One device with two cylinders of different thicknesses
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As the title suggests, in one piece of equipment, the upper and lower tube sections have different thicknesses – this is because the upper tube section has larger openings. My question is: when preparing the calculation sheets in SW6, what method do you experts use? Should the lower tube section be provided with separate components and reinforcement through openings? 》
What is the structure of the device like? If it is a tower, it can be segmented; for other structures, the calculation sheets available for the components can be used. Strength calculation for cylinders of different thicknesses and calculation for reinforcement through openings
It’s a regular U-tube heat exchanger; the upper tube section has holes with a diameter of DN250, which is not sufficient, so it needs to be thickened to 16 mm. The lower tube section does not require thickening – a thickness of 10 mm is sufficient. As for the reinforcement of the openings in the lower tube section and the end caps, should we simply use the relevant component specifications to prepare the calculations?
Why is it necessary to increase the thickness of the tube section? Can’t just thicken the pipe connection or add a reinforcement ring instead?
What if the load to be carried is too large, forcing the need to thicken the cylinder?
Why not use a reinforcement ring for reinforcement? For unequal-thickness welding, the thick-walled end also needs to be thinned.
To summarize the answers from other users, let’s first determine whether the cylinder needs to be thickened because the reinforcement calculated for the openings is insufficient, or due to excessive loads on the connections. If opening reinforcement is not sufficient, use forged thick-walled pipes (note that the thickness of the larger end of the forged pipe must not be greater than 2 times the thickness of the cylinder wall), or employ reinforcement rings (note the limitations on the scope of use for such rings). If the load to be taken up is too large, it becomes necessary to thicken the cylinder. Then there’s no dispute. Then, 16 thick tube sections and 10 thick tube sections are butted together; the thicker ends are tapered before butting. (It is not recommended to thicken thin areas.)
Are these 16mm-thick tube sections and 10mm-thick tube sections located in the shell-side cylinder section or in the tube box cylinder section? Could you draw a sketch to show where it is?
For the shell-side cylinder, 16 refers to the air inlet, which has a relatively large opening. Since the tube bank is under high pressure and requires inlets and outlets for water, it must use end sections of 16 mm. What I mean is: when you prepare the official calculation documents, will the cylinder sections be divided into two parts? Also, regarding the hydrostatic pressure of the liquid column, does it need to be based on the actual length?
For U-tube heat exchangers, it is not necessary to divide the shell into two sections for calculation; calculating it as if it has a thickness of 10 mm is sufficient. In the case of a fixed-tube-sheet heat exchanger, the shell is calculated at thicknesses of 16 mm and 10 mm respectively; the wall thickness of the shell side in such a heat exchanger affects the thickness of the tube sheet, whereas this problem does not exist in U-tube heat exchangers. Also, with SW6, U-tube heat exchangers cannot be segmented for calculation, whereas the PVelite software allows segmentation. . .