When Should Seamless Pipe And Welded Pipe Be Chosen?

When choosing steel pipe, how to judge whether seamless pipe or welded pipe should be used is a common problem. Understanding its applicable scenarios is crucial to ensure the stability, durability and cost-effectiveness of the pipeline. Generally speaking, when the nominal size is greater than 2 inches, seamless pipe is more suitable; when the nominal size is less than 2 inches, welded pipe is more economical and practical. This article will analyze the applicable occasions of seamless pipe and welded pipe in detail and help you make the best choice.

What is the nominal size

The nominal size refers to the standard size of the steel pipe, usually in inches or millimeters. The nominal size is not equal to the actual size, but a standard value.

The nominal size is used to distinguish between the selection of seamless pipe and welded pipe because the nominal size reflects the size of the pipe, which affects the pressure bearing capacity, production process and cost of the pipe. Pipes with a nominal size greater than 2 inches usually need to withstand higher pressures and extreme environments, and pipes with a nominal size less than 2 inches have lower pressures. Understanding this is crucial to the correct selection of seamless pipes and welded pipes.

Comparison of advantages and disadvantages of seamless pipe and welded pipe

When to choose seamless pipe

The production process of seamless pipe is complex and the production cost is high, but it has excellent performance. The nominal size of seamless pipe is generally greater than 2 inches. Seamless pipe can withstand higher pressure than welded pipe, and will not crack at the joint, which is particularly suitable for applications in high pressure and harsh environments. Therefore, when using pipes with a nominal size greater than 2 inches, seamless pipes should be preferred, such as oil and natural gas transportation pipelines, OCTG pipe, etc.

When to choose welded pipe

Compared with seamless pipes, welded pipes have a simple production process and low cost. The nominal size of welded pipes is generally less than 2 inches. Compared with seamless pipes, welded pipes are more prone to problems such as cracks at the weld, but their performance is still very good when used in pipes with small nominal sizes. Because of its simple production process and low cost, welded pipes should be preferred when using pipes with a nominal size less than 2 inches. Common application scenarios include household water supply pipes, heating, ventilation and air conditioning (HVAC) systems, etc.

Summary

In summary, when choosing steel pipe materials, the size of the nominal size needs to be considered. Seamless pipes should be used when larger than 2 inches, because large-sized pipes require stronger pressure-bearing capacity and higher quality; welded pipes should be used when smaller than 2 inches, because the cost of small-sized pipes is more important. In addition, when choosing, it is necessary to make comprehensive considerations based on the specific situation and choose the most suitable steel pipe material.