AutoPIPE's StressISO Add-on software does not show disconnected pipe / beam trunninons as beam members in the exported iso drawing file.
StressISO has some limitations, one of whcih not being able to export disconnected systems or AutoPIPE beam members. An enhancment request has been filed with Alias about these limitations who commented it would be availale in the next releases of Alias StressIso software.
For details about StressIso Limitations see the following file installed with AutoPIPE:
C:\Bentley\AutoPIPE V8i SELECTseries\StressISO_Troubleshooting.pdf