I don't have it at my sugarhouse, but back when I was a dealer/installer of outdoor furnaces, when we encountered a steel roof to run the stack thru (wood shed or just a roof), we had our local tinshop make a roof jack. He needed the pitch of the roof and a sample of the roofing. If it was going thru at the peak he also needed to know if the ribs lined up side to side, if not he needed to know how far offset the 2 sides were.
When we got the roof jack it had the exact shape needed to fit the steel roofing profile. A cone shape stuck up for the stack to pass thru and then there was an adjustable rain collar to put on the stack a few inches above where the stack went up thru that cone. We simply pushed the stack up thru after attaching it to the roof and sealing it with silicone caulk, then put the rain collar on and it worked perfectly.
However, I've not gotten to that on my sugarhouse. I simply have the stack pass thru the steel roof (the opening is close, but slightly larger than the stack so it can expand and contract up and down as the temperature of the stack goes from cold to hot, if too snug thru the roof it will expand upward but as it contracts the roof can grab it and create a gap at the arch and base stack joint. I had that, but then I opened the roof hole slightly and now it is good. Even though not perfect, I get little or no rain down the outside of the stack and I have a flip cap on top that is closed when not in use.
For my steam stacks (2@15") they just go up and terminate at the lower edge of the door opening on the cupola. The 15" SS stacks go up a few feet and stop, then from in the cupola I have 13" aluminum stacks that are suspended from a thru rod in the cupola. Those extend about 6" down into the 15" stacks below. This way, when I need to raise the hood, the 15" stacks simply telescope over the 13" stacks as the hood raises on winch cables. I lift and lower it with a small boat winch attached to a post on one wall.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.