Vacuuming solvent tank after N2 assist?

Anyone kno if this diaphragm pump would be safe to purge n2 outta my solvent tank? Trying to be able to use one tank instead of 2 but need to get the n2 out so I don’t slow my recovery


What is your solvent?
What temp is your tank?

Throwing a semi-permeable membrane in there (salvaged from an N2 generator) would make it appropriate, but most don’t bother with pumps.


Just ntane and the tank is buried in dry ice no slurry an a coil in front of it in dry ice an iso. Which I removed at the end to finish the vapor path into the tank. Don’t do iso on the tank cause it’s so big would take a lot

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Only using the pump to vac out nitrogen otherwise just making the switch back to passive

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That response suggests you failed to follow the link…


What would you expect the vapor pressure of your solvent to be under these conditions?

And/or have you looked at how the boiling point changes under vac?

Just reread it thought you ment use it in front of the pump. Thanks

Can’t get an exact temp on solvent but just want the n2 out so if I pulled a little solvent vapor off to get all the n2 out I wouldn’t mind. I’d b venting that outside just was wondering if the diaphragm pump I have on hand would b resistant to ntane an n2 vapor

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N2 is quite inert. It’s trivial to look up compatibility of the elastomer in your pump with butane.

To make the trick safe you need to understand the vapor pressure of your solvent at the temp at which you are performing it, and the boiling point at the vac depth you’re aiming at.

At least one of those can be found laying around here, the former can be sourced from and the latter calculated with help from NIST if you understand how to work the Antoine equation

By adding a membrane that is permeable to N2, but not butane or propane, you can be fairly confident you’re not going to blow yourself up. link above to where those can be found.

The vacuum pump you’re suggesting using is not AtEx rated, so it’s not really the right tool for the job.

IF you’ve pushed all the liquid solvent out of your tank with N2, AND it’s sitting on dry ice, chances are pretty good you can pull 50mbar (pumps rating) on the tank and vent it directly outside without issue, I personally would just vent it to zero and call it good. Or I’d find a membrane to install.

Edit: @Northeastlabs understand that this level of repetition was explicitly provided for those who are following along at home…