As an important component of the urban water supply system, the safe and stable operation of the tap water pipe is directly related to the daily lives of residents and the normal operation of the city. However, with the increase of service life and the influence of external environment, water pipes often experience leakage problems. Leakage not only causes waste of water resources, but may also have a negative impact on the stability and reliability of the water supply system. Therefore, timely detection and location of water leakage points, taking effective measures for repair, is an important part of ensuring the normal operation of the water supply system.
1、 The main cause of water pipe leakage
1. Aging of water pipes: If the water pipes have been used for too long and the materials have aged, they are prone to cracking, leading to water leakage.
2. Loose joint: If the water pipe joint is not tightened or the sealing ring is aged, it is easy to cause water leakage.
3. Excessive water pressure: Excessive water pressure may cause water pipes to rupture, leading to water leakage.
4. External damage: Water pipes are damaged or squeezed by external forces, resulting in water leakage.
5. Natural disasters: Natural disasters such as earthquakes and floods may also cause damage and leakage of pipelines.
2、 Method for detecting water leakage in tap water pipes
（1） Observation method
1. Turn off all water devices in the home and observe if the water meter is rotating. If the water meter is rotating, it indicates a leakage phenomenon.
2. Turn off the faucets and water devices in the home one by one, observe the changes in the water meter pointer, and find the leakage point.
（2） Auscultation method
1. Turn off all water equipment in the home, use a pipe leak detector close to the water pipes and joints, and listen carefully for any response. If there is a reaction, it indicates that there may be water leakage in this area.
（3） Dyeing method
1. Add food coloring to water and observe if any colored water flows out. If there is dyed water flowing out, it indicates that there is a leakage point.
（4） Stress testing method
1. Use professional water pipe pressure testing equipment to perform pressure testing on the water pipe and observe the reading on the pressure gauge. If the pressure gauge reading is abnormal, it indicates that there may be water leakage in the water pipe.
（5） Environmental Investigation Law
1. Check the position of the water pipes according to the installation drawings, including their connections, distribution, materials, and surrounding media.
2. Observe road conditions, the melting of early winter snow, the growth of vegetation above pipelines, and the continuous flow of clear water in wells and ditches to determine the leakage point.
（6） Sound listening leak detection method
1. There are three methods for leak detection: valve plug listening, road listening, and drilling positioning. Among them, the valve plug listening method uses a listening rod to directly measure the leakage sound of the dew point outside the pipeline (such as fire hydrants, drilled holes, and exposed pipelines). The frequency range of water leakage sound is usually between 100-2500Hz, and the higher the sound frequency, the closer it is to the water leakage point.
（7） Residual chlorine detection method
1. Using the principle of reacting residual chlorine with ortho toluidine to generate yellow quinone compounds, analyze the collected water samples and determine whether there is a leak in the water supply network through visual colorimetric method.
3、 Practical application cases
In a practical case, an old water pipe suddenly broke near the construction site, causing a large amount of water to gush out, affecting the surrounding roads and residents' lives. Through the comprehensive use of observation, auscultation, and environmental investigation methods, it was ultimately determined that the leakage point was located at an old joint of the pipeline. Subsequently, the water company quickly organized a professional maintenance team to repair the area, effectively preventing further expansion of the water leakage problem.
4、 Summary
The problem of water pipe leakage not only affects residents' daily lives, but may also have a serious impact on the water supply system. Therefore, it is crucial to promptly detect and locate the leakage point. By comprehensively utilizing various detection methods such as observation, auscultation, staining, pressure testing, environmental investigation, and auditory leak detection, the leakage point can be accurately and quickly identified, providing strong support for subsequent repair work. At the same time, strengthening regular inspections and maintenance of pipelines is also an important measure to prevent water leakage problems.
