Dear experts,

Our designer specified certain welds shall be ground flush with the base material considering the function requirement,However the QC guys said we didn't tell them the tolerance for the ground,they means they can't perform and judge the "flush" condition. is that so? Do I need to specify a tolerance to them to perform the VT?

thanks in advance!

QC Guys are right.
mauro

thx,mauro,

i got the reply from the designer,they said the requirment is zero tolerance, no reinforcement,that really let me puzzled.

Zero tolerance is not a technical answer.
Mauro

hi
i think in code they mensioed maximum Renforcement but Not mensioned Minimun I Think Minimum is zero and it is applicable for ground flush welding

OK, not very "technical". So we can say ground flush is flat with zero tolerance, that means flat like the plate can be.
BUT:
Impossible to obtain with a grinding machine.....manually operated.......unless we can tolerate a certain uneven.
Tolerate? do we mean we accept a tolerance?
The circle is closed.
Mauro

ZERO tolerance is impossible. Flush needs to be better defined and what tools are appropriate for measurement. I'm sure we all understand the designer probably wants the weld ground as flat as the plate but as suggested, by using a manual grinding operation there may also be some base metal removed... naturally, base metal thickness has a manufacturing "tolerance" but need to go back again and get clearer definition of flush from the designer... does flush mean 0.0000000001 mm above surface? Who knows?

Hey guys, I'm new to the forum, glad to be here and looking forward to getting to know you guys.

So here we go......I've been in the welding industry for around 30 years, everything to fish cookers to pressure vessels. I hold a CWI, ASNT NDT Level III VT, and an API 510. My question is recently the company I work for sent one of their design engineers for a "PE" cert. Since he got back weird things have been going on that I don't know if right or not. Most of the pipe fittings we build are to B31.1, B31.3, B31.4, B31.8, a few to API 1104. The other day while doing a visual weld inspection there was a 12" area that was slightly concave that I rejected. The "PE" said it was OK. I said it didn't meet the requirements of the code. He informed me that as a design engineer with a "PE" that he could override me and the code. Does this sound right? I have not read B31.3 in it's entity, what does it say about this? Any info would be great.
i think you will give me some thing reason able so please share some thing to me,,

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ac repair houston

You cannot override or take exception to the Code unless he can show you where it says he can do so. Otherwise you can't certify it to those requirements.

Also, Flush is defined as being essentially even, but not below, the surface of the adjacent base material. Some codes allow you to be slightly under by whatever the undercut allowance is. I've seen a lot of customers specify what flush means, as it usually depends on service conditions, but typically is -0" to +1/16"