Leaks in pipelines give rise to hydraulic parameters changing with the time at inlet and outlet. This fact leads to a new method of finding leaks. After the leaks present, inlet discharge increases abruptly comparing with the steady flow situation, whereas inlet pressure, outlet discharge and pressure decrease abruptly. Thus, the theory of abrupt change is used to on-line detect the abrupt points of hydraulic parameters at inlet and outlet of the pipeline to detect leak. The presence of abrupt points indicates there are leaks in pipelines. The technique has been successful in detecting leaks from a laboratory pipeline.
Long-distance pipeline, one of the most important transportation means, has been widely utilized around the world. However, leak in pipelines often occurs owing to different reasons, which causes much larger economic loss and environmental destruction. Therefore, it is necessary to study the leak detection methods to minimize damage. The researchers have developed many leak detecting methods during the past of a few years. Developed detecting methods are divided into two groups: direct leak detection methods and hydraulic methods. Direct leak detection methods are including the observational method, pig-based leak detection method, acoustic leak detection method etc. Hydraulic methods are including reflected wave method, transient model method, mass balance method, pressure gradient method etc. Each of these methods for finding leaks has its advantages and disadvantages in different circumstances. However, traditional methods are not suitable for the long-distance pipeline due to their expensive price, difficult maintenance and the influence on normal running, etc. especially, the random characteristics of hydraulic parameters causes a large error. So, a statistical analysis method is introduced in this paper for the purpose of minimizing the error. That is the motivation of this paper.
