I have issues with the design calculations for pressure vessels; I hope experts can help me out
Thread Content
When designing the pressure vessel, several large openings were considered first; using SW6-2011V3.0 for the calculations, no test pressure was entered, and the calculated test pressure came out to 1.13 MPa. After adding some smaller pipe openings, again no test pressure was entered, and the calculated test pressure was 1.05385 MPa. According to the formulas, the test pressure should be 1.13 MPa. Both software calculations yielded satisfactory results. The thicknesses of the connections and the vessel walls were set quite high, so no reinforcement rings were necessary. I would like to ask the experts why the test pressures calculated by the software differ in these two cases.
You should take a screenshot of the calculation sheet to see; nothing can be understood from it
It’s probably just that the stress correction factor for the pipe material is too low. According to Note 2 of 4.6.2.2 in GB150.1, the smallest value shall be selected.
Are the takeover materials entered twice the same?
The first time, I only checked whether the strength of the three large pipes met the requirements; the second time, I added the remaining few small pipes with diameters not exceeding 150, while everything else remained unchanged, and as a result the test pressure was different
According to the formula for calculating test pressure given in the calculation sheet, the value should be 1.13; however, when using the software for a second calculation and taking into account the test pressure resulting from the openings in several small tubes, the value becomes 1.05
Thank you all. I understand now – it’s because the small tube at the back is made of stainless steel that the experimental pressures differ. Thank you to all the experts.