The first stage in the manufacture of steel tube assembly is to properly clean the input steel tubes before they are taken into the manufacturing process. Steel tubes are first pickled in an Acid tank.

Treatment with acid solution helps in removal of oxides and scales from the tube surfaces.

After Acid pickling, the steel tubes are dipped in an alkali bath.

Treatment with alkali helps in removing a wide variety of soils from the tube surfaces. Soils removed by alkaline cleaning include oils, grease, waxes, metallic fines, and dirt.

After the steel tubes have been subjected to acid and alkali treatment, they are thoroughly cleaned with water to neutralise any remaining chemicals from the tube surface.