Report on Boeing pipeline leak detection system

Testing was performed on both simulated (test) and existing (water) pipelines to evaluate the Boeing leak detection technique. This technique uses a transformer mounted around the pipe to induce a voltage level onto the pipeline. The induced ground potential is measured from a distant ground probe, inserted into the surrounding soil, with respect to the excited pipeline. The induced voltage level will depend on the soil characteristics, the distance from the excited pipeline, and the probe types. If liquid should leak from the excited pipeline, the escaping liquid will modify the induced potential of the soil surrounding the excited pipeline. This will change the response of the quiescent soil characteristics and cause the voltage level on the detecting probes in the area of the leak to increase. This voltage increase will indicate a soil anomaly. However, the liquid does not have to reach the detection probe to reveal an anomalous soil condition. Several different detection probes were used and evaluated for sensitivity and response time. Although not evaluated during this test, results indicate that a wire laid parallel to the pipe axis may be the best probe configuration. A general sensitivity figure for any of the probes cannot be made from these tests; however, the technique used will reliably detect a pipeline leak of ten gallons. An additional test was performed using the Boeing pipeline leak detection technique to locate the position and depth of an underground pipeline. This test showed that the location and depth of an excited pipeline could be determined from above the ground where other methods for pipeline location had previously failed