How to Export Autoplant drawing file to Step(stp) format ?

Dear Bentley Family,

 In our Bentley Prostructure(Prosteel) , we have option to export to step(stp) format.

 Then for Autoplant Piping, why this export to step(stp) format is not available?

  Please let me know how we can export our Autoplant drawing to step(stp) format ?

 Waiting for your earliest reply.


Note - We are using:

 Software :  Bentley Autoplant V8i - SS4 version : , Autocad 2012-64Bit , Naviswork 2013 , Inventor Ultimate 2014-64 Bit , MS-Office 2010 - 64 Bit.

 Hardware : Workstation Dell Precision T3600