Case studies
| No | Client type | History of leaks | Trial with
Magic Carpet | Benefits of use of
Magic Carpet | Estimated annual cost saving |
|---|
| 1 | Large Water Company | The leak was located to a confidence of 2 metres by first phase leakage detection methods. The inspectors had been unable to detect any noise on the surface with other methods so could not verify that there was a leak. | Use of the Magic Carpet quickly identified a leak profile (gain set at 60%). Excavation followed and confirmed a leak exactly in the position identified by the Magic Carpet. | The Magic Carpet can quickly detect leakage noise to finally position a leak where other methods cannot. Prevented dry hole. | Applied to 10% of the leak investigations:-
£450,000 cost savings. |
| 2 | Large Water Company | The leak position had been previously identified and positioned with first phase detection and other listening device methods. Excavation was about to be undertaken. | Use of the Magic Carpet confirmed there was noise at the existing identified leak position. However, the display profile was not consistent with a normal leak and it was suspected that the noise was reflective and the identified position incorrect. The stopcock feeding No 11 was shut and the Magic Carpet showed the noise source disappeared. The Magic Carpet was then laid along the line of the communication pipe to No 11 and a strong leak signal (gain at 50%) found approximately 1.5m from the proposed excavation hole. | Demonstrated that the Magic Carpet is able to distinguish between reflective noise and leak noise. Had the Magic Carpet not been used, a dry hole would have been excavated. Time saving of 30 minutes and prevention of hole extension. | Applied to 5% of investigations:-
£45,000 cost savings. |
| 3 | Medium sized Water Company | Outside a pub. Considerable time had been spent in trying to locate the leak and a number of positions were suspected. However it had not been possible to get consistent results. This was a particularly noisy area so the test was conducted at night. | The Magic Carpet was used along a length of 20m and identified a leak position with a gain at 60%. Other listening methods were then employed and identified noise approximately 0.75m from the position identified by the Magic Carpet. A hole was excavated that just encompassed both positions and the leak proved to be located in the exact spot as identified by the Magic Carpet. | More accurate than other listening methods preventing hole extensions. | Applied to 5% of investigations:-
£45,000 cost savings. |
| 4 | Small Water Company | Residential area. Cast Iron main? It was quite windy and there was transient background noise from cars and pedestrians. A very experienced inspector using first and second phase methods had already made a mark positioning the leak. The 2nd phase of this positioning had taken considerable time, as it had been difficult to find the peak of the noise. This was partly because the noise was very faint and it was known that the main was at least 1.3m below the ground. Wind noise had also interfered. | An operative who had very little experience used the Magic Carpet. Starting from the first phase leak location the Magic Carpet was laid over a distance of some 10m and within 3 minutes showed a clear leak profile approximately 200mm from the mark identified by the other methods. The gain was at 60%. A hole was excavated the next day and the leak found within 200mm of the position identified by the Magic Carpet and 400mm away from the position found by the other method. | Magic Carpet not affected by wind noise. Inexperienced user can pinpoint leaks quickly and accurately. Potential time saving of 30 minutes per leak. Potential training costs significantly reduced. (These have not yet been estimated) | Applied to 40% of leak investigations:- £30,000 cost savings. |
| | | | | Total annual saving
£570,000 |
