A pressure exchanger for transferring pressure energy from a high-pressure fluid stream to low-pressure fluid stream. A ducted rotor is positioned on a central axle between two end covers inside the vessel with a coaxial inlet and outlet pair that is in communication with a pair of low pressure ports having inclination forming an inlet tangential velocity vector in the direction of rotor rotation and an outlet tangential velocity vector in opposite direction imparting a rotational momentum on rotor. A pair of high-pressure ports is adapted for flow without inclination and imparts no momentum to the rotor. The end covers have a sloped surface following a flat sealing area that increases the clearance in the direction of rotation causing increased outflow during depressurization and lower duct pressure. This also causes increased inflow during the pressurization phase which will dissipate pressure energy as opposed to producing cavitation or pressure waves.