Burping Butane Tank

[SDgrower]

Is there a thread somewhere that I could be directed to for burping air out of butane tank? I have not been able to come across the procedure for this. If not would someone please explain the process, I have 99.5% N-butane in a 50 Lbs tank.

 

[Jhhnn]

Is there a thread somewhere that I could be directed to for burping air out of butane tank? I have not been able to come across the procedure for this. If not would someone please explain the process, I have 99.5% N-butane in a 50 Lbs tank.

What makes you think there's air in the tank & why does it matter?

It matters w/ refrigerants, which is what I know. In a closed container, a pure aromatic substance will achieve a known pressure at any given temp, summed up in a vapor pressure chart. If the pressure is too high for the temp, there's air in the container. Air is non-condensable, existing as a gas. The way to get it out is to burp gas, not liquid, out of the bottle in a well vented space. Just let out a nice big 1 second whoosh. You will lose some small amount of butane. Let it sit 12-24 hrs, check temp & pressure. Burp it again as necessary.

 

[Skunkxx]

The guy who filled it should have bled it b4 filling.
Peace Out
Skunkxx

 

[Jhhnn]

Double post

 

[HG23]

It would also be a good idea to chill the tank below the boiling point of n-butane before burping.

 

[Jhhnn]

It would also be a good idea to chill the tank below the boiling point of n-butane before burping.

Not at all. The butane needs to evaporate a little bit to displace the air out of the bottle.

 

[icdog]

Let the tank sit in ice for a few hours till its around 30f. Put a gauge on the liquid line and open it, check the pressure. You want it around 10 - 15 psi from what I've read. Open the vapor gauge till its in the range. Do it outside only.
Hopefully GW will chime in as well.

 

[Young Bull]

Propane boils at -42C, and Isobutane at -11.7C. The N-Butane boils at -.5C.

With a pressure gauge attached to a tank at -20C if the pressure was not zero that would be evidence of gas other than butane and the tank could be bleed to zero, while of course observing standard safety precautions. Cooling the tank to -20C it should be possible to recover the propane and atmospheric gases to another tank and then chill the second tank to less than -42C to separate the at atmospheric gases from the propane. If you were so inclined.

All the info I found in the Terpenation at Terpene Station thread where I very recently asked a *cough* few *cough* questions of my own if anyone in the terp community can help please do I'll be back at it on Sunday hopefully cram packed full of knowledge

 

[Gray Wolf]

I just cool the tank to around 32F in an ice bath, and crack the vapor valve. At first there is a high pressure release from trapped air, followed by a lower pressure release of propane. You can hear the octave shift and if you stick you nose close, you can pick up on the smell.

 

[Rickys bong]

If you suspect there is air in the tank get a temp pressure chart an look at the pressure for the current temperature. Make sure the tank is sitting at a constant temp for 8 hours or so to stabilize it with the room it's in.

Put a gauge on the tank and if the pressure is significantly greater than the chart for n-butane then of course burp the tank.

No special procedure needed, other than the tank should be relatively cool if possible.

If you can cool the tank to 35-40 deg F then you won't lose much butane when you vent the tank.

If you cool the tank too far you actually may have less pressure in the tank than atmosphere and risk introducing more air in the tank if you open the valve.

RB

 

[SDgrower]

I just cool the tank to around 32F in an ice bath, and crack the vapor valve. At first there is a high pressure release from trapped air, followed by a lower pressure release of propane. You can hear the octave shift and if you stick you nose close, you can pick up on the smell.

G/W is there propane in N-Butane? I was able to use one of my connections down here to order some 99.5 thru AirGas. I didn't get a case of ISO-Butane which leads me to another question, does N-butane have a smell. Up until this point I have not been able to detect a smell when cracking the valve open and I know what ISO-Butane smells like from my past days of tube blasting.
Thanks for all the information guys!!

 

[Jhhnn]

I just cool the tank to around 32F in an ice bath, and crack the vapor valve. At first there is a high pressure release from trapped air, followed by a lower pressure release of propane. You can hear the octave shift and if you stick you nose close, you can pick up on the smell.

Basically, you wait until you're ready to use it, purge it then. Which is what HVAC techs do with recycled refrigerants, except that cooling refrigerants isn't required for using them.

 

[Gray Wolf]

G/W is there propane in N-Butane? I was able to use one of my connections down here to order some 99.5 thru AirGas. I didn't get a case of ISO-Butane which leads me to another question, does N-butane have a smell. Up until this point I have not been able to detect a smell when cracking the valve open and I know what ISO-Butane smells like from my past days of tube blasting.
Thanks for all the information guys!!

n-Propane is typically one of the contaminant gases 99.95% pure n-Butane contains. The other two most prevalent are Isobutane and Pentane, because they are closest to the same molecular weight.

n-Butane and Propane both have an odor, just a very mild one, which is why they add mercaptans for leak detection.

 

[Gray Wolf]

Basically, you wait until you're ready to use it, purge it then. Which is what HVAC techs do with recycled refrigerants, except that cooling refrigerants isn't required for using them.

Good point! The longer it sits, the more stratified it becomes.

 

[Gray Wolf]

If you suspect there is air in the tank get a temp pressure chart an look at the pressure for the current temperature. Make sure the tank is sitting at a constant temp for 8 hours or so to stabilize it with the room it's in.

Put a gauge on the tank and if the pressure is significantly greater than the chart for n-butane then of course burp the tank.

No special procedure needed, other than the tank should be relatively cool if possible.

If you can cool the tank to 35-40 deg F then you won't lose much butane when you vent the tank.

If you cool the tank too far you actually may have less pressure in the tank than atmosphere and risk introducing more air in the tank if you open the valve.

RB

Good idea on the tank pressure gauge!