Just went out and bought the set up. B tank,turbo torch. Still haven't found a place that handles nitrogen. I'm installing a 2.5 ton split system,talked with 2 techs. One said go ahead and use Staybrite 8 on anything under 4 tons. The other said he just installed a 2.5 ton unit and brazed. Do you guys also braze at evap.? My other question is what type of tip on torch and also what kind of brazing rod do you suggest? Brazing flux?