STEEL storage tank floors are often covered with a fiberglass coating, which makes it difficult and expensive to monitor corrosion, both on the inside and outside. A saturation-low-frequency-eddy-current tank floor scanner (SLOFEC) has been developed that may be able to detect the condition underneath .250 inch of coating, according to information presented at the Independent Liquid Terminals Association meeting June 11-14 in Houston, Texas.
Morris Kline, sales manager of HMT Inspection, Houston, said the scanner was developed by a German company and has been purchased by a Netherlands firm. It is being tested in the United States. “We're very encouraged with what's going on,” he said.
The scanner has been tested on four storage tanks in the Midwest and one tank in Louisiana. Kline estimates the system efficiency at 30% to 33% more than the magnetic flux leakage system that is currently used to detect corrosion.
Although the scanner appears to improve corrosion detection, it is unable to determine the depth of pitting, Kline said. Its cost will be higher than current methods because it requires two inspectors with advanced training on each job.
His company will be training more employees to conduct the testing to determine further results, he said.