Underground Structure Corrosion

Underground Structure Corrosion

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