Abstract: A steam turbine includes a rotor supporting a plurality of turbine buckets. The rotor has shaped grooves for receiving a complementary-shaped bucket hook formed on an end of each of the turbine buckets. A rope seal is disposed in each interface between the bucket hooks and the shaped grooves, respectively. The rope seal serves to seal a leakage path that may exist over the bucket hooks between the buckets and respective rotor grooves.

Abstract: Spline seals are provided in registering end faces of upper and lower diaphragm segments in a steam turbine at each of the horizontal joints. The diaphragm segments each include inner and outer semi-annular rings with circumferentially spaced partitions extending therebetween. The registering end faces of each of the inner and outer semi-annular rings of the segments are spanned by spline seals which may comprise a sheet metal plate, a sheet metal body having reversely-curved ends, a solid body having bulbous ends or a sheet metal plate covered by a metallic or ceramic woven cloth. Leakage paths, both in axial and radial directions, are minimized or precluded.

Abstract: Spline seals are disposed in circumferentially registering slots of adjacent arcuate packing seal segments disposed in grooves on inner hooks of a steam turbine diaphragm assembly. The spline seals extend in a gap between the endfaces of the segments and minimize or preclude steam leakage flows past the endfaces. The spline seals may be oriented in axial and circumferential directions to minimize leakage flow paths in a generally radial direction and/or may be inclined radially in a downstream direction to seal against steam leakage flow in an axial direction. The spline seals are disposed in the slots which may be formed as part of original equipment manufacture or may be machined in segments with spline seals provided as retrofits.

Abstract: A seal between the inner ring of a diaphragm nozzle segment and the periphery of a rotor in a steam turbine includes a honeycomb structure brazed onto the radial inner surface of the inner ring segment. The labyrinth teeth on the rotor cut or rub into the surface of the honeycomb structure, forming a seal. The honeycomb structure is preferably a cobalt-based nickel alloy brazed to the inner ring having multi-sided cells opening radially inwardly toward the rotor. The seal precludes or minimizes steam leakage flow between the high pressure upstream flow region and the downstream lower pressure region on opposite sides of the nozzle/rotor interface.

Abstract: A method and apparatus for sealing between an inner casing and an outer casing is provided. The method includes positioning a first sealing member in a leakage path defined between an inner casing and an outer casing such that leakage flow in a first direction activates the first sealing member, and positioning a second sealing member in the leakage path such that leakage flow in the first direction bypasses the second sealing member, and such that leakage flow in an opposite second direction activates the second sealing member. The apparatus includes a pair of circumferential grooves in a channel, a divider positioned in the channel that defines a leakage path, a first sealing member positioned to seal against a flow in the leakage path in a first direction, and a second sealing member positioned to seal against a flow in the leakage path in a second direction.

Abstract: A steam turbine includes a stator supporting a plurality of turbine nozzles. The stator has shaped grooves for receiving a complementary-shaped nozzle hook formed on an end of each of the turbine nozzles. A rope seal is disposed in each interface between the nozzle hooks and the shaped grooves, respectively. The rope seal serves to seal a leakage path that may exist over the nozzle hooks between the nozzles and respective stator grooves.

Abstract: A method is described for establishing load limits for pipe connections to a turbine casing including the steps of: identifying a plurality of the pipe connections as key pipe load connections; developing transfer functions to model deformation of the casing based on loads applied to the key pipe connections; establishing individual load limits for each of the key pipe connections in the group by optimizing solutions to the transfer functions, and establishing a cumulative load limit for the group of key pipe load connections by optimizing solutions to the transfer functions.

Abstract: A steam turbine includes a rotor supporting a plurality of turbine buckets. The rotor has shaped grooves for receiving a complementary-shaped bucket hook formed on an end of each of the turbine buckets. A rope seal is disposed in each interface between the bucket hooks and the shaped grooves, respectively. The rope seal serves to seal a leakage path that may exist over the bucket hooks between the buckets and respective rotor grooves.

Abstract: Spline seals are disposed in circumferentially registering slots of adjacent arcuate seal strip segments disposed in grooves of diaphragm assemblies of a steam turbine in radial opposition to the rotating tips of the buckets. The spline seals extend in the gaps between the endfaces of the segments and minimize or preclude steam leakage past the endfaces. The spline seals are disposed in slots which may be formed as part of original equipment manufacture or may be machined in segments with the spline seals provided as retrofits.

Abstract: Spline seals are disposed in circumferentially registering slots of adjacent arcuate sealing segments disposed in grooves of the casing of a steam turbine about a rotor. The spline seals extend in the gap between the endfaces of the segments and minimize or preclude steam leakage past the endfaces. The spline seals may be oriented axially or inclined radially to minimize leakage paths in the radial inclined and axial directions, respectively. The spline seals are disposed in the slots which may be formed as part of original equipment manufacture or may be machined in segments with the spline seals provided as retrofits.

Abstract: Spline seals are disposed in circumferentially registering slots of adjacent arcuate seal strip segments disposed in grooves of diaphragm assemblies of a steam turbine in radial opposition to the rotating tips of the buckets. The spline seals extend in the gaps between the endfaces of the segments and minimize or preclude steam leakage past the endfaces. The spline seals are disposed in slots which may be formed as part of original equipment manufacture or may be machined in segments with the spline seals provided as retrofits.

Abstract: Nozzle segments mounting vanes are received in circumferentially extending, generally dovetail-shaped grooves in an outer casing of a steam turbine, the nozzle segments forming part of a stage with rotating buckets of the steam turbine. The inclined slashfaces of the adjoining bases of the nozzle segments are provided with circumferentially opening slots to receive spline seals. The spline seals preclude or minimize steam leakage flow past the gap between the adjoining nozzle segments thereby enhancing the steam flow through the partitions of the nozzles.

Abstract: Spline seals are disposed in circumferentially registering slots of adjacent arcuate packing seal segments disposed in grooves on inner hooks of a steam turbine diaphragm assembly. The spline seals extend in a gap between the endfaces of the segments and minimize or preclude steam leakage flows past the endfaces. The spline seals may be oriented in axial and circumferential directions to minimize leakage flow paths in a generally radial direction and/or may be inclined radially in a downstream direction to seal against steam leakage flow in an axial direction. The spline seals are disposed in the slots which may be formed as part of original equipment manufacture or may be machined in segments with spline seals provided as retrofits.

Abstract: Spline seals are disposed in circumferentially registering slots of adjacent arcuate sealing segments disposed in grooves of the casing of a steam turbine about a rotor. The spline seals extend in the gap between the endfaces of the segments and minimize or preclude steam leakage past the endfaces. The spline seals may be oriented axially or inclined radially to minimize leakage paths in the radial inclined and axial directions, respectively. The spline seals are disposed in the slots which may be formed as part of original equipment manufacture or may be machined in segments with the spline seals provided as retrofits.

Abstract: Spline seals are formed at the joints between packing casing shells in a steam turbine having high pressure and intermediate pressure turbine sections sealing between the high pressure and intermediate pressure regions on opposite axial sides of the packing casing. The spline seals extend in registering grooves from adjacent the seal segments of the rotor radially outwardly to adjacent axial load surfaces cooperable between the outer shell and the packing casing. The spline seals minimize or eliminate steam leakage paths through the horizontal joint of the packing casing shells.

Abstract: A gas turbine has circumferential arrays of nozzles and shrouds and a plurality of combustors for flowing hot gases of combustion through respective sets of adjacent nozzles and shrouds. First and second nozzles of each set of nozzles are subject to different known inlet conditions of the hot gases of combustion flowing from the associated combustor and transition piece. The first nozzle in each set is preferentially located relative to the second nozzle of that set at a circumferential location relative to the associated combustor based on the known different inlet conditions. The first and second nozzles are therefore qualitatively different from one another dependent on those different inlet conditions. Similarly, the shrouds are subject to different inlet conditions and are preferentially designed and located based on those known inlet conditions.

Abstract: An impingement insert sleeve is provided that is adapted to be disposed in a coolant cavity defined through a stator vane. The insert has a generally open inlet end and first and second pairs of diametrically opposed side walls, and at least one fail-safe tab defined at a longitudinal end of the insert for limiting radial displacement of the insert with respect to the stator vane.

Abstract: In a closed-circuit steam-cooling system for the first-stage nozzle of a gas turbine, each vane has a plurality of cavities with inserts. In the second cavity, a main insert receives cooling steam from an inner plenum for impingement-cooling of the side walls of the vane, the spent cooling steam exhausting between the main insert and the cavity walls into a steam outlet. To steam-cool a localized surface area of the vane adjacent the outer band, a secondary insert receives steam under inlet conditions from a first chamber of the outer band for impingement-cooling the localized surface area. The spent impingement-cooling steam from the secondary insert combines with the spent cooling steam from the main insert for flow to the outlet. Consequently, low-cycle fatigue is improved in the localized area by the impingement-cooling afforded by the secondary insert because of the cooler steam supplied, as well as the increased pressure drop driving the steam through the impingement openings of the secondary insert.

Abstract: An impingement insert sleeve is provided that is adapted to be disposed in a coolant cavity defined through a stator vane. The insert has a generally open inlet end and first and second pairs of diametrically opposed side walls, and at least one fail-safe tab defined at a longitudinal end of the insert for limiting radial displacement of the insert with respect to the stator vane.

Abstract: Turbine stator vane segments have radially inner and outer walls with vanes extending therebetween. The inner and outer walls are compartmentalized and have impingement plates. Steam flowing into the outer wall plenum passes through the impingement plate for impingement cooling of the outer wall upper surface. The spent impingement steam flows into cavities of the vane having inserts for impingement cooling the walls of the vane. The steam passes into the inner wall and through the impingement plate for impingement cooling of the inner wall surface and for return through return cavities having inserts for impingement cooling of the vane surfaces. At least one film cooling hole is defined through a wall of at least one of the cavities for flow communication between an interior of the cavity and an exterior of the vane.