If you are talking about stress analysis, there are programs such as Coade's Caesar II, Rebis Autopipe, and Piping Solutions Triflex.
If you are talking about 3D piping layout/plant design, then you're wanting something like Intergraph PDS, Rebis Autoplant, or PDMS (don't remember who makes that one) Edward L. Klein
Pipe Stress Engineer
Houston, Texas
All opinions expressed here are my own and not my company's.