I have found a new piping tool called 3Skeng.
Within this tool you are able to create very easily a complete pipeline including all the components you need like flanges, elbows, T-pieces and valves.
It is very easy handable. The tool includes all very large libraries of all the upper mentioned components according to ANSI or DIN standart.
The related link is:
http://www.3skeng.com/de/index.htm
The programm is actually made for engineers to design an industrial plant like heating plant, chemical plants or water or wastewater treatment plants where it's need to built pipes.
Best regards
Schimannski