Water Leakage Detection (Physical Water Losses)
If the routes of the network pipes and valve locations in the area where physical water losses
are to be detected are unknown, priority should be given to the detection of pipes and valves.
In pipe location detection work, a cable-pipe locator that operates on the principle of detecting the naturally occurring magnetic field around conductive lines should be used for locating conductive pipes. For detecting non-conductive pipes, a ground-penetrating radar (GPR) should be employed, which operates based on the principle of radio signals reflecting off different density materials underground. Lost valves should be detected using a metal detector. WATER LEAKAGE
For the most accurate and efficient completion of the aforementioned location detection tasks, it is imperative that the detection devices used are of the highest quality and precision. Additionally, all location detection work should be conducted with the aid of a GPS device to record the coordinates of the detected pipes and lost valves. The coordinates of the detected network pipes and valve points should be compared with any existing maps, and necessary corrections and/or additions should be made electronically on the maps if required. If no existing map is available, a new map of the network to be inspected for water leaks should be created based on the coordinates collected in the field.
On main pipelines, ultrasonic flow meters are utilized at strategic points to estimate the approximate amount of leakage in that area. Example: In a neighborhood or district served by a main pipeline, an ultrasonic flow meter measures the flow rate. For accurate measurement, approximately two pipe diameters of the main pipeline must be exposed. This can be achieved by using valve chambers if available or by excavating at suitable points to expose the pipe. The average flow rate obtained from the measurement is then compared to the average flow rate calculated from the billed water amount for the neighborhood or district served by that pipe. This comparison allows for an approximate assessment of the water leakage in the area.
During this phase, noise levels from water usage and surrounding sounds (such as vehicles, pedestrians, nearby machinery, equipment, etc.) are minimized by conducting the noise recording between midnight and dawn. Noise loggers are fixed to the valves identified in the previously described areas, and noise is monitored and recorded. The noise recordings are then transferred to a computer for graphical analysis in the office. This analysis helps pinpoint the intervals of valves where water leakage is detected and marks them on the map. The pinpointing of water leaks within these marked valve intervals is achieved through two distinct methods. The first method is "correlation." To apply this method, it is essential to know the following data about the pipe within the valve interval:
The second "spot detection" method involves the use of an "acoustic listening microphone" to conduct precise listening along the pipe. This acoustic listening technique is applied when correlation methods are either unsuitable or fail to detect water leaks. In this method, a sensitive acoustic microphone, responsive to sound, is used to listen at specific intervals along the pipeline. The point(s) with the highest sound level are identified as the locations of the water leak. For accurate and rapid water leak detection, it is imperative that the water leak detection devices used in these operations are of high quality and precision.
Water leak points identified through correlation and acoustic listening methods are excavated for repair. The repair process generally involves two methods, depending on the type and extent of the damage: The first and most commonly applied method is the use of a "quick repair clamp" suitable for the pipe diameter. This method's primary advantage is that it does not require interrupting the flow within the network.The second repair method involves cutting the pipe at the leak point and installing a replacement segment (preferably made from the same material) to bridge the gap. This method necessitates stopping the flow in the network, making it less preferred except in urgent situations.In both methods, the area around the leak must be fully exposed. After the repair is completed, it is crucial to test the repair thoroughly before closing up the pipe to ensure that the repair has been executed correctly.