Condition assessment of pipelines using a bi-directional layer-peeling method and a dual-sensor configuration

Abstract

Over the past two and a half decades, hydraulic transients have been proposed and also used to assess the condition of pipeline systems through detection of anomalies such as extended pipe wall corrosion and blockages. This paper proposes a new bi-directional layer-peeling method which is capable of reconstructing estimates of the spatial distribution of the pipe wall thickness section by section both in the upstream and the downstream direction from the measurement site. Effects of branched pipes connected to the main pipe are also incorporated into the developed approach. A dual-sensor (a pair of closely placed pressure transducers at one measurement site), instead of a single pressure transducer, is used to both measure the pressure traces and to separate the directional hydraulic transient waves. The layer-peeling method originally developed in the acoustics field has been adapted and further developed to allow bi-directional reconstruction for pressurized water pipes. Numerical verifications are performed on a pipeline with three deteriorated sections and a uniform branch. The deteriorated sections in the pipeline are successfully detected using the pressure traces simulated by the method of characteristics (MOC). Experimental verification is also conducted on a laboratory copper pipeline, and two sections of pipe with thinner wall thicknesses, located on both sides of the dual-sensor, are successfully detected.