The Experimental Research And Application Of Acoustic Emission On-line Inspection Of Vertical Storage Tanks

As the economic development goes so fast, the storage of petroleum and its products turns to be more and more important, so vertical storage tanks become absolutely necessarily important equipment. When we use the vertical tanks, they inevitably suffer from various damages such as corrosion, erosion, distortion, leak, etc. In order to guarantee the safety of vertical tanks, we need to test them periodically. Conventional non-destructive testing (NDT) methods can be used to inspect storage tanks only when they shut down and the bottom plates are cleaned thoroughly. Even so they have some disadvantages. For example, higher expenses, much more labor force and resulting environmental pollution to some extent. By using conventional methods, it's hard to get a complete testing result, because they can't find out active defects. However, AET has many advantages such as its dynamic property, sensitivity to active defects, whole monitoring one time, fast and economic inspection etc. It can greatly improve the efficiency of testing, and cut down labor force to minimum. Almost owners or users expect their storage tanks to be inspected by this advanced testing method. Meanwhile, the inspection companies also hope to apply this effective testing method to their work so that they can advance the level of inspection. Therefore, in order to make this technique effective enough to be used widely, it is necessary to do some experimental and theoretical study on the on-line inspection of vertical storage tanks.The bottom plates of vertical storage tanks are easier to break than other parts of them. The corrosion and leakage resulting from the break of tank bottom are main acoustic emission sources. This paper hereby did some research on the corrosion and leakage of tank bottom with the AET technology. This paper analyzed the mechanism of producing effective acoustic sources by analyzing the corrosion and leakage of storage tanks, and also verified source location methods and the reliability of AET technology by experimental study on test tanks or plates and field inspection of real tanks.The results from the experimental research and field applications have proved the great practicality of the AET technology, so we should apply this new testing method widely with our great effort.