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

Picture 1 of 3.

Fuel flowed down two adjacent tubes, cooling the engine wall (known as "regenerative cooling"). It reached 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 exited through these flow vanes on the aft end of the turbine exhaust manifold, entered the double-walled nozzle extension, and finally entered the main exhaust flow through gaps in the shingles comprising the nozzle extension inner wall, thus providing 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 single main No. 60 tube at the bifurcation joint.