Hi I just joined having some questions about purging and found all of my answers in this thread rite hear. First off I want to say I been on multiple sites researching for weeks and u guys are the best. I am new to bho but been intrigued for quite some time, I finaly got a great opportunity to run a large amount of material for a friend and hoped on the opportunity and bought a 3gal best value vac chamber(awesome lid an gasket no issues so far) and a robinair 15300(3cfm-2stage) with this setup I am pulling a complete vac past 30 and was wondering why the bubbling never stop at 110-115*f thin film, I now know thanx to use I had a feeling that couldn't still be butane bubbles. My question is what can I do to stop my chamber from going past 29.5hg? I really don't want to play with the valve for an hour bak an forth trying to keep it in range.
You can close the ball valve between the chamber and the pump, and open it again as the pressure decays, or you can crack the back fill valve and bleed just enough air in to keep the pressure at the level that you desire.