Development of LaserPro System for External Corrosion Mapping With Integrated Assessment

This paper presents the design and application of a new semi-automatic tool for mapping external pipeline corrosion. The device hardware is complemented by the implementation of current corrosion assessment techniques via online software. The development of this device is based on over 10 years of experience in external corrosion mapping and automated scanner development, in support of an experimental research program at the University of Waterloo. The mapping device hardware consists of a novel position measurement system which is coupled to a laser-based depth measurement device to generate a surface map of corrosion defects. Direct comparison with manual (pit gauge) and fully automated measurements has shown that a given defect can be quickly and accurately mapped using the new system. Automated data capture and evaluation has demonstrated significant improvements over fully manual pit gauge-based methods. In addition, the manual position of the measurement head allows the user to map only those areas which are pertinent to the assessment. This is in contrast to fully automated methods which require continuous measurements over predefined areas of a pipe. Online feedback compliments this system and allows the operator to determine if the data set is complete by providing information on the convergence of the predicted failure pressure. Using this new mapping device, measured surface maps of natural complex corrosion defects are shown to compare favorably with other mapping devices and manually measured defect dimensions.