There is no way per say to merge the cv's of NURBS patch together.
You have to understand that a nurbs surface is a 4 sided patch and even though you have a primitve that is a cylinder it is still made up from a 4 side patch curving around to take the shape of a tube which is why you always have an open edge on the tube , so the best you can do is scale the cv's so they are close together but it can't be merged.

You can however join two patches together to make a single larger patch but you still have to get your head around that whatever shape it is, it will still only have 4 sides ( U and V directions ).