METHOD OF DETECTION OF GAS LINES SUBJECTED TO CORROSION CRACKING UNDER STRESS Russian patent published in 2003 - IPC

FIELD: construction engineering; operation of pipe lines. SUBSTANCE: proposed method includes detection of zones where pipe line is subjected to considerable tensile stresses in lower portion (gully bottom, concave sections of upthrust folds). Opening of pip line to upper generatrix and locating circumferential welds through insulation. Then, pipe line is opened on sides below lower generatrix and trench is manually dug under pipe line. Zone of weld is cleaned and lower part of pipe is checked to transversal cracks by means of flaw detector. If such cracks are revealed, near-weld zone is cleaned from insulation and sizes of transversal cracks are determined. EFFECT: enhanced efficiency. 2 dwg