A sleeve mountable on a rotatable shaft and configured to form a non-contacting seal with a seal ring surrounding and radially spaced from the sleeve, the sleeve including a radially inner surface configured to be mounted on the rotatable shaft, a radially outer surface, an axially inner surface between the radially inner surface and the radially outer surface, an axially outer surface between the radially inner surface and the radially outer surface and a bore configured to provide fluid communication between gas at the axially inner surface of the sleeve and the radially outer surface of the sleeve.

An alignment tool includes a mounting flange, a support leg fixedly coupled to the mounting flange and cooperating with the mounting flange to define a partial annular ring that extends in an arc between 190 degrees and 350 degrees, and a second quantity of jack bolt pairs movably coupled to the support leg, each jack bolt pair arranged to engage one of the first quantity of seal segments. A third quantity of mounting fasteners is positioned to fixedly attach the mounting flange to the inner casing.

A machine comprising a rotor having: an inner member; an outer member encircling the inner member; and a groove in one of the inner member and the outer member. The groove has a first side wall, a second side wall and a base. A split ring seal is accommodated in the groove and contacts a surface of the other of the inner member and the outer member The first side wall has a plurality of open radial first channels and the second side wall has a plurality of open radial second channels.