On the calculation of arbitrary flanges
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This post was last edited by benin on 2017-9-26 08:31. GB150.3-2011 stipulates that flanges of any type should be treated as integral flanges, which is generally no problem. But what should be done when the material strength of the cylinder or sleeve connected to the flange is lower than that of the flange material? Table 7-5 uses only the allowable stress of the flange in the calculations. Is it calculated based on a loose flange? Taking the cylinder material Q245R and the flange material as 16Mn forged as an example, should it be designed according to Type A flanges? How to calculate
This post was last edited by benin on 2017-9-26 09:16. Perhaps my description isn’t clear enough: I have a pair of device flanges, with a design pressure of 2.5 MPa, which exceeds the requirements specified in GB150.2-7.4.4. It would be possible to simplify the calculation using the method for swage flanges, but it is necessary to design them as integral flanges (according to Table 7-5). Per Table 7-5, the part where the cylinder and the flange are welded together should be considered part of the integral flange in the calculations, and its material strength should be no less than that of the flange itself. Currently, the material used for the flange rings is 16MnII forged steel, while the cylinder is made of S31603; these two materials are welded directly together, with a lining ring added afterward. This approach allows the use of an inner liner tube to be omitted. However, since the strength of the cylinder material is lower than that of the flange, I am currently using a conservative calculation method based on the allowable stress of the cylinder. I’m not sure if this is appropriate; are there any better solutions? I hope someone can help clarify this issue. Thank you!