Leak detection by testing vapor in tank foundation

Abstract

The petroleum products leakage from the storage tank bottom could not be discovered in time without store contents emptied out because of the bottom not being accessed easily and the amount of leakage in the beginning being too small to be detected by the ways now available such as interstitial monitoring, liquid sensing probes and cables, volumetric and mass measurement methods, statistical inventory control methods, automatic tank gauging, passive-acoustic sensing etc. The experiments of the leak detection by testing vapor in the tank foundation is proposed and its experiments made on two model tanks with 300cm capacity and two real tanks in site with 3000cm capacity, in which a Photo Ionization Detector (PID) is used for testing oil vapor concentration in the tank foundation, its sensitivity up to grade PPM, and that means “fine” leak detection. Still, based on the results from the experiment, studied are the testing time and location of the leak detection and the distribution and trend of oil leakage and vapor diffusion. The results of the experiments on both model and real tanks show that the leakage from tank bottom could be detected in time by testing and monitoring oil vapor in tank foundation, and also prove that vapor testing and monitoring in tank foundation is a feasible and efficient method to detect the leaks from tank bottom much more earlier than other way to discover these leaks. And also the detection of vapor testing in tank's foundation were taken in the cases when the leakage suspected exciting in two tanks with diesel oil storage and capacity more than 20000 cm, and that further verified and demonstrated the availability and effectiveness of this technique.