Tolerances on what?  

What code are you operating to?

Hg

Eng-Tips policies:  FAQ731-376

We are fabricating .5 inch astm a-53 b steel pipe (maximum 50PSI.)  Applicable code either aws d1.1 or asme section 9.  Customer doesn't want us to use GMAW-S unless we can pass UT testing; we were off by .001 inch and failed; is there any tolerance?

You're talking about underfill of a CJP weld?

Hg

Eng-Tips policies:  FAQ731-376

Yes.

Section IX (9) of the ASME Boiler and Pressure Vessel Code is not a construction code, it is a Guideline for qualification of welding procedures and welders (brazing procedure and brazers), so you won't find any specific guidance there for construction tolerances.

Quote:

Customer doesn't want us to use GMAW-S unless we can pass UT testing; we were off by .001 inch and failed; is there any tolerance?

Go back and ask the customer what the specifications are for this project, including acceptance criteria. Your last sentence makes no sense.

D1.1 doesn't really address underfill in groove welds very well, although Fig. 5.4(E) implies it isn't allowed.  There is an allowance for undergrinding by 1/32" on welds required to be finished flush.

But I don't understand why underfill would be a process-specific problem.

Hg

Eng-Tips policies:  FAQ731-376

Underfill would not be a process related discontinuity.

What is the application? AWS D1.1 is not be used for pressurized piping systems. I believe D1.1 states that the groove welds shall be made with minimum reinforcement, implying they have to be filled to their full cross section.

Best regards - Al

None of this makes any sense.  If they get underfill with GMAW, there's no reason they wouldn't get underfill with any other process.  And GTAW is right; D1.1 does not apply to pressurized piping systems.

Hg

Eng-Tips policies:  FAQ731-376

Maureen,
I was wondering if you got your answer elsewhere?

The person doing the UT had to use a standard / Code to know what the acceptable discontinuities are for your work. ( I hope )
Generally, your description would be covered under ASME B31.3 for Process Piping. (Another may be designated in your contract)
You should be able to find the Acceptance criteria listed there.
(1/1000th over the allowable discontinuity permissable, may be considerable)

Tom