Hot Finished Seamless (HFS) as differentiated from Cold Drawn Seamless (CDS) pipes and tubes are made by heating a solid billet or bloom and then punching or piercing it to make a hollow out of it. This hollow is subsequently passed through one or multiple stands with or without a tool inside to give it the final pipe or tube dimensions.
It is possible to manufacture large diameter and thick pipes of various grades in high volume through the HFS process. With the improvement in technology, HFS pipes & tubes now come with close dimensional tolerance & good surface finish.
MSL has 3 hot mills with different process technologies to cover a wide size and grade range.
CPE (Cross Piercing & Elongation) process is suitable for small diameter thin-medium wall carbon-low alloy grade pipes & tubes and has a range upto 7”. The process ensures close variation of the wall thickness and minimizes longitudinal & transverse defects. This is a highly versatile process which can even roll any odd size within its range.
Plug Mill process is suitable for large diameter thick wall carbon-medium alloy grade pipes and has a range of 8” – 14”. While the plug controls the ID, world-class reelers are used to achieve close tolerance on the wall thickness. The process is capable of rolling pipe thickness of upto 40 mm. MSL produces expander pipes in diameter 16” – 20” to meet the requirements of large diameter pipes.
MPM (Mandrel Pipe Mill) process is suitable for small diameter thick wall carbon-high alloy grade pipes & tubes and has a range of 6”. Elongation through six stand continuous rolling mill with high precision mandrel in this mill ensures smooth surface and close OD & thickness tolerance.