Maintenance and Operation of Cathodic Protection Systems

Custom Search

Back

Maintenance and Operation of Cathodic Protection Systems

Maintenance and Operation of Cathodic Protection Systems
Distribution
Foreword
Abstract
Change Control Sheet
Table of Contents
Table of Contents -Cont.
Table of Contents-cont.
Table of Contents-Cont.
Table of Contents-Cont.
Table of Contents-Cont.
Figures
Figures -Cont.
Figures -Cont.
Figures -Cont.
Tables
Chapter 1. Introduction
Responsibilities
Responsibilities -Cont.
Chapter 2. Principles of Operation
The Electrochemical Cell
Cathodic Protection
Sacrificial Anode Cathodic Protection Systems
Table 2-1. Current Requirements for Cathodic Protection of Bare Steel
Table 2-2. Current Requirements for Cathodic Protection of Coated Steel
Impressed Current Systems
Figure 2-4. Impressed Current Cathodic Protection
Chapter 3. Economic Analysis-Maintenance and Operation of Cathodic Protection Systems
Determne Costs and Benefits
Cost Documentation
Perform Sensitivity Analysis
Economic Analysis
Cost/Benefit Analysis
Cost/Benefit Analysis -Cont.
Figure 3-3. Cash Flow Diagram - Retrofitting Cathodic Protection Protection on Exisiting Line
Figure 3-4. Cash Flow Diagram- Replacement of Exisiting Line
Economic Analysis
Cost/Benefit Analysis
Figure 3-6 Cash Flow Diagram- Cathodic Protection System Maintenance Discontinued
Additional Comments
Chapter 4. Components of Cathodic Protection Systems
Types of Anodes
Table 4-2. Standard Alloy Magnesium anodes Standard Sizes for Use in Water
Table 4-4. Standard Alloy Magnesium Anodes Elongated for High Current Output
Table 4-6 High Potential Alloy Magnesium Anodes for Use in Soil or Water
Table 4-7. Composistion of Magnesuim Anodes
Table 4-10 Standard Sizes of Zinc Anodes for Use in Seawater
Table 4-12 Composition Of Zinc Anodes
Connection to Structure
Figure 4-3. Thermite Welding Equipment
Figure 4-4 Thermite Welding Process
Test Stations
Impressed Current Systems
Figure 4-9. Catholic Protection Rectiifer
Figure 4-9b Circuit Diagram for Typical Cathodic Protection Rectifier
Types of Anodes
Figure 4-10 Typical Graphite Anode Cable Connection
Table 4-14. Standard HSBCCI Anodes
Table 4-14. Standard HSBCCI Anodes -Cont.
Table 4-15. Special HSCBCI Anodes
Figure 4-11 HSCBCI Type M Anode
Figure 4-12. Typical HSCBCI Duct Anode
Figure 4-15. Typical HSCBCI Anode to Cable Connection Epoxy Encapsulated Type
Installation of Anodes
Connection to Rectifier and Structure
Chapter 5. Instruments and Equipment for Inspection and Maintenance of Cathodic Protection Systems
Figure 5-1. Digital Voltmeter Manufactured for General Use
Figure 5-3. Combination Meter
Figure 5-5. Temperature Correction for Copper/Copper Sulfate Reference Electrodes
Reference Cells
Wire Reels
Measuring Tapes
Shunts
Current Interrupter
Equipment List
Ph Test Equipment
Chapter 6. How to Perform Scheduled Field Measurements
Connection to Structure
Placement of Reference Electrodes
Test Stations
Paved Areas
Marine Structures
Figure 6-7. Locations for Potential Measurements on Buried Vertical Tanks
Interpretation of Readings
Criteria for Protection
Copper
Coating Disbondment
Hydrogen Embrittlement
Table 6-1 Safe Limits of Potentials for Hydrogen Embrittlement of Steel
Routine Rectifier Inspections
Visual and Mechanical Inspections
Chapter 7. How to Perform Non-Routine Field Measurements
Two Pin Method
Interference Testing
Figure 7-4. Soil Resistivity Measurement Using a Soil Box
Principles of Interference
Detection of Interference
Figure 7-7 Example of Interference Testing
Figure 7-8. Plot of Structure to Electrolyte Potentials Showing Interference
Control of Interference
Figure 7-10. Correction of Interference by Direct Bonding/ Resisitive Bonding
Figure 7-11 Potential at Crossing with Resistive Bonding
Figure 7-13. Use of Sacrificial anode to Control Interference
Chemical Methods
Anode Bed Testing
Continuity Testing
Figure 7-17 Locating Faulty Anodes in Anode Bed
Figure 7-19 Conductivity Testing by IR Drop Method
Insulation Testing
Coating Conductance Testing
Short Line Method
Long line Method
Figure 7-25. Coating Conductance -Long Line Method
Chapter 8. Scheduled Inspection Requirements
Mechanical Inspection
Figure 8-1. Form for Recording Rectifier Output and Settings
Figure 8-2 Form for Recording Structure to Electrolyte Potentials
Chapter 9. How to Tell If the System is Working
Mechanical Condition
Chapter 10. Preventive Maintenance Troubleshooting
Figure 10-2 Rectifier Stack Reverse Leakage Test -Center Tap Circuit
Forward Voltage Drop Test
Figure 10-5 Rectifier Stack Forward Voltage Drop Test Three Phase Bridge Type Circuit
Figure 10-7. Rectifier stack Forward Voltage Drop Test Three Phase Wye Circuit
Figure 10-8 Limits for Stack Forward Voltage Drop
Half Wave Testing
Table 10-1 Rated Voltage for Use In Determining Half Wave Reverse Leakage Current
Figure 10-10 Half Wave Reverse Leakage Test Three Phase Bridge Type Circuit
Figure 10-12 Half Wave Reverse Leakage Test Three Phase Wye Type Circuit
Half Wave Forward Voltage Drop Check
Figure 10-16 Half Wave Forward Voltage Drop Test Single Phase Center Tap Type Circuit
Figure 10-18 Half Wave Forward Voltage Drop Test Using Variac as Voltage Source
Figure 10-19 Limits for Half Wave Forward Voltage Drop
Table 10-2 DC Current Rating for Half Wave Stacks
SIlicon Stacks
Rectifier Meters
Impressed Current Anodes
Figure 10-23 Vertically Buried Impressed Current Anode
Waterside
Sacrificial
Figure 10-28. Typical Installation of Direct Mounted Anode Hot Water Tank
Connections
Test Stations
Chapter 11. Checklist for Repair and Troubleshooting
Rectifiers
Table 11-1 Minimum Ratio of AC Input Voltage to Secondary Voltage
Figure 11-1 Rectifier Filter Circuit
Impressed Current Anode Beds
Sacrificial Anode Systems
Appendix A Economic Life Guidelines
Appendix B Project Year Discount Factors
Appendix C Present Value Formulae
Index
Index-Cont.
Index-Cont.

Maintenance and Operation of Cathodic Protection Systems