A combined nitrogen purge and helium leak-detection system has been developed to safely pressure test and commission oil and gas process equipment. The system is able to detect leaks of a much lower magnitude than conventional leak detection systems and it offers several advantages over conventional hydrostatic testing. Inert nitrogen gas (used as the pressurizing medium) also safely purges the process system of oxygen and flammable gases, while helium in trace amounts provides a means of detecting leaks as low as 0.03 m3/yr. A mass spectrometer is used to detect extremely low levels of the helium detector gas.

Once the process equipment has been certified as leak free, a low pressure nitrogen blanklet can be left in the system. Gas process equipment also can be operated under simulated working conditions using nitrogen. This has proved beneficial for instrument calibration and training purposes.

You can access this article if you purchase or spend a download.