The UC-Berkeley, California spin-out 4D Imaging has unveiled a pipeline integrity monitoring system based on magnetic-resonance imaging (MRI). The system transmits the status of a pipeline to the internet and gives pipeline operators a real-time picture of the health of the pipeline, checking for fractures at welds or support systems and corrosion failure.
According to 4D Imaging, the system can be installed on any pipeline, small or large, and is cost effective. The pipeline MRI involves wrapping the pipe in wire coils. One set of coils is electrified which magnetizes the steel pipe. Then a second set of coils detects the magnetic field being given off by the now magnetized pipe. ‘Conveniently, when steel corrodes and degrades it becomes less magnetic, so variations in the pipes magnetism represent areas that may have corroded or become compromised,’ said 4D.
‘If the level of corrosion exceeds 0.008 of the pipe the system will issue a warning that the area of pipe has become compromised. The pipe’s temperature is also measured, both to account for changes in magnetism unrelated to corrosion and to keep track of the heat or cold stresses that the pipe has been under.
‘To minimize electricity usage, the coils electrify and record their data one at a time in sequence along the length of the pipeline. It takes the system about three seconds to thoroughly test a segment of pipe. Once the check has been performed the data is sent back to a computer and can be plotted against a schematic of the pipe, displaying which areas might require attention.’