Abstract: An adjustable labyrinth seal for a steam turbine wherein the packing rings may be displaced from a larger diameter position, affording a relatively larger shaft clearance, to a smaller diameter position, affording a relatively smaller shaft clearance. Steam conduits are provided in the turbine casing communicating with the annular space between the individual packing rings and the grooves in which they are retained. The rings are provided with seals and are so configured as to maintain pressure- retaining contact with the sidewalls of the grooves. Steam, at a pressure in excess of the operating pressure of the individual seal, may be admitted to the annular space of the upstream ring to controllably effect the displacement thereof. Steam, at the turbine inlet pressure, is admitted to the annular spaces of the remaining rings to effect their displacement.

Abstract: An expansion joint for sealing the periphery of a component passing through a bore in a member comprises a component sealing element and a bore sealing element, each having a respectively alignable hole therethrough for defining an opening for receiving the component through the expansion joint. The radial outer surface of the bore sealing element sealingly engages the bore and the radial inner surface of the component sealing member that defines the hole therethrough is radially outwardly relieved over a first portion so that a second portion of the inner surface sealingly contacts the periphery of the component along a line which is everywhere tangent to the component, thereby accommodating skew between the central axis of the component and the central axis of the bore. Lateral surfaces of the component and bore sealing elements are mutually sealingly engaged during assembly.