Hi. I success
Cyan pipe is group, I not create T part of pipe in that group (avoid some errors with slection etc) So I make this part separate on this group, make guide first, on that guide make circle, use push/pull tool to make cylinder, then with offset tool make another circle on top of cylinder, push/pull tool and make tube, triple click on what I make, go to Edit / and copy this object. Delete object, open grouped cyan tube and goto Edit / paste in place, right click on pasted part and select Intersect faces / with model, then delete parts that do not need.
Maybe this will help some newbie like me
Thank you again.
[image: ZA3u_hole-done.png]