Recent close-interval potential surveys have raised concerns about the accuracy of potential measurements on some older pipelines. Two significant sources of error were identified: metallic IR-drops and equalization currents. These resulted in measured on and off potentials which differed by hundreds of millivolts from the […]
In recent years, effective techniques have been developed for conducting integrity assessments along cross-country pipelines. In order to provide similar confidence in facility integrity, it was proposed to apply a modified external corrosion direct assessment process to a small station. Until now, congested facility environments […]
This paper summarizes the results of ten years of External Corrosion Direct Assessment (ECDA) application on more than 100 projects and includes a number of important lessons learned during the process. The large majority of the ECDA projects resulted in “clean bills of health” for […]
The analysis of indirect inspection data is a critical factor in conducting a successful External Corrosion Direct Assessment (ECDA) process. Any “out of range” data must be validated prior to being considered an ECDA indication. Furthermore, standard methods of validating the accuracy of the field […]
Two leaks were found on a recently installed (1999) pipeline which was coated with extruded polyethylene and protected with directly connected magnesium anodes. This paper describes the use of external corrosion direct assessment (ECDA) principles to identify locations where corrosion could pose a threat to […]
The interpretation of the indirect inspection data is a critical factor in conducting a successful ECDA process. The data must be validated, discrepancies must be resolved, and indications must be identified, classified and prioritized, in order to select the sites for direct examinations. The pipeline […]
The quality of the indirect inspection data is a critical factor in conducting a successful ECDA program. New NACE standards (SP0207-20071 and TM 0109-092), improved instrumentation, experience sharing, and extensive training during the last several years, has resulted in a significant improvement in the accuracy […]
