This paper introduces two models. First, it introduces a model for geometric pressure loss in horizontal pipe junctions with arbitrary amounts of in-/outlets, under assumption of steady-state, incompressible, single phase flow and no wall friction. The model is shown to be in agreement with experimental data via another model. Second, the junction model is incorporated in a pipe flow network model under the same assumptions as the junction model. The resulting pipe flow network model is compared to a pipe flow network model in which pressure loss due to junctions is neglected. The results show that for long pipes L 600 m the addition of junction pressure has negligible influence on the total static pressure drop in the network. However, for L < 600 m the influence is bigger than 10%.