Anyone can recommend me which software is the best for 3D drawing for piping?
What is your budget? Look at http://www.procad.com/ [Broken]
You'll have to define "best," and what you consider "3D drawing" while you're at it... As Greg mentioned, prices and capabilities of different software packages vary wildly.
for 3d modeling of pipe I would recommend Inventor that last time i used it, it had the ability to do piping pretty easily. I am a personal fan of solidworks, it can do piping pretty easily with a simple sweep. like stated above it is all about your budget
solid works is good if you know how to use it. thats what i know, although i havent tried any others.
Google sketch-up is free and has a "follow" utility that you could use to run pipe. If you can afford something better, I would go with most anything else though. Piping is easy in solid works and Catia but both cost several thousand dollars unless you are a student in which case they cost a hundred or so dollars for a year long license.
Here is a great list of free 3d design programs that you could use.
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