Is there any limitation in Sect.VIII Div.1, to the extent of the Part certified in Form U-2 or U-2A? May be all fabrication and test, leaving the design, stamping and MDR Form U-1 or U-1A to another stampholder who is "the Manufacturer"?
Mauro Gonzaga

Yes, see UG-120(c). Only thing about designing is UG-120(c)(2), which makes me think that the part manufacturer should design what he's doing. But that should be up to AI's decision in particular case.
Note: A pressure test is not required for parts. So the AI does not need to witness it. So he signs the U2 form on basis of paperwork you submit to him. This theoritically allows production without AI's presence at all! Strange, isn't it?

Konrad

See also UW-11

UG-120(c) (2)requires to specify extent of design, which could be could be "none".
Last sentence of yours is not understood. I know that if the Part manufacturer with his AI does not make hydro. it shall be done by the stampholder with his AI.

Hi there,

U-part stamp fabrication without AI?!?

That is not possible, because the UG-90 duties still remain in place. The AI shall be given the opportunity to place his holdpoints BEFORE start of fabrication, and the AI shall witness the U-PART stamping, and so on and so on...

With respect to the design, there are two options:

Design responsibility by vessel manufacturer (typical for welded head parts) or

Design responsibility by part manufacturer (typical for parts like expansion joints)

Nice discussion.
Dirk

Right, The AI has less to do, but still it's not nothing.

If the part manufacturer does not perform the design, he will not be able to make any change, like material substitution or change in thickness or so. He will not be able to check whether a weld imperfection is acceptable or not. Similar problems may occur when the part is heat treated. In general, any nonconformity will most probably lead to scrapping!

Konrad

Not to scrapping, but to a question to the Vessel manufacturer.

The main problem in this area is that the subcontracts are often not specific enough with respect to the design responsibility.

DK

Maybe I'm pessimistic, but I would expect situation when, say during final inspection, something wrong is found. A truck is waiting to get loaded with few tons of the crap, but the Inspector is asking how come one small weld is too small and who can ensure him that it's still OK?

And what if it's a demo for a joint review, and the client is 9hours away, and it's Independence Day...

Konrad

Konrad,

you are perfectly showing how important good planning and an early involvement of the AI can be.

This can not be underestimated. At the end the AI does not enjoy to reject a weld, all AI are happy to accept acceptable vessels. They jsut do not have the authority to overrule the Code. Some people think they have.

Dirk

You know, when one begins a job, he is far away from the end, that's common. And in the end he reads last lines of the last piece of paper that is left to make. And it says "By signing this certificate neither the Inspector nor his employer makes any warranty, concerning the pressure vessel described in this MDR.". Then he realizes that bamboozling this guy didn't mean he won something!

Konrad