Apparatus and method for making internally finned pressure vessel

A method of fabricating a plurality of internally finned pressure vessels, the method comprising:

• providing an apparatus including a plurality of positioning discs, each of the positioning discs defining a plurality of circumferentially spaced slots extending radially into the positioning disc from a perimeter thereof, the apparatus further including one or more rods extending through the plurality of positioning discs, the plurality of positioning discs being held in axial alignment by the one or more rods;
• loading a plurality of fins into the slots of the positioning discs;
• inserting the apparatus containing the plurality of fins into a pressure vessel;
• attaching the plurality of fins to the pressure vessel by a brazing process;
• removing the apparatus from the pressure vessel;
• loading a new plurality of fins into the slots of the positioning discs;
• inserting the apparatus containing the new plurality of fins into a new pressure vessel;
• and
• attaching the new plurality of fins to the new pressure vessel by a brazing process.