Answer: The purpose of geometric dimension inspection is to prevent stress concentration and other additional stress caused by geometric dimension exceeding the standard or not meeting the design requirements, which will affect safe use. It is also used as a basic parameter for strength verification.
For those that have been inspected for geometric dimensions, they are generally not inspected again. For those that may change during operation, they should be reviewed in detail.
Geometric dimension defects generally do not change due to changes in operating conditions. In other words, the geometric dimensions will not change during use. Therefore, for those with data to confirm the geometric dimensions of the pressure vessel, generally one or two main dimensions can be checked without repeated inspection. For geometric dimensions that may change during operation, such as the out-of-roundness of the cylinder, the diameter of the head and the cylinder may bulge or expand, they should be reviewed in detail.
