Hi all, I don't presume to know anything about vacuum engineering, but I'm considering trying to build a small homemade medium vacuum, and I was wondering: Is it practical to nest vacuum chambers inside each other? I've been surfing the web and can't seem to find any info about it - but it sounds feasible. In case I wasn't detailed enough: Say you had a vacuum chamber of maybe 3kPa. Couldn't you encase this chamber with another of equal quality, and simply evacuate them in stages? I'm sure i'm missing something, or they would be doing/have tried this already.