Appendix "Y" flange with slotted holes

[bogu]

Dear All

Can anybody help me with the design of an ASME VIII appendix “Y” flange with slotted holes? From an appendix 2 approach you would use dimension “A” as the bottom of the slot and dimension “B” as the id I am not sure of the approach using appendix “Y”

Thanks

Bogu

 

[prex]

The calculation of App.Y flanges involves the relative stiffesses of flange, hub and bolts: you can see this from the presence of a bolt hole flexibility factor, that accounts for the added flexibility of flange ring due to bolt holes, and that would have to be completely reworked for slotted holes. So I don't think you can realistically adapt that method to your conditions.
However in my opinion the behavior of an App.Y flange with slotted holes is much closer to that of an App.2 flange: I think you should be safe if you calculate it per App.2 (assuming you have an OR joint).

prex

http://www.xcalcs.com

Online tools for structural design

 

[esce]

Bogu,
I have programmed in Mathcad the Appendix "Y", class 1,
category 1 flange pairs.
If you would like a copy go to "esce.freeservers.com"
and download it.
I am not sure how to handle the slotted hole issue.
You may need to resort to FEA.


Erie Shore Consulting Engineers, Inc.

http://esce.freeservers.com

 

[bvi]

In my opinion, neither Appendix 2 or Y apply. Appendix 2 does not apply because it does not consider the counter moment created by the metal to metal contact outside of the bolt circle. Appendix Y does not strictly apply because it does not provide for the case with slotted holes. The slotted holes will effect flange stiffness which will effect the magnitude of the contact force between the flanges on the outside diameter of the flanges, in addition to effecting the resistance of the flange to rotation (which is considered by using the diameter on the inside of the slot in Appendix 2). I think FEA may be your best bet.