Abstract: Length adjustable braces (56, 56A-D) attached between a gas turbine exhaust diffuser (40) and an exhaust casing (34) along a horizontal joint (50) between upper and lower halves (40A, 40B) of the outer diffuser shell. Brace lengths are adjusted to align bolt holes (52A, 52B) in respective bolt bosses (43A, 43B) on the upper and lower halves of the shell. The braces may be turnbuckles (56, 67) welded to or releasably attached at one end to the shell and at the other end to the casing. Exemplary fittings on the diffuser shell and casing for the brace ends may be clevis fittings (62) or eye fittings (72). The fittings may be configured to support both tension (58) and compression (59) of each brace. Two opposed fittings (70A, 70B) across the joint may be configured for insertion of a respective clevis bolt (63A, 63C) in both fittings from the same side.

Abstract: Length adjustable braces (56, 56A-D) attached between a gas turbine exhaust diffuser (40) and an exhaust casing (34) along a horizontal joint (50) between upper and lower halves (40A, 40B) of the outer diffuser shell. Brace lengths are adjusted to align bolt holes (52A, 52B) in respective bolt bosses (43A, 43B) on the upper and lower halves of the shell. The braces may be turnbuckles (56, 67) welded to or releasably attached at one end to the shell and at the other end to the casing. Exemplary fittings on the diffuser shell and casing for the brace ends may be clevis fittings (62) or eye fittings (72). The fittings may be configured to support both tension (58) and compression (59) of each brace. Two opposed fittings (70A, 70B) across the joint may be configured for insertion of a respective clevis bolt (63A, 63C) in both fittings from the same side.

Abstract: Manufacture of a gas turbine exhaust diffuser shell (40A/40B) to achieve a final cross-sectional shell geometry by forming an opening (76) in the shell to receive a strut shield collar (46); forming a compensating outward bowing (78) of the shell around the opening that departs from a desired final shell geometry in an amount and shape that compensates for a welding shrinkage when welding the collar in the opening; and welding the collar in the opening. This produces the desired shell geometry after the welding. The collar may be welded proximate an edge (74) of the diffuser shell, such as along an intersection of an axial plane with the diffuser shell. A multi-bolt flange (68) may be welded to or otherwise formed along this edge for assembling an annular exhaust diffuser duct (38A-B, 40A/B) in an exhaust section (20) of a gas turbine engine.

Abstract: Manufacture of an arcuate diffuser shell (38A/38B) assembled from an axially forward portion (38A) and an axially aft portion (38B), the two portions welded to respective sides of an arcuate flange (58A) via two respective pairs of circumferential welds (70A/70B and 72A/72B or 80/84 and 82/86 or 80/88 and 82/90). Each pair of welds comprises first and second welds on opposed surfaces (58, 74) of the shell. The first and second welds compensate each other with respect to welding process shrinkage, eliminating weld warping (68) of the shell. The first and second welds may have equal cross sectional areas or equal masses over a circumferential span of the flange.

Abstract: A method for casting a collar (44, 46) for a heat shield (36) of a strut (32) in a gas turbine exhaust section (20). A casting geometry (60, 70) is defined with extra wall thickness (56, 68) in an area of wall curvature (53, 54), which provides a flow path beyond a final geometry of the collar to facilitate a flow of molten metal in the mold (63, 64). The extra thickness is removed after casting, leaving the collar in its final geometry, which may have uniform wall thickness (T, T2). The extra thickness in the casting geometry may be provided by increased radius (R3) in the wall curvature and/or by casting feed portals (66, 68) that span the wall curvature between a tubular portion (50) and a flange (52) of the collar.