Problems in calculating standard flanges
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A 20592 DN150 PN16 flange cover was selected, along with a standard spiral-wound gasket. However, a fitting was welded into the hole at the center of the flange cover. When calculating the reinforcement required for this hole, it turned out that the area of the flange cover’s bolts was insufficient. After changing to a different gasket, it was noted that the bolt spacing was too large. How do people typically handle such situations?
First, open-hole weld joints? What type of connector? What is the relationship between calculating the opening reinforcement and the bolt area? The maximum design pressure inside the pipe is >1.6 Mpa, so the threads on the flange are certainly capable of withstanding that pressure. Besides, I’ve never heard of a situation where reinforcement is needed for a flange that’s this small.
It’s a bit strange. If you don’t make any holes and treat the cover as flat, is the area of the bolts sufficient without needing to replace the gasket? Since the specific pressures for different gaskets vary, the required bolt preload also differs. In your case, it seems that the required preload for the gasket is too high, resulting in an insufficient bolt cross-sectional area. For instance, if you replace the spiral-wound gasket with a graphite gasket, the calculations should yield acceptable results. I just don’t get what it has to do with the centrally located hole.
If there are no holes in the middle, I don’t need to do any calculations, as a standard blind plate is being used