Small damages in crude oil pipes such as cracks or holes lead to "creeping" leakages. This is a relatively small amount of escaping oil (>20l/h). These leaks are not detected without special detection equipment and therefore pose a great danger to the environment because these leaks may remain undetected.
The FFT Leak Detection Pig has been developed to detect these creeping leaks. The principle is based on the detection of cavitation noises which occur in the range of 20khz - 40khz with this type of leakage. The pig records these ultrasonic signals with pressure and distance information. After the pig run, the FFT evaluation software can be used to read out and evaluate the stored signal curve over the entire distance. By means of further signals, the location of the creeping leakage can be determined to within a few meters.
The FFT leak detection pig can be used for pipeline diameters from 6" and larger.