Wheat Beer kegged

The disasters keep in coming with this beer. I racked it into a pressure barrel when fermentation steadied at 1.012 (for an ABV of 4%). Unfortunately the pressure barrel valve is knackered and doesn't seem to be holding pressure. I did purge with CO2 prior to racking which has hopefully helped keep it. It's certainly tasting pretty good at the moment, but I'm on operation drink it speedily.