Seamless steel tube is made of round billet by hot rolling, cold rolling or cold drawing process. There is no seam on the tube body.
The welded steel pipe is made of flat steel plate and has welds on the tube body.Including ERW tube, LSAW tube, SSAW tube.
The difference between seamless steel pipe and welded steel pipe:
1. Differences in appearance
Seamless steel tube is made of billet.The external surface defects of the billet cannot be eliminated by the hot rolling process and can only be polished after the product is finished.In thinning the wall, only part of the defect can be eliminated.
The surface quality of the hot rolled coil is exactly the same as the surface quality of the pipe. It is easy to control and the surface quality of the hot rolled coil is high.
As a result, the surface quality of welded steel pipe is better than that of seamless steel pipe for many years.
2. Differences in molding process
Seamless steel tubes can be formed once during rolling.
Welded steel pipes are made of steel or sheet steel by bending or by different welding processes.
3. Performance differences
Seamless steel tubes have better pressure bearing capacity and are stronger than ERW welded steel tubes.Therefore, it is widely used in high pressure equipment, heat, boiler industry.
First of all, the welding seam of welded steel pipe is weak, and the quality affects the overall performance.