METHOD AND APPARATUS FOR MEASURING CURVATURE AND CURVATURE VARIATIONS IN PIPELINES AND THE LIKE

摘要

Pipeline curvature is detected, measured and recorded by an instrumented pig carrying an array of sensing wheels down a length of pipeline with the sensing wheels engaging the inner wall of the pipeline in a symmetrical configuration about the axis of the pipeline. The rotation of the sensing wheels is encoded as a function of the distance travelled by each wheel over predetermined increments of axial travel of the array down the pipeline to provide periodic readout of curvature parameters between known positions (over known increments of length) of the run of pipeline traversed by the pig. A magnetic tape recorder in the pig records the curvature readout for each incremental length of pipeline traversed to provide a recorded profile of curvature correlated to position along the run to establish initial acceptable curvature conditions therefor. A succeeding run of the pig through the same run of pipeline results in a second profile which can be compared with the first profile in a computer to determine variations in curvature from the initial conditions together with the location of such variations along the run.