Abstract
This thesis studies the practical appraisal for pipeline inspection using the guided wave T(0,1) mode. The characteristic of reflected signals from the features of pipeline for various coated materials and fluid-filled pipes are also evaluated. The attenuation and the traveling distance of the guided wave are then calculated from the above-mentioned data for pipeline inspection in petro-chemical industries. In the experimental setup, the torsional mode is excited at one axial location using an array of transducers distributed around the circumference of the 6-inch test pipe. The reflected signals from various features, such as flanges, welds, supports, bends, defects and patches are analyzed at first at specific frequencies in the experiments. The effect of various coated material such as bitumen, PE and insulated material are also evaluated for the propagating torsional mode T(0,1) in the pipe. The results show that the attenuation of reflected signal is heavy for the bitumen-coated case because its viscosity is much higher than the other cases. Furthermore, the effect of pipe contents for defect detection using T(0,1) mode is investigated in this thesis. Various pipe contents, such as water, diesel oil, lubricant and fuel oil are deposit into the test pipe, respectively, to evaluate the influence to T(0,1). For the attenuation evaluation of reflected signal from flange in pipe, the reflected signal from an air-content pipe is measured for reference to compare with the measurements of other pipe contents in the experiments. The results show that the low viscosity liquid deposit in the pipe, such as water, diesel oil and lubricant, has no effect on the torsional mode; while the high viscous of the fuel oil deposit in the pipe attenuates the reflected signal heavily. It became evident that the torsional mode T(0,1) is most suitable for use in fluid-filled pipeline inspection.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0813104-151418 |
| Date | 13 August 2004 |
| Creators | Li, Bing-Hung |
| Contributors | Ruey-Chang Wei, Shyue-Jian Wu, Shiuh-Kuang Yang, Bor-TsuenWang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0813104-151418 |
| Rights | not_available, Copyright information available at source archive |
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