Air in CLS

Accidently recovered some air into my butane source tank, about 15 gal @ 1atm, what should be done? Safety issues? Autoignition temp for butane (405C) is way higher than any temps seen in cls, not sure if that even applies, as I believe that value is for STP

source: engineering toolbox (don’t have the privilage to post links on here yet i guess…)

1 Like

You can chill your solvent tank sub zero(dry ice) and once is super chilled. Say after an hour. You open the vent on your solvent tank and purge the air out safely.


@Killa12345 We don’t have a vent on our solvent tank, it’s just a regular LPG cylinder with dip tube

1 Like

I think you can chill that the same way. Flip it upside down and purge the air that way if possible. Sorry that’s all I got. :sob:


Yeah, not really the right tool for the job. ideally you want pressure relief, liquid AND vapour ports, and a pressure gauge on your solvent recovery tank. The pressure gauge would have told you you had a problem.

@Killa12345 is correct, your best bet is to get your tank well below the 0oC/32oF boiling point of Butane, and turn it upside down so that you can bleed off the atmosphere.

I’m guessing that also means you’re not distilling your solvent before use. Highly recommend it.

You are using non-oderized butane right?


I know :disappointed: trying to get my boss to invest in a real solvent tank, but for now this is what I got.
Not odorized yes, not distilling unfortunately. Will start distilling when we upgrade, recovery is slow with these tanks.

Let it sit over night and burp the tank before work, I burp my tank everyday anyway

1 Like

I don’t know how much I’d trust my boss if they can’t splurge for a $100-300 carbon steel tank at least to protect their employees.

These are not ideal, but they will work. You will be able to distill and recover your gas right and probably faster. You can purge off the atmosphere as well.

Here is a big 100# one for under $300. Tell your boss to come look at this thread and we will convince him.

Flame King YSNR239 Refrigerant Recovery Cylinder Tank

And a 50# for $100

Flame King YSNR501 50 lb Pound Refrigerant Recovery Cylinder Tank


presumably you had to pump it in there.
do you know what the pressure is now?
do you have anyway of figuring it out?

depending on how much liquid you’ve got in there, your description suggests it could be easily be above 50psi. just “burping it in the morning” isn’t gonna cut it [works great with jacketed tanks, on chillers over night, way easier with a vapor port. but the OP isn’t there]

At rm temp, your butane should be at about 17psi* in the headspace. however, if the headspace is only 20% of your tank, then you’ve compressed your guestimated 15gal a couple or six times.

how are you pumping (which pump) into your tank? do you have a condenser in-line, or is your tank getting hot?

A trash can of full ice water will solve that. some go much colder.


CMEP-OL. We pump in above 100psi, as it gets hotter it pumps over 200.
I bought an in-line condenser from a BHO extraction company recently, but the ball valves leaked. It was apparently pressure tested… I also had issues with butane (lq) hanging out in the condenser, even with the condenser mounted above. So I said to hell with it for now.
Not sure what the pressure was when this happened though, the tank was cooled down, my guess is somewhere between 60 and 80, as that was the highest psi on my material tube gauge last blast.

The trash can with ice sounds appealing, maybe one with a spigot and hose at the bottom for easy draining

Wouldn’t you want to keep it warm, vent off appropriately and have the vapors push the atmosphere out. If you are going to be chilling your tank all the way down, with dry ice. Go a couple more steps. Pour in some alcohol to get better surface area and helping you get colder. Once you get that cold, if you have a vac guage of sorts, vac out the atmosphere. The problem here, with getting it that cold, you will freeze any moisture from he atmosphere you let in. I would get it room temp and vent off until she doesn’t have much “uuummmpphhhh” left and tighten her back up and pretend it didn’t happen. You’ll lose a few lbs, but whatevs. Trapping moisture in your solvent is worse. I’ve done it.


I’m just doing this to notify you of my response. And I like the little jingly bouncy notification that you need to type enough characters.

1 Like

Dry ice and ethanol will lower the temp of the tank way more than necessary to get the “air” out. It would be helpful during recovery, but is unnecessary and possibly even counter productive for purging the atmosphere.

Ideal would be about -20C. which is about 20C below the boiling point of butane. So ALL his solvent will be a liquid. the “air” on the other hand will all still be a gas. at that temp, is is safe to vent ALL the pressure in then tank. except of course the OP only has a dip tube, so if they just “burp the tank” like @Concentrated_humbold suggests, all the liquid (their butane) will come out first. @spitzenkorper has to turn their tank upside down to vent gas from that tank.

As far as trapping moisture: molsieves!

Then there is the pump. The CMEP-OL’s used to come with a forced air heat exchanger plumbed after the pump, it did a great job of pulling off most of the heat put into the solvent by the pump. I’ve been told that so many folks were deleting that heat exchanger and adding a larger liquid cooled one, that the manufacturer deleted it to save money. Problem is, that means folks like @spitzenkorper’s boss think they are designed to run without a heat exchanger…they’re not.

How do I know?
See 1k word substitute above!!

Because I’ve run both versions, and had to implement heat exchangers on two of the newer flavor in the last month. Otherwise the tank heats up, and you get increasingly high back pressures. Took me by surprise on the first one, because I’ve run three of the old style…

It doesn’t take much water to remove that heat. even the mt-69 in a 5gal bucket with some ice water will greatly speed OP’s recovery. using a heat exchanger designed to self drain once the pump has been turned off is ideal, but those are usually enclosed and cooled by a circulating chiller.

Both machines I was adding CMEP-OL’s to had those heat exchangers built in already…does that tell you how important they are?!?

Edit: venting the tank till it self chills and stops is another option. it’s faster, but distinctly less safe.

the tank mentioned below had a dip tube, and no condensed liquid. Making it a slightly different critter than the OP’s


food for thought: what happens in a diesel engine when we compress a way less flammable gas and some air?


That’s kinda why I said it wasn’t probably the best idea to get it that cold, after the thought. But, the main problem is, he’s already introduced atmosphere to his solvent tank. He has most likely pulled in moisture and now that solvent is contaminated, quite possibly. He’ll know when he does his next runs. I would personally, evacuate your tank “safely” (hard finger quotes), sweep with nitro, pull vac and start over. You gotta let your boss give you a day for distilling solvent. Your extracts will thank you. At least two washes. At least give you that. @spitzenkorper. I spend an entire day on distilling.


Tell us, tell us!


it fucking explodes!
which is how the thing runs…


How did you know I was a dummy

1 Like