The various processes involved in the manufacturing of welded tubes are:
Depending on the specification of the product aspired by the customer, mother coil of required grade and thickness is trimmed to a width corresponding to the dimensions of the section required by the customer.
Tube Forming and Welding
Slitted width is given as input to the tube mill where the tube forming, welding and sizing in the desired section and dimension take place.
The heat treatment is an optional process depending on customer application of the tube. It is done in order to reduce the internal stresses incurred in the tube during the forming process.
Cold drawing or Sizing
If the customer tolerances are too close for the internal of external dimensions of the tube, then it is passed through this step.
The process is done in order to reduce the bend caused due to forming and welding process and it also reduces the minor ovality, if any in the circular tubes and pipes.
It is the surface treatment done in order to remove the scale formed due to annealing or grease and oil from the tubes, externally as well as internally.
Cutting and End Finish
Products having requirement in cut lengths undergo this process. They are further end finished or deburred.
Customer having different application of tube demand for surface finishes like matte or mirror. In this process, a thin layer of material is removed using various media to obtain desired finish.
Swaging and Expansion
Swaging is usually a cold working process, used to reduce the diameter, produce a taper, or add a point to the tube. Expansion or Flaring is usually a cold working process, used to expand the diameter along the length of the tube.