Difference in load-bearing capacity between seamless pipes and welded pipes

Seamless pipes and welded pipes have significant differences in load-bearing capacity, mainly due to their different manufacturing processes:

1. Load-bearing capacity of seamless pipes

The load-bearing capacity of seamless pipes mainly comes from their manufacturing process and material properties. Seamless pipes are made by punching, drawing and other processes through a whole section of solid steel billets. There are no welded joints and no gaps, which makes them more reliable when subjected to high pressure and high temperature, because welds are potential weaknesses of welded steel pipes.

Under high pressure and high temperature, seamless pipes can withstand very large pressure and weight. Therefore, in some occasions that need to withstand large loads and high pressures, such as oil, natural gas, and chemical industries, seamless steel pipes are the preferred pipes. In addition, the strength of seamless steel pipes is relatively high, which is suitable for mechanical structures that withstand high pressure and strength.

2. Load-bearing capacity of welded pipes

Welded pipes are made by welding multiple steel plates or strips into pipes. Due to the existence of welded joints and certain gaps inside the steel pipe, the load-bearing capacity of welded pipes is relatively weak. The weld is a relatively weak link. Although modern welding technology is very mature, it may still become a weak point when under pressure. In some high-demand occasions, such as high pressure, high temperature, high-precision mechanical equipment, construction and other fields, welded pipes may not meet the requirements.

Specific application scenarios:

Seamless pipe: Due to its superior load-bearing capacity and pressure resistance, seamless pipes are often used in occasions that need to withstand large loads and high pressures, such as oil, natural gas, chemical and other industries. In addition, seamless pipes are also commonly used in high-pressure equipment such as pipeline connections of hydraulic equipment.

Welded pipe: Although the load-bearing capacity of welded pipes is weak, its production cost is low, its production efficiency is high, and it can be mass-produced. Welded pipes can be made into various shapes and sizes to meet the needs of different customers. Therefore, welded pipes are often used in general low-pressure application scenarios or occasions with high cost requirements.

Differences in cost and maintenance: 

Seamless pipe: The production cost is high and the production efficiency is relatively low, which limits its application range to a certain extent.

Welded pipe: The production cost is low, the production efficiency is high, and it is suitable for mass production. However, since there may be welding slag, protrusions and defects at the welding point, surface treatment is required to prevent rust.

In summary, seamless pipes are superior to welded pipes in load-bearing capacity and pressure resistance, but the cost is higher; while welded pipes have advantages in cost and flexibility. When choosing pipes, the type of pipe to be used should be determined according to the needs of the specific application scenario.

Read more: Choosing seamless tubes: cold rolled vs. hot rolled or Seamless vs Welded pipe