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Natural gas leakage from gas pipelines usually leads to human intoxication. Further, it may even cause fires and/or explosion accidents or make an indirect chemical contribution to climate change in the long term because of its high global-warming potential. As a clean, potential, and effective method for controlling/mitigating the risk of natural gas leakage, water mist is tested to suppress gas jet leakage from a lab-scale pipe in this study. Based on actual natural gas leakages in pipelines or practical emergency management measures, both tilted and non-tilted gas jet cases were considered to evaluate the performance of gas jet suppression by water mist. A series of small-scale experiments has been conducted to deepen the understanding of the dynamical behavior and mechanisms of the gas jet water mist interaction by visualizing the two-phase flow via planar particle image velocimetry. The results indicate that different shapes of leakage nozzles with a similar effective diameter are highly consistent regarding the interacting flow field characteristics. In addition, guidelines for optimizing a water mist system for leakage gas suppression/control are presented based on gas spray momentum ratio and dimensionless gas jet suppression height analyses. Owing to the lack of applications on natural gas leakage with water mist, this study is valuable toward optimizing water mist systems for leakage gas suppression/control of such applications. (C) 2019 Elsevier Ltd. All rights reserved.