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Detailed views of the fuel return manifold and turbine exhaust manifold flow vanes.

Picture 1 of 3.

Fuel flows down two adjacent tubes, cooling the engine wall (known as "regenerative cooling"). It reaches the fuel return manifold (the silver ring at the exit plane of the thrust chamber), where it returned through two "up" tubes, reaching the fuel manifold and then being injected into the combustion chamber.

The turbine exhaust gases exit through these flow vanes on the aft end of the turbine exhaust manifold, enter the double-walled nozzle extension, and finally enter the main exhaust flow through gaps in the shingles comprising the nozzle extension inner wall and thus provide film cooling to the nozzle extension.

Note the marking for No. 60 tube. Even though this is a "fuel-down" tube, the arrow is for some reason pointing up (i.e., toward the throat). This marking is between two tubes; presumably, the tubes on either side of this mark lead back up to the No. 60 tube at the bifurcation joint.