I'm going to be putting a couple of batches in to plastic kegs in a week or so for priming. Do I need to purge them with Co2 at this time or do I let the co2 produced purge the oxygen I think they have 10psi blow off valves. I know they need to be pressurised with aditional CO2 at the time of serving.
Another question I have is regarding O2 ingrestion, if the barrels are presurised with this stop the O2 getting in. I know that a fair few Microbreweries around here use this type of kegs for transporting and serving small batches of cider.