Internal Corrosion Monitoring in Pipelines by using Helical Ultrasonic Waves

Overview

Main Objective

The main objective of this research program is to design, implement and validate a nondestructive evaluation (NDE) technology for detecting, evaluating and monitoring the progression of internal corrosion in pipelines. Overall it is proposed to use a novel class of sensing system, helical guided ultrasonic waves (HGUW) and advanced data processing techniques for supporting corrosion diagnosis and decision-making.

Public Abstract

Corrosion is a leading cause of failure in metallic pipelines (both gas and hazardous liquids) in the United States. While corrosion processes are inevitable, their rate of progression can be significantly curtailed by appropriate mitigation strategies. Since corrosion processes are cumulative, periodic inspection is often not the optimal procedure for identifying areas requiring timely action to mitigate corrosion. There is an urgent need to change from periodic inspections where the time intervals are often established on the basis of limited-to-no-knowledge of likely corrosion to a more cost-effective condition-based inspection. This paradigm shift can be achieved by equipping pipelines with sensing and analysis systems to enable real-time, continuous and autonomous monitoring. With a paradigm shift into condition-based inspection, the objective of this research program is to design, implement and validate a NDE technology for detecting, evaluating and monitoring the progression of internal corrosion in pipelines. Overall it is proposed to use low profile piezoelectric transducers, helical guided ultrasonic waves (HGUW), and advanced data processing techniques for providing an accurate assessment of wall thickness degradation caused by corrosion. The approach leverages multiple echoes and reverberations present in recorded ultrasonic waveforms (generated by the cylindrical geometry of the pipe), in order to detect, locate and quantify corrosion damage. The key advantages of HGUW include: (1) the ability to probe a pipe (also inaccessible), locating damage from only a few monitoring points, thus increasing the inspection cost effectiveness, (2) the ability to inspect simultaneously the entire circumferential area of the pipe, (3) the increased sensitivity to many structural defects (e.g.: corrosion, fatigue cracks, etc.) owing to the wave structure choice, (4) the possibility of multimode/frequency examination for defect classification and sizing, and (5) the capability to detect both active damage and pre-existing damage by toggling between the modes of "passive" acoustic emission testing and "active" ultrasonic testing. The proposed technology will prevent catastrophic failures but also flag warnings of early deterioration to reduce the costs associated with mitigation strategies.

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