Straight from ATV Control Centre in Toulouse, France:
ATV-5 refuelling operations continue this week. Monday, the tanks containing fuel and oxidiser liquid (the propellants) were pressurised by injecting high pressure helium gas into them. On Tuesday the main refuelling event took place, this is the transfer of the fuel and oxidiser liquids from ATV’s tanks into tanks in the Russian FGB Space Station module. To do this the high pressure helium gas lines were reconnected to the tanks in ATV. Then the valves connecting the ATV tanks to the Space Station were opened allowing the propellants to flow through into the Station’s tanks. The time taken for the full amount of more than 800 kg of propellants to transfer was about half an hour. The valves are now closed but a small team of experts remain in ATV-CC overnight to keep a careful eye on pressures and temperatures in the propellant lines which are full of liquid. On Wednesday refuelling operations continue with purging operations which will clear the propellant lines of the remaining liquid.
As well as the refuelling operations, on Monday ATV-5 carried out its final oxygen transfer. Early in the morning Alexander Gerst opened the valves in ATV Georges Lemaître cargo carrier to start the oxygen flow. As most of the oxygen had already been transferred, the valves were left opened for the whole day to make sure that the tanks were completely emptied; the estimated amount transferred was about 8 kg.