Keg pressurisation mad thought

[Cabbagephart]

We need to pressurise kegs but do we need co2? The main washer on my kingkeg is dead and I can't get one. I have had a bizarre idea. I have a football bladder and thought I'll cut it up but then thought why not sterilise it and inflate it in the barrel. I could inflate with air and save money on co2 and it would help form a seal. But I'm thinking order a standard tyre valve and replace s30 and have inflatable bladder as a permanent feature. Any thoughts. Would it taint the flavour?

 

[Dr_Jeff]

Not the best idea.
CO2 is needed to keep the beer fresh.
The O2 in the air will oxidize the beer, and give it a nasty taste, (like wet cardboard)
Your bladder, likely would contribute off flavors as well.
Either find the seal that you need or choose another solution to deliver CO2.

 

[Special Hops]

Also CO2 is used for carbonation.

 

[Bobby_M]

If the beer is already carbonated via external CO2 or sugar priming, a bladder for creating serving pressure would technically work. You're not going to make it work in a leaky keg and the requirement for the bladder is such that when fully inflated it would occupy the entire inner volume of the keg so that it displaces all the beer. A football bladder is not going to do that. The other difficulty is that you need to keep topping off the bladder to keep it at about 10-12psi. CO2 is too cheap to consider this.