There are significant differences between seamless steel pipe and seamed steel pipe (also known as LSAW or welded steel pipe) in terms of manufacturing process, usage scenarios, and performance:

Manufacturing process:

Seamless steel pipe is produced directly by piercing, hot rolling or cold rolling to form a continuous steel pipe without any welds throughout the pipe body.

Seamless steel pipe is formed by rolling steel plates or strips into round shapes and then welding them along the length of the pipe. Welded seams in seam steel pipe are created during its manufacturing process and can be either straight seam welded (ERW) or spiral seam welded (SSAW).

Strength and pressure resistance:

Seamless steel pipe is usually stronger and performs better especially under pressure and high temperature resistance, as there are no weaknesses associated with welded seams. This makes seamless steel pipe widely used for piping under high pressure, high temperature or in harsh environments, such as transmission piping in the oil and gas industry.

Seamless steel pipes may be slightly less strong than seamless steel pipes, especially in the welded areas. This type of steel pipe is suitable for the transportation of low and medium pressure fluids as well as for some structural applications such as construction scaffolding.

Appearance Quality:

Seamless steel pipe has a smooth, even surface and no welded seams, but its production process is complex and expensive to manufacture.

Seamless steel pipe is simpler and less expensive to manufacture, but the welds may have minor imperfections, resulting in a slightly poorer appearance than seamless steel pipe.

Application Scenario:

Seamless steel pipe is commonly used in high-pressure vessels, boilers, oil drilling pipelines and other industrial applications that require high pressure and temperature resistance.

Seamless steel pipe is suitable for water pipes, building support, structural piping and other areas that do not require high pressure.

To summarize, seamless steel pipe performs better in high-pressure, high-temperature and higher strength requirements, while seamed steel pipe is less costly and suitable for common fluid transportation and structural support.