1. Differences in the production process
After rolling steel sheets or strips, stainless steel pipes are welded together to form equipment and molds. The inner wall of the pipe usually has welds, and the seamless pipe is made of round pipe blanks, which are drilled, cold-rolled, and cold-drawn through the hot extrusion production process, and there are no welding points in the pipe.
2. The appearance difference of the steel pipe
For stainless steel welded pipe, wall thickness tolerances are very tight and the thickness is very uniform across the circumference. The steel pipe has high precision, high brightness inside and outside the pipe, and the length can be set arbitrarily. Seamless steel pipes have low precision, uneven wall thickness, low brightness on the inner and outer surfaces of the pipe, high cost of fixed dimensions, internal and external installation and black spots. Therefore, seamless pipes are usually produced with thicker walls.
3. The difference between performance and price
Seamless pipes have higher corrosion resistance, pressure resistance and high temperature resistance than welded pipes. With the improvement of the manufacturing process of the welded pipe, the mechanical properties and mechanical properties are gradually approaching that of the seamless pipe. Seamless pipes are more complicated to manufacture and more expensive than welded pipes.
According to the characteristics and differences of stainless steel seamless pipes and welded pipes, in order to achieve economical, beautiful and reliable effects, it is necessary to choose a reasonable application.
1) When used as decorative pipes, product pipes, and support pipes, the general surface effect is good, and stainless steel welded pipes are generally required;
2) Generally, stainless steel welded pipes are used for low pressure fluid transportation, such as water, oil, gas, air, hot water or steam and other low pressure systems.
3) Power plants, nuclear power plant boilers, high temperature, high pressure, high strength requirements, high pressure, high pressure infusion pipelines, industrial engineering and large equipment infusion pipelines, stainless steel seamless pipes should be used.
4) Stainless steel welded pipes are usually used for liquid transportation below 0.8MPa, while seamless pipes can withstand liquid transportation above 0.8MPa. If the pressure requirements are not high, it is more economical to use welded pipe.