Thank You all guys!
It worked. And I also found out about routing add-in to make all the piping and sketching centerline easier.

Hello ! I have designed a piping system by joining different pipes and flanges in assembly mode and then giving it a degree of freedom, rotated its parts to reach my final destination by try and error. Now I want to save and export new piping system centerline in a new separate file.  If there is an...