Guidance on Practice for Cathodic Protection (BP)

[sasirkumar]

Hi all


Guidance on Practice for Cathodic Protection (BP)



Table of Contents - Page


Foreword.......................................... .................................................. ........................................... 2
Introduction...................................... .................................................. ............................................ 5
1. Scope .................................................. .................................................. ............................... 6
2. Normative references........................................ .................................................. ................... 6
3. Terms and definitions....................................... .................................................. .................... 7
4. Symbols and abbreviations..................................... .................................................. ........... 10
5. The importance of cathodic protection .................................................. ............................... 11
5.1. Corrosion threats .................................................. .................................................. .. 11
5.2. Hazards identification and mitigation........................................ ................................. 11
6. Competent person .................................................. .................................................. ........... 11
7. Cathodic protection principles .................................................. ............................................ 11
7.1. Corrosion control........................................... .................................................. .......... 11
7.2. Coatings .................................................. .................................................. ............... 12
7.3. Cathodic protection .................................................. ................................................. 12
7.4. Polarization .................................................. .................................................. ........... 14
7.5. Protection criteria onshore .................................................. ...................................... 14
7.6. Protection criteria offshore .................................................. ...................................... 14
7.7. Current density .................................................. .................................................. ..... 15
7.8. Under-protection and over-protection........................................ ................................ 16
7.9. IR drop.............................................. .................................................. ...................... 16
7.10. Coupons .................................................. .................................................. ............... 16
8. Galvanic anode systems........................................... .................................................. ......... 17
8.1. Galvanic anodes .................................................. .................................................. ... 17
8.2. Aluminium anodes .................................................. .................................................. 17
8.3. Magnesium anodes............................................ .................................................. ..... 18
8.4. Zinc anodes .................................................. .................................................. .......... 18
8.5. Applications marine and offshore .................................................. ............................ 18
8.6. Applications onshore........................................... .................................................. .... 19
8.7. Connection........................................ .................................................. ...................... 19
8.8. Installation...................................... .................................................. ......................... 20
8.9. Risk of failure .................................................. .................................................. ........ 20
9. Impressed current anode systems .................................................. ..................................... 21
9.1. Introduction...................................... .................................................. ....................... 21
9.2. Applications marine and offshore .................................................. ............................ 21
9.3. Applications onshore........................................... .................................................. .... 23
9.4. Power sources .................................................. .................................................. ...... 25
9.5. Anode types............................................. .................................................. ............... 26

9.6. Reference electrodes........................................ .................................................. ...... 28
9.7. Cables and connections....................................... .................................................. ... 28
9.8. Installation...................................... .................................................. ......................... 29
9.9. Risk of failure .................................................. .................................................. ........ 29
10. Hybrid systems .................................................. .................................................. ................ 29
11. Retrofit systems........................................... .................................................. ...................... 30
12. Advantages and disadvantages – galvanic and impressed current systems ........................ 31
13. Design objectives and considerations .................................................. ................................ 32
14. Safety and integrity .................................................. .................................................. .......... 34

Annex A (Informative) Basics of corrosion......................................... ............................................ 36
A.1 General........................................... .................................................. .................................. 36
A.2 Anodic and cathodic reactions .................................................. ........................................... 36
A.3 Electrolytes .................................................. .................................................. ...................... 37
A.4 Resistivity .................................................. .................................................. ........................ 37
A.5 Bimetallic corrosion......................................... .................................................. ................... 38
A.6 Microbial corrosion......................................... .................................................. .................... 38
A.7 Stray current corrosion......................................... .................................................. .............. 39
A.8 Electrochemical series .................................................. .................................................. ..... 39








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Regards
Sasikumar

[mbc.engg]

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[Achmad Nur Eddin]

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[Swami]

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[mkhurram79]

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[jury]

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[rahul_chengineer]

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[hadip]

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[muhammad usman]

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[FATHI]

thanks for this serious stuff ..really

[panthere0rose]

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[aragorn]

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