Transneft Diascan revamped combined magnetic ultrasonic defectoscopes of two nominal sizes: 20-DKK and 28-DKK. The works were performed from January 2015 to December 2017.
The first inspection complex provides for the inspection of pipelines with the diameter of 530 mm using an ultrasound (WM, CDL and CDS) and magnetic (MFL) measuring system. The following characteristics were improved in the course of revamping:
- measuring system resolution capacity increased more than twofold due to a greater number of ultrasonic WM sensors;
- the minimum sizes of pipe wall defects of the scratch-mark type to be detected decreased by 2.5 times in width and by 1.5 time in depth;
- power consumption of electronic equipment was halved.
The second defectoscope is meant to inspect pipelines with 720 mm and 820 mm diameters. The measuring system resolution capacity rose 1.6 times after the modernization due to a higher number of ultrasonic WM sensors. The minimum sizes of detectable pipe wall defects of the scratch-mark type decreased by 2.5 times in width and by 1.5 time in depth; the power consumption of electronic equipment is down 25%.
During the comprehensive acceptance testing, both devices showed good resistance to climatic and mechanical impact; the testing also proved the passport specifications of defect detection and measurement errors to be compliant with with the job requirements.