ASME IX impact requirements vs ASME VIII impact requirements

[JasonLouie]

We have a vessel to be manufactured with an MDMT of -42C (SA 516-70N). The vessel calculations indicate that it is impact test exempt as per ASME VIII UCS-66 (all the nozzles, flanges, shell materials are exempt).

Do I need a weld procedure that has been charpy tested to at least -42C? If so, do all the supplementary essential variables kick in, or do I only need the essential variables since the vessel is impact exempt?

Thanks in advance for any help you can offer!

 

[metengr]

JasonLouie;
Please review UCS-67 of ASME B&PV Code, Section VIII, Div 1. You will find your answer there. Regarding Supplementary essential welding requirements, they must be used for procedure qualification with impact testing (see Section IX).

 

[JasonLouie]

metengr,
Thank you very much for your help. The code is quite clear and I guess this shows my lack of knowledge in the ASME Section VIII Div 1 code. Perhaps I will start reading Section VIII on the bus ride to/from work...