Queries on ASME codes!!

[gbratis]

Hi everybody,
I have the following three questions for you :
1)Do we always have to take 12,5% wall undertolerance into account while performing ASME VIII,ASME 31.4, 31,8,31,3 wall thickness calculation. Where do the above mentioned codes clearly diclare the necessity of it?(specific paragraph per code).If the manufacturer assures me that his product is according to the specs dimensions (no wall th.deflections between the purchased and theoritical)is it mandatory to introduce it (undertolerance) in the calculation?
2)If the pipeline specs do not demand a PED certificate which are the lower metal temperature thresholds for the most common material, under which an impact test must be performed?. Please do not direct me to UG-20 or UG-84 ASME VIII div.1 code. I don't need the exemptions, just a reliable source to obtain the Minimum Design Metal Temeperatures.!
2)Where can I verify the validity of the post weld heat treatment necessity for wall thickness equal or greater that 19 mm? (I need the specific paragragh pee code i.e ASME VIII,ASME 31.4, 31,8,31,3)
Thanks in advance.

 

[deanc]

You must always consider mill undertolerance.

See SecVIII Div 1,Appendix 3 for some of your answers.

Material:
Go to Sec II. The required info.is listed under the spec. for the material.

MAKE SURE: Read the documents or sections listed as reference on the first 2 pages. Some of your tolerance will come from a general spec.