The present invention relates to a method for internal inspection of storage tanks containing a large volume of residual product and having a very short maintenance window, being applicable mainly in the inspection and maintenance activity of fixed-roof and floating-roof storage tanks, by any refinery or process plant that has a tank storage area (for example, refineries, terminals and petrochemical plants). The aforementioned method comprises installing a stainless-steel cylinder (1) within the storage tank to delimit a confined area inside the equipment, said area being cleaned and decontaminated so that it may subsequently undergo non-destructive thickness measurement and magnetic particle testing to determine the thickness of the bottom plates and to detect possible cracks in the weld seams of the bottom plates.

The present invention relates to a method for internal inspection of storage tanks containing a large volume of residual product and having a very short maintenance window, being applicable mainly in the inspection and maintenance activity of fixed-roof and floating-roof storage tanks, by any refinery or process plant that has a tank storage area (for example, refineries, terminals and petrochemical plants). The aforementioned method comprises installing a stainless-steel cylinder (1) within the storage tank to delimit a confined area inside the equipment, said area being cleaned and decontaminated so that it may subsequently undergo non-destructive thickness measurement and magnetic particle testing to determine the thickness of the bottom plates and to detect possible cracks in the weld seams of the bottom plates.