BVPC VIII DIV 1 - DN Flange Question
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Question

BVPC VIII DIV 1 - DN Flange Question

Jacob7 (Mechanical)

(OP)

5 Jun 23 23:29

I have a customer who wants to put a DN flange fittings on their ASME Section VIII Div. 1 vessels. UG-44 lists only B16.5 and B16.47 flanges. However, my understanding was the code essentially stops after the first weld. That is to say I could post a pipe stub coming out of the tank and have that certified/inspected. Then attach the DIN fittings later? I recall something similar being done on a tank I worked on in the past, but wanted to ask around to see what others have done.

cbPVme (Mechanical) · Answer 1 · 2023-06-06 01:14:03

Per U-1(e)(1)(-c) the scope of the code is up to the face of the first flange or bolted flange connection. The DIN flange is within the scope of ASME VIII-1 and as it is not an adopted standard, the flange must be designed in accordance with Appendix 2.

TGS4 (Mechanical) · Answer 2 · 2023-06-06 02:12:29

However, you could define it as a welded connection and use the scope definition in U-1(e)(1)(-a), and then the DN flange would be outside the scope.

XL83NL (Mechanical) · Answer 3 · 2023-06-06 07:59:58

DN flange (thus saying something about the size only), or DIN flange?
The latter doesn't exist anymore, that is now included in the 'new' EN 1092-1. You could look at ISO 7005, which covers B16.5 flanges.
Otherwise, verification by ASME VIII-2 App 2 is the way to go.

Huub
- You never get what you expect, you only get what you inspect.

LittleInch (Petroleum) · Answer 4 · 2023-06-06 10:29:34

Or just fir a set of fitting to fitting flanges with one side the ASME B 16 flange and the other the DIN or EN flange?

Code mismatches make people nervous and the AI might reject it.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

Jacob7 (Mechanical) · Answer 5 · 2023-06-06 17:10:15

Yes, apologies DN600 and DN100 flanges. I'm not as familiar with DN/DIN fittings as I should be.

Thank you all for the feedback/suggestions!

SnTMan (Mechanical) · Answer 6 · 2023-06-06 17:49:10

Jacob7, whichever way you choose to go, early agreement among the parties would be beneficial.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

LittleInch (Petroleum) · Answer 7 · 2023-06-06 17:59:43

So actually just ASME B16.5 flanges, 24" and 4 " ??

Or actually flanges not to ASME B 16.5?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

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BVPC VIII DIV 1 - DN Flange Question
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