FLAW DETECTOR-TOOL FOR INTERNAL EXAMINATION OF PIPE-LINES Russian patent published in 1996 - IPC

FIELD: devices for internal examination of condition of walls, and/or geometric configuration, and/or attitude of pipe-lines mainly intended for distant conveying of natural gas (cross-country gas lines). SUBSTANCE: the flaw detector-tool uses a conveying unit, power unit, flaw detector unit, indicating unit and devices for determining the flaw coordinates placed in the pipe-line to be examined and moved in it by the flow of conveyed product, mechanically linked and positioned on the base (bases). The flaw detector is supplemented with a by-pass branch-pipe used to pass the conveyed product through the pipe-line under examination, and an automatic conveyance speed control system using a speed transducer, control unit and one or two control members, one of which is made as a shut-off-regulating device installed in the by-pass branch pipe, and the other - in the form of a retardation device engageable with the pipe-line. Depending on the number (one or two) and type of operation matching of the above control members, four variant of the automatic conveyance speed control system are probable. The flaw detector-tool is also provided with a detection signal generator ("beacon") and a circuit of special control of its operation in preemergency and emergency operating conditions at probable clogging of the pipe-line. EFFECT: enhanced reliability. 19 cl, 10 dwg