thank you for the answer. Concerning the dynamic mesh I have the calculation in progress (I launched the transient calculation after the static calculation) and I have the residuals which are a little strange

I defined the 6dof :

The valve and the boundary layer area around the valve are respectively in 6dof-on and 6dof-off. All other areas (internal and the rest) are in deforming. But it seems to me that the residues are not convergent enough and the calculation will crash in my opinion. What do you think about it rob?