Design of 10000 lbs Flange

[rashidmaqbool]

We have a flange in a pipeline from wellhead with a design pressure of 8800 psi. Originally it was under API 6A but due to temperature constraints, it is now out of API 6A's scope.
My question is can we design this flange as per ASME B&PV Code Section VIII Div I Appendix 2 (considering the fact that design pressure is 8800 psi) or a FEA would be more appropriate.
Please advise.
Design Conditions are:
Design Pressure = 8800 psi
Design Temperature = 150 C
Flange Material A859 Gr A Cl 2
Octangonal Ring Joint Gasket - Incoloy 825

 

[SnTMan]

Div 3 would be more appropriate. What diameter did you have in mind?

What, if any, Codes and/or Standards are you obligated to meet?

Regards,

Mike

 

[rashidmaqbool]

We have a little variety in diameters, however, as a test case, we are taking NPS 10 pipe (API 5L).
As far as code / standard is concerned, we need to exactly identify under which code / standard or even the design procedure (FEA) should this case fall.
Originally, we started with API 6A (wellhead piping) for 10000 lbs flange, however, due to minimum temperature going below 0 degF, the case went out of the scope of API 6A. Then B31.3 was referred, however, that does not cover flanges beyond 2500 lbs rating (refers to B16.5). B31.3 does give cross reference to ASME B&PV Section VIII Div 1 Appendix 2 for the design of flanges other than its own scope.
I used PV-Elite (Code Calc) to perform a sample calculations as per design conditions specified and noticed that it used Appendix 2 for flange design.
I want to confirm whether there is any provision within the ASME B&PV Code that a flange be designed as per Appendix 2 regardless of whatever pressure it holds.
I have not checked Div 3 as yet, though considering the pressure this seems the most appropriate.
Looking forward for further value added comments.
Thanks in advance.

 

[gr2vessels]

Hi Rashid,
You may consider the compact flanges (refer to NORSOK flanges, Specification L-005 and Vector compact flanges), check out the DNV-OS-F201 specification and ISO 13628-7. Except the ISO standard, the rest if free on the internet.
Cheers,
gr2vessels