Spunding valve on liquid post?

[Djangotet]

I want to use a spunding valve for pressure fermentation. Here was my plan:

1. Add my wort and yeast to my first keg
2. Connect the gas posts of the fermentation keg to the gas post on the empty keg
3. Attach my spunding valve to the liquid out post of the second empty keg

My idea is that the gas from fermentation will purge my second keg. The excess gas will escape the liquid out post with the spunding valve.

My question is, will this work? Since the keg with the beer is only connected to the top keg with the gas post it will be hard for the beer to travel up. Even if it does, it would have to do it again in the second keg then push through the spunding valve. Do you think this plan would work or should I just put the spunding valve on my first keg and transfer later?

The obvious benefit is basically no co2 is needed besides a small amount for serving pressure. The fermentation gas will carbonate and purge the second keg.

 

[Bobby_M]

Just reverse the connections on the purge keg so there's no possible way blowoff would contaminate the spunding.

 

[Djangotet]

Just reverse the connections on the purge keg so there's no possible way blowoff would contaminate the spunding.

Thank you for your response! I’m sorry I’m trying to understand. So on the empty keg I would have the gas in post connected to the the gas in post of the fermentation keg. So both of the gas posts would be used up. I then have two unused liquid posts. On the empty keg I was gonna put the spunding valve on the liquid post. Are you saying that I should connect the gas in post of the fermentation keg to the liquid post of the empty keg?

Aren’t CO2 lines and liquid lines different sizes? I was thinking of doing it this way but then I wasn’t sure about the size difference. Thanks again!

Edit: forgive me I’m such a noob. I thought that they had to be different sizes but I realized I can just swap the quick connect barbs to the same size.

 

[Bobby_M]

The fermenting keg obviously has to be connected via gas out or all the wort will dispense itself immediately. Then you go into the purge keg's liquid post from there. Yes, the black connector can only go on the liquid and grey can only go on gas, but you would make up the specific jumper line you need. A lot of these QDs have non-removable barbs in specific sizes, but I don't recommend them and would never sell them. If you get the ones with male flare threads (MFL), you are never married to a barb size again.