Cold ethanol pumps


Hello I was curious what kind of pumps everyone’s using to transfer cold ethanol (-40C) to and from vessels. Trying to source one rated and approved for the job has been difficult. It seems this is a very specific application not commonly found in most industries. Currently using an air operated diaphragm pump. It does the job but it starts to slow after a few minutes of operation plus I don’t like the pulsating flow. Would like to switch to gear pumps or something else better suited for the job. I’d love to hear what everyone else in the community is doing currently!

Extracting Cold without a Chiller
Diaphragm pump that can handle -80°C

I suspect that the slowing after a few min means your air compressor is too small (not enough CFM)

What are you using for a pump?
What are you using as an air compressor?


These pumps kick ass. I’ve pushed one to -65C to -70C for about 12 hours. EPDM seals + PVDF housing are rated for -40C. Viton seals + Polypropylene housing should be rated for -35C I think.

Low HP explosion-proof pumps can be hard to find.



I’m finally in the market for appropriate pumps too…

Up to this point I’ve been moving my solvent around with either positive or negative pressure. Sucking has the advantage that there is no tank of nitrogen to accidentally empty, but cold boiling some or all of your solvent is an option with vac.

Right now either of the pumps described here will get the job (I need) done, but I suspect a community effort to document what we’ve found that works, and what doesn’t, would be extremely useful.

I’m going to dig around here and see how much has already been documented. Pretty sure I’ve seen at least 5 unique suggestions (any other guesses?)


Are you moving cold ethanol? If so I use the beaker and wrench pump. Grainger has the same pump with different seals. If not moving cold I go fuel transfer pump


Thank you!!
Not sure how I got here, but it seems relevant…

Pumping considerations

As ethanol is a volatile fluid and also toxic, the containment of the fluid should be the first consideration. The prospect of a leak, particularly in a refinery can be exceptionally dangerous and cause costly downtime. Where shaft-sealed pumps are in use it is recommended switching to a mag drive pump…

I recommend reading the rest of it…


No experience with any of the above yet.

Although I’m pretty sure there is one of last one linked that came in the door with my previous employer’s 100gal moonshine still…

I’m torn between the first and last options as far as ordering today. Leaning towards the fuel pump because I think it will handle -80 better. I’ll let you know :wink:


Really? I like the cpe systems specs, it has an impeller which means it can survive much colder temps without breaking a diaphragm.Not to mention it already has sanatary plumbing. what kind of pressure or head feet do you require?
Also the tolerance will change in the gear pump @-80^c, idk if it would perform the same.


I need something inexpensive for R&D, preferably on my doorstep when I get back to OR next week.

I totally agree on all of your points, and assuming testing goes well, the cpe looks like a strong candidate for the real deal.

Finding something that the engineers will certify at -80 seems non-trivial. Gonna have to set that bridge on fire at some point too :wink:

(I’ve noticed folks tend to cross bridges faster when you light a fire under them…)


How big is the r&d pilot plant?


About 900lbs

although it appears to be floating in this image :thinking:


An old man once told me this. Buy the best you can, even if you have to save a little longer for it. Down the road you will eventually buy the better thing, why buy it twice?
-Bill Krause


What speed does the b&w pump at?


Masterflex sells tubing that has an excellent rating on ethanol compatibility and flexible till -60 so maybe a peristaltic could work. -80, IDK.


Seems like they should have something viable up in Alaska to transfer fuel during the winter months.


which is why I have the CPE in hand now :wink:


Hows she go?


How’s she working so far? Magnatex has a mag drive rated rated to -101c but they want almost $12k​:neutral_face::money_mouth_face: plus it requires a constant flow of N2 as a blanket to prevent I’ve buildup on the magnet housing. I’ll post the spec sheet when I get into work. I have a feeling that the local fire inspectors won’t approve anything that isn’t rated for the exact temp/pressures Im running. More and more it’s looking like a large industrial vacuum and a nitrogen generator to push and pull is the safest, most flexible and best valued option​:thinking:


Here is some info on a Magnatex Mag Drive Pump MAXP pump rated to -101c. I have not used one nor do I own one but thought I’d share for informational purposes. See the attached document for the data sheet and quote:
Magnatex_QUOTE M-28152.pdf (166.4 KB)

They have a -760c version for around $7k.


thank you @Jay-TL!

Having a pump that is actually rated, that one can show the local fiefdom’s box ticker, if the subject ever comes up, seems like an invaluable thing to have up ones sleeve.

especially as we all know @Dred_pirate’s solution is likely to inspire apoplexy in a regulator of any ilk.