CHAPTER 19
CATHODIC PROTECTION SYSTEMS

TABLE OF CONTENTS

CERTIFICATION SHEET

RECORD OF CHANGES

SAFETY SUMMARY

SECTION 1 - INTRODUCTION

19-1.3 APPLICABILITY

19-1.4 PRINCIPLES OF CATHODIC PROTECTION SYSTEMS

19-1.4.1 Theory of Corrosion

19-1.4.2 The Galvanic Series

19-1.4.3 The Principle of the Impressed Current Cathodic Protection System

19-1.4.4 Anti-Corrosion Paint

19-1.4.5 Hull Areas Most Likely to Corrode

19-1.4.6 The Hull-Mounted Components of the ICCP System

SECTION 2 - PLANNING AND PREPARATION

19-2.1 GENERAL INFORMATION

19-2.1.1 Isolation of the ICCP System

19-2.1.2 Identifying the Task

19-2.2 REFERENCE DOCUMENTS

19-2.2.1 Ship Drawing Index

19-2.2.3 Technical Manuals

19-2.2.4 Military Specifications and Standards

19-2.2.5 Records and Reports

19-2.3 SHIP CHECK

19-2.4 INSPECTION DIVE

19-2.5 CHOOSING THE APPROPRIATE ANODE REPLACEMENT PROCEDURE

19-2.6 TYPICAL REPAIR TASK DURATION

19-2.7 TOOLS, MATERIALS, AND EQUIPMENT REQUIREMENTS

SECTION 3 - INSPECTION

19-3.2 INSPECTION PROCEDURE

19-3.2.1 Inspection Dive Considerations

19-3.2.2 Anode and Dielectric Shield Inspection

SECTION 4 - REPAIRS

19-4.1 INTRODUCTION

19-4.2 ANODE REMOVAL AND REPLACEMENT PROCEDURE - DRY

19-4.2.1 Anode Removal

19-4.2.2 Anode Replacement

19-4.3 ANODE REMOVAL AND REPLACEMENT PROCEDURE - WET

19-4.3.1 Anode Removal

19-4.3.2 Anode Replacement

19-4.4 REFERENCE CELL REMOVAL AND REPLACEMENT PROCEDURE

19-4.5 DIELECTRIC SHIELD REPAIRS

19-4.6 POST-REPAIR PROCEDURES

Section 5 - LPD 17 CLASS ICCP SYSTEM REPAIRS

19-5.1 INTRODUCTION

19-5.2 ANODE REMOVAL AND REPLACEMENT PROCEDURE

19-5.3 REFERENCE CELL REMOVAL AND REPLACEMENT PROCEDURE

19-5.4 POST-REPAIR PROCEDURES

LIST OF APPENDICES

APPENDIX A - UNDERWATER EPOXY PAINTS

APPENDIX B - SETUP AND OPERATION OF THE SANDBLASTER

LIST OF ILLUSTRATIONS

Figure 19-1 Electromechanical Corrosion Cell

Figure 19-2 Basic Impressed Current Cathodic Protection System

Figure 19-3 Impressed Current Cathodic Protection System Units

Figure 19-4 Anode

Figure 19-5 Reference Cell

Figure 19-6 Capastic Dielectric Shield for a 4-Foot Anode

Figure 19-7 Diver Hull Inspection Data Sheet

Figure 19-8 Anode Assembly

Figure 19-9 Anode Gland Assembly Internal Blanking Plug

Figure 19-10 External Blanking Plate

Figure 19-10A Removal of Dielectric Shield.

Figure 19-11 Reference Cell and Gland Seal Assembly

Figure 19-12 High Hat

Figure 19-13 Reference Cell Gland Assembly Internal Blanking Plug

Figure 19-14 Guide Rod

Figure 19-15 LPD Class Four Foot Anode

Figure 19-16 LPD Class Eight Foot Anode

Figure 19-17 LPD Class Reference Electrode

LIST OF TABLES

Table 19-1 Materials for Anode Replacement

Table 19-2 Materials for Reference Cell Replacement

Table 19-3 Material for Dielectric Shield Repair

Table 19-4 LPD 17 Class Four Foot Anode Kit

Table 19-5 LPD 17 Class Eight Foot Anode Kit

Table 19-6 LPD 17 Class Reference Electrode Kit

Table 19-7 LPD 17 Class List of Anodes and Reference Electrodes

Table A-1 Approved Epoxy Paint