A rotary machine (12) comprises a housing (14), a rotor (16) that is rotatably disposed within the housing and having an axis (18) about which the rotor may spin, and a seal (24) disposed upon the housing. The seal comprises a support (26) disposed on the housing and a plurality of flexible non-metallic bristles (28) that extend from the housing and engage the rotor, such that the seal provides a barrier to fluid flow between a first region (22) located in a first axial direction from the seal and a second region (34) located in an opposite axial direction from the first region. The first region is filled with a bearing liquid and the second region is filled with a process fluid.