Fermenting with two corny kegs

[Mossy]

I'm looking to use two corny kegs to ferment a batch of beer under pressure and without any additional oxygen.
I'll use one keg as FV and another as a SK (serving keg).
What I'm thinking of doing is filling the SK with sanitiser and using the co2 from the fermentation to purge the SK of the sanitiser. I would also like to try this under pressure also.
So I'll have the two kegs connected to each other via the gas post on both.
So a few of my questions would be,
Can I put one of these on the beer out post of the serving keg with this set up?
Is it ok to have the sanitiser run through one of these or are they only for pressurised gas?
What would be a good amount of pressure to ferment under?
Can I then keep the SK pressurised while transferring the beer into in?
If anyone around here uses a set up like this I'd love some pointers, cheers.

[itsclinto]

I have started just fermenting in the serving keg with a floating dip tube and a spundling valve to ferment under pressure.  Still early days but i have noticed that the beer holds up well compared to my previous way of bottling.  The thought is that it won't be spoiled by oxygen which was a killer for me and also that it won't be around long for the yeast to give off flavours.  I have seen a couple of videos of your idea but i don't like the thought of having one corny held up when it could be used.

[nigel_c]

Gas to gas till keg is empty of sanitizer through liquid out. This will purge the keg of co2. Out sounding back on primary till fermentation is done. Hook up liquid out of primary to liquid out of serving keg and put spunding on gas in. You don't want liquids in spunding.

[Mossy]

You don't want liquids in spunding.

Cheers, this was something I couldn't find online.
I take it then that there's more that enough co2 created to empty my serving keg of sanitiser?
Also, what a good psi to ferment under?

[Tom]

Should be enough CO2, if you think about the volume of CO2 created by just your priming sugar.

What yeast are you using? I'm given to understand that most yeast don't like working under pressure, but that White Labs do have some that work well under pressure? I'd love to give them a go, but I think they're limited edition yeasts.

I suppose a US05 type yeast might work okay under a little bit of pressure. Should produce a beer utterly devoid of yeast flavour in that case...

[nigel_c]

I've used Nottingham fermented at about 12 psi. Works well.

[Tom]

What was it like? I find notty dull AF at the best of times!

Do you do anything else, like extra oxygen and so on? Like I say, I'd give it a go except for lack of yeast choice. I imagine Kvieks would work.

[Mossy]

Safale US 05 is my go to yeast. I'm sure there will be a good bit of trial and error involved

[phildo79]

Won't you need constant pressure on the FV during transfer to stop both vessels creating equilibrium? I ferment under pressure using a fermentasaurus and have encountered this problem when transferring to a keg. I need to have a constant set pressure on the FV and the spunding on the keg dropped a couple of psi lower for a smooth transfer.