Thank you very much Rob,nIt is patched at 5 bar and the initial temperature of the tank is equal to the saturation temperature at this pressure (288.8 K). The inlet fluid is at 283.8 K accordingly (5k sub-cooled)nI have tried to outlet BC and different results, both wrong: npressure outlet: pressure in the tank is decreased a bit that seems normal due to pressure of the liquid column, so in the tank must be a bit less that the outlet pressure (5 bar). BUT the outlet mass flow is positive and much higher than the inlet flow! nMass flow outlet: set equal to inlet mass flow, but the pressure goes up to very high values. nMaybe VOF should be tried using default tuning coefficients. I tried it before and at least the volume fraction contour was more physical than Eulerian model. but the same high pressure/outlet mass flow was observed with VOF as well! nThere is no other BC that can be tried I dont know why the models are failed like this.n