For designing capsule pipeline systems the designer needs preferably simple mathematical models, to make quick calculations of the main characteristics of the system. For this purpose an easy to handle mathematical model for horizontal concentric capsule flow is proposed. In this model separate friction coefficients for the moving capsule wall and the pipe wall are introduced. These friction coefficients can be taken from the Moody chart. In the model only relatively long capsules are considered so that end effects can be neglected. The model gives expressions for the capsule velocity and the pressure difference across the capsule. Test results are in good agreement with the proposed model.