ASME Sec VIII Div 1, Appendix 2-13 K value
ASME Sec VIII Div 1, Appendix 2-13 K value
(OP)
I am designing loose ring type reverse flange per ASME Sec VIII Div 1, Appendix 2-13. My flange OD is 168.28 mm and flange ID is 60.33 mm. So, K=2.789. Appendix 2-13 says reverse flanges shall be designed in conformance with the rules in 2-3 through 2-8, but with the modifications as described in 2-13. Mandatory use of these rules is limited to K less than or equal to 2. When K is greater than 2, results become increasingly conservative.
Question - Our customer is commenting that appendix 2-13 cannot be used because K is greater than 2. If I understand this correctly, we should be more concerned when K is less than or equal to 2, but we can use 2-13 when k is greater than 2 with conservative results.
Can someone confirm my understanding and if I am not correct, what can be done for K is greater than 2 to use 2-13. Thank you.
Question - Our customer is commenting that appendix 2-13 cannot be used because K is greater than 2. If I understand this correctly, we should be more concerned when K is less than or equal to 2, but we can use 2-13 when k is greater than 2 with conservative results.
Can someone confirm my understanding and if I am not correct, what can be done for K is greater than 2 to use 2-13. Thank you.





RE: ASME Sec VIII Div 1, Appendix 2-13 K value
Too conservative means the design becomes excessive and less feasible, compared with other similar design. However, if the thickness, weight and cost is no object, then you can design and manufacture the flange with K=2.789. If not, the U-2(g) tells you to use alternative design methods, perhaps even FEA or ask the forgings manufacturer to design it and certify it for you.
Cheers,
gr2vessels
RE: ASME Sec VIII Div 1, Appendix 2-13 K value
Cheers,
Kumar