An axial flow element for use in a liquid separation system for an internal combustion engine includes a hub, a groove, a locking member, and a flat layer. The hub includes a cylindrical outer surface. The groove is disposed in the outer surface. The groove extends in a substantially longitudinal direction along the hub from a first end of the hub to a second end of the hub. The locking member is disposed in the groove. The flat layer is disposed between the hub and the locking member.