Demand for pipeline leak detection and location systems is increasing rapidly. Unfortunately general knowledge about these systems is still limited and the view that these systems ‘will only detect catastrophic leaks’ or ‘give false alarms all the time’ is still heard regularly. This view may be the result of bad experience in the past, unrealistic expectations, or a combination of the two. This presentation shows the benefits of using a leak detection system which combines several API 1130 technologies into one system. Following an introduction to the principles behind PipePatrol E-RTTM and its model supported negative pressure wave method, field data is presented to show the capabilities of the system in a real-world, operational environment. It will be shown that modern leak detection systems do allow leak detection without false alarms, even on gas pipelines operated in dynamic (transient) conditions. Leak tests were performed on ethylene and an average leak detection time of 450 seconds and localization accuracy of 0.04% was achieved.