The next generation MEC technique has been successfully tested and demonstrated the ability to detect corrosion on the underside of the tank floor extending alongside the double fillet weld near the shell.
Corrosion formed on the underside of the tank floor extending alongside the double fillet weld at the area approximately 75mm from the shell is a critical tank integrity issue experienced by a major petroleum and petrochemical Operator, particularly for their storage tanks in Asia.
As a result, the Operator requires an inspection technique having a higher accuracy with targeted depth sizing of at least ±10% whilst the tank is out of operation and having the ability to penetrate the GRP lining and provide details of the defect profile.
The TÜV certified MEC-F15 Floorscanner was used to perform the tests on the sample with a side wall mock-up as shell simulation. Despite the 10mm clearance due to the obliqueness of the shell, pitting defects such as 20mm dia. round bottom holes underneath the shell were well detected. The same defect detection results were produced with the addition of a 4mm thick plastic layer mimicking the GRP lining.