Major changes in the energy sector pose a challenge on the flexibility of hydropower plants and hydraulic turbines. With their wide operating ranges and high part-load efficiencies, multi-injector Pelton turbines can master these challenges well as long as a high-quality jet is maintained. The jet shape is largely determined by the flow in the distributor system, so we derived criteria to evaluate the flow in distributor systems with a single inlet and multiple outlets. With these criteria we examined four designs of a Pelton turbine distributor system with axial inflow. Parametric studies revealed that the shape of the transitions from the penstock line to the manifold and from the manifold to the branch lines had the most significant influence on flow quality.