TRYCKTRANSIENTER FÖR STUDIUM AV HYDRAULISKA FÖRHÅLLANDEN I RÖRLEDNINGAR / The use of hydraulic transients for studying hydraulic conditions in pipelines
Hydraulic transients occur at rapid flow changes in pressurized water conveying pipelines. Normally such transients (waterhammer) are considered to be a problem as they might damage the pipeline due to strong pressure peaks, subatmospheric pressures or fatigue. However, normally occurring hydraulic transients have also a potential to be utilized in an advantageous manner. ’The idea is that transients could be looked upon as a ”probe” that propagates through a pipeline and at the same time being affected by certain conditions of the pipeline. Measurement and subsequent analysis of transients might thus provide information on some aspects of the hydraulic status of a pipeline. This paper discusses the analysis or measured transients in order to extract information on hydraulic conditions of pipelines. This is done by means of a number of specific measurements
on pipelines in the field or in the laboratory, Thus it is shown that the effect of an air pocket, a pipe material change, a change in pipe diameter, a leak, an unknown check valve and finally a slow check valve can be traced on the transient pressure shape.