I am trying to use routing, using the NPT threaded fitting supplied with SolidWorks. I used an extrude on a tank to create a half nipple that is welded into the tank by the fabricator.  I've been trying all day to get a route started with an elbow off the tank.  I can get a route started if I use a flange, but is there a way to start a route using somthing other than a flange ( like a NPT elbow)? If so how?

I running SW2011 SP0 windows7 64