Blowtie spunding valve

[Bobby_M]

My question was theoretical - what would happen if it was set up that way. The spunding valve is meant to push out any excess co2, but if it's going to a sealed keg then the keg will eventually try to push the excess co2 back into the fermentation vessel. It sounds like the spunding valve wouldn't be able to release the excess pressure so it would build up in both the keg and the FV.

That's exactly right and there is no practical purpose for the configuration you describe. There are hundreds of other impractical ways to hook things up but I'm not sure what the point is.

 

[OzzyPeeps]

The spunding valve is attached to the gas post on the keg. You could daisy-chain kegs. The last in the chain gets the spunding valve.

View attachment 764474

Not to derail the thread too much, but

Can you explain how purging and sanitizing multiple daisy chained kegs works in practice?

I understand the gas out from the FV goes to the gas in on the first keg, which is filled with sanitiser and operates exactly like a normal keg - the CO2 from the fermenter pushes the sanitiser up the liquid dip tube and out of the liquid post, thus purging and sanitizing keg 1.

But where is the liquid out connected to on the next keg?

It can't be the liquid post as this would leave no way for the sanitiser to escape into the following keg?

But if you connect it to the gas in, then how would the air inside keg 2 be able to escape to make room for the starsan?

As soon as there is enough starsan in keg 2 to cover the bottom of the liquid dip tube, surely either:

A) the O2 contaminated air would have nowhere to go and cause a blockage which would prevent the sanitiser from moving any further forward

Or

B) when the pressure inside keg2 got high enough, starsan would be forced up the liquid dip tube without displacing the O2 rich air trapped in keg 2 - and therefore neither purging nor sanitizing the keg.

Being able to symultaneously purge and sanitize all my kegs with FV gas ready for closed transfers would be a god send ... But I just can't get my head around how it would work for more than one keg at a time.

I guess you could pull the prv on keg2 till sanitiser comes out, then close it and repeat for subsequent kegs ... But I'm guessing this would lead to excess sanitiser in your beer ... And also obviate the need for the sounding valve in the first place ?

 

[OzzyPeeps]

@Carolina_Matt
As @GilSwillBasementBrews says heres a picture giving a hint but this is two kegs being purged ( after they have emptied) . If I'm purging kegs the water pressure exerts a fair back pressure but if you get a siphon going the primary fermenter if a PET one will collapse as the liquid siphon is strong. The valve is one way lying underneath the yellow key so unless the valve fails pressure goes normally from ferment to the open air. In the case of higher pressure mentioned beyond the valve then that would be the restricting factor.
View attachment 764447

Same question ....

 

[GilSwillBasementBrews]

Same question ....

Fv->gas in keg1->keg 1 liquid out -> gas in keg 2-> spunding valve on liquid out keg2

 

[marc1]

Fv->gas in keg1->keg 1 liquid out -> gas in keg 2-> spunding valve on liquid out keg2

That's not how I do it.

FV -> Keg 1 Liquid -> Keg 1 Gas -> Keg 2 Liquid -> spund on Keg 2 gas

If you are using all the fermentation gas, you don't need to push liquid.

 

[OzzyPeeps]

Fv->gas in keg1->keg 1 liquid out -> gas in keg 2-> spunding valve on liquid out keg2

But what if there are 3 kegs?

Ideally what I want to do is daisy chain my 8 cornys such that the starsan in keg1 is pushed through all of them to keg8, thus ensuring they are all 100% purged of O2 and sanitised.

Starting to think the only way to do it might be to do as you with 2 kegs at a time, swapping the out one by one, swapping the gas out from the FV from the liquid in to the gas in on the keg to be purged

 

[OzzyPeeps]

That's not how I do it.

FV -> Keg 1 Liquid -> Keg 1 Gas -> Keg 2 Liquid -> spund on Keg 2 gas

If you are using all the fermentation gas, you don't need to push liquid.

Trying to consolidate the two jobs of sanitising and purging into one job.

Ideally one plug and play job for all my kegs in one go...


I am a lazy bar-steward

 

[balrog]

no need to push saniziter out
There is enough CO2 produced during 5 gal ferment to purge an EMPTY keg of O2 by running FV to LIQUID of empty keg and GAS of said empty keg to airlock

 

[DuncB]

If you want to sanitise and purge then fill to the brim the first keg with no rinse sanitiser, Gas out fermenter, to gas in first keg, liquid out to gas in second keg ( full of air initially).
You need to make a connector with liquid ball lock one end and gas the other end.
Then I use liquid out second keg to open tube and collecting vessel for the starsan.
Once both kegs have been emptied of liquid I then attach spunding valve to the gas out of second keg set for whatever your pressure aim is.
The kegs are then connected gas out fermenter to gas in of first keg, then liquid out first keg to liquid on second keg and spunding valve on gas post.

Don't push liquid thru the kegland spunding valves it's not good for them and not necessary.

Plenty of people just sanitise the kegs and then just purge with lots of the ferment gas. This will leave a very low level of oxygen in your kegs, I prefer to purge kegs full of sanitiser as that way I'm starting with even less available oxygen. A 20 litre keg with air in it will have about 4litres of oxygen in it. A keg full of sanitiser will only have the amount of oxygen dissolved in the sanitiser and this gets moved across so during equilibrium there is much less to dilute by your fermentation flush.

Do be careful to not allow a siphon to set up from keg one to two, if you have a collapsible pressure fermenter such as a fermentasaurus which is thin PET, then the siphon will collapse the fermenter and possibly do enough to squeeze fermenting beer up your gas post on fermenter and then chaos ensues!!

 

[marc1]

Trying to consolidate the two jobs of sanitising and purging into one job.

Ideally one plug and play job for all my kegs in one go...


I am a lazy bar-steward

If I was trying this, I'd set it up like @GilSwillBasementBrews but put a 1 way valve on the final keg instead of the spund until the sanitizer was all gone, then put the spund on.

FV -> Keg 1 Gas -> Keg 1 Liquid -> Keg 2 Gas -> Keg 2 Liquid -> Keg 3 Gas -> Keg 3 Liquid -> Keg x Gas -> Keg x Liquid ->
Keg 8 Gas -> Keg 8 Liquid -> one way valve

 

[DuncB]

@marc1
Could do, but if the pipe coming out of final keg going to the collection bucket is long enough once the liquid in collection bucket reaches the level of the pipe you have a blowoff situation anyway with an " airlock".

 

[jerrylotto]

And you better make sure that your fermentation vessel can hold some pressure. Pushing 5 gallons of liquid out through a 3 ft vertical tube is not a passive activity The cross section of that tube is small enough that it's going to take at least 10 psi over atmospheric to push everything through without any back pressure. And of course your system is going to have to be airtight across multiple kegs to get that pushed all the way through.

 

[McMullan]

Can you explain how purging and sanitizing multiple daisy chained kegs works in practice?

I don't use so much sanitiser. It's wasteful and potentially harmful to friendly bugs and beasts in the environment. About 1-2L of sanitiser solution is more than enough for an FV, few kegs and tubing, and even usable for a while after that.

I purge air from the sanitised kegs by going FV gas/in to keg liquid/out and keg gas/in to keg liquid/out, etc. Without any liquid my floating dip tubes sit on the bottom of the keg(s) and CO2 from fermentation enters low enough for the air to be pushed out. Spunding fitted to gas/in on terminal keg. If available I daisy-chain 2 kegs and be about to pressure transfer (by bleeding pressure from receiving keg, i.e., 'sucking' over the beer), pressurise and even serve a bit, all using home captured CO2. Note I make half to single (5 Gallon) batches. Others might be making double batches of r more so might daisy-chain more kegs.

 

[balrog]

I don't use so much sanitiser. It's wasteful and potentially harmful to friendly bugs and beasts in the environment. About 1-2L of sanitiser solution is more than enough for an FV, few kegs and tubing, and even usable for a while after that.

I purge air from the sanitised kegs by going FV gas/in to keg liquid/out and keg gas/in to keg liquid/out, etc. Without any liquid my floating dip tubes sit on the bottom of the keg(s) and CO2 from fermentation enters low enough for the air to be pushed out. Spunding fitted to gas/in on terminal keg. If available I daisy-chain 2 kegs and be about to pressure transfer (by bleeding pressure from receiving keg, i.e., 'sucking' over the beer), pressurise and even serve a bit, all using home captured CO2. Note I make half to single (5 Gallon) batches. Others might be making double batches of r more so might daisy-chain more kegs.

I think the math shows a 5 gallon typical batch produces enough CO2 to fully purge O2 (to 5 ppb) from a single 5 gallon keg. I am unsure about half batch and multiple kegs.

 

[McMullan]

I think the math shows a 5 gallon typical batch produces enough CO2 to fully purge O2 (to 5 ppb) from a single 5 gallon keg. I am unsure about half batch and multiple kegs.

If I'm doing a half batch it's fermented in a 19L corny keg with a 9L keg attached.