meshing at a pipe intersection
 

Hi all, sorry that if this type of questions has become one of the most-frequently asked, I still don't quite get the core concept of creating a cube, splitting from the main volume and making edges and faces before a mesh scheme can be applied at the intersection of 2 pipes. I have done the tutorial with the 3-pipe intersection and thought i know what i was doing. I also searched the forum and read all the suggestions. Still, when it comes to my problem, i just couldn't do it right and don't know what to do.

My set-up is not complex; just two pipes of different diameters and lengths intersect at the centre of the longer one at 45 degrees. The steps include (1). create large pipe of dia. 8mm and lengh 260mm at the centre of Z. (2). create small pipe of dia 6mm and length 60mm in -Y direction. (3). roate small pipe by 45 degrees so it makes an 45 deg intersection with the large pipe. (4). unite both pipes.

Then I am lost after step 4. I am yet to figure out the dimension of the cube i have to create and where to position it. but most importantly, i need a good pointer to tell me what i am actually trying to achieve here as what the core concept is to split the volumes to create that face(s) at the intersection. sorry for the long msg. I am new to fluent and i hope i am clear about my problem. thanks in advance and happy holidays!! -cyn