Share a way to identify seamless steel pipe and welded pipe

Steel pipe appearance, seamless steel pipe, and welded steel pipe difference in the welded pipe inside the wall there are welding tendons, while the seamless no.
seamless steel pipe and welded pipe identification method: look at the inside of the tube, because the outside will be processed, welded pipe is a gap inside some can see, in some processing, it is not easy to see, you can slowly touch it with your hands, or look at the specifications, welded pipe are relatively thin, seamless steel pipe manufacturer, a welded pipe is made directly from stainless steel strip with a machine (rolled up), seamless is made from round steel or pipe billet perforated through.

Seamless steel pipe production principle

Production and manufacturing methods can be divided into hot-rolled tubes, cold-rolled tubes, cold-drawn tubes, extruded tubes, etc. according to different production methods. Hot-rolled seamless pipes are generally produced on automatic pipe-rolling units. Solid billets are inspected and cleared of surface defects, cut to the required length, centered on the perforated end face of the billet, then sent to a heating furnace for heating and perforated on a perforating machine. In the perforation, while continuously rotating and advancing, under the action of the rollers and the top, the internal cavity of the billet is gradually formed, called the hairpin. Then sent to the automatic tube rolling machine to continue rolling. The wall thickness is evenly adjusted by the equalizing machine, and the diameter is sized by the sizing machine to meet the specifications.