Use of Non-dimensional Transient Pressure Traces to Characterise Leaks in Water Pipelines

Fluid transients are important for water distribution systems both for its design and for operations. Controlled water transients have become an outstanding tool to locate and characterize faults or anomalies in pipelines. Results in this area of research have shown that transients can be successfully used for detecting and characterizing anomalies in pipelines. However, applications of these techniques usually depend on knowledge of the main characteristics of the analyzed system. The main objective of this paper is to present a non-dimensional transformation of transient pressure traces that is valid for characterizing the presence of leaks. Equations describing the non-dimensional transformation of pressure and time are presented, followed by the specific dimensionless numbers proposed to describe the characteristics of a leak. Numerical examples obtained using the Method of Characteristics (MOC) are included to show that the proposed transformation is general for pipelines with different dimensions (in terms of length, diameter and pipe wall material). In addition, a laboratory validation is presented, demonstrating that the proposed equations are valid to transform transient pressure traces and to compare the presence of leaks in pipelines. By presenting this transformation, transient based techniques with the capability of identifying different features simultaneously can be developed and existing techniques can be expanded to work without prior information on the dimensions of the pipeline.