METHOD FOR DETECTING PENETRATION DEFECT OF LINE AND LINE PENETRATION DEFECT DETECTING APPARATUS USING THE METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method for detecting penetration defects of a line which is capable of detecting whether or not there are penetration defects of the line as well as specifying the locations of the defects in a short time with high accuracy, and an apparatus therefor.;SOLUTION: A pair of elastic rubber films 12a and 12b expanding toward the inner peripheral surface of the line A on being exerted with pressure fluid are inserted into the line A while in predetermined spaced relation along the direction of the pipe axis and are expanded by the fluid pressure until making contact with the inner peripheral surface of the line A to form sealing walls αand β dividing the interior of the line A along the direction of the pipe axis; the sealed space 33 of the line A divided by the sealing walls α and β is pressurized, after which a pressure sensor 34 detects whether or not there are penetration defects of the line depending on the rate of pressure drop in the sealed space 33. Thus, detection of penetration defects of the line A leading to leakage can be carried out not for the entire line but for each part of the line A, so that only a sealed space of small volume is needed.;COPYRIGHT: (C)2001,JPO