I find the Edwards 30 bare minimum for A12 L flask that is When running on full potential 400v 60 htz
Alcatel 2033
Edwards 2e40
Hmm leybold has Some mid ranges
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Thanks @Roguelab, you’re the real MVP! Is there a formula for sizing pumps to RBF size or anything? How do you know what size pump to go with?
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Not realybut i take 4 cfm /L
Minimum
And 8cfm the L maximum as a guide line
Gooing larger can make. Your crude kn boiling flask to muffin acording to @anon42519203
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So by that logic a 12L flask needs 48 CFM?!
The Edwards 40 only does 25.9 CFM… does this have something to do with the frequency and voltage?
Yes probably a vacuum frequencie controler can solve that
I use second hand vacuum frequency controlers from the cow Milking industrie
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By the way the rule of thumb i described
Has not calculated volt and hertz diffrance
So guess that most of usworking on low voltage only use 80% of what the pump is Capable of 
I solved the mystery high micron reading. On the 2L chemglass system the take off for vac gauge is too close to head were seeing to much fluctuation , moving the gauge down onto K25 T just before the condenser were seeing sub 32 microns. So in theory when we hook up to the new 5L wide bore that should come down again.
Quick question u might be able to help with. The edwards RV has a mode selector as well as gas ballast selector setting. The mode selector is factory set for throughput this can be changed for better dept but the selector switch does bot budge even with a pliers iv read instructions like five times now to try see why it wont budge but no obvios answer, are u familiar with it? Its in section 4.2.2 of manual
sorry man can t help
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Keeping DI to chill any glass that doesn’t restrict your flow . . . meaning any of your receiving flasks cold trap or otherwise but make sure the neck for the distillate isn’t cold enough to slow the flow, but I chill the top and bottom of my monocow and by keeping everything cold can run from 20 down to single digits during most of the run.
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By making an aluminum foil pouch to keep ice surrounding the far end of the monocow
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Oops! Failed to mention this is also on a 10 l system
I have an alcatel a few edwards and leybold’s as my precision pump only used above 160c on first passes and i get better performance with the leybold imo. I dont ice anything other than the 3 cold traps ans regularly see 12 micron on 1st pass. Im also 1” from pump to glass which has mad a world of difference, if your using hose there is only a certain amount of air that can pass theu it per minute sonit would be easy to have a pump bigger than what tour hose can deliver
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Nice numbers! Any pics?
Use a valve and fine tune… but so far 112Cfm on a 20L for volatiles is great.
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