Storage vessel pressure has dropped, how do I get it back?

Hash and Stuff Extraction
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I wanted to see if I can get some input from members about a new challenge I am having. I recently added more gas (butane/propane)(70/30) to top off my main tank, added around 10 lbs to a 50 lbs tank.

I run a terpp extractor MK IV with CMEP, dry ice for coil on recovery.

Did a run after that transfer and everything went smooth.

Came back 48 hours later and hook up for a run, start my normal process, adding dry ice to column and nitrogen around the solvent tank, and when I turn on to bring gas over pressure fell to floor, near zero and when trying to do run went under vac level.

Couldn’t get gas to move at all. Thought the nitrogen got gas too cold. Came back next day to try again and my butane storage tank has very low pressure around 50 and normally is 70-90.

When I start run get a lil gas push before system equalizes across all pressure gauges, when opened.

After unhooking from this one the tank pressure is below 20 and when I open valves bleeds to zero and I get no gas pushing out the liquid tube.

Anyone have any advice on how I can get pressure back in the vessel? Do I need to drain out some of butane mix and add back more?

I’m confused on how I lost all the pressure, if anyone can share I’d sure appreciate it.

Thanks

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You said you put nitrogen around the solvent tank. Is this a jacketed tank you are chilling with liquid nitrogen? What is your tank temp at?

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Could be leaking or it could just be that the pressure dropped because you’ve got more empty space inside your tank.

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Are you sure the gas you added is 70/30 propane/butane? Kinda sounds like what would happen if you added straight butane, expecting pressures and temps that align more with your preferred mix.

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It is jacketed, tank is back up to room temp, call it around 80 and tank is at 10 psi

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Not detecting any leaks with the gas meter. It’s like the gas went flat….

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How efficient is your recovery? How much solvent are you losing per run?

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It’s the same tank I been running on, was just topping off.

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Sounds like thw propane is gone or almost gone from your mix, I think you should be seeing higher pressure if you’re using 70/30.

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Is your gauge broken?

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sounds like you need a refrigerant scale

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Same question.

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This. Especially running a mix. Between weight, pressure, and temp, you can use math to know exactly what’s in the tank.

Like said above, check the guage. Good step 1.

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did you try turning it upside down and using the vapor valve? it could be clogged. I also have no idea if your tank has a guge directly attached. you said all the guages in the system are matching right? My first guess is you are out of tane.

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Alright, I can confirm the gauge is working. I tried a nitrogen boost and was able to move the gauge but still not pushing liquid just vapor through liquid port.

I shot these videos, this first video is about 3-4 hours after the nitrogen was run in the jacket of the solvent tank.

This next video is 2 hours after the first video, where i removed solvent tank and put outside in 80ish degree weather to see if that would help build pressure. Still hangs around 10-20 psi, with the tank being nearly full of gas. All I am getting is wispy vapor from the dip tube. I did this to try and ensure the nitrogen was clear, I could hold my palm to the bottom of the tank, it wasn’t cold.

So I left farm for a couple hours and returned, the tank had moved up to 45PSI after about 3 hours more. I cracked the dip tube line and it appeared to be air pressure but still sputters and pressure dropped to 10. I then tried nitrogen boost and no further progress. After chatting with some others, I am gonna try and move gas through empty system and see if we get gas moving, then its breaking down the tank and checking dip tube area to see whats up there.

I did try turning tank on side and when I do, the liquid gas flows through the dip tube as you would expect, but I got the tank on side…

If anyone has seen anyhing like this and knows a fix or way to avoid in future, lmk.

Really perplexed.

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Also I worked my way all around the tank with a hand held gas detector and got no reading except when I would open the valves and I needed to be fairly close to the ports…

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totally agree, i haven’t ever had this challenge before…

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I have a scale and saw around 1 lbs move over and then it was like the tank locked up.

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No I believe the gauge is in working condition.

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I have one and use it all the time, normally it is covered in ice from the nitrogen on the bottom of the tank.