Identification Methods of Seamless Steel Pipes and Welded Steel Pipes (Part Two)
Performance of welded steel pipes
Welded steel pipes are processed by high-frequency welding, cold rolling and other processes, so they have the following properties:
- Welded steel pipes have good heat preservation functions. The heat loss of welded steel pipes is relatively small, only 25%, which is not only beneficial to transportation, but also reduces costs.
- Welded steel pipes are waterproof and corrosion resistant. During the construction of the project, there is no need to set up a separate pipe trench. The steel pipe only needs to be buried directly underground or underwater, which reduces the construction difficulty of the project.
- Welded steel pipes have impact resistance. Even in the low temperature environment, the steel pipe will not be damaged. Therefore, performance of welded steel pipes has certain advantages.
The performance of seamless steel pipes
Tensile strength of metal materials of seamless steel pipes is great, so seamless steel pipes have good destructive resistance. Seamless steel pipes have a hollow channel, so they can effectively transport fluid and have good transport capacity. Corrosion resistance of seamless steel pipes is better than that of welded steel pipes, and rigidity of seamless steel pipes is relatively better. Therefore, seamless steel pipes carry more loads, which are widely used in projects with higher construction requirements.
Identifying welded steel pipes and seamless steel pipes according to the process
In the process of distinguishing between welded steel pipes and seamless steel pipes according to the process, pipes which are welded by cold rolling and extrusion are welded steel pipes. In addition, when the steel pipes are high-frequency, low-frequency arc and ERW welded, spiral steel pipes, straight welded pipes, round steel pipes, square steel pipes, oval steel pipes, triangular steel pipes, hexagonal steel pipes, rhombus steel pipes, octagonal steel pipes and even more complex steel pipes can be formed. In short, using different processes will form steel pipes with different shapes, so that welded steel pipes can be clearly distinguished from seamless steel pipes. However, seamless steel pipes are distinguished by hot-rolled and cold-rolled processing methods. Hot-rolled seamless steel pipes are formed by piercing and rolling processes, especially seamless steel pipes with large diameters and great thickness are welded by this process. A tube blank is cold drawn to form cold drawn pipes. The material of the cold drawn pipe has lower strength, but smooth outer and inner appearance.
Distinguishing between welded steel pipes and seamless steel pipes by applications
Welded steel pipes have better bending and torsion strength and greater load-bearing capacity, so they are generally widely used in the manufacture of mechanical parts. For example, steel scaffolds used in oil drill pipes, automobile drive shafts, bicycle frames and construction are manufactured by welding. However, seamless steel pipes can be used for conveying fluids due to their hollow cross-sections and there are no long steel strips with seams around them. Seamless steel pipes can transport oil, natural gas, gas, water, etc. In addition, bending strength of seamless steel pipes is relatively small, so they are generally widely used in low and superheated steam pipes and boiling water pipes for medium pressure boilers and superheated steam pipes used for locomotive boilers. In short, through the classification of uses, welded steel pipes and seamless steel pipes can be clearly distinguished from each other.
Tensile strength of metal materials of seamless steel pipes is great, so seamless steel pipes have good destructive resistance. Seamless steel pipes have a hollow channel, so they can effectively transport fluid and have good transport capacity. Corrosion resistance of seamless steel pipes is better than that of welded steel pipes, and rigidity of seamless steel pipes is relatively better. Therefore, seamless steel pipes carry more loads, which are widely used in projects with higher construction requirements.
Identifying welded steel pipes and seamless steel pipes according to the process
In the process of distinguishing between welded steel pipes and seamless steel pipes according to the process, pipes which are welded by cold rolling and extrusion are welded steel pipes. In addition, when the steel pipes are high-frequency, low-frequency arc and ERW welded, spiral steel pipes, straight welded pipes, round steel pipes, square steel pipes, oval steel pipes, triangular steel pipes, hexagonal steel pipes, rhombus steel pipes, octagonal steel pipes and even more complex steel pipes can be formed. In short, using different processes will form steel pipes with different shapes, so that welded steel pipes can be clearly distinguished from seamless steel pipes. However, seamless steel pipes are distinguished by hot-rolled and cold-rolled processing methods. Hot-rolled seamless steel pipes are formed by piercing and rolling processes, especially seamless steel pipes with large diameters and great thickness are welded by this process. A tube blank is cold drawn to form cold drawn pipes. The material of the cold drawn pipe has lower strength, but smooth outer and inner appearance.
Distinguishing between welded steel pipes and seamless steel pipes by applications
Welded steel pipes have better bending and torsion strength and greater load-bearing capacity, so they are generally widely used in the manufacture of mechanical parts. For example, steel scaffolds used in oil drill pipes, automobile drive shafts, bicycle frames and construction are manufactured by welding. However, seamless steel pipes can be used for conveying fluids due to their hollow cross-sections and there are no long steel strips with seams around them. Seamless steel pipes can transport oil, natural gas, gas, water, etc. In addition, bending strength of seamless steel pipes is relatively small, so they are generally widely used in low and superheated steam pipes and boiling water pipes for medium pressure boilers and superheated steam pipes used for locomotive boilers. In short, through the classification of uses, welded steel pipes and seamless steel pipes can be clearly distinguished from each other.
