50L roto vap assembly questions

Hey guys so we’re hooking up our 50L roto right now. Noticing there’s something called a self-closing valve. Is it this thing?-

Now does this go in between the smaller condenser and the receiving flask?

If so, what direction? Do I take the plastic off the edges?

It goes where it can pop up when it opens it goes between the collection ball and the glass column


Ok, do I leave the weird plastic ring on there?

And also- so am I holding it right side up in this picture? Is this how it would install or flip it around?

That’s how it goes just like you have it leave it like it is and stick it between the two pieces of glass and tighten clamp up

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It just stops you from losing vacuum in the whole system when you take vacuum off of the collection ball to dump it


You’re the fuckin man thanks brother

Hold on flip it over when it’s up it should be closed is open in the picture correct if so turn it over


@Ncfarmer is correct. did you RTFM? (I didn’t :wink: )

there are pictures…

I put the glass receiver in storage and hooked up two kegs (thanks @Rowan)

see Optimizing your RotoVap

Edit: I placed it at the very top of my condenser, where it should act as a check valve…currently running a rotatory vane pump on there, don’t want oil heading back that way…


Does RTFM stand for read the full manual? Because I’m broke and bought Chinese. You ever try to read one of those? :joy:

Been reading through that thread this AM! Haven’t got to the bit about the kegs yet, but I’m sure I’m not far from it!

Do you explain how you bypass the collection flask? Assuming you hook up the valve on bottom of collection flask to bottom of smaller condenser

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1k word substitute.

Full? :thinking:

Sure, that works…

After coffee: Optimizing your RotoVap


Wonder if I can get something like this for a 5l. I didn’t know there was such a thing


Pop out the center valve. Your rotovap will run faster.

No idea I didn’t realize the smaller ones did not have one on them …thought they were standard on rotos with 1 collection ball

Mine is re-501 from China. Does not have that function. I also need to stop the receiving flask valve from leaking. It’s ok if vacuum isn’t all the way down but just annoying, I think I may have overtightened and jumped the threads one time. Now all the Teflon and grease in my toolbox won’t stop the airbubbles coming in

Dude you got instructions?!?! Lucky.

Although I can’t bitch, mine came with UL sticker a few weeks after I bought it.

Also don’t worry too much about leaks. It’s not shortpath. Unless of course you aren’t getting good vacuum at all.


you got an explanation for how?

unless your receiving flask is being cooled to reduce it’s vapor pressure I can see no reason removing a check valve would effect the laws of thermodynamics.


Instructions, not really, but there was some loosely translated. It works ok, I just put a hose with a clamp on the outlet. I want to find an adapter so I can use the condenser with other things maybe.

No, that valve is a flaw china made in the design. It flutters and slows the system down.

Trust me. Pop it out of that gasket ring. And install the ring without the core component.it has nothing to do with thermo dynamic properties. It’s to lock up the column condenser so you can break atmosphere from flask and drain. Now adays pumps are so fast you can just break vac and drain, then close the valves and be pulled down relatively fast.

You got a ul listed roto from china?

Sure, it flutters, but it is below the condenser, how does it being open verses closed change the evaporation or condensation rate?

I’ve never pushed one to the point that I flooded the condenser, the pump usually complains, or pisses alcohol (depending on how appropriate the pump is). Mainly because nobody ships enough chiller with their systems, and even “no trust me, get the next size up” doesn’t seem to cut it sometimes.

I’m asking because I want to know…

This thing causes a very similar gurgling on the way into the receiver (keg).


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