The equilibrium vapor pressure of water at 180 C is about 10 bars. If you add the pressure of the air in the head space, that would give a pressure of over 11 bars. So, you need to evaporate all the water you initially have in the container to keep the final pressure below 10 bars.
A total pressure of 10 bars is not too high for the ideal gas law to provide a pretty good approximation. Assume that the initial amount of liquid water in the container was very low. How much water would have to be present along with an initial volume of 1 liter of air for the final total pressure to be 10 atm? Once you have this result, you can check it (and improve it, if necessary) by treating the final mixture as a non-ideal gas and taking into account the initial volume of the liquid water.