TPI Valid?

Date 05-15-2013 14:12

We fabricated a 14" diameter round section from 10mm plate for a customer. There was no requirement for RT on the longitudinal butt weld to be carried out in shop.
After our customer completed the site circumferential welding on the round section, third party was on site to perform RT on the circumferential weld.
As our longitudinal weld is right next to the circumferential weld, unfortunately a small line showed up on the RT film. This was intrepreted as lack of fusion on our longitudinal butt weld by the third party.

We are not denying there is a defect based on the RT report but what we would like to know from those with similar experiences are:
1. The scope of RT report from third party can include those welds that are "nearby" when their main task was on the site weld?
2. How much liability do we have now that customer is claiming rework?

Regards
Boon

By TimGary (****)

Date 05-15-2013 14:23

If your contract with your customer states that the work is to performed within the requirements of a specific code, then you are responsible for producing code compliant product.
The fact that there was no requirement for RT on the longitudinal butt weld to be carried out in shop, is a moot point.

Tim

By 803056

Date 05-15-2013 16:35

You didn't cite a specific welding code, but D1.1 provides a remedy if that is the applicable code. You may wish to dig into the code that applies to your job to see if it has similar provisions.

AWS D1.1-2010 Clause 6.6.5 Nonspecified NDT Other than Visual. If NDT other than visual inspection is not specified in the original contract agreement but is subsequently requested by the Owner, the Contractor shall perform any requested testing or shall allow any testing to be performed in conformance with 6.14. The Owner shall be responsible for all associated costs including handling, surface preparation, NDT, and repair of discontinuities other than those described in 6.9, whichever is applicable, at rates mutually agreeable between the Owner and Contractor. However, if such testing should disclose an attempt to defraud or gross nonconformance to this code, repair work shall be done at the Contractor's expense.

The question arises, "Who requested RT?"

Did the TPI do it on his own without the Owner's authorization? If so, bill the TPI for all the work associated with completing the repair.

Did the Owner decide after the job started to initiate RT? If it isn't specified on the drawing or the project specifications, then clause 6.6.5 applies.

If the RT is specified by the drawing or the project specification your employer will have to swallow the cost of the repair.

I assume there was no intent to defraud the Owner, so any "defect" discovered does have to be repaired, but the Owner must pay for the associated costs as per clause 6.6.5.

Best regards -Al

By Boon

Date 05-16-2013 05:17

Thank you for your comments.
Our customer did not specify welding code and we fabricate based on our WPS and welder qualifications according to ASME code.
Not sure if there is similar clause in ASME as the AWS 6.6.5

The RT was requested by customer for the field weld.
We did not perform field welding, not our scope.

We have no intent to default and would work out the repair with customer.

Our thought is how to prevent such defects in weld occurring again.
Welders to go for more training (they are qualified 6G welders and performing almost daily) and/or regular tests?

By CWI555

Date 05-17-2013 10:12

Section IX of ASME code covers welder quals, WPS qualification etc. It is considered a dependent code as does cover any particular form of fabrication independent from a referencing code. The referencing code (B31.1, B31.3, Section I, Section III, Section VIII, etc) drives the requirements for quality, not Section IX.
More often than not, the referencing code will invoke a component/materials standard such as an ASTM, NFPA, API, ASME Section II, etc for a given component to be manufactured by.

Your welders may in fact be qualified through Section IX, but what was the referencing code?

By Shane Feder (****)

Date 05-18-2013 01:10

Boon,
First thing - if no code/standard was referenced for fabrication how can you have a "defect" ?
A "Defect" is a discontinuity that doesn't comply with the referenced code/standard.

I agree 100% with Al's response based on whose responsibility it is for any repairs.

Tim,
It is a common misconception that if fabricating to a specific code all welds must comply with that code.
It is our aim as manufacturers to try and produce 100% code-compliant welds all the time but in reality it doesn't always happen.
If you want 100% code compliance you will have to pay for 100% NDT with all the associated time and costs involved.
If you have determined that you can live with a piping system with some defects or discontinuities you will nominate 5% random inspection - obviously less time and money involved from the fabricators perspective.
Walt Sperko has an excellent paper on this on his website.

This is an excerpt from B31.3

Random or spot examination will not ensure a fabrication product
of a prescribed quality level throughout. Items not examined
in a lot of piping represented by such examination may contain
defects which further examination could disclose. Specifically, if
all radiographically disclosable weld defects must be eliminated
from a lot of piping, 100% radiographic examination must be
specified.

As you can see, as an Owner/Client you get what you pay for - in Boons case if no RT was required on the longitudinal weld then the owner/client did not require a 100% defect free item.

Regards,
Shane

By Joey

Date 05-22-2013 09:19

Boon

Boon you sounds like you are from Spore?

How can you quote a job without a contract specification?

Are you sure that there is no construction code stated by client?

~Joey~