HG/T20582-2020
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Regarding the design of semi-circular tube jackets per HG/T20582, the 2011 version states that \"this chapter applies to the design of circular, spherical, butterfly, or elliptical end caps equipped with semi-circular tube jackets\"； The half-circular tube jacket is at positive pressure.” The 2020 version states that \"this chapter applies to the calculation of the strength of half-circular tubes with jackets, where the shell or head is subjected to internal pressure and the jacket itself is also a half-circular tube under internal pressure, etc.\" The difference between the two can be understood as whether the condition of a negative design pressure for the inner cylinder in 20582-2020 is not applicable? Looking forward to everyone's answers
This change is quite significant; the difference is really big. I’ll keep an eye out to see if anyone knowledgeable can provide an answer.
The new standard applies when both are at positive pressure
The inner cylinder is under negative pressure while the semi-tube is under positive pressure; this increases the magnitude of the negative pressure in the inner cylinder, making it impossible to determine stability accurately using conventional calculations. Alternatively, a conservative approach can be adopted by increasing the negative pressure in the inner cylinder
The inner cylinder is under positive pressure, as is the half-tube; for the inner cylinder, the actual pressure can be considered to have offset part of that pressure. The inner cylinder is subjected to separate strength calculations, so the results are more conservative. Furthermore, in the case where the pressure in the half-tube is higher than that in the inner tube, it cannot be simply assumed that the inner tube is under negative pressure, as the allowable pressure for the half-tube is determined based on yield criteria
The above is purely my own interpretation; just take it as a reference
It seems the new standard is more reasonable and easier to understand
In my opinion, there are still some issues in the new standards.
I’ve learned it; thanks for clarifying things and helping me broaden my thinking.
Later on, a senior expert sent me screenshots of a paper; the paper itself has also been found, for everyone’s reference, so we can learn together*.