embodiments of the invention relate generally to steam turbines , steam turbine systems , and methods for their operation and , more particularly , to high - pressure - intermediate - pressure steam turbine configurations having pressure drop - limited seals and exhibiting reduced mid - packing and / or end - packing leakage . one embodiment of the invention provides a combined high - pressure - intermediate - pressure steam turbine comprising : a high - pressure section ; an intermediate - pressure section sharing a common rotor with the high - pressure section ; at least one packing ring disposed along a length of the rotor and between the high - pressure section and the intermediate - pressure section ; and at least one conduit having a first end disposed adjacent a packing ring and a second end disposed adjacent a steampath stage of the high - pressure section .