Peristaltic pump against a vacuum application?

Hash and Stuff Extraction
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Inspired by the thread last week about hooking up a pump to the bottom of a cold trap…

I’m curious for those of you who are using peristaltic pumps, does anyone make a purpose-built unit that is meant to pump against vacuum? Having some previous experience with them I was just wondering if they use special tubing or ever have problems with either the tube collapsing where the rollers contact it or with leakage (backwards) through the pump towards the vacuum source.

Thinking about changing up some equipment and using a peristaltic to drain roto collection pots and run a cold trap application continuously.

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As far as the tubing collapsing I’m unsure but you would want a vacuum pulled on the collection pot as well you wouldn’t want atmospheric pressure pushing against the pump discharge.

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Why not? I’d be fine with a bit of additional strain on the motor as long as it isn’t going to leak a significant amount of atmosphere backwards through the pump and into the roto collection flasks

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@Lilibel Beaker and Wrench has a sweet one they are using in deep vac applications

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Thanks; yes we do have a peristaltic pump and we are also launching a gear pump for outlets.

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From what I see on your link you’re using the peristaltic as a dosing pump, most of the peristaltic pumps I’ve seen have about half as many rollers as yours does, is that to prevent leakage past the roller stages? Do you ever have problems with vacuum collapsing the tubing in your peristaltic pumps?

Also, is there a reason to use the gear pump for your outlet as opposed to a (presumably larger) peristaltic pump? From my understanding of how gear pumps work IRL I’d expect that you would need to remove the vacuum from the liquid you are trying to pump out or block the outlet of the pump when it isn’t turning otherwise the gear pump wouldn’t ever prime

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Our first prototype had less rollers. We did this so the tube could go in the top and exit the bottom. The tubing does not collapse unless its worn out. It costs .25 cents to replace and this should be done around once per week. We include 25 ft of tubing with each purchase.

There is a check valve on the gear pump for exactly the purpose you described.

Please see our Instagram page for videos of the dosing pump. @beakerandwrench.

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