1....sacrificial anodes cp

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cathodic protection

Transcript of 1....sacrificial anodes cp

  • 1. 1D4e-1l7ta M carocnhs, 2u0lt1i1ng 1

2. Corrosion Control Techniques5.Cathodic ProtectionDelta consulting 2 3. Corrosion Control Techniques5.Cathodic ProtectionTypes of CP SystemsAccording to the source of external supply of electrons,there are two types of CP systems:1- Sacrificial anode system2 - Impressed current systemDelta consulting 3 4. Corrosion Control Techniques5.Cathodic ProtectionMagnesiumZincAluminumIronLeadTinNickel (Active)BrassCopperNickel (Passive)410 StainlessTitanium304 StainlessSilverGoldPlatinumACTIVESimplified GalvanicSeriesNOBLE1- Sacrificial anode systemZnFee-Delta consulting 4 5. Corrosion Control Techniques5.Cathodic ProtectionGalvanic Couples in Saline WaterFe/Al Fe Fe/Cu Fe/AgCu/AgWithout electrolyte With electrolyteDelta consulting 5 6. Corrosion Control Techniques5.Cathodic ProtectionArrangement of a Sacrificial CP SystemIAnode e- Fe Drain PointDelta consulting 6 7. Corrosion Control Techniques5.Cathodic ProtectionCommon Sacrificial AnodesDelta consulting 7 8. Corrosion Control Techniques5.Cathodic ProtectionCommon Sacrificial AnodesAnode Recommended Electrolyte(Magnesium (Mg Soils & hot water(Zinc (Zn Soils & fresh / sea water(Aluminum (Al Sea watersAt temp. > 600 C : Al & Zn oxidize leading to Reverse PolarityIndium is added to aluminum to avoid its oxidationDelta consulting 8 9. Corrosion Control Techniques5.Cathodic ProtectionGeneralization :Aqueous media with low resistivity, Al anode arepreferred, e.g. seawaterMg anodes are used in higher resistivity aqueousmedia, e.g. wetted soils.Delta consulting 9 10. Corrosion Control Techniques5.Cathodic ProtectionPrepackaged Sacrificial AnodeFor soil applications: prepackaged Mg & Zn anodesBackfill:75% Gypsum +20% Bentonite clay +5% Sodium sulfateRole of Backfill: to absorband maintain the soil water,so keeping the anode inwet environmentDelta consulting 10 11. Corrosion Control Techniques5.Cathodic ProtectionMain types and shapes of Al & Zn anodes:1. Slender ( stand-off (2. Flush mounted3. Half-shell bracelet4. Spherical5. Ribbon11Delta consulting 112244 33 12. Corrosion Control Techniques5.Cathodic ProtectionRibbon Anodes 55 ( Zinc / Magnesium (Delta consulting 12 13. Corrosion Control Techniques5.Cathodic ProtectionApplications of sacrificial cathodic protection system:Buried / sub sea pipelinesBuried pipingPlatforms and rigsMaine pilesTank internalsDelta consulting 13 14. Corrosion Control Techniques5.Cathodic ProtectionSacrificial anodes foronshore pipingDelta consulting 14 15. Corrosion Control Techniques5.Cathodic ProtectionTypical CP of a buriedpipeline with prepackagedsacrificial anodesDelta consulting 15 16. Corrosion Control Techniques5.Cathodic ProtectionSacrificial anodes forplatform jacketsDelta consulting 16 17. Corrosion Control Techniques5.Cathodic ProtectionSacrificial anodes forplatform jacketsDelta consulting 17 18. Corrosion Control Techniques5.Cathodic ProtectionSubsea pipeline layingBracelet anode FLUSH withcement coatingDelta consulting 18 19. Corrosion Control Techniques5.Cathodic ProtectionSacrificial Anode CathodicProtection for External Sideof Tank BottomDelta consulting 19 20. Corrosion Control Techniques5.Cathodic ProtectionSacrificial anodes for vessel internalsMist EliminatorSacrificial AnodeDelta consulting 20 21. Corrosion Control Techniques5.Cathodic ProtectionAir in as Tank BreathesSever Corrosion Due toCondensed Aerated MoistureVaporCrude OilCorrosive Formation WaterProtectiveCoatingsCoatings +CPSacrificialAnodesDelta consulting 21 22. Corrosion Control Techniques5.Cathodic ProtectionSacrificial anodes for tank internalsPainted Anode SideFacing Tanks ShellDelta consulting 22 23. Corrosion Control Techniques5.Cathodic ProtectionAnodes Distribution onTank ShellEL +7500EL +5500EL +3500EL +1500EL +500HH LevelSEC A-ASEC B-BSEC A-ASEC B-BLL LevelSEC A-AN NSEC A-ASEC B-BDelta consulting 23 24. Corrosion Control Techniques5.Cathodic ProtectionSacrificial Anodes Layout onInternal Tank BottomDelta consulting 24 25. Corrosion Control Techniques5.Cathodic ProtectionSacrificial anodes for tank internalsTack weldFull filtweldAnode Fixation on Tank ShellU-BoltAnode Alloy Tank Floor BracketSteel BarAnode InsertAnode Fixation on Tank BottomAnode Fixation on Tank Bottomby WeldingDelta consulting 25 26. Corrosion Control Techniques5.Cathodic ProtectionSacrificial Anodes for Ship HullsDelta consulting 26 27. Thank You and Good LuckDelta consulting 27