- NII as replacement of IVI
- Pressure Vessels
- Heat Exchangers and Tubing
- Data Science
- Equipment integrity and reliability
- Robotic Tank Inspection
Inspection under external corrosion blisters
External corrosion is a growing threat to the integrity of ageing pressure equipment. Consequently, plant owner/operators usually have in place fabric maintenance programmes aimed at preventing external corrosion but where it is found already active the focus shifts to rectification. This relies on removal of corrosion product, cleaning and repainting or repair using composite wraps. Before the corrosion product can removed it is necessary to establish that there is sufficient remaining wall thickness to allow the work to be completed safely. Hence there is a need in the industry to reasonably accurately measure the remaining wall thickness under regions of external corrosion.
Sonomatic offers a number of inspection solutions for measurement of steel thickness under corrosion.
Performance of Sonomatic’s W-skip and Multiskip techniques for this application has been assessed in blind trials conducted by the HOIS Joint Industry Project. These techniques were shown to provide the highest accuracies of all techniques tested. The measurement accuracy is such as to allow reliable decisions on whether a safe repair can be performed with the pressure equipment still in operation.
The best technique for each application depends on the pipe wall thickness, the general external condition and the extent of the external corrosion. Sonomatic can assist clients in identifying the most appropriate approach in each case.