Plate Fin Exchangers consist of fins or spacers sandwiched between parallel plates.
The fins can be arranged so as to allow any combination of crossflow or parallel flow between adjacent plates. It is also possible to pass up to 12 fluid streams through a single exchanger by careful arrangement of headers. They are normally made of aluminum or stainless steel and brazed together. Their main use is in gas liquefaction due to their ability to operate with close temperature approaches.