The allowable deviations of the outer diameter and wall thickness of seamless steel pipes of different standards are not the same. In recent years, ASTM A53 seamless steel pipes have been used in an increasing proportion in my country. Due to its wide range of uses, quality requirements have also been raised. High requirements, among which the outer diameter and wall thickness deviation of seamless steel pipes are one of the important indicators of its quality.
The allowable deviations of the outer diameter and wall thickness of seamless steel pipes of different standards are not the same. In recent years,
ASTM A53 seamless steel pipes have been used in an increasing proportion in my country. Due to its wide range of uses, quality requirements have also been raised. High requirements, among which the outer diameter and wall thickness deviation of seamless steel pipes are one of the important indicators of its quality. Wall thickness deviation will directly affect the use of seamless steel pipes.
During the production process, since the actual size is difficult to meet the nominal size requirements, that is, it is often larger or smaller than the nominal size, the standard stipulates that a difference between the actual size and the nominal size is allowed. A positive difference is called a positive deviation, and a negative difference is called a negative deviation.
The wall thickness of seamless steel pipes cannot be the same everywhere. There is an objective phenomenon of uneven wall thickness in its cross section and longitudinal pipe body, that is, uneven wall thickness. In order to control this unevenness, let us give an example respectively. For example, when the outer diameter of the GB/T8162 standard seamless steel pipe is greater than 50 mm, the allowable deviation of the outer diameter is plus or minus 1%. The outer diameter of the seamless steel pipe is generally above For example, for a seamless steel pipe with an outer diameter of 60 mm, the allowable deviation of the outer diameter is plus or minus 0.06 mm. The allowable deviation of the wall thickness is plus or minus 12.5%. For example, if the wall thickness is 4 mm, the allowable deviation range is 4*12.5%=0.5 mm.
For example, ASTM A53 standard seamless steel pipe, when the outer diameter is greater than 48.3 mm, the allowable deviation of the outer diameter is plus or minus 0.4 mm-0.79 mm, and the allowable deviation of the wall thickness is plus or minus 12.5%.
