Stack size for 3 x 12?

[minn]

I bought a set of 3 x 12 drop tube pans but the arch was a pile of unrecognizable scrap. So I guess I have a summer job of building an arch. What would the proper stack size be for this size arch? I am planning on forced draft with air over fire as well. Thanks in advance.

[TF Maple]

Check the threads on "The evaporator, accessories and boiling on it" for this kind of information. This has been hashed over a few times already, unless someone wants to add to this one, thanks.

[Sbascom]

12 or 14" top stack some companies went with a 12" others with 14" either way you should be fine.