Bvv closed loop

Considering a new extractor
It seems like best value vacs has stepped up a bit
I found http://www.bestvaluevacs.com/90-180truestage1.html
What are your guy's thought on this system
And what is the point of the ball bearings in the sight glass

Looks like a bad location for that type of sight glass to me. I know of two column sight glasses that have ruptured while full, from hydraulic expansion, dumping column contents.

If you need it certified to NFPA-51 or ASME, the sight glass will need to meet the standards for 6" and under, which is 350 psi. I'm guessing that design sight glass isn't rated half that much.

It is also designed so it conceivably could fill with liquid between the two valves and experience a hydraulic pressures through thermal expansion. It will require a pressure relief valve.

The ball bearings are surface area and nucleation points for the plant waxes to stick to.

honestly good work(CLS) is not cheap and cheap work is never good.