There are a few videos with various methods for creating bends in pipes in Blender3D. But by far the best way I’ve found is by using the Bend Transform. https://docs.blender.org/manual/en/latest/modeling/meshes/editing/transform/bend.html

There are a few steps required to make it work:

  1. Create your pipe. extrude a circle and subdivide it.
  2. Select the vertices that you want to participate in the bend.
  3. Place the 3D cursor at the point where you want the bend to begin.
  4. Place the mouse at the point where you want the bend to end.
  5. Press Shift-W and drag the mouse to set the pivot point. Pressing alt will apply the bend to the entire selected shape
Bending Cylinders with Blender’s Bend Transform