UG-44 flange loads

[KevinNZ]

Revisiting old posts

https://www.eng-tips.com/viewthread.cfm?qid=464449#post

What is the failure mode QG-44 is first avoiding and how conservative is the calculation? Is it a gasket and sealing issue? How much higher would the loads need to go start failing the studs and flange body?

 

[TGS4]

It's a leakage issue. You would need to go through the WRC 538 calculations to determine the stud and flange failing determination. There are design margins built into the values published. The value of that margin depends on the size.

 

[KevinNZ]

Thanks TGS4

Would be conservative on sealing them as it needs to cover all gasket types.

 

[Krausen]

Failure mode is the bolted flange face unseating the gasket from external loading. So it's not evaluating the flange bolting or flange hub. My experience is this calculation is pretty conservative. If I recall right, this calc only applies to weld neck (WN) flanges. I see the latest B31.3 (2022) just added a new reference to this calc too now in App. F I believe.