<p>A sudden contraction and expansion pipe coupled with a return bend is intended to avoid the necessity of an abrupt change in direction, orientation, or change in the cross-section of the tube during the simultaneous oil-water flow. The volume of fluid (VOF) model based on the Eulerian-Eulerian approach offered by Fluent was used to determine the flow pattern and local pressure drop of oil and water flowing through a sudden contraction and expansion pipe via a return bend for different sets of the superficial velocities of lubricating oil, kerosene oil with water, and Excol D80 with an aqueous phase. The research findings showed that, among the three configurations, the pressure drop and strain rate decrease are larger in more viscous oil, while the wall shear drop is only significant on return bends as well as in the sudden expansion section of the pipe.</p>