The first with a pipe, tube/tubing roughly divides into the stainless steel pipe with pipe and the structure with steel pipe 2 broad categories (with a distinction between P, T), respectively.

Pipe is defined in the English dictionary as a Pipe for the conveyance of liquid or gas, as specified in the ASME Pipe standards.

Need to pay attention to is put forward by ASME NPS, namely dimensionless label applies only to pipe, steel pipe scale may not apply to the tube/tubing. Because NPS12, NPS Numbers after 1/8, 1/4,...

, not directly on behalf of the outside diameter of 12 inches values, rather than directly expressed in inches diameter Tube/Tubing is much larger (for example NPS1/8 pipe, diameter of 10.29 mm;

Only 1/8 of the tube, the diameter of more than 3.2 mm) but NPS14 inches value of digital means outside diameter, or with no more tube/Tubing.

Note also that this distinction is not found in the UK, European or ISO standards.

Tube can also be used as a pipe or vice versa.

But in examining the American standard which is the basis of the user orders or choose the standard must pay attention to the distinction, if the Tube/Tubing corresponding standards, steel pipe dimension can't be with NPS.

Manufacturing method is also an important feature of distinguishing stainless steel pipe product standards in the United States, including three standards for rolling (Wrough) seamless pipe (that is, seamless steel pipe commonly referred to in China), nine standards for seamless and welding, and ten standards for welded pipe;

There are also jet forming (a special technology of powder metallurgy) seamless steel standards 2;

Centrifugal cast pipe standard 3.

In total, there are 12 applicable American standards for rolling seamless stainless steel tubes and 19 applicable standards for welding stainless steel tubes.

In addition, since 2000, when the us anti-deep cold processing (HCW) welded pipe appeared independently as a new method in the ASTMA312/A312M standard, the us standard for stainless steel pipe manufacturing methods has increased to 5 categories, three of which are not included in the Chinese standard.