PECULIARITY OF ULTRASONIC METHODS CONTROL OF EQUIPMENT FILLED WITH TRANSPORTING OR STORING FLUIDS

Abstract

The paper considers the issue of the difference in the results of ultrasonic testing of newly installed equipment and equipment in the process of operation. In most defects located directly in the cavity of the metal, there is a vacuum, the acoustic properties of which are significantly different from the acoustic properties of the base metal. Therefore, defects in the weld cavity or in metal are well reflected, and are easy to be identified and make it possible to estimate their equivalent area by amplitude. All existing ultrasonic testing methods provide device setup taking into account the absence of technological fluid in defect. This is true only for new equipment that is not in practice yet. In practice, it is often necessary to control equipment that is under operation already. It is often not adequately prepared for the survey, because of presence of transporting or storing fluids in it. If in the weld or in the base metal there is a defect with opening into the inner cavity, then it can be filled with the technological fluid under the action of capillary forces. Thus, under standard setting of the flaw detector the fluid will mask the defect, influencing the magnitude of the amplitude of the reflected signal. So not all defects are fully rejected, especially flat ones, which are the most dangerous from the point of view of equipment operation. The simulation of the studied equipment diagnostics issue using two different models of flaw detectors and the filling of the cavity of a bulk defect by various substances is performed in the work. The authors obtained the results of the influence of chemical and physical properties of fluids on indications of a defect detection.