ASME B31.3 Visual Examination

[Janimi]

Hi all,

we are struggeling with the amount of VT for normal fluid service.
In the latest revision 100% VT is required for all completed welds except those in components made in accordance with a listed standard. Components in that case are valves etc.? So 100% is required for all fittings, pipes etc.?
In case we have to check all of the welds why is there a minimum amount of 5% additionally given?

Thanks in advance

 

[XL83NL]

Components in that case are valves etc.?

Refer to listed standards in table 326.1. Valves are an example, yes. Or welded ASTM-pipe.

So 100% is required for all fittings, pipes etc.?

100% of completed welds, refer to 341.3.1(a)(3).

In case we have to check all of the welds why is there a minimum amount of 5% additionally given?

That 5% refers to fabrication as defined in 300.2:

[tt]fabrication: the preparation of piping for assembly,
including cutting, threading, grooving, forming,
bending, and joining of components into subassemblies.
Fabrication may be performed in the shop or in the field.[/tt]​

Think of flanged joint where you check for correct bolts/studs, gaskets, assembly fit-up. Or threaded joint with correct sealants, etc.


Does this answer your question?

Huub

 

[LittleInch]

Kind of curious wording, but to me this would be 5% of the act of fabrication should be visually examined followed by 100% of the "completed welds", i.e. the welds that the fabrication has undertaken, not those welds in pipe, fittings etc which were welded by someone else and delivered to you as a tested or examined item.

BTW XL83NL has a digit wrong - the 2018 version is 341.4.1 (a)(3)

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

 

[Janimi]

The reason why I am asking is that from edition 2016 to 2018 the amount has been increased from 5% to 100% VT i.e. for the circumferential welds. All our fabricated piping will be tested by third party so this will highly increase the costs.
I am just wondering because the 341.4.1 (a)(3) in 2016 was just about the longitudinal welds and now we are talking abount all welds including the circumferential welds.

But okay, then we have to do 100% VT now.

Thanks guys.

 

[LittleInch]

They seem to have changed it to all welds you do, not just longitudinal ones.

Really not sure how you visually check for some of the items in the check list. Having to do it several times before bolt ups obscure the inside e.g. may be challenging alright, so a lot will depend on what the owner wants.



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

 

[XL83NL]

https://www.eng-tips.com/viewthread.cfm?qid=466354

Second link in my post, sheet 12.

Huub