While we are at it.. May I ask the proper way to purge the lines when switching refers?
I believe that you ensure that the refer is drawn through hi to low hoses into suction line. Then remove and open gauges and manifold to atmosphere.
Then when hooking up to new system with different refer, purge the manifold and lines with the new refer at the manifold connection? What about the yellow/middle hose? I want to ensure that I am not mixing refers. Also what is the best way to purge N2 through them? Just flow it through one hose and open the manifold and ball valves? Does anyone ever do that?