In front view, draw a circle.
In plan view, extrude the circle about an axis of the appropriate distance away from the circle. Trim the torus as needed.
You can create a 3d polyline representing the pipe. Then, as IFRs said, draw a circle and place it's center at the end of the polyline (so that when you look at the circle, you see a dot in the middle where the polyline is). Then you can use the extrude command, and select the path option, and select the polyline as the path. It will follow the polyline and create bends appropriately.
It may be more productive overall to make blocks for standard fittings like elbows, flanges, etc. Then use blocks for increments of piping like 12", 24", 48", 96", 120", 240". Make good useful insertion points. Then when you have built your piping run, you can create a list of parts real easily.
A more dramatic, and possibly more versatile approach would be as follows :
*bring up the solids toolbar
*In front view - draw a cylinder the appropriate
and length
* make a block for a 90 long radius degree ell by...
(e.g. is for 8 inch)
- draw a torus with radius=12in dia=8.625
- slice through center vertically and horizontally
- wblock (LISP command) invokes the make block function
* make additional blocks as needed for things such as 45
ells, etc.
It has a 3d-piping program in the download section.
The demo is fully functional, only limited dimensions.
Maybe you can scale the given dimensions to the wanted dimensions?
Draw two circles, "revolve" them both 90 degrees, then subtract one shape from the other?
And now that I think about, McMaster Carr has drawings and "3D Models" of many (but not near all) of their items- worth a look. I never have checked out the 3D models to see what they really are.
