modelling pipe with internal pressure

[wklim7]

Hi,

I'm a student trying to learn Ansys Workbench on my own for a project. I am trying to model a straight thin circular pipe with an internal pressure and compare the hoop stress to that of theory. I'm not sure what the boundary conditions are though. I tried applying a cylindrical support to the inner surface of the pipe only leaving the radial direction free. I also applied a cylindrical coord system to the model. Are my boundary conditions correct?

Thanks in advance.