Abstract: A rotary machine has a stationary component with circumferential grooves and a rotatable component, as well as annular packing or sealing ring segments movable toward and away from the rotating component. To prevent circumferential displacement of the lower side packing ring segments by gravity forces and enable the lowermost segment in the lower housing to be moved radially inwardly, the side segments of the lower housing are supported adjacent the casing midline in a manner preventing downward movement and enabling horizontal movement. In an exemplary embodiment, the lower side packing ring segment is elongated so as to extend above the horizontal joint of the housing and a key bar extends from a key bar groove in the housing to engage a corresponding groove in the segment. The key bar may be disposed to define a seal key for the horizontal joint.