Magnesium alloys have been well known as active metals. Thus, magnesium alloys in molten state must be handled with extreme care during melting and casting. In this study, water model experiments and numerical analyses were carried out to optimize a pipe flow that can transport magnesium alloys in molten state safely from melting to casting furnace. Especially, during a transportation of molten magnesium alloys, a flow pattern in a pipe becomes important, because the interface between air and melt can be the source of the metal oxidation, and therefore, an air/melt interface area must be minimized. For these purposes, two vessels connected with a long pipe having two elbows with different diameters and radii of the curvature were simulated as melting and casting furnace for magnesium alloys. Optimized conditions with minimized air/melt interface area for the melt transportation were discussed in several pipe configurations.