A multistage separation system, comprising: a rotating fluid separation system attached to a rotatable shaft, the rotating fluid separation system comprising a radial inlet and a fluid drain outlet of the rotating fluid separation system configured to capture fluid separated by the rotating fluid separation system; and a static separation system coupled with a front end portion of the rotating fluid separation system, the static separation system comprising: an axial inlet configured to receive a fluid stream; means for directing the fluid stream radially-outward toward a static separation turn; the static separation turn configured to change the flow path direction of the fluid stream to travel radially-inward so as to separate liquid from the fluid stream by centrifugal force, the static separation turn being fluidly coupled with and disposed radially outward of the axial inlet, the static separation turn positioned upstream of the rotating fluid separation system such that an output of the static separation system feeds the radial inlet of the rotating fluid separation system, the separation turn being positioned radially outward of the rotating fluid separation system; and a fluid drain outlet of the static separation turn configured to capture fluid separated by the static separation system, wherein the fluid drain outlet of the static separation turn is in fluid communication with the fluid drain outlet of the rotating fluid separation system, the respective fluid drain outlets being at the same pressure. a rotating fluid separation system attached to a rotatable shaft, the rotating fluid separation system comprising a radial inlet and a fluid drain outlet of the rotating fluid separation system configured to capture fluid separated by the rotating fluid separation system; and a static separation system coupled with a front end portion of the rotating fluid separation system, the static separation system comprising: an axial inlet configured to receive a fluid stream; means for directing the fluid stream radially-outward toward a static separation turn; the static separation turn configured to change the flow path direction of the fluid stream to travel radially-inward so as to separate liquid from the fluid stream by centrifugal force, the static separation turn being fluidly coupled with and disposed radially outward of the axial inlet, the static separation turn positioned upstream of the rotating fluid separation system such that an output of the static separation system feeds the radial inlet of the rotating fluid separation system, the separation turn being positioned radially outward of the rotating fluid separation system; and a fluid drain outlet of the static separation turn configured to capture fluid separated by the static separation system, wherein the fluid drain outlet of the static separation turn is in fluid communication with the fluid drain outlet of the rotating fluid separation system, the respective fluid drain outlets being at the same pressure. an axial inlet configured to receive a fluid stream; means for directing the fluid stream radially-outward toward a static separation turn; the static separation turn configured to change the flow path direction of the fluid stream to travel radially-inward so as to separate liquid from the fluid stream by centrifugal force, the static separation turn being fluidly coupled with and disposed radially outward of the axial inlet, the static separation turn positioned upstream of the rotating fluid separation system such that an output of the static separation system feeds the radial inlet of the rotating fluid separation system, the separation turn being positioned radially outward of the rotating fluid separation system; and a fluid drain outlet of the static separation turn configured to capture fluid separated by the static separation system, wherein the fluid drain outlet of the static separation turn is in fluid communication with the fluid drain outlet of the rotating fluid separation system, the respective fluid drain outlets being at the same pressure.