Nozzle Stress Question

[maddocks]

This might seem like a dumb question, but it's late and I'm stuck on this one. Does the pipe in a nozzle wall have to meet B31.3 wall thickness requirements or does it have to comply with ASME Sec 8 Div 1?

If it's constructed of A106B, do I use 20,000 Psi stress? Is there a way to disregard the mill tolerance if I UT the entire nozzle? The pipe is listed as 12" STD A106B.

 

[SNORGY]

ASME VIII Div. 1 would apply.

To waive Mill Tolerance by doing UT, you would not be able to change anything on the the material certificate, so "formal, legal" credit could not be obtained without a professionally endorsed engineering assessment.

Regards,

SNORGY.

 

[DSB123]

It's part of the vessel therefore the appropriate vessel Code applies.

 

[SnTMan]

maddocks, allowable stress for Sec VIII, Div 1 is 17100 up to 650 F.

For UG-37 calculations, for neck wall thickness tn, mill tolerance is disregarded, use the nominal.

Regards,

Mike

 

[maddocks]

Thanks guys (or girls?), this is good info. Unfortunately, it now looks like I have a situation....not good news.

Thanks again for the rapid help - eng-tips works again.

 

[JStephen]

Note that in some of the reinforcing calculations, the mill tolerance IS disregarded on the nozzle wall. See UG-16(d) and the definition of tn.