Application of eddy current and magnetic structuroscopy at complex control of pipelines

Alexey G. Efimov JSC RII “Spectrum” Moscow, Russian Federation
Andrey E. Shubochkin JSC RII “Spectrum” Moscow, Russian Federation
A stress-corrosion cracking is one of the most common defects of transfer pipelines. The applied methodsand calculations of residual life assessment of pipes repair do not include changes the properties of metal in areas prone to this typeof defects. The article considers the problem of determining the residual life of oil and gas pipelines during repair areas prone to stress corrosion cracking. It was proposed the technique of integrated control, using magnetic and eddy current NDT methods, in order to increase the precision in estimating the period of trouble-free operation of the pipeline.
Materials and methods
Pipes of the main oil and gas pipelines were tested by eddy current and magnetic methods.
Obtained results clearly indicate the need to consider the magnetic characteristics of the metal after the repair areas prone to stress corrosion cracking in the strength calculations.
During performing the diagnostics to assess the residual life of thepipe is necessary to apply a complex of the eddy current, magnetic and UAE NDT methods to clarify theresults of calculations of residual life assessment of the controlled object. Measurement errors at each stage of monitoring pay an additional error in the final assessment. According tothe requirements of industry standard report should contain all the results of the control and gamma-percent life with a probability of 90-95%. This means that the highest requirements of NDTare reasonable and timely renewal of equipment needed.
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nondestructive testing magnetic testing eddy current testing coercive force residual life