Abstract: A nuclear low pressure packing casing having reduced horizontal joint leakage. This is accomplished by providing packing ring carriers that are separately formed from the casing so that thermal distortion loads will not be transmitted to the horizontal joints. In an embodiment of the invention, the packing ring carriers are fit in place in pre-machine grooves in the casing rather than being welded directly to the casing. According to further, optional feature of the invention, the vent or seal steam enters or exits at only one of the bottom quadrants rather than the entire bottom half so that the packing case design can be simplified to reduce fabrication and material costs.

Abstract: A pair of steam turbine inlet ports are disposed at opposite sides of a steam turbine housing for flowing steam in opposite circumferential directions in a generally annular steam chamber to first stages of a turbine through axially opposite outlets. Portions of the chamber in the upper and lower housing have decreasing cross-sections in a generally circumferential direction away from the steam inlet portions to provide a substantially uniform flow of steam about the chamber in a generally radially inward direction and about and through the axial outlets.

Abstract: A pair of steam turbine inlet ports are disposed at opposite sides of a steam turbine housing for flowing steam in opposite circumferential directions in a generally annular steam chamber to first stages of a turbine through axially opposite outlets. Portions of the chamber in the upper and lower housing have decreasing cross-sections in a generally circumferential direction away from the steam inlet portions to provide a substantially uniform flow of steam about the chamber in a generally radially inward direction and about and through the axial outlets.

Abstract: A turbine shell assembly includes radially inner and outer shell components; axial alignment fits on the inner and outer shell components, each alignment fit comprising a male fit component on one of the inner and outer shell components and a female fit component on the other of the inner and outer shell components, the female fit component comprising a pair of flanges forming a U-shaped channel with opposed faces, and the male fit component comprising a projection received within the U-shaped channel; and a pair of axial alignment keys, each key having a mounting flange for securement along an outer edge of a respective one of the pair of flanges and an alignment flange engaged along a respective one of the opposed faces.