A pressure exchanger (200, 300) comprising: a rotor configured to exchange pressure between a first fluid and a second fluid; a first seal plate having a first substantially planar seal plate surface and a second substantially planar seal plate surface disposed opposite the first substantially planar seal plate surface, wherein a piston extends from the first substantially planar seal plate surface to form a substantially planar piston surface that has a first surface area and is substantially parallel to the first substantially planar seal plate surface, wherein the first seal plate and the piston form a first hydraulic chamber routed from a first opening formed by the substantially planar piston surface to a second opening formed by the second substantially planar seal plate surface, and wherein the first hydraulic chamber is configured to direct flow of the first fluid at a first pressure between the substantially planar piston surface and the second substantially planar seal plate surface; wherein the rotor forms a set of rotating longitudinal channels configured to: receive the first fluid on a side of the rotor; receive the second fluid on a second side of the rotor; and exchange the pressure between the first fluid and the second fluid; characterized by a first end cover forming a first set of apertures (506A, 506B) configured to direct flow of the first fluid between the first hydraulic chamber and the rotor, and a first seal structure configured to create a hydraulic seal between the first seal plate and a substantially planar end cover surface of the first end cover, wherein the first seal structure forms a first boundary of a first region of the second substantially planar seal plate surface, wherein the first region of the second substantially planar seal plate surface has a second surface area, wherein the second opening is formed within the first region, and wherein the second surface area is larger than the first surface area, wherein the substantially planar end cover surface is coupled to the second substantially planar seal plate surface via the first seal structure; and by the set of rotating longitudinal channels being configured to: receive the first fluid on a side of the rotor from the first end cover. a rotor configured to exchange pressure between a first fluid and a second fluid; a first seal plate having a first substantially planar seal plate surface and a second substantially planar seal plate surface disposed opposite the first substantially planar seal plate surface, wherein a piston extends from the first substantially planar seal plate surface to form a substantially planar piston surface that has a first surface area and is substantially parallel to the first substantially planar seal plate surface, wherein the first seal plate and the piston form a first hydraulic chamber routed from a first opening formed by the substantially planar piston surface to a second opening formed by the second substantially planar seal plate surface, and wherein the first hydraulic chamber is configured to direct flow of the first fluid at a first pressure between the substantially planar piston surface and the second substantially planar seal plate surface; wherein the rotor forms a set of rotating longitudinal channels configured to: receive the first fluid on a side of the rotor; receive the second fluid on a second side of the rotor; and exchange the pressure between the first fluid and the second fluid; characterized by a first end cover forming a first set of apertures (506A, 506B) configured to direct flow of the first fluid between the first hydraulic chamber and the rotor, and a first seal structure configured to create a hydraulic seal between the first seal plate and a substantially planar end cover surface of the first end cover, wherein the first seal structure forms a first boundary of a first region of the second substantially planar seal plate surface, wherein the first region of the second substantially planar seal plate surface has a second surface area, wherein the second opening is formed within the first region, and wherein the second surface area is larger than the first surface area, wherein the substantially planar end cover surface is coupled to the second substantially planar seal plate surface via the first seal structure; and by the set of rotating longitudinal channels being configured to: receive the first fluid on a side of the rotor from the first end cover. a first end cover forming a first set of apertures (506A, 506B) configured to direct flow of the first fluid between the first hydraulic chamber and the rotor, and a first seal structure configured to create a hydraulic seal between the first seal plate and a substantially planar end cover surface of the first end cover, wherein the first seal structure forms a first boundary of a first region of the second substantially planar seal plate surface, wherein the first region of the second substantially planar seal plate surface has a second surface area, wherein the second opening is formed within the first region, and wherein the second surface area is larger than the first surface area, wherein the substantially planar end cover surface is coupled to the second substantially planar seal plate surface via the first seal structure; and by the set of rotating longitudinal channels being configured to: receive the first fluid on a side of the rotor from the first end cover.