Computerized Eddy Current Flaw Detector VD-89NM with Higher Reliability of Detection and Danger Level estimation of Stress-corrosion cracks when Inspecting Gas Pipeline under Stress-Corrosion

摘要

Since 1995 multichannel and computerized eddy current flaw detector VD-89NM is used for stress-corrosion cracks parameters evaluation mainly after getting results of inpipe pigs (magnetic flaw detector shell) using for gas pipeline of 1420 mm. Modern model of flaw detector is provided with matrix of probes allowing to get necessary view resolution and high speed of tests. Additionally flaw detector can be used with one probe or matrix of two probes for more precise testing of cracks. Stress-corrosion crack depth is evaluated by microprocessor with formal operation of its software, which eliminates personal influence of an operator to the results. Special software for IBM computer and methods been developed by VNIIGAZ allow evaluation and qualification of stress-corrosion defects with its level of danger. That software and methods are developed in conjunction of "Instruction on stress-corrosion defects qualifying with its level of danger."