Regarding GB/T16749-2018
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I have a question for everyone regarding the requirement in GB/T16749-2018 for the peak/trough radius: ≥3t. These days, there are many cases of upgrading old equipment, and the R-radius of expansion joints does not meet the requirements of the 2018 version of the standards. Increasing the R-radius would result in the expansion joints failing to meet the specifications; in some cases, thickening the tube sheet may also be necessary. How do you handle similar problems? Thank you all
This post was last edited by Shutong on 2019-12-17 at 19:25. What the original poster is referring to is that the R-radius of the expansion joint is too large, right? Does it mean that the peak/trough radius is less than 3t, thereby failing to meet the requirements of the 2018 version of the standards? Here comes the question: Since the old device R is large, the corresponding peak/trough radius is also large – how is it then not in compliance with ≥3t? Could it be that my understanding is wrong? Even if there is a misunderstanding on my part, if it does not meet the requirements specified in GB T 16749-2018 for pressure vessel bellows expansion joints, it can still be handled in accordance with GBT150 4.1.6
Just talking about the views on compliance: The standard used for this question is the standard for pressure vessel wave expansion joints. The content of this question relates to major repairs and modifications of pressure vessels. Therefore, the TSG regulations must be followed.
The equipment can be modified in accordance with the original standard requirements； If the requirement is not met, then strength calculations are performed for verification; the result obtained through these calculations serves as the first standard