Particle velocity, acceleration length and velocity profile evaluations are essential for the design and modeling in conveying systems. Although the subject has been widely researched, the relationship between pneumatic and hydraulic systems has not been addressed and still lacks a model that will be consistent over various operating conditions and materials and that includes both conveying media. The current paper presents a thorough experimental investigation of the above-mentioned characteristics obtained from a 75 mm (3 '), 50 mm (2 ') and 38 mm (1.5 ') hydraulic conveying system. Experiments with various operating conditions and conveyed materials in vertical and horizontal pipes of a hydraulic transport system were conducted. The experimental results were compared and combined with experimental data on pneumatic conveying. The particles' velocities in the pipe were obtained using a high-speed camera combined with image processing. Data was obtained for each particle allowing an investigation of the effect each component has on the phenomenon. Correlations are suggested for the characteristics' evaluation in the range of the tested operating conditions. (c) 2020 Elsevier B.V. All rights reserved.