The difference between tube and pipe

The general technical specifications for Pipe are A530, while those for Tube are A450. The main differences between them are as follows: For A530, the wall thickness is specified in terms of nominal thickness, with an allowable deviation of ±12.5%; the allowable deviation for the outer diameter is relatively loose (with a minimum upper deviation of 0.4 mm). There are no requirements regarding flaring tests, crimping tests, or hardness. A450: The wall thickness is specified using the minimum value; the allowable tolerance for wall thickness is zero for negative values. The allowable tolerance for the outer diameter is quite strict (with a maximum upper tolerance of 0.4 mm). Requirements are also in place regarding flaring tests, crimping tests, and hardness. Additionally, each Pipe and Tube type has its own technical requirements specified in its own standards, which should be carefully read before use. It is difficult to establish a clear boundary as to whether Tube or Pipe should be used in ordinary pipelines. However, for heat exchanger tubes, furnace tubes, and fittings used in instrumentation that are connected by expansion joints, Tube must be used; for welded tubes, both Tube and Pipe can generally be used. Since Tube requires stricter manufacturing and inspection standards, it can be employed in industrial applications with more demanding pressure and temperature conditions, though it is also more expensive

This post was last edited by Gongsun Yang on 2018-5-13 20:22. There are answers on Zhihu. In simple terms, TUBE is identified by its outer diameter and wall thickness, while PIPE is identified by its nominal diameter and wall thickness code. There are different standards. See the links below: http://www.e-umc.com/materialtypehome/CLA http://www.e-umc.com/materialtypehome/CLB