Expansion column temp

Hi so I’m curious what I should be heating my expansion column too exactly. I haven’t found much information on it.

I would say around 100f. Basically enough to push things over to the crc

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Can someone explain the expansion tank?


Basically a column between your material column and crc, to collect your solution prior to pushing through Crc.

Have Read people are using it so they limit soak time in material while pushing through crc and also to heat the jacket to build pressure instead of using n2

Atleast that’s my understanding, sure there are other benefits too


Not as exciting as I hoped it would be


Maybe someone will shed more light, but this is what I’m gathering from reading @Waxplug1 posts


Be cautious applying that definition uniformly

ETS, which has been using that term for a good 7-10 years, defines an expansion column as a larger column after recovery for catching entrained resins that are traveling along with the recovered vapors, and prevent them from entering your recovery pump

ETS systems tend to fill that space with mole sieve, and use a diptube to make the vapor travel further. I’m not sure what it’s heated to, but warm enough to keep your recovery pump from seeing unevaporated butane and resin.


What a stupid fucking term for something where thermodynamics are wildly at play.

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Yeah I have seen those. Heard them also called a resin trap by some people


Seems like three different explanations for an expansion column.

A little confused on the term myself.

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This is what @Tech1145 says he uses his for.

I remember him sharing pics in the mol sieve debate


Why the hell is it called an expansion column lol.

I assumed it was something to do with adiabatic expansion.


Some ppl call it a surge tank/buffer tank/expansion tank. It’s basically what you stated. A tank to allow you to control your soak time and to push without using nitrogen. A good way to look at it is like making tea. You have control when to pull the bag out and the longer it soaks in the hot water the more bitter it will taste. For us we get phospholipids that are hard to bleach and have those bitter tastes. When we push from the material column into the crc we are soaking the whole time as it pushes through. That’s why it helps to have a buffer/expansion/surge/secondary/etc. tank


@Pupparoo That’s a better name, since that’s what it does.

@Curious_Roberto That’s effectively how ETS uses their expansion column, since they pack it with molecular sieve. They didn’t used to, however. Pretty sure it was stainless steel scrubbies/brillo back in the day, to catch any resin and keep it from entering the recovery pump.

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I mean technically, the vapor does have to expand again after traveling through the 3/8 dip tube.

Agreed tho, it’s a dumb name.

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In the way you referenced, was the vapor going down the diptube then up through the beads? Technically isn’t that still a giant mol sieve? Not saying you’re wrong, btw.

Also, I’ve been referring an expansion tank as holding tank when trying to explain things to my gf.

All the same I suppose?


I’ve got the parts sitting at my spot waiting to build that nice mole sieve. I love the way that things built


“Holding tank” definitely explains the purpose a lot better than “expansion tank”.

I guess it expands the volume of solvent/resin solution above the CRC? Lol…


It is essentially a mole sieve column! It does also seem to trap resin, but hey, a corken sucks pretty hard.

I don’t exactly agree with how they’ve phrased it, but it does remain that there a few manufactures calling different things the same thing

Personally, I think grey wolfs cyclonic design remains the most interesting version of this hash trap/molecular sieve drier.

Its like my bfe before my crc or my honey pots