WTB: 50L rotary evaporator glass flask

voltabiotech · April 6, 2024, 10:50am

Hi future,

We broke two 50L rotary evaporator flasks this week and want to buy 2 to 3 more in USA.

I have these coming from cheena (country next to china where I can buy cost effectively) in about 40 days but we are down this next week without more balls.

What’s your best price (preferably around $100 each since that’s what I pay for replacements) and I’d be happy to ship you our replacement flasks once they arrive in 40 days. Our lab is in Oklahoma City.

Details about our balls in case you need it:

Details/Specifications
4.75” Outer diameter joint on 50l roto
3.5” Inner diameter joint on 50l roto
1/4” lip on joint for 50l roto

As a side note - our team overtightens the flasks because it’s not sealing effectively in the rotovap consistently, causing lost production time. We think we can surround it by rubber so we don’t cause unnecessary pressure on the balls going forward. Anyone can share tips/tricks how you avoid overtightening while making sure it seals every time?

Cassin · April 6, 2024, 2:40pm

Check your seals as part of routine maintenance and cleaning. Use a torque wrench to tighten - that way you are not over or under tightening. Make sure the ball and the evap are the same size and style of tightening neck and seal.

Once upon a time I ran a farm of evaps… like 60 of them…all day…every day. I often had to change the seals out around once a month, sometimes more. something else I found is that you can have evaps for different stages - so you don’t need as much vac to make things work nicely. And then you use a little tube to suck stuff from stage to stage.

I moved away from rotovaps a while ago to save time and stress and cleaning and what not. You might consider that sometime soon.

cyclopath · April 7, 2024, 5:12pm

Correct units are often important…

120mm OD x 90mm ID is almost certainly the OEM’s target.

edit: 1/4" is often translated as 6mm, but I suspect that lip is closer to 8mm.