Seamless steel pipes are made from the round steel billet, through hot rolling, cold rolling or cold drawn processes, no seam on the pipe body.
Welded steel pipes are made from steel plate, with welding seam on the pipe body. Including ERW pipes, LSAW pipes, and SSAW pipes.
In this blog, we collected some differences between seamless pipes and welded pipes on raw material, manufacturing processes, performances, appearances, sizes, applications, and cost prices. JS Steel Pipes always aim to make your purchase of Chinese steel pipes fast and efficient.
About the Raw Material and production process
How is Seamless steel pipe made.
For API 5L and ASTM seamless steel pipes, the steel ingot or solid tube be perforated, then be formed via hot rolled, cold rolled or cold drawn.
Hot rolled seamless steel pipes are formed by billet forging, perforation, rolling, shaping and other processes. Large diameter pipes, and thick-wall seamless pipes usually made in this way.
Cold drawn seamless pipes used cold-drawn forming technology. The strength of material is relatively low, the appearance and internal control surface is smooth. Small diameter and thin-wall seamless pipes usually made in this way.
The seamless steel pipes are rolled by carbon steel, low alloy steel, alloy steel and stainless steel. Seamless steel pipes are widely applied in different industries such as pipelines, thermal services, mechanical industries, chemicals etc.
How is Welded steel pipe made
API 5L & ASTM welded steel pipes include SSAW pipes, LSAW pipes, and ERW steel pipes. These pipes are made with steel strip or steel plate.
Steel plate, for example, bending the steel plate at first, then welded into circle, square or other shapes.
Welded steel pipes has the excellent characteristics of high production efficiency, low cost and saving material. They are widely applied to aviation, aerospace, energy, electronics, automobile, light industry and other industries. Welded steel pipes have strong corrosion resistance in the acidic environment.
The reason why most of the people prefer seamless steel pipe over welded steel pipe is that
Differences in a summery
1. Surface quality
The raw material of seamless steel pipes is steel billet. The outer surface defects of billet cannot be eliminated by hot rolling, only polished after the product finished. In the process of wall reduction, the defect can only get partially eliminated.
Welded steel pipes are made from hot rolled coil, the surface quality of coil is just the pipes’ surface quality, and easy to be controled.The surface of hot rolled coil have high quality.
So, the surface quality of welded steel pipes is much better than the seamless steel pipes.
2. Molding process
Seamless steel pipes are formed one time in the rolling process.
Welded steel pipes are manufactured from steel strip or steel plate, through bending and welding.
3. Performance and Applications
The pressure capacity of seamless steel pipes are better, the strength is higher than ERW welded steel pipes. Seamless steel pipes are widely applied in high pressure equipment, thermal, boiler industries.
Generally, the welding seam of the welded steel pipes will affect the overall performance, such as pressure capacity and strength. Welded steel pipes can withhold 20% less working pressure than seamless ones. As a matter of fact, most of the industrial pipelines are done with seamless pipes only because of the pipes undergo extreme thermal, chemical and mechanical workloads. Welded pipes are more preferred in aerospace, automobile and electronics industries where the budget is comparatively less, and working pressure lower.
4. Available NPS
For seamless steel pipes, the biggest OD is general smaller than DN 600, some factories can only supply pipes smaller than DN 400. This is because of the production equipment.
However, the OD of welded steel pipes can be made from DN 40 to DN 2000, even bigger.
5. Cost and prices
Usually, the seamless steel pipe cost is higher than welded steel pipes, because of the raw material, manufacturing equipment, and processes. Please choose the seamless steel pipes or welded steel pipes according to the application and budget. It’s best only when it fits you.
PS: High-pressure projects’ purchasers
seamless pipes can withstand extremely high pressure without cracking. But the seam or welded pipes cannot do the same as the welded points are vulnerable to cracking up under high pressure. Furthermore, it is very easy to accurately calculate the pressure of seamless pipes. Seamless pipes are also thinner and lighter than welded ones, and they also have uniformity of shape as they are made up of uniform extrusion of an alloy.
Contact us to get the latest price list of seamless steel pipes now!
#JSFITTINGS #RAYOUNG #STEELPIPE #FLANGE #STEELPIPE #MADEINCHINA #MANUFFACTURER #FACTORY #PIPEELBOW #PIPE REDUCER #INDUSTRYFLANGE
Email: admin@jsfittings.com
Whats App: 008618003119682
