Efficient cooling of the target material is a key issue in the design of a spallation target. The aim of the RTFT (Rotating Target Flow Test) facility at ESS Bilbao (Zamudio, Spain) is the characterization of coolant flow in rotating targets. Maps of flow velocity along cooling channels are obtained with PIV (Particle Image Velocimetry) techniques. Tests are performed with water flowing at up to 30 l/s and 5 bar, for different disk rotation rates, and are used to evaluate target designs in terms of potential flow instabilities and adverse effects -such as flow stagnation and recirculation-, to benchmark calculation and simulation models, and to assess final target designs.ESS Bilbao and SNS have recently performed a first test campaign on a full scale mockup of the latest SNS design for a 1.5MW rotating target. Tests included runs at several operation conditions, plus an emergency stop simulation, for observation of the water flow evolution in a pump sudden stop event.