The market for large plate heat exchangers (>0.3 sqm/plate) are today dominated by products produced by either welding or by applying gaskets between the plates (and hybrides thereof; semi-welded heat exchangers).
In applications where it is possible to use copper as a filler, brazed heat exchangers are possible to produce up to approximately 0.5 sqm/plate.
As the heat exchanger grows larger the thermal movements in absolute figures (and other geometrical variations) increase.
This leads to large fillets, hence the need for a filler metal with good gap filling properties.
If a copper-free heat exchangers must be used, Ni-brazing can be an alternative. This alternative does however require small fillets (at least <200 µm, generally lower).
Another aspect of joining large plate heat exchangers are the larger (planar) surfaces that must be joined in a safe way. Problems with controlling the consistency of the capillary volume and the movements of the filler are common.

By using a recently developed Fe-filler and specially designed joints (brazing traps) it is now possible to produce large ready-to-use plate heat exchangers after only one heat treatment without copper. Providing the same corrosion behaviour as Ni-brazed heat exchangers.