I think this is what Joseph_Culbert suggests as well, but if it is just for rendering/looks then I have curve arrayed (with overlap) a disk around the intersection of the pipes, boolean all the disks, custom mesh to get even density, extract render mesh, then smooth, then trim out the inside mesh if needed:
I guess realism depends on the disk geometry…
Maybe a more controlled method is to go ahead and fillet/blend the pipes and then flow the disks on the blend surface. I had some extra time so I tried it out spending more time on the disk:
This one was booleaned/meshed before flowing and it was much faster to flow:
Smoothed a couple times after the flow operation caused some pinching in the center.
Waiting for traffic to clear, with some positional randomness in the disks pre-union: