Abstract: Certain embodiments of the invention may include systems, methods, and apparatus for modifying a turbine casing. According to an example embodiment of the invention, a method is provided for modifying a turbine casing. The method can include providing one or more casing retention pin bores in the turbine casing; inserting a retention pin in the one or more casing retention pin bores; providing one or more patch ring segments configured to be radially constrained by at least a portion of the turbine casing and further configured to slide circumferentially in cooperation with at least a portion of the turbine casing, wherein the one or more patch ring segments comprise at least one retention pin locking bore; installing the one or more patch ring segments in the turbine casing to radially constrain the one or more patch ring segments; and engaging the retention pin in the at least one retention pin locking bore to circumferentially constrain the one or more patch ring segments to the turbine casing.

Abstract: Disclosed is a fuel nozzle for a combustor which includes a tip section and a tube section. The tube section, in which a first end is connected to the tip section includes an outer tube having a tube axis and connected to the tip section and an inner tube disposed at least partially inside of the outer tube and connected to the tip section. The inner tube includes at least one flexible portion capable of reducing stresses in the fuel nozzle. Also disclosed is a fuel nozzle which includes a tip section, a base section, and a tube section disposed between the tip section and the base section and connected to the tip section at a first end and connected to the base section at a second end. The tube section includes an outer tube having a tube axis and an inner tube disposed at least partially inside of the outer tube and connected to the tip section. At least one rib is disposed on the outer tube and extends radially outwardly from an outer surface of the outer tube.