[geekindenial]

Hi folks, I refilled my CO2 5lb tank from LFS and up on reconnection the high pressure gauge shows ~1800psi. Is this too high? Should I take it out and vent it?

On the last refill it was about 1000psi, and slowly went down to 600, at which point I took it to refill.

 

[Bettatail]

it is too high, but wait a couple days to connect the regulator and measure again.

600 psi is ok during cold weather, not necessarily mean liquid co2 is all gone, and even if the liquid co2 are all gone, you still have about 1/6-1/5 of the 5lb co2 in the cylinder, in gas form.
you can wait until the co2 pressure drop to 100psi or less for normal usage, yours is a double stage regulator, it will handle the pressure drop.

I think the problem is at 600 psi the tank is not yet empty, There is probably plenty of liquid co2 in the cylinder, but the refilling station put in another 5Lb or less, over filled.

 

[geekindenial]

So this also means no drastic action needed? Do I need to panic?

If in a couple of days I disconnect/reconnect the regulator it's the same should I vent it or it's OK to just leave it?

 

[jeffkrol]

https://www.privatedata.com/doomlabs/science/co2pv.gif

So about 25% over filled at 75F.

So if tank temp goes to 85-95F the safety burst disc on the cylinder may vent.

If you want put it on a scale and vent off one pound.

It would probably bother me.

 

[geekindenial]

Thanks. The graph is really cool BTW. I couldn't find anything online showing these 3 way relationships.

 

[Bettatail]

just to make it clear, I mentioned give it a couple days because it is fresh filled, need a couple days to reach the room temperature, then you can test it again.

After two days if it is still around 1800psi, it should be fine because the cylinder and the regulator are both ok to handle the pressure, you don't need to the release the extra co2,(just avoid high temperature, more than likely not the case) but if you prefer to release, do it outside without regulator attached, slow and steady turn open/close the cylinder valve in intervals, avoid large flow of co2 in prolonged of time.

you can not release the large volume of co2 through the common pressure regulator, because the regulators to handle fast flow of co2 are special designed.
The valve seat inside the common pressure regulator will frozen and cracked if co2 rush out too fast.

 

[geekindenial]

Just to be on the safe side i did vent it outside (without the regulator of course).

But i think might have overdone it LOL. The whole tank is soooo cold it's covered with a thick layer of snow now. Have to let it thaw out before i can hook the regulator back on. Luckily I suspected something like that might happen and wear gloves.

Thanks for the advices guys.

 

[PlantedRich]

Venting a tank is sure to cool it as that is the way AC and refrigeration work. A compressor squeezes the gas into liquid and then when it expands to becomes gas it cools!
But the experience of getting that much overfilled does bring up a point that I avoid when I can. I do not like getting gas from folks who do not know what they are doing as it can lead to real problems and they are also often way too expensive. I go to the places which deal with gas full time like welding gas suppliers, etc as they are full time folks and also deal with working guys who don't want to pay the premium price of hobby items.
The CO2 they put in welders or your soda are both pretty much the same for our use, so look for the pro.
The guy who fills a tank like that doesn't get near anything I use!

 

[geekindenial]

On this topic, does anyone know of any place around CA bay area that refill CO2 and let you keep your own tank?

 

[Bettatail]

On this topic, does anyone know of any place around CA bay area that refill CO2 and let you keep your own tank?

I know there are a couple places in Hayward/san leandro, but any co2 refilling station that can do fire extinguishers refill and hydrotesting should have the equipment to refill on spot.
I think there are more refilling stations that can let you keep your own tank, in santa clara area, make some phone call first before you go.

but if you prefer to keep the co2 cylinder, you need to pay for your own fee for hydrotesting, and there is wait time between you drop off the empty cylinder and pick it up, sometimes need two trips. Swap is much more convenience, save time and lower cost, you can simply ask for a nice/newer condition co2 cylinder when you do the swap.

 

[misterdom]

On this topic, does anyone know of any place around CA bay area that refill CO2 and let you keep your own tank?

Carbonic Service in Santa Clara does refills. Very reasonable compared to my LFS. I had my 10lb tank refilled for $30 and wait time was less than 5 minutes.