Regarding the reinforcement calculation for large openings in Section 7 of HG/T20582-2011, the calculation is carried out using the pressure area method
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There are openings in the cover; the diameter of the equipment is 1300, the size of the connections is 712x16, the pressure is 0.6, and the temperature is 180. When reinforcement rings are used, SW6 is not taken into consideration in the calculations; however, calculations can be done successfully without using those reinforcement rings. That’s why I’m asking: according to HG20582, when d/D is greater than 0.5 and the connections meet the requirements after calculation, is it possible to add reinforcement rings as well? I’m going to reply that since all the calculations have passed, there’s no need to add reinforcing rings – it’s unnecessary. This is meant for discussion; let’s talk about this issue. I think reinforcing rings can be added. In the original text, “using reinforcing rings for reinforcement” likely refers to the situation where the calculations for the pipe connections are not satisfactory. When using reinforcing rings, it is required that d/D be less than 0.5. What do everyone think?
This post was last edited by SDHZZXM on 2017-2-18 at 11:18. Please note that the applicable ranges for splice reinforcement and loop reinforcement are different:
Can the pressure area method be used for the calculation of pressure vessels?
Unless it’s absolutely necessary, the pressure area method doesn’t seem to be widely accepted in China. Thank you for the screenshot from post 3; we did build one unit where the original diameter of the cylinder was 1600, but after making the cut the diameter became 1400. We used the analytical method to determine the required reinforcement, and in practice we added reinforcement rings. As a precaution, we also installed vertical reinforcement plates, as well as internal ring plates. However, the calculation software ignored the existence of these reinforcement rings, and we didn’t input the reinforcing effects of those plates and rings either. Is this acceptable? Is doing this against the regulations? Could it cause excessive constraints on the equipment, leading to a loss of flexibility in its operation, as well as high local stresses that may result in damage?
The personnel involved in formulating standard HG/T20592 and standard GB150 are not the same, and GB150 considers the pressure area method to be an invalid calculation approach.
Uh. . . It seems like you don’t understand what I’m saying. The constraints are certainly different; otherwise, the question I’m asking wouldn’t make any sense. What I’m asking is: if, using the method of reinforcement through sleeves, the wall thickness of those sleeves meets the requirements, can an additional reinforcement ring be added at that point?
Of course, this calculation method is available in SW6
Our problems are actually similar. Before, I thought it was necessary to include safety measures related to insurance, but now my opinion has changed; I feel that this could lead to changes in local stress levels, and there’s a possibility that it wouldn’t comply with the relevant standards. . . . Sigh. . I’m torn; my thoughts keep changing. . . .
Well, that makes sense. But in cases like the one I mentioned, for the calculation of end fittings, when d/D is greater than 0.5, only the pressure area method specified in HG20582 can be used for such calculations. Is it necessary to use this method in all such cases? Moreover, when SW6-2011 encounters this situation, it will automatically use the pressure-area method for calculation, so. . . It can be considered a basis as well
The SW6 software was developed by the Chemical Equipment Technology Center; those responsible for formulating the HG/T20592 standard also work at this technology center. It is therefore natural to incorporate the pressure-area method into SW6. Since SW6 offers this calculation method, we use it – after all, there is no explicit rule prohibiting its use.