Rotary Evaporator Flask Size HELP!!!!

Does anyone know if they make adaptors to fit 24/29 flasks for a 5L rotary evaporator The model of the rotary evaporator is RE-501. I got it off eBay but I never got a size. I used a caliper and it said 47mm for the diameter of the 5L flask but can not for the life of me find an adaptor or a small flask with an opening that large. Any Help on where I could purchase an adaptor?

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I dont think there are adapters. im pretty sure its some wonky chinese specialized flask joint just for the RE501:

collection flask:

its possible the joint is the same as a buchi or heidolph inner joint… you would need to do some digging though if you wanted to convert it.

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Sounds like you bought a usalabs 5l rotovap. I own the same one. I also bought a 2l rbf and he adapter to run the 2l on my 5l.

Email usalabs in livonia Michigan. Tell them you need the adapter. I think it’s like 50.00 or so.


Thank you for your help. It’s 60$ + Tax. Thank you for telling me the site and that they sell if you ask. I am so appreciative you have no idea. The Endeavor is finally over of the part that was to be found.


I’ve got the re501 also. I’m looking for a one way check valve if there is such a thing or any other vacuum valce/adapter combo that will fit. I don’t know what the joint is called where the receiving flask meets the condenser. I’d like to be able to empty the receiving flask without Breaking the vacuum on the whole system

I guess it’s an s35 20 female spherical ball joint to male s35 20 with a cutoff valve? Anybody have that?

Change tour recieving flask to one with a drain and run a hose to a larger vessel and you wont have to break vac or not nearly as often

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I do have a drain, it’s a 3L. Thanks that might help. I have a 2L filter flask I might could plug. Wait a second, that’s genious and then the drain valve does what I need and I just empty the 2L flask. I think that solves it.:+1:

I have mine hooked to a 7gallon gama lid bucket plus how many gallons the flask is already.

I thought I heard someone talking about a check valve that sits inside the joint of the condenser/receiving flask. Ever seen that?

Only on the bigger ones 10l and bigger usually, i have a 5l with a valve so i would only loose the bac from the flask but my 20l doesnt have the valve. Also depends on what company makes the roto.

Nice, that would be plenty big enough for me, what’d you have to do to get a hose in it with a vac tight seal?

Just a thick wall hose, the 3/8 across sells works and then just drilled a hole and sealed with silicone

The gama lid buckets ( not sure if thats the real name) they have a seal on the inside there like the preppers buckets for food etc. So water tight etc.

I was looking it up, hadn’t heard of before. One like this, right hdpe?
5 Gallon White Bucket & Gamma Seal Lid - Food Grade Plastic Pail & Gamma2 Screw Seal Tight Lid (Black)

Cool I figured you would need a bulkhead fitting

Ya thats the style, you could put a fitting. I tried my way and it worked so i never tried the fitting.

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