To provide a system and a method to use a bent pipe in high-purity fluid handling systems capable of incorporating the bent pipe in a supply line, a production line and a vacuum preliminary step line in high purity fluid handling systems without heat treatment polishing or after bending.

This new method of bending a tube suitably used in the high- purity fluid handling systems, comprises selecting the tube made of a material having at least a grain size number 5, and shaping a bend on the tube with a bending radius 1.5 times greater than a diameter of the tube.