Granular matter transported by hydraulic conveying behaves under several transport regimes. Thetechncal challenge is to predict the dilute or dense regime of transport as well as the pressure drop requiredin order to design properly a granular hydraulic conveying system. We address this problem with a laboratoryscale experimental setup able to reproduce the key features of hydraulic conveying of grains. Pressure dropmeasurements as well as image analysis have been used to characterize a slug transport regime and its crossovertowards a moving bed transport regime. A dimensionless characteristic curves diagram has been established anda reasonably good pressure drop prediction with a generic power law is explained in details. This preliminarywork has the potential to open perspectives for the design of a predictive tool for pressure drops in hydraulicconveying systems.