Underground Structure Corrosion
ECDA (External Corrosion Direct Assessment)
￭ Inspection CP system and coating
￭ Structure Failure Direct Exam.
￭ Analysis of corrosion root cause
Underground Pipeline Integrity Inspection 1
CP management and routine surveys
￭ On/OFF potential measurement
￭ Soil resistivity measurement
￭ Pipeline locating survey
￭ Isolation test
￭ Soundness of CP facilities (TB and rectifier, etc)
Underground Pipeline Integrity Inspection 2
CP in-depth surveys
￭ CIPS (Close Interval Potential Survey)t
￭ Coating Defect Survey (DCVG)t
￭ Static (dynamic) interference survey t
￭ Temporary ICCP tests for CP retrofit
Damaged Coating Detection
Underground Pipeline Integrity Inspection 3
ECDA (External Corrosion Direct Assessment)
￭ Based on NACE RP0502-2002
￭ Inspect the soundness of CP system and coating quality, basically.
￭ Direct (excavation) inspection of points having a high probability of corrosion
￭ Provision of root cause for corrosion
ECDA
