Pump for Buchner funnel

I was wanting to know what pumps you guys are using for your Buchner funnels with flammable liquids. I have a couple Hardware factory store 12 cfm pumps that come with their ovens. Will those work safe? If not have any of you used a handpump with positive results? Thanks

Hand pumps don’t work…u need continue flow

A water aspirated vacuum the you hook up to the sink…or hose pipe, no motor for fuems to get to…that works for small filtering…but if ur doing large scale I think you can get large cold trap for those pumps but I’m not sure there

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12 cfm is pretty hefty. You need to throttle that thing, but I’m using both a 2.3 cfm diaphragm pump and a normal 5 cfm vane pump with my buchner. Just make sure you’re not pulling to hard.

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Welch wob-l diaphram pumps

They work perfectly. And I use these for my 5l rotovap as well


I have a 50l Buchner coming from China (they call it a vacuum nutsch filter) with a diaphragm pump and vacuum regulator.

What would be an appropriate vacuum level to set my regulator to for a filter this large?


I’d surmise that the pump they give you just go full blast. You want a proper vac so that the filter really gets sucked down. I had an issue when I connected a 3/8 manifold between my roto and filter. Little did I know that the inside was 1/4, this lead to the paper not sealing properly. It took me a second to find that strangle point. So full vac is what I recommend.

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You need steady vac not deep vac, gast and a few ither diaphragm pumps is what i use on my karge bel art and they wirk great and easy to rebuild. Deoending on your budget and volume you do.

Are the pumps you guys using ignition proof?

Not that I know. The diaphragm pump is safer to use, has no oil.


Are you still using the 50L vacuum filters? I’m curious what kind of flow rate you’re able to pull on that? Thinking about getting one but not sure

diaphragm vacuum pumps

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I’d say I can filter a 5 gallon bucket in about 15 min when doing a room temp winterization of crude in methanol, faster when doing a second cold methanol winterization over celite 545.

if you wanna go the extra mile.there are ones with PTFE coated insides