Abstract: Turbine vane segments having outer and inner bands and a vane extending therebetween are welded one to the other by E-beam welding along their adjoining margins and from the outside of the bands. The adjoining margins on the hot gas path sides of the outer and inner bands are chamfered, TIG-welded and machined to provide a smooth, continuous gas path surface. The aft hook of each segment is cut back to provide inset faces in a radially projecting flange and a flange extending axially from the radial flange. A filler piece having a body shaped to correspond to the shape of the space between the inset faces of the radial flange is E-beam welded to the radial flange. Gaps between a tongue on the filler piece and the inset faces of the axially extending flange are provided with weld filler material and TIG-welded to complete the welding of the aft hook.

Abstract: A steam-cooled second-stage nozzle segment has an outer band and an outer cover defining a plenum therebetween for receiving cooling steam for flow through the nozzles to the inner band and cover therefor and return flow through the nozzles. To measure the temperature of the buckets of the stage forwardly of the nozzle stage, a pyrometer boss is electron beam-welded in an opening through the outer band and TIG-welded to the outer cover plate. By machining a hole through the boss and seating a linearly extending tube in the boss, a line of sight between a pyrometer mounted on the turbine frame and the buckets is provided whereby the temperature of the buckets can be ascertained. The welding of the boss to the outer band and outer cover enables steam flow through the plenum without leakage, while providing a line of sight through the outer cover and outer band to measure bucket temperature.

Abstract: Turbine vane segments having outer and inner bands and a vane extending therebetween are welded one to the other by E-beam welding along their adjoining margins and from the outside of the bands. The adjoining margins on the hot gas path sides of the outer and inner bands are chamfered, TIG-welded and machined to provide a smooth, continuous gas path surface. The aft hook of each segment is cut back to provide inset faces in a radially projecting flange and a flange extending axially from the radial flange. A filler piece having a body shaped to correspond to the shape of the space between the inset faces of the radial flange is E-beam welded to the radial flange. Gaps between a tongue on the filler piece and the inset faces of the axially extending flange are provided with weld filler material and TIG-welded to complete the welding of the aft hook.