How many cfm is a minimum to run a full bore 5L SPD set up

Hash and Stuff Distillation
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I am trying to get a 5L full bore SPD kit and need to know what kind of vacuum pump I need. I was told 8cfm is not enough, but i don’t want to spend 3000 bucks on a 21 cfm pump.

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Gonna need 20cfm or more.

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Thank you, any suggestions for a pump less than $3000?

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Search results for '2021' - Future4200 they’re only 14cfm, but folks use them extensively and they can be found used cheaply

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We refurbish and resell a lot of Edwards e2m30s, $2850. People get away with the Alcatel 2021i as well… You can usually make one of those happen for less than $1500. The e2m28/30 is sort of the industry standard rotary vane for a 5L SPD.

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Dual 2021’s would do it

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A single 2021i works just fine for a 5l full bore

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I got a leybold d25b coming back from a fresh overhaul if your interested

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Is it possible to link multiple smaller pumps to achieve the same level of vacuum? Say aseries of 3 pumps at 8 cfm each?

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It’s not the same

So example. 2x20cfm pups don’t equal 40 cfm. It’s closer to 30-35 at best but it might better than nothing. Also three pumps or more than one really, must be same health. If ones weaker than the other it will be as powerful as the weakest link.

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Thanks for the help, is it possible for the pump to be too strong? Say I found a pump that does 53 cfm for like 700 bucks?

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It’s a leybold d65b

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Not as long as your vac line size is big enough, go 1” and the leybold will rip

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2021 should be fine on a 5 liter.

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If you go 2021i a glass sight is a worthy upgrade. The stock one is plastic and gets nasty real quick

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Thanks for the help y’all I’m doing my first set up to run cbd crude into distillate. I’ll probably be asking a ton of questions trying to take my business to the next level.

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If you decarb before first pass 8cfm is okay

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The key to usinf an 8cfm pump is just go slow and watch your gauge. There are typical vac pressure high spots. But just keep it at or under 2torr. And usually 300mtorr or less during mains. This is bare minimum not ideal. Ive done 1x10^-10torr on a 5L but its not essential

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Vac depth is super essential. The leybold doesnt have that great of vac depth for when you get to mains. Its a good “dump” pump though.

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I’m looking at some used e2m30s, this seems to be the way to go

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