In modern industry, steel pipes, as an important transportation tool, are widely used in petroleum, natural gas, hydraulics, chemical industry and other fields. Steel pipes can be divided into two categories: seamless steel pipes and welded steel pipes according to production methods. Welded steel pipe refers to a steel pipe welded after the steel strip or steel plate is bent and deformed into a round, square, etc. shape. The raw materials for welded steel pipes are steel plates or strips.Since the 1930s, with the rapid development of continuous rolling production of high-quality strip steel and the progress of welding inspection technology, the welding quality has been continuously improved, the types and specifications of steel pipes have been increasing, and seamless steel pipes have been replaced by more and more categories.The cost of welded steel pipes is lower than that of seamless steel pipes, and the production efficiency is high. When it comes to the choice of steel pipes, welded steel pipes and seamless steel pipes are two common choices. So, which one is better, welded steel pipe or seamless steel pipe? This is a topic of great concern.
Welded pipes are divided into straight seam steel pipes and spiral steel pipes. Straight seam pipes are divided into ERW steel pipes (high frequency resistance welding) and LSAW steel pipes (straight seam submerged arc welding). The difference between SSAW steel pipe and LSAW steel pipe lies in the welding method. The difference between SSAW steel pipe and ERW steel pipe is the difference in welding process. Submerged arc (SAW) adds media such as welding wire and flux, which is not required for ERW steel pipe. ERW steel pipe is melted by medium frequency heating. The production process of straight seam welded pipe is simple, high production efficiency, low cost and rapid development. The strength of spiral pipes is generally higher than that of straight seam welded pipes. It can be used to produce welded pipes with large diameters, or it can also use bad materials of the same width to produce welded pipes with different diameters. However, compared with straight seam pipes of the same length, the weld length is increased by 30~100% and the production speed is low. Therefore, small-diameter welded pipes mostly use straight seam welding, and large-diameter welded pipes mostly use spiral welding. Seamless plain tube radiators and steel seamless fin tube radiators are both made of seamless steel pipes, and the performance of seamless steel pipes is better than that of welded steel pipes. Seamless steel pipe has strong pressure bearing capacity. The seamless welding of the steel pipe itself provides the basis for the pressure-bearing capacity of the radiator. Seamless steel pipes are not easy to crack during use and are safer to use.
Seamless steel pipes are made of high-quality carbon steel or alloy steel. They are steel pipes made by perforating the blank and hot rolling, cold drawing or cold rolling. According to the production method, it can be divided into: hot-rolled steel pipe, cold-drawn pipe, precision steel pipe, thermal expansion pipe, cold spinning pipe, kneaded pipe, etc. Its advantages are mainly reflected in the following aspects:
Strong integrity: Seamless steel pipes have no welds, have good integrity, and can withstand greater pressure and tensile force.
Good corrosion resistance: Since there are no welds, seamless steel pipes have better corrosion resistance in some corrosive environments.
Smooth surface: The surface of seamless steel pipe is smooth, the inner wall resistance is small, and the fluid transportation efficiency is high.
Advantages of welded pipe
Welded pipes, including LSAW (long seam submerged arc welded steel pipes) and pipes made by other welding processes, also have their unique advantages in some aspects:
Short production cycle: The production cycle of welded pipes is relatively short, which is suitable for projects with tight construction schedule requirements.
Relatively low cost: Compared with seamless steel pipes, welded pipes have lower production costs and are suitable for some cost-sensitive projects.
Wide scope of application: Welded pipes are suitable for a variety of engineering projects, such as transporting natural gas, oil, etc.
The difference between seamless steel pipe and welded steel pipe
1. Different processes
Seamless steel pipes are made by perforating steel billets or solid tube blanks and hot rolling or cold rolling. Welded pipe is made by bending and welding steel plates or strips.
2. Different appearance
There are no seams on the surface of seamless steel pipes. There are generally welding seams on the surface of welded pipes.
3. Different wall thicknesses
The precision of seamless steel pipes is low and the wall thickness is relatively thick. The steel pipe of welded pipe has high precision and the wall thickness is usually thin.
4. Different raw materials
Seamless steel pipes use steel billets or solid tube blanks. Welded pipes use steel plates or strips.
Summarize:
Taken together, seamless steel pipes perform better in terms of integrity, corrosion resistance, fluid transportation efficiency, etc,and are suitable for areas with high pipeline performance requirements, such as high pressure, high temperature and other environments. Welded pipes, on the other hand, have certain advantages in terms of production cycle and cost control, and are suitable for some engineering projects with tight schedules and cost-sensitivity. Therefore, seamless steel pipes and welded pipes each have their own advantages, and the choice needs to be based on specific project requirements, budget, construction period and other factors. In practical applications, engineers and designers should make reasonable choices based on project requirements and material characteristics to ensure the quality, safety and economic benefits of the project. In short, seamless steel pipes and welded pipes have their own advantages, and there is no absolute good or bad. The key lies in how to choose the appropriate pipe material according to the specific situation to achieve the smooth progress and long-term stable operation of the project.