Inspection of Internal Tank Welds using the ACFM Inspection Method

This paper describes the application of the ACFM technique for weld inspection and focuses on recent experience in both Europe and Central America in the use of the technique for the inspection of steel storage tanks. Inspection of the tank floor is usually conducted using magnetic flux leakage methods but it is recognised that this cannot be applied to the detection of cracking in the welds joining the plates. The paper describes recent developments of the ACFM technique and describes several case studies where ACFM has been used to inspect the internal plate welds on large steel storage tanks in refineries.. For weld inspection, conventional methods such as magnetic particle inspection or vacuum box testing are generally used. This paper presents comparisons of the results from ACFM with those from the conventional methods, from which conclusions are drawn as to the benefits this technique offers in terms of cost, time savings and inspection reliability.