The strip passes through a series of drive forming and fin rolls and takes the required closed shaped and is welded continuously by page of an electric current of high frequency i.e. 4, 50, 000 cycles/second across the edges.
The pipes and tubes thus formed and welded pass through the sizing section where the pipes are allowed to pass in round shape while tubes are given the required shapes by passing them through a series of dies and finally dimensional deviations if any are corrected before the pipes or tubes are cut into required length by automatic cutting machine.
The pipes and tubes are then end faced and pressure tested. Thereafter protective surface finishing operations such as hot dip Galvanizing or varnishing is done as per specific requirements. The tubes are offered as plain, beveled, threaded ends or white flange.