Acoustic signals for fuel tank leak detection

Speaker:
Duan, Wenbo; Brunel University London; United Kingdom

Authors:
Duan, W.; Brunel University London; United Kingdom
Tavakoli, S.; Brunel University London; United Kingdom
Kanfoud, J.; Brunel University London; United Kingdom
Gan, T.-H.; Brunel University London; United Kingdom
Ocakbasi, D.; Floteks Plastik Inc. Co; Turkey
Beysel, C.; Floteks Plastik Inc. Co; Turkey

ID: ECNDT-0356-2018
Download: PDF
Session: Civil Infrastructure 2
Room: J1
Date: 2018-06-11
Time: 15:20 - 15:40

Plastic and composite fuel tanks are widely used in the automotive industry. Quality control systems normally require a non-destructive testing method to ensure they are leak-free during the production stage in the factory before delivery to market. In this paper an acoustic method to inspect the tanks non-destructively and efficiently is proposed. To initiate possible acoustic signals due to leaks, a compressor is connected to the tank which is then sealed and immersed in water. Air is pumped into the tank at a pressure of 1.3bar. If there is a leak, the pressurised air will squeeze out through the leak and bubbles will appear in the water. Four hydrophones are placed in the water surrounding the tank to detect the acoustic signal generated by the bubbles, revealing the presence of leaks in the tanks. The technique is proposed for application in the factory environment where environmental noise may be very high. The bubble signal is found to be very weak and immersed in the noise floor. To improve the signal to noise ratio, a band-pass filter is used where the signal is band-pass filtered around 4100Hz. A number of parameters, such as root-mean-square (rms), standard deviation, etc are extracted after filtering. These parameters are used for automatic inspection of fuel tanks.