CO2 TRANSFER

[Hangover68]

I pressure fermented a hard seltzer and after i had transferred it to a keg i was left will still a fair amount of pressure in the FV, i tried using 2 gas ball lock fittings to transfer that co2 to my 4ltr mini keg but nothing happened.
Was this the wrong process and if so how can i achieve this ?

 

[S.E]

Your keg is most likely already at the same pressure as your FV. Was it a closed transfer to the Keg?

If not and you are sure there is little or no pressure in the keg try connecting one fitting to the gas post on the FV but depress the pin on other gas fitting with a screwdriver, pencil or something to see if gas flows out before connecting it to the keg.

 

[MHB]

I'm not sure what you were expecting to happen, but if you have a clear connection the pressure will equilibrate.
That is to say the some CO2 will move into the mini keg until the whole system is at the same pressure.
There is a law that tells you exactly what that pressure will be.
If we assume the temperature doesn't change then its just P1V1=P2V2
If your fermenter had a total volume of say 35L and was at 200kPa (2 bar), connect up a 4L mini keg and the total volume becomes 39L, apply the equation and the pressure becomes: -
35*200=39*P2, (35*200)/39=179.5kPa.
That is sort of assuming the 4L keg is a vacuum, it wont be so there probably wont be that much CO2 move over, unless you purge the mini keg with CO2, it will be a mixture of Air and CO2 and you want to be a bit cautious using air around brewing, there are times when Oxygen is good but mostly not.
Mind you 4L of CO2 at 179.5Pa is stuff all. I cant see it being useful for anything.
Mark

 

[Hangover68]

i dont think i was clear, the mini keg is different to what i had already transferred the seltzer to, i had the mini full of lager but i haven't carbed it yet so was seeing if i could use the o2 from the FV.

should 2 gas ball lock fittings allow a bi-directional flow ?

 

[S.E]

should 2 gas ball lock fittings allow a bi-directional flow ?

Yes they should, at least any I have seen will. So unless you have connects with one way valves?

What sort of pressure is in your FV? Probably not enough to carb your lager anytime soon though?

 

[Hangover68]

Yes they should, at least any I have seen will. So unless you have connects with one way valves?

What sort of pressure is in your FV? Probably not enough to carb your lager anytime soon though?

Just the usual cheap plastic fittings .Probably 10 psi .
Its in no rush, overflow from a corny.
Was just seeing if i could use it instead letting it out.