Self reinforce nozzle (SA105) for -29¦C (-20¦F)

[hockchong]

Dear All;
I have a problem here. Currently, I have a thick wall vessel 90mm with ID of 1500mm design in Div. 2. I am using self reinforce nozzle for all the opening. The problem is the minimum design temperature is -29°C and I am trying to use SA105N for these nozzles. As per AM-218.4 Div 2, the impact test only exempted for LWN but not for HB or other type where the barrel OD is more than OD of HUB given in ASME B16.5. From my understanding, SA105N is not meant for impact test. Is there no way for me to avoid using SA350 LF2? I need advise from you all whether I've miss out something.

Thank you.

Regards,
Lee

 

[ijzer]

It is just not safe to use SA 105 in a thick wall ASME VIII-2 vessel at -29 Deg. C ,so why look for impact test exceptions.

 

[codeeng]

I agree with ijzer. Use SA105 only when you get exemption, otherwise switch to LF2.

 

[johnnymist2003]

Gentlemen,

in my opinion, the correct specification to use for the stub neck forging would be SA-765 Gr.II. SA-350 Gr.LF 2 should be used for the flange attached to the neck only.
John

 

[rkg]

It is possible to order SA 105N with impact test. Also, -29 deg. C is not a very low temperature and my experience says that impact will pass easily. This way, LF2 could be avoided.

 

[codeeng]

Yes you can order SA105 with impact testing but you'll have to wait for it and it'll likely cost more than LF2.

 

[hockchong]

Alls,
Thanks for all the suggestion. If impact tested SA105N will cost more SA350 LF2, then I might as well settle with SA350 LF2.

Regarding impact test for SA150N, I've check with ASME II part A and it don't have supplement for impact test on SA105. Can anyone point out any part of ASME code which explain more on impact test on SA105N.

Thnaks again.

 

[GenB]

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