ahhhh... makes sense why you use the pressure pot instead seems like building another IIIa might be a better way to go with a 6x12 spool potentially.
quick question greywolf... i froze my recovery tank so that i could bleed off excess pressure as it was taking longer to flood the columns. i then found i couldn't draw the butane into the IIIa. now it turns out we only had about 5 or 6 lbs of butane left in the recovery tank and we did freeze it with dry ice. any thoughts as to what might be up? we've run the system cold before without any issues other than long reclaim times. so either purging almost all the pressure out or being low on butane is the issue...
5lbs is around the bottom end of where the system runs well. I try to keep it closer to 10 lbs and add when it gets close to 5lbs.
If you chilled the tank in dry ice, you probably had little pressure left, so that it was strictly a push pull effort by the pump. Do you know what temperature it went down to?