Xmas Tree - Limits for API 6A classes
Xmas Tree - Limits for API 6A classes
(OP)
Hi everybody...
With reference to thread408-266082: Christmas Tree Rating, I have a similar issue.
I am designing the surface facilities of a wellhead, with the tree itself out of my scope.
Design conditions provided by the Customer (who is Himself engineering the Xmas Tree) are 380barg @ 115 degC.
Therefore I am going inside my s.o.w. with ASME 2500#.
Now my issue.
The Customer is telling me that Tree flanges (which I should connect to) are API 5000#.
When I highlighted that given design conditions are outside the limit for this class, the Customer replied that the flanges are standard API 5000#, but tested and certified for API 6500#.
Does anyone know if this is acceptable for API 6A?
This because couter-flanges are in my scope and I do not know which corner i should bang my head against (to me flanges should be API 10000#).
Any help would be greatly appreciated!
With reference to thread408-266082: Christmas Tree Rating, I have a similar issue.
I am designing the surface facilities of a wellhead, with the tree itself out of my scope.
Design conditions provided by the Customer (who is Himself engineering the Xmas Tree) are 380barg @ 115 degC.
Therefore I am going inside my s.o.w. with ASME 2500#.
Now my issue.
The Customer is telling me that Tree flanges (which I should connect to) are API 5000#.
When I highlighted that given design conditions are outside the limit for this class, the Customer replied that the flanges are standard API 5000#, but tested and certified for API 6500#.
Does anyone know if this is acceptable for API 6A?
This because couter-flanges are in my scope and I do not know which corner i should bang my head against (to me flanges should be API 10000#).
Any help would be greatly appreciated!





RE: Xmas Tree - Limits for API 6A classes
RE: Xmas Tree - Limits for API 6A classes
If this is possible I would do exactly the same in my s.o.w with mating flange.
Thanks again!
RE: Xmas Tree - Limits for API 6A classes
However it remains a #5000 flange, but approved to operate at 6500 psig.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Xmas Tree - Limits for API 6A classes
But in order to actually rate such a 5000-psi flange to 6650 psi working pressure, it requires an engineering review to ensure suitability. And as previously mentioned by SPDL310, this would not be API monogrammable.
RE: Xmas Tree - Limits for API 6A classes
They mention "flanges are standard API 5,000PSI, but tested and certified for API 6,500PSI",
means those flange was designed by using API 6A 5,000PSI dimensions.
hence, you can use this information for designing the mating flange as the boundary of your equipment facilites.
please remind if there's a note if you want to mate API flange and ASME flange.
you can check on this: http://www.woodcousa.com/flg_cross_ref_main.htm
The recognized working pressure (WP) based on API6A are 2k, 3k, 5k, 10k, 15k, and 20ksi.
If tree manufacturer design it with those WP, then the they can monogrammed the tree.
For this particular case, 6,500PSI is not mention on API6A, as per SPDL310 said, its not monogrammed.
But still, tree manufacturer can produce 6,5k WP rating based on customer demand provided they can verify their design can fit for purpose.
(verification consist of pressure test, calculation, etc).
Hope this helps.
RE: Xmas Tree - Limits for API 6A classes
I will look what should be done practically for the approval to operate @ 6500 PSI.
Last doubt remains the responsibilies in case of failure and major accident as I am now operating outside the code.
In principle it would be like taking a carbon steel flange ASME #150, test it @ 45 barg and, if it does not fail, state that it is suitable to work @ 30 barg. ASME B 16.5 gives me much lower figures, therefore I would be working outside the code and in a big mess in case of failure....
Thanks again!
RE: Xmas Tree - Limits for API 6A classes
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way