I am installing a toilet in my basement, there is a 3" PVC stub coming up through the concrete. My local hardware store helped pick out what I need. The flange I bought fit's over the PVC pipe not inside of it. Is this what I want or should the flange go inside of the PVC that is coming up through the concrete? It fit very snug and if glued in place it don't think it will leak but not sure this is why I am in need of some good advice. Any thoughts?
Brian

If it's 3", then you want to glue it on the outside of the pipe.

I would recommend you do a dry fit to make sure the riser is cut down low enough.

Also, some closet flanges have a beveling just under the ring, so you may have to chip out a bit of concrete to accommodate for this bevel.