External Corrosion Direct Assessment (ECDA)

The Direct Assessment Pipeline Integrity Management program consists of 3 primary assessment programs.  They are:

  • External Corrosion Direct Assessment (ECDA)
  • Internal Corrosion Direct Assessment (ICDA) and
  • Stress Corrosion Cracking Direct Assessment (SCCDA)

ECDA programs encompass four major phases and they are:

Pre-Assessment – In the Pre-Assessment phase, as-built design, construction, operations and maintenance records are collated and analysed, including historic and current data, to determine ECDA feasibility.  Then, selection of indirect inspection tools for the respective regions is also identified.

Indirect Inspection – This is the second phase where pre-inspection planning is carried out followed by indirect inspections.  The common indirect inspection tools include Close Interval Surveys (CIS), Direct Current Voltage Gradient Surveys (DCVG), Soil type and Topography surveys.

Direct Examination – During this phase, analysis of the indirect inspection data will be carried out to select excavation sites for direct pipe surface examination and data collation.  Defect measurements are carried out followed by remaining strength analysis, root cause analysis and mitigation measures recommended and implemented.

Post-Assessment – This is the last phase where the remaining flaw sizes and corrosion growth rates are estimated for determining the next re-assessment interval.  Lastly, the data collated from the last three phases are also analysed to determine the effectiveness of the entire direct assessment process and updated for the next assessment cycle.

Expertise – GreenScience Technologies provides the complete range of ECDA inspection programs and analysis including data integration and program development.