Scheduled Preventive Maintenance Balancing Program

Introduction

To comply with environmental regulations, public law and industry standards, preventive maintenance is required for all installed cathodic protection systems.

Cathodic Protection Survey: Sacrificial Galvanic System and Impressed Current System

The purpose of this survey is to ensure that adequate cathodic protection is maintained over the entire protected structure. It should be thorough and comprehensive to identify problems within the protected structure.

The surveys measurement errors must be considered, typically through application of sound engineering practices, which address the location of the reference cell, the protected structure, the anodes.

The cathodic protection survey must be conducted ½ yearly or annually. Reference to BS7361 and NACE RP0169.

The test CP system components in accordance to the following and accomplish potential measurements of the protected structure.

Aerobic Environment

• -0.80 volts vs Ag/Ag Chloride
• +0.25 volts vs zinc
• -0.85 volts vs Cu/CuSO4

References

NACE Recommended Practices

• Underwater Inspection

  

  Laboratory Anode Efficiency Test

  

  ICP - Optical Emission Spectroscopy

  

  NACE Cathodic Protection Course
  RP0169 Control Of External Corrosion On Underground Or Submerged Metallic Piping System
• RP0286 Electrical Isolation Of Cathodically Protected Pipelines

British Standard

• BS7361 Cathodic Protection – Part 1 – Code Of Practice For Land And Marine Applications