Thank you for your comments.
I would like to add that the problem is not symmetrical. Currently I have finally found the way to import STEP files. However I still have the software recognize it as one volume. Now everything comes to finding out how to create two volumes that would share one...
I am trying to run a CFD of a pip with a lot of internal plates. I created geometry into Pro/E and tried to bring it into Gambit as an iges file. According to my professor I have to brake the inside volume into a number of volumes with different flow parameters. If I import iges as solid I have...