Checked ASME B16.9 end caps per UG-81 (ASME VIII Div. 1)

[Mechanimal]

Hi,

I did come across this:

Link

Would having a head template be the best approach to verify a ASME B16.9 end cap for a code vessel to fulfill UG-90(a)(9) requirements?

It's a little confusing with UG-44 and UG-11(c), which allow ASME product standards to be used in code vessels and are considered complying with the product specification if the markings on the part are per the specification. Could you argue that if a B16.9 end cap had the proper markings it would meet the product specification which includes material and dimensional requirements (for example SA-403 WP316-S, and B16.9) and would not need to be checked for correct shape?

Or because of UG-96 you have to verify thicknesses and shape regardless of what it is?

 

[Mechanimal]

I was just going over UG-81(d) for out of roundness of the skirt and comparing it to the tolerances in B16.9 table I-12 for out of roundness. For a 10" cap, 1% X 10.75" = 0.11" permitted out of roundness for UG-81(d), but per table I-12 the allowed out of roundness is 0.16"+0.12"=0.28".

Am I missing something? Is the correct approach assuming it's a fitting not a formed head? Or do you also need to specify allowed out of roundness requirements when ordering a pipe cap?

UG-80(c) permits when pipe is used for vessels and components that the allowable tolerance be per the piping specification ( for 10" NPS SA-106 it would be 0.125" that over the 1% of the nominal diameter specified in UG-80(a)).