Generally, the radiographic determination of wall thickness of piping systems is based on the visual evaluation of radiographs carried out by an inspector. This results to wall thickness values, which strongly depend on the human factor. A new technique based on the algorithm of Computed Tomography (CT) has been developed to overcome that problem. The operation of this new technique called Computed Tomographic evaluated Pipe Wall Thickness (CTPWT) was simplified for application by technicians. Measurements with the CTPWT method have shown, that the CTPWT method yields an accuracy better than 50 microns for a wall thickness less than 4 mm, and an accuracy better than 100 microns up to 7 mm wall thickness for a pipe diameter of 150 mm. An additional advantage of the CTPWT method is its independence of geometric unsharpness in a wide range. It allows the reduction of the source to object distance, because it operates reliable at high geometric unsharpness of up to 50 percent of the wall thickness. The CTPWT method provides accurate information about the condition of the piping system. This allows the user to increase the margin of plant safety by forecasting the wall strength and determining its remaining life.
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