Ghetto filtration

Absolutely not meant as a description of a PRV defeating valve…

Pretty sure that “on the housing itself” comes from me repeatedly stating that the PRV should be non-defeatible, ie NOT on a tri-clamp fitting that can simply be left off of today’s assemblage during @Akoyeh’s formative years :shushing_face:

If you’ve only got one 6” tri-clamp lid, the first keg is just fine, but as soon as you throw compatible parts without the PRV into the mix, you want “…a prv on the housing…”


Yep. Reread it. I’m the asshole. To be fair, despite the fact that proportional relief valves are supposed to have low hysterisis, closing the inlet valve to a vessel that has one starting to go will probably only stop the deluge after you’ve thoroughly sprayed whatever it is that you really, really didn’t want to (potentially including yourself). It’s always a good idea to make sure your relief goes somewhere other than just “out” especially if the service is flammable or toxic for this purpose but yeah, I interpreted @Akoyeh’s suggestion as a valve in the wrong place but apparently it’s me in the wrong place lol


No harm, no foul! You got us to think critically about our systems, and there is only benefit from that. Without questioning there can be no conviction. Cheers!


Whole reason for the witness protection program :rofl:


Here here!

1 Like

My setup is kind of ghetto, but it works nice. Was doing 2 dimensional , buchnner style filtration for a while to remove sub 220 micron sediment after cold EtOH extraction. Was using the 5 gal refinement filter from BVV with a 5 micron sintered disc. That thing sucked (but not in the good way that it should). Very slow, clogged easily, etc. Tried that setup every which way - with a celite cake, without, with filter paper, without paper, etc. Either way it was just too slow. And the sintered disc clogged so much that I’d have to bake it in a 450C muffle furnace to make it usable again (never tried ultrasonic bath tho that probably would have worked too).

This works good for our scale. And was way cheaper than a larger set up from Rosedale or similar companies.

I use negative pressure (diaphragm pump) to suck solution to be filtered thru these staged filters (50-10-1 micron) and into a holding vessel. Works nice. Super fast. Takes under 1 minute to filter 5 gallons of cold (viscous) ethanol. I’ll probably keep the 5gal buchner around for filtering over carbon or clays, or whatever, but I am happy to be done with 2D filtration for removing sediment.

And yeah, I know I should probably ground those housings and get tubing that can be grounded. Got to do that and a few other modifications.

My only real problem with this method is the large holding volume in the housing. Have to flush a good bit of clean solvent thru to get everything out.

Some things I learned in the process of switching to this method that might help anyone that wants to do something similar. McMaster Carr has solvent compatible cold temperature tubing. However from what I understand, due to static electricity, tubing is probably not the best option. A braided stainless steel hose is probably the correct way to do this. Also, not all 2.5 x 10 filters are the same height. Tried a few different brands and some were a mm or 2 taller than others preventing them from fitting in the housing. It seems the typical Big Blue style houses have a greater tolerance for slightly different size (height) cartridges. I have the same staged filter assembly before the rotovap, but they are PP housings and every filter I’ve tried fits in them. Not the case with the stainless ones.


turn them upside down.
hold up volume goes away.
does introduce it’s own cons.

edit: in your case, one of those cons would be running afoul of the electrical outlets.
maybe you should tape over them :shushing_face:

that is a really clean setup. not sure it qualifies as ghetto…there is no sign of cannabinoid infused wall or floor.


Maybe @tetramethylsilane had a minion clean it up before the shot was taken, much in the same way you had me do it way back when. Haha. Super slick looking solution, all jokes aside. Would be easy to integrate upgrades as well.


I considered inverting them, but I think I’ll need new mounting hardware to do that. I don’t think the brackets I have will work in that orientation. Not a hard fix tho. How do you deal with all the sediment sludge if you run them inverted? Hmm, I wonder…do you know if these can be cleaned out by back flushing?

Unfortunately I was pretty limited on space, so had no choice but to install the filters right below those outlets. You think I should just get a sealed plate thing to put over those outlets? Something like this:

That would be the safest thing to do huh?

In terms of spills, I haven’t had any major ones yet, or even really any small splashes. Aside from the condensation from cold buckets dripping on to floor, which I’m pretty good about cleaning up. I let the lab get pretty messy at one point and it had a bad effect on my mood and morale, so now I try to clean up pretty thoroughly after each day. I used to justify a messy lab as a productive lab, but damn it is so much nicer being in a clean and orderly space.

I figured it was ghetto compared to the really nice, big, fast filtration set ups I see in larger labs with big bag filter assemblies and pumps designed to move solvents. This set up cost ~$250 or so I think not including the 100L keg.


Damn, I wish I had a minion(s). Maybe one day lol.


if you don’t need them, then removing (covering with plates) those outlets is probably not a bad idea.

I was referring to the clown who put extract (fresh pour from his extractor) on the kitchen stove and had it catch fire…one of his responses was to tape up the electrical out lets in the hallway.

In this case, especially if you invert the housings, the proximity of those outlets to your solvent probably does warrant disabling them. It’s not uncommon to generate sparks on occasion when plugging things in.


Oh wow, that thread…

Have you run a setup like that upside down before? Or seen someone doing so? It would require backflushing to do that without a mess right?

Yes, I’ve run the upside down. I’ve only nailed them to the wall upside down once. They were still mounted that way next time I showed up, so my assumption is they were workable.

1 Like

A panda, with a stack of descending size synthetic wool micron filters from Duda … you just need to wrap the cloth a few times no need to sew anything really… put a metal bowl upside down on the bottom of the basket so the liquid hits it instead of going thru the bottom…

That’s about as fast as I can get with ghetto resources