About the Dangerous Error at the Ultrasonic Inspection of the Process Pipelines Welded Joints


Annotation:

Owners of hazardous production facilities at technical diagnostics of the process pipelines with a wall thickness of less than 8 mm due to objective reasons are increasingly do not allow to apply radiation methods for welded connections control and require replacing it with ultrasonic testing. GOST 32569—2013 does not contain the norms of sensitivity and rejecting the results of ultrasonic testing in this range of thickness. Some of NDT inspectors use the norms established for boiler inspection facilities. Others mistakenly apply a single standard maximum allowable equivalent area of 1.6 mm2 for all the options of thickness less than 10 mm, including less than 8 mm. This leads to the fact that safety of such pipelines majority after their inspection remains not guaranteed. Therefore, it is required urgently to make changes to GOST 32569—2013 with regards to the regulation of ultrasonic testing of the welded connections of the process pipelines with a wall thickness of 2 to 8 mm. And before making these changes (additions), training centers and independent bodies for personnel certification in the field of non-destructive testing, when training ultrasonic control specialists to monitor process pipelines, are recommended to pay special attention to the importance of the differentiated approach to the norms of rejection depending on the wall thickness of the object and logical choice of these norms. Independent bodies for certification of non-destructive testing laboratories when checking inspection services and consultations are also recommended to pay attention to the logical choice of the norms for ultrasonic testing of the welded connections of process pipelines with a wall thickness up to 8 mm in those conditions when x-ray is forbidden or impossible.

A.A. Selskiy, Cand. Sci. (Eng.), Lead Specialist, nondist@mail.ru ChOU DPO NUTs «Regiontekhservis», Krasnoyarsk, Russia E.E. Melchikova, Specialist OOO «RTS-NK», Krasnoyarsk, Russia V.A. Selskiy, Specialist OOO «IKTs «Industriya», Krasnoyarsk, Russia

References:

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DOI: 10.24000/0409-2961-2018-11-64-67
Year: 2018
Issue num: November
Keywords : wall thickness process pipeline ultrasonic testing maximum permissible equivalent area of the defect
Authors: