Seamless line pipe
1:What is the seamless line pipe?
Seamless steel pipe, or SMLS, refers to a hollow steel pipe having no seam around. Due to its unique feature of strength and anti-bending, seamless pipe is widely used in construction, oil refining and chemical industries.
2:What is the seamless line pipe used for?
Seamless pipes are widely used in nuclear devices, natural gas, petrochemical, shipbuilding and boiler industries.
3:What is the difference between seamless pipe and ERW pipe?
Seamless pipe is formed when steel in the billet is heated and then either pushed or pulled over a mandrel with a piercing point located in the center of the billet. This produces a hollow tube or “shell”. The tube is then further processed until it becomes the desired size and wall thickness. The whole manufacturing process doesn’t involve any welding part, so there is no welding line in seamless pipes. ERW pipe is cold formed a strip steel into a round pipe section, the edges of which are heated by high frequency welder. Then the welding is inspected electronically and cooled down. The biggest visible difference between seamless pipes and ERW in structure is that ERW pipe has a welding seam which is produced by the welding process while seamless pipe doesn’t. The less recognizable the welding line is, the better ERW pipe will be. Nowadays, with the advancement of the technology, two ways are coming into use to eliminate the welding line, the geometric seamless and physical seamless. Geometric seamlessly is to remove the burr inside and outside of the ERW pipes. Physical seamlessly refers to the difference between the micro structure and the parent metal on the inside of welding line resulted in decrease of the welding area and mechanical properties.In contrast to the ERW pipes, seamless pipes, without the seam or the welding line, is able to maintain a uniform shape and great strength under high pressure, temperature
4:How to make the seamless line pipe?
The overall production method fo both processes involves three stepls. First, raw steel is converted into a more workable form. Next, the pipe is formed on a continuous or semicontinuous production line. Finally, the pipe is cut and modified to meet the customer’s needs.
5:What is the specification of the seamless steel line pipe?

6:What is the maximum size of seamless pipe?
The biggest outer diameter of the line pipe is 457mm., and the thickest is 60mm.
7:The manufacturer of the seamless steel pipe
Baotou Steel Union Co.