Views: 21 Author: Site Editor Publish Time: 2018-12-11 Origin: Site
Every drop of clean water is precious. Unfortunately, 30–50% of water is lost through aging infrastructure. Water is lost through leaks and cracks in pipes and their fit tings. Since most infrastructure is underground, it is virtually impossible to visually determine the location of these leaks unless the water has reached the surface (causing ponding and sink holes, structural damage, buckling pavement, etc.), and the exact location may be indeterminate. Leak detection requires special technologies that allow inspectors to precisely determine the location and severity of pipeline leaks. This is a field that continues to grow and advance by utilizing both established technology and by adopting emerging methods.
THE IMPORTANCE OF LEAK DETECTION
The accumulation of losses over long durations can result in signi ficant losses even from insignificant leaks. And if water can get out, impurities (soil, bacteria, organics, etc.) can get in and impair the quality of the water, even rendering it unfit to drink.
LEAK DETECTION METHODS
Acoustic detection remains the primary means of detecting and locating pipeline leaks. The method of acoustic leak detection is described as the systematic method of using listening equipment to survey the distribution system, identify leak sounds, and pinpoint the exact locations of hidden underground leaks. Water escaping under high pressure from a pipe leak or crack makes a distinct rushing or hissing sound that can carry considerable distance along the length of the pipe itself (in contrast, the loose soil surrounding the pipe in its backfilled trench makes a poor conductor of sound). In this sense, the pipe acts as a medium for transmitting sound. In doing so, it can act like the strings on a guitar, vibrating with different pitches for different pipe lengths, diameters, and materials. Small diameter metal pipes carry sound the greatest distance, up to 1,000 linear feet, while large diameter polyvinyl chloride (PVC) pipes can carry sound only 100 feet.
The listening devices used to detect this sound come in various operational modes. They can be mobile or fixed, direct or indirect, external or internal, or transit data via radio or utilize manual download into laptop computers. There are mobile acoustic sensors that are manually operated or run along the pipe segment on wheels. In either case, the sensors consist of ground microphones that listen below the surface as the operator walks along the pipe segment. As he operates his sensor, the signal will get louder as he zeroes in on its location. There are also permanently mounted units in fixed locations along the pipe network. Accuracy is typically between 3–4 feet—more than sufficient to allow digging operations to expose and repair the leak. The use of mobile devices can be hampered by local environment and engineered structures. Sound at the surface can be muffled by deep soil, thick roadway pavement, or heavy local traffic.
Secondary leak detection methods utilize pressure differences. These are measured by strategically located flow meters and pressure gauges that can, by differences in the readings, bracket the location of the leak. For example, if flow rates at the start of the pipe length are significantly higher than at its terminus, it is likely that there is a leak occurring between these two points. Pressure drops compared to initial operating condition immediately after installation will indicate the escape of water and subsequent lowering of pressure from its original state. The two systems can be used together with the pressure and flow differentials used to bracket the leak’s location and mobile acoustic sensors running along this bracketed length to pinpoint its location. The use of the former saves considerable time and tedious effort by the latter.
We provide a good water leak detection
PQWT-CL Series underground pipes water leak detector is high performance leak detection equipment, has powerful anti-jamming and data processing capabilities, you can make your work easier.
1. The use of latest digital signal processing chip and a digital filter chip, 16M cache controller integrated, more responsive. In particular,it can filter with the interference of environmental noise, screening out the leakage noise, allowing the operator to lock leakage points quickly.
2. 7-inch high-definition digital color LCD touch screen with a resolution of 800 * 480, can provide 12 display pages, can show the measurement parameters more clearly and intuitively, and full touch screen design, simple operation.
3. Each has 1 ~ 5000Hz frequency range (spectrum analysis), can be displayed the distribution of the noise signal at each frequency in real-time.
4. Automatic drawing continuous noise curve (Long-Term Mode) within a certain time, So that the leakage point position is determined more quickly.
5. Sensor is built-in preamp circuit, using a rubber ring seal and cushion, and the application of professional acoustic methods,making the ability to capture the noise is higher than similar products.
6. Adopt latest noise detecting element, sounds clear.
7. Save 8 sections totaling eight minutes of recording, which is not lost after shut down, could be analyzed at any time.
8. Using a large capacity battery, can work for more than ten hours , and can be removed charging and online charging.
9. Super anti-jamming circuit design, digital signal and analog signal effectively isolate and eliminate the noise generated by the digital circuit.
For more information, please contact PQWT Team.