Manufacturing Process
Stainless Steel Seamless Pipes and Tubes
Mother Hollow is taken and coated with Chemical and Soap one by one where a thin layer of soap is formed on the outside and inside surface of the tube. The mother hollow is then drawn with the help of Tungsten Carbide Die and Plug to get the desired diameter and thickness. It is then annealed, straightened, cut, deburred, pickled and passivated. The tubes then undergo a 100% hydro-testing, visual and dimensional examination, 100% PMI testing They are then marked and suitably packed before dispatch.
Mother Hollow is taken and then pilgered with the help of internal men drill and external rolls to get the desired diameter and thickness. Then all pilgered tubes/pipes undergo the digressing an cleaning to remove oil, grease and other foreign particles. It is then annealed, straightened, cut, deburred, pickled and passivated. The tubes then undergo a 100% hydro-testing, visual and dimensional examination, 100% PMI testing, then marked and suitably packed before dispatch.
Stainless Steel Welded Pipes and Tubes
Stainless Steel Welded Tubes and Pipes Division has two welding lines for manufacturing welded tubes and pipes. Stainless Steel Welded Tubes/Pipes are manufactured on Continuous Tube Mill using Multitorch TIG (Tungsten Inert Gas) welding process. Prime quality stainless steel strips having trimmed edges are fed to the tubes mill after thorough quality checks. Strip passes through various sets of rollers fitted in mill as per the required size. This strip is gradually converted in to a tabular shape. The Edges are welded using TIG welding process by welding unit fitted on the mills the inside weld bid is instantaneously removed by online bid removing machine. Rolled Tubes/Pipes thus produced are cut to required length. This is further subjected to heat treatment (annealing) after proper cleaning to remove the stresses included while formation as well as welding and to restore the original grain structure.
Heat Treatment is carried out on the continuous roller hearth furnace fitted with temperature controller and recorder. After heat treatment Tubes/Pipes are straightened and subjected to pickling to remove scale on the surfaces. In case the final size cannot be produced from the mill directly, the same is produced by cold drawing operation. To make the tube/pipe suitable for cold drawing, it is coated with oxalate & shop solution which acts as a lubricant and reduces friction while drawing. In the drawing operation, the tube/pipe is drawn over the draw bench using precision tooling i.e. Dies Plugs as per the requirements of finished size. The drawn tube/pipe undergoes heat treatment, pickling and other operations as specified above after surface cleaning.
Finished pipes/tubes are marked with computerized ink Jet Marking Machine. Each pipe/tube is marked as ‘Manufacturing Standard’. Grade of Material, Size, Heat No., Stamp of third party inspection agency to Correlate with our Test Certificate. Finished tubes/pipes thus produced undergo various testing and quality checks followed by proper packing and dispatch.