This video shows how to use a pipe bender to bend some copper tube.  When a pipe or tube is bent it increases in length by the diameter of the pipe or tube so for example if you bend a piece of 3/4 inch copper tube to 90 degrees it will stretch in length by 3/4 inch. This can make a massive difference when you are planning a new installation. Bending copper tube has many advantages over using elbows as there is no join to leak and flow is increased with a sweeping bend rather than a elbow.