Comprehensive inspection and evaluation technique for atmospheric storage tanks

In China, atmospheric storage tanks are not included in the regulations governing the management of special equipment, and their inspection is therefore not compulsory. There is a greater discrepancy between China and developed countries regarding atmospheric storage tank inspection techniques, compared with other techniques for the inspection of pressure vessels. It is widely believed that the reduction in strength and perforation of the tanks is due mainly to serious corrosion occurring on the bottom surface of the tank floors. The currently available nondestructive testing methods for atmospheric storage tanks are analysed in this paper. We discuss the principles, the use of inspection equipment, and the application of acoustic emission testing, magnetic flux leakage testing and ultrasonic crawler testing techniques for atmospheric storage tank inspection. The problems associated with the inspection methods are discussed. A practice for inspecting and evaluating atmosphere storage tanks using these testing methods is proposed.