Bimorph sensor based in-line inspection method for corrosion defect detection in natural gas pipelines

Abstract

Recently, bimorph sensors based on the in-line inspection (ILI) method have shown considerable promise for detecting surface defects (e.g., corrosions) in gas pipelines. However, the effect of physical parameters such as bimorph position and scanning speed on the performance of the bimorph sensor has not yet been investigated. As a result, the capability of the bimorph sensor for defect detection in pipelines is not clear. This study aims to optimize the physical parameters and investigate the influence of physical parameters on the performance of the bimorph sensor. For this purpose, first various corrosion defect sizes were considered and analyzed using piezoelectric theory. Next, an analytical relationship between the vibration response of the bimorph sensor and defect is derived using the Euler-Bernoulli beam theory. Finally, a real-time field test was conducted based on the installation of the proposed method on a developed smart PIG to demonstrate the detection efficiency of the bimorph sensor. The novel contributions of this study are as follows: (1) The proposed analytical method uses cantilever beam vibrational mode shapes together with the piezoelectric effect to detect and quantify the corrosion defects. (2) The current study proposed a bimorph sensor method capable of performing high scanning speed (0.5 m/s) in real-time pipeline inspection. (3) The performance of the proposed method on the various position of bimorph on the cantilever probe and scanning speed is studied analytically and experimentally. (4) Multiple corrosion defects and pipeline joints were detected and localized successfully in complex pipeline networks. • Proposed a bimorph sensor method to detect corrosion defects in gas pipelines. • Performance of the proposed method is investigated analytically and experimentally. • Bimorph sensor is designed and tested in a laboratory testbed. • Effectiveness of the proposed method on various physical parameters is presented. • Field test is conducted with the designed bimorph sensor array.