Patent ID: 8511976

Claim:
A system, comprising: a multi-stage turbine, comprising: a first turbine stage comprising a first wheel having a plurality of first slots spaced circumferentially about the first wheel, and a plurality of first blade segments each coupled to at least one of the first slots; a second turbine stage comprising a second wheel having a plurality of second slots spaced circumferentially about the second wheel, and a plurality of second blade segments each coupled to at least one of the second slots; a one-piece interstage seal extending axially between the first and second turbine stages, wherein the one-piece interstage seal comprises a first radial support coupled to the first wheel and a second radial support coupled to the second wheel, and the one-piece interstage seal extends circumferentially across at least two of the plurality of first slots or at least two of the plurality of second slots, wherein the plurality of first slots comprises a first lower radius and a first upper radius, the plurality of second slots comprises a second lower radius and a second upper radius, the one-piece interstage seal comprises a wall extending between the first and second turbine stages, the wall has an inner radius, wherein the inner radius along the entire length of an innermost portion of the wall between the first and second radial supports is greater than the first lower radius and greater than or equal to the second lower radius, and the inner radius along the entire length of the innermost portion of the wall between the first and second radial support is greater than or equal to the first upper radius and less than the second upper radius.