I run a 10"x15" collection vessel which is including a 3" shatter platter for a 4"x48" column with 4" to 2" concentric reducers which brings the column to a 678 cubic inch volume or 11.11 liters. I can use roughly 20 lbs of a 70/30 butane/propane mix, which is 1.31 lbs per liter, per pass which fills my collection pot to an 80% full mark. It would be nice to be able to run 25 lbs but this works for me. The bigger you go, as far as triclamps go, the less pressure they can handle. I have heard of 12" lids being leaky, not that I haven't had a small leak myself.. that's just one of the many variables to running a closed loop.