Appendix 2 vs custom forging

[curlyjackme]

If a rough forging is purchased for a LWN type flange on a PV is it to be designed to App 2 or can it be calculated as a custom forging with standard dimensions. Example. For a 18" Type F flange.

 

[fegenbush]

If you meet the dimensional and materials requirements of B16.5, you do not need to perform calculations to Appendix 2. You will need to have proper evidence of material qualification marked on the finished flange.

If any of the dimensions are different beyond the tolerances outlined in B16.5, you will need to perform the Appendix 2 calculation.

 

[SnTMan]

curlyjackme, Sec VIII, Div 1 recognizes forged neck flanges as meeting B16.5 / B16.47 P-T ratings, subject to UG-44(i) requirements.

Anything else going to be a special design. Be aware the B16.5 flange patterns may not survive an Appendix 2 calculation.

Manufacturers such as FVC list their products as per B15.5 pressure classes, and as a practical matter I suppose a copy could be expected to have the same rating.

Regards,

Mike

 

[curlyjackme]

Just to follow up I talked with our AI and he has to look into it further, but he said that as long as the forging was machined to ANSI specifications and dimensions that it probably be acceptable. I am waiting on him to get back with me with a definite answer.

Thanks for the input.

 

[trivedidn]

curlyjackme,
if your LWN is CS/Low alloy steel please also refer clause UCS-66(c)(4).
Dhaval