Abstract: A fluid-to-fluid shaft seal assembly including at least one pressure breakdown bushing within the sealing region encompassing the shaft of a rotary machine and being loosely housed within the machine frame. The bushing includes an inwardly extended arm passing downwardly into an undercut formed within the shaft. A balancing ring extends between the arm and one wall of the stator opening. The ring is strategically located in respect to the bushing whereby the forces exerted upon the bushing by the sealing fluid are pressure balanced to permit the bushing to move freely in a radial direction to comply with the shaft as the shaft deflects and thus prevent the bushing from locking against the machine frame.

Abstract: An end wall closure device for supporting the end wall of a pressure vessel against axial movement when subjected to load conditions. A retaining member made up of a segmented shear key and a segmented compression key is inserted within an internal groove provided within the vessel casing. The shear key is seated in a recessed shoulder formed in the end wall and is provided with a pair of raised moment control pads which, in assembly, act upon the compression key and the casing wall. The pads are strategically positioned to negate the bending moments acting on the retaining member thus minimizing the deflection of the retaining member when placed under load.