilities and determine their depth . 178 13. Terrescan downwa
30、rd-looking radar . 179 14. Standard gas location marking from A.G.A. Suggested Temporary Stake and Marking Procedures for Underground Facilities booklet . 184 x CORROSION CONTROL / SYSTEM PROTECTION 15. Cutting and capping main service when construction is at right angles to the facility . 187 16. S
31、ample notice to party responsible for facility damage 198 TABLES 1. Chronological summary of damage prevention legislation 196480 148 2. Utilities color codes 181 3. Recommended symbols for underground facilities 182 4. Typical blasting standoff distances 190 PREFACE Arlington, Virginia February 198
32、6 This book on Corrosion Control/System Protection is one of 12 consti-tuting the six-volume A.G.A. Gas Engineering and Operating Practices series of texts addressing the various topics of gas supply, transmis-sion, distribution, measurement, untilization, and related technical ser-vices. Contributi
33、ng authors are veteran practitioners in the gas industry who were selected for their subject knowledge from 22 technical com-mittees in the A.G.A. Operating Section, as well as consultants, sup-pliers, and other specialilsts. Corrosion Control/System Protection is one of two books that will make up
34、the GEOP Technical Services Volume, the other being Analysis/Purging/Odorization/Metrication. A work of this sort, by its nature, does not afford the detailed treat-ment possible in more specialized publications. The references provided, including the List of Codes and Standards and the Bibliography
35、, greatly expand the usefulness of the Corrosion Control/System Protection book by referring readers to other sources. We trust that you will find this and other books in the GEOP series to be a valuable addition to your professional library. Robert H. Holder Robert L. Parker Chairman, GEOP Task Gro
36、up Editor xi GEOP TASK GROUP The following Operating Section members have served on the Gas Engineer-ing and Operating Practices Task Group of the Section Managing Committee through the development of the GEOP Series. Robert H. Holder, Chairman (1985present), Vice President and Chief Engineer, Wisco
37、nsin Gas Company Anthony A. Bobelis, Chairman (19821985), Principal Engineer, Engineering Department, The Brooklyn Union Gas Company Ty S. Miller, Chairman (19791982), Manager, Distribution (Deceased), Southern California Gas Company C. William Ade (19801983), Vice President, Gas Transmission and Pl
38、anning, Mississippi River Transmission Company Anthony A. Bobelis (1979present), Principal Engineer, Engineering Depart-ment, The Brooklyn Union Gas Company Alton T. Davis (19791980), Vice President, Gas Division, San Diego Gas and Electric Company Robert H. Holder (1982present), Vice President and
39、Chief Engineer, Wiscon-sin Gas Company: George M. Hugh (19791983), Senior Vice President, Engineering and Opera-tions, TransCanada PipeLines Ltd. Vernon E. Percell (1983present), Senior Vice President, Gas Operations, Kansas Power and Light Company Marvin D. Ringler (19791981), Engineer, Gas Supply
40、Planning, Consolidated Edison Company of New York, Inc. O.L. Slaughter (19831985), Senior Vice President, Gas Company of New Mexico Robert D. Stegner (1983present), Senior Vice President, Operations and Engineering, Indiana Gas Company Andrew Tarapchak (19791984), Vice President, Distribution, Washi
41、ngton (D.C.) Gas Light Company Milton M. Walther (19791983), General Manager, Gas Department, New Orleans Public Service, Inc. Robert L. Parker (1980present), Manager, Engineering Series Publications, American Gas Association xiii ACKNOWLEDGEMENTS It is appropriate to express special thanks here to
42、George A. Hend-rick, System Protection Committee Task Leader, and Corrosion Con-trol Committee Task Leaders Virgil L. Johnston and Robert A. Moody for their hard work and organizational efforts in bringing this book to fruition. The following additional members of the Corrosion Control and System Pr
43、otection Committee also contributed to the book. Contributing Authors, Corrosion Control: Robert J. Ambrose, Divi-sion Manager, Gas Systems Engineering, Long Island Lighting Com-pany. James L. Banach, Supervisor, Engineering, TransCanada PipeLines, Ltd. Hugh L. Banks, Corrosion Engineer (Retired), N
44、orthern Natural Gas Company. Peter A. Bernasconi, Senior Engineer, Corro-sion Control, Consolidated Edison Company of New York, Inc. Jerry L. Berry, Manager, Corrosion Control, Mississippi River Transmission Corporation. William E. Cook, Jr., Sales Manager, PLEXCO. Jack A. Evans, Supervisor, Corrosi
45、on Control, Natural Gas Pipeline Company of America. John. H. Fitzgerald III, Vice President, The Hinchman Com-pany. Harry J. Hagan, Manager, Technical Services Southern Connec-ticut Gas Company. John W. Haught, Supervisor, Corrosion Services, The Peoples Natural Gas Company. Edward H. Holland, Fiel
46、d Superintendent, Cathodic Protection, Florida Gas Transmission Com-pany. Bernard Husock, Vice President and Chief Engineer, HARCO Cor-poration. Virgil L. Johnston, Chief Corrosion Engineer (Retired), Panhandle Eastern Pipeline Company. Ted Kennedy, Jr., President, The Trenton Corporation. Brian A.
47、King, Supervisor, Corrosion Control, Southern California Gas Company. George W. Kurr, P.E., Consultant. William R. Lambert, Manager, Operations Engineering, Columbia Gas Transmission Corporation. R. D. McDonald, Manager, Corrosion Con-trol, Oklahoma Natural Gas Company. Edward J. Michalek, Superviso
48、ry Engineer, Peoples Gas Light and Coke Company. Charles H. Montague, Senior Vice President, People Gas System. Robert A. Moody, Chief Cor- xiv ACKNOWLEDGEMENTS XV rosion Engineer, Panhandle Eastern Pipe Line Company. James A. Mulhern, Manager of Consulting, Henkels and McCoy, Inc. Richard M. Neidbala (Deceased), Chief Engineer, Michigan Gas Utilities Company. Frank A. Perry, Senior, Corrosion Engineer, Henkels and McCoy, Inc. Al Robertson, National Accounts Manager, NALCO Chemical Company. Dennis L. Rossi, Corrosion Engineer, Boston Gas Com
