This article presents a design and commissioning of a multiphase flow loop, which was developed for scrutinizing the partial phase separation characteristics of pipe Tees. Its length is 9 m and its primary diameter is 0.078 m (3 inches). For the ease of modification, its design was kept modular, so that it could be used for testing various other pipe profiles. To validate this flow loop, the separation of a stratified-wavy flow was tested in a regular diameter ratio pipe Tee, and the gathered results were compared with previously published data. A good agreement was observed between the two data sources, which suggests that this flow loop is suitable for a further experimentation. © Czech Technical University in Prague, 2019.