Abstract: Arcuate seal segments have radially directed seal faces forming part of a labyrinth seal in a turbine. The segments are adjustably spaced from the locating flanges of the groove formed on a stationary part of the turbine housing to compensate for any distortion of the groove through use. Where the locating flanges of the segments normally engage the locating flanges of the groove, variable clearances are provided between those flanges by using locating elements in circumferentially spaced slots along the seal segments such that the seal faces of the segments are maintained concentric, notwithstanding distortion of the locating fits. The locating elements each include a pin secured to the sealing segment, a shim of a selected thickness selected from a set of shims of different thicknesses and a nut for threading onto the pin to project the shim below the locating flanges of the sealing segment for engagement with the locating flanges of the groove.