Seamless pipe means a pipes with hollow sections and are used in large quantities as pipelines for transporting fluids, such as pipelines for transporting oil, natural gas, gas, water and certain solid materials. Compared with solid steel such as round steel, the steel pipe is lighter in weight when the bending and torsional strength is the same, and is an economical section steel.It can improve the utilization rate of materials, simplify the manufacturing process, save materials and processing time, and have been widely used in steel pipe manufacturing.

Welded steel pipe, also known as welded pipe, is a steel pipe made of steel plate or strip steel after being crimped and welded, generally with a fixed length of 6 meters. Welded steel pipes have simple production process, high production efficiency, many varieties and specifications, and less equipment investment, but the general strength is lower than that of seamless steel pipes.

1. The production process of seamless and welded pipe is different
Welded pipe is made by coiling and welding strip steel; seamless pipe is perforated with billet and has no welding points on the pipe. Steel pipes with seams. The blanks used for welded steel pipes are steel sheets or strips; seamless pipes are long steel bars with a hollow section and no seams around them.

2. The production capacity of seamless pipe and welded pipe is different
The production capacity of seamless pipes is low; the production capacity of welded pipes is high. Since the 1930s, with the rapid development of continuous rolling production of high-quality strip steel and the advancement of welding and inspection technology, the quality of welds has been continuously improved, the varieties and specifications of welded steel pipes have been increasing, and more and more fields have replaced non-ferrous steel. Seam steel pipe; welded steel pipe has higher production efficiency than seamless steel pipe.

3. The base metal of seamless pipe and welded pipe is different
The base material for seamless tube production is a tube blank, which has a square round bar, which is processed into a seamless tube through perforation and other processes;The base material of welded pipe production is steel plate or steel strip, which is processed into welded pipe through cutting, bending, welding and other processes.

4. The use of seamless pipe and welded pipe is different
Seamless steel pipes are mainly used as petroleum geological drilling pipes, cracking pipes for petrochemical industries, boiler pipes, bearing pipes and high-precision structural steel pipes for automobiles, tractors and aviation;Welded pipes are widely used in tap water engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, urban construction; welded pipes are used for liquid transportation: water supply and drainage;For gas transmission: gas, steam, liquefied petroleum gas; for structure: for piling pipe, for bridge; for wharf, road, building structure, etc.

5. The price of seamless pipe and welded pipe is different
Seamless pipes are more expensive; welded pipes are cheaper. The cost of welded steel pipe is lower than that of seamless steel pipe. According to different welding methods, it can be divided into arc welded pipe, high frequency or low frequency resistance welded pipe, gas welded pipe, furnace welded pipe, Bondi pipe, etc.