FH-3G Straightening machine is mainly used for straightening and repairing bent and deformed pipes in the process of pipe making or annealing. The machine is composed of 3 groups or (S groups) of roll assemblies connected with transmission, motors, etc. It does not require replacing the straightening wheel while straightening of different pipe diameters, straightening the empty pipe and filled pipe within a certain range. The machine is equipped with a frequency converter, which is used to control the speed adjustment of the different tubes.