Forming system

A forming system for forming a metal pipe including a pipe portion and a flange portion by heating and expanding a metal pipe material that comprises a plate material and a welded portion, wherein end portions of the plate material are welded to each other to form the welded portion, the forming system comprising:

• a forming apparatus that comprises:
• a set of dies configured to retain, when heating and expanding the metal pipe material, the metal pipe material, wherein one of the dies comprises a longest position on a surface of the one of the dies, and
• a heating and expanding part configured to supply a gas that is configured to deform the metal pipe material, after receiving the metal pipe material from a supply device and clamping the metal pipe material between the dies, to the metal pipe material;
• a position detection unit that comprises:
• a welding position determination unit configured to detect, before the supply device supplies the metal pipe material to the forming apparatus, a position of the welded portion, wherein
• the position detection unit is configured to output data that specifies the position of the welded portion;
• and
• a control device that is configured to:
• receive, from the welding position determination unit, the data, and
• control, according to the data, the supply device to dispose the metal pipe material between the dies such that the position of the welded portion is not located on a straight line connecting a center of the metal pipe material and the longest position, wherein a distance between the center and the surface is the longest at the longest position.