Welded and seamless pipes

　　It is not uncommon to believe that all metal pipes are manufactured in the same way, and at first glance, the differences between pipes may not be significant. However, metal tubes can be formed in several different ways. The two most common types of metal pipes are welded pipes and seamless pipes. It is important to understand the differences between metal pipes when selecting them for your project.

　　Welded pipe

　　As the name suggests, welded pipes are made by connecting one end of a metal plate or plate to the other end and welding them together. To connect the two ends together, a series of metal rollers are used to form metal longitudinally, and the ends of the rolling station are welded and the two sides of the material are connected together. The welding process used varies depending on the material type, thickness, and preferences of the pipe manufacturer. Common processes include resistance welding, high-frequency induction welding, and laser welding. After welding the material into the shape of a pipe, cut the newly formed pipe into specific lengths and remove excess welding material.

　　seamless steel tube

　　Seamless pipes are metal pipes that do not rely on welding and can be formed through several different processes. A popular process for manufacturing seamless pipes is through rotary piercing. For rotary piercing, a solid cylindrical metal billet has a small dent in the center of one of its faces. Then, the material is usually fed through a roller system using mechanical or hydraulic pressure. The outer roller forms the outer diameter of the seamless tube, while the inner mold (called the piercing roller) aligns with the small indentation and forms the inner diameter. For certain materials, the billet will be heated before this process to improve formability.

　　After forming the initial inner and outer diameters, they are usually not the exact dimensions required for the final pipe product. Therefore, the mandrel then passes through the newly formed inner diameter of the seamless tube. Then, the seamless tube is fed into several other sets of molds to achieve the final desired shape. Subsequent processes, such as annealing, can be used to improve the mechanical properties of seamless pipes. The cutting process is also used to achieve the required length.

　　Benefits of Welded Pipe

　　The main benefit of welded pipes is that they are usually more economical to purchase. This is because compared to seamless pipes, the cost of manufacturing welded pipes is lower. Welded pipes can generally be manufactured faster and reduce costs. Faster production times also mean that welded pipes typically reduce delivery times when ordered.

　　The Benefits of Seamless Pipe

　　Although seamless pipes are usually more expensive, they have several advantages compared to welded pipes. Many of its benefits stem from the uniformity of its composition, as it does not have welds. Generally, compared to welded pipes, uniformity can improve corrosion resistance, tensile strength, and compressive strength. In addition to producing more uniform pipes, the seamless pipe manufacturing process is also very suitable for thick wall applications.

　　Common uses of welded pipes

　　Welded pipes are typically used for applications that do not require extreme service but may require very precise dimensions, such as in construction applications. It is also an excellent choice for general pipe materials in various industries, as it is cost-effective and capable of rapid manufacturing.

　　Common uses of seamless pipes

　　Seamless pipes are used in applications with critical strength requirements, such as critical components of industrial machinery. Seamless pipes can also be used in conditions that require high corrosion resistance, such as some oil and gas extraction or chemical processing environments.