METHOD OF AND DEVICE FOR CHECKING CONDITION OF INSULATION IN PROCESS OF OPERATION OF UNDERGROUND MAIN LINE Russian patent published in 2004 - IPC

FIELD: underground pipelines. SUBSTANCE: invention relates to monitoring condition of underground main lines with manufacturer's polyethylene coating and shrinkable cups. Group of leak detectors are installed on metal surface of near-weld zone and shrinkable cup is fitted. Common electrode and post of check-and-measure point are installed on ground surface over detectors. Reduction of electric resistance in circuit "leak detector - common electrode" indicates that adhesion characteristics of anticorrosive coating and shrinkable cup have changed. Leak detectors are made in form of metal plates and insulating envelopes and they are coupled with measuring unit through communication line. Measuring unit is made in form of connector and it is installed in post of check-and-measure point. Invention makes it possible to evaluate and dynamics of changes of adhesion properties of insulation coating owing to influence of medium in near-pipe space, stress-deformed state of pipe and cathodic polarization. EFFECT: improved method of checking condition of main line. 3 cl, 2 dwg