Copper coil pre heater

[devils11217]

How small copper diameter coil can i go to get adequate flow into my 2 x 4 smoky lake float box. Feed line is 3/4 inch from tank but would like to go with the smallest copper coil for cost sake around pipe but want to maintain good supply flow into boxx.

[Ghs57]

Is it a flat pan? How far do you have to go? I was on a SL 2x4 last year and used 1/2 pex to the float box. It really depends on your setup and boil rate, but with a 2x4, even 1/4 might work.

Note: I wrote this before I saw you were talking preheater. I did not run a preheater. Are you planning to heat with steam or off the stack?