Abstract
Pipework, pressure vessels, storage tanks and other safety-critical components are designed to contain liquids, gases and solids to avoid contamination and losses. However, when these pipelines suffer any flaws, their integrity is compromised. The eventual result from this compromise is an accident, which sometimes tends to be catastrophic, especially when these pipelines are noted for conveying flammable and hazardous fuels. When some of these flaws are located early, they are remedied quickly. Welding is one of the methods used to remedy some of these flaws especially when the flaw is a leakage. Despite the potency of weld to join steel and pipeline systems very well, various metallurgical phenomena occur in the weld and this mostly leads to defects in the welded joints. Non-Destructive Test (NDT) is, therefore, used to detect some of the defects in the weld as it does not affect, destroy or disturb the main features of the product or material. This study has investigated the performance of the NDT methods used in the inspection of fuel pipelines in order to prevent occurrences of accidents. The objectives that formed the basis of the study are to determine the detectability of various flaws in fuel flow pipelines using conventional NDT methods and to ascertain the most suitable of these methods. The study was carried out at the worksite of Inspectors and Engineers Company Limited located in Takoradi, Ghana. Taguchi method of experimental design was used to gather the data. The data were analysed statistically with Rstudios and the graphs were plotted with Microsoft Excel. The tests that were conducted on the 2-, 6- and 10-inches pipes were; Radiography test, Manual Ultrasonic Test and Magnetic Test. The result from the data showed that there is not so much difference between the Radiographic Test and Manual Ultrasonic Test in terms of flaws detection in 2-, 6- and 10-inches pipelines as they all recorded mean values of 19.75mm and 19.25mm defect length when compared with the Purposely Inserted defect at 20mm. Furthermore, the Magnetic Particle Test was convenient for detecting flaws at the surface of the weld as it had shallow penetration in the welds. Moreover, the Magnetic Particle Test showed a poorer defect detection when it recorded the same 5mm defect lengths for all three pipelines as against 19.75mm for the 6 inches pipe, 20mm for both the 2- and 10-inches pipes for Manual Ultrasonic Test. The analysis pointed out that, both Radiography Test and Manual Ultrasonic Test could be used interchangeably. It is recommended that further analysis could be carried out with different pipe sizes to ascertain whether there would be any difference between Radiography Test and Manual Ultrasonic Test. Again, the study further recommended...
M.Phil. (Mechanical Engineering)