Nondestructive testing of penetration welds 1

[ARKeng]

I need some help in determining if certain welds require nondestructive testing. Typically, our project notes have always said "all complete joint penetration welds require nondestructive testing".

In my situation, it's been discovered it wasn't provided, but the welds are now well covered up so I'm trying to determine if they're necessary. The few instances I have are non-seismic -- they're basically for rigid connections of cantilevers to the supporting beam. The IBC '03 just requires continuous visual inspection + requirements of AWS D1.1-00. My AWS is the '98 version but gives no guidance as to when NDT is required, just how to do it.

Does anyone have the AWS D1.1-00? Does it give any better guidance? If not, does anyone no if there are any REQUIREMENTS? Any recommmendations?

Thanks.

 

[metengr]

ARKeng;
Your statements;

Typically, our project notes have always said "all complete joint penetration welds require nondestructive testing".

In my situation, it's been discovered it wasn't provided, but the welds are now well covered up so I'm trying to determine if they're necessary.

Based on your first statement, followed by your second statement, you indeed have a nonconformance, and it could be a serious one at that because the project notes were not followed.

So, without knowing your specific application and your involvement with this project, I would attempt to uncover one or more of these weld joints (a random percentage) and have a volumetric NDT performed to decide on how you want to disposition the welds that should have been subjected to NDT.

If you can't locate the weld joints, you will need to justify having no NDT by some type of engineering analysis that evaluates worst case flaws and their impact on load carrying capacity.

 

[henri2]

Like the 98 version, D1.1-00 only provides procedure.

The only code related reference I know of that stipulates NDT(and it does not specify frequency of testing)) for CJP welds is AISC 341 Sec 16(2) which is triggered by IBC-03 Sec 2205.2. Based on your explanation, it does not seem that this provision will apply in your case. Nevertheless, it is prudent to adhere to your standard practice, which requires NDT for CJP groove welds.

 

[ARKeng]

Thanks guys.

Metengr, you're absolutely right that this is a non-conformance item. We're trying to determine how much we're going to let them "off the hook" if at all. I first wanted to determine if it was required by code -- in which case there'd be no doubt we'd make access them and test them all.

In the absence of an absolute code requirement and given a static loading, I think we're a little more accepting of the situation. Also, our "typical" notes are probably the way they are because 90% of the CJP welds we do are normally for seismic moment frames where I wouldn't even consider waiving the requirement. Thanks for your help and we'll keep pondering the situation.

 

[gtaw]

If you have access to one side of the welded joint, you might want to consider ultrasonic examination.

You stated that you typically require all CJP welds to be nondestructively examined.

That in itself is not adequate. Visual inspection as well as penetrant and magnetic particle testing are all considered to be nondestructive tests. As such, the NDT requirement is fulfilled if one of them was employed.

You need to specify volumetric examination if you want ultrasonic or radiographic examination. While your are at it, you should specify the minimum level of certification of the individual(s) performing the NDT. I would recommend ASNT ACCP certification as a Level III or Professional Level III to assure third party involvement in the certification process.

Best regards - Al

 

[gtaw]

Opps, correct the levels of certification to ASNT ACCP Level II or Professional Level III.

The ACCP examinations are administered by facilities approved by the American Society of Nondestructive Testing and includes the written examination and hands-on practical examinations.

You should also review the NDT contractor's Written Practice. That document delineates how the contractor qualifies and certifies their NDT personnel.

SNT-TC-1 is a recommended practice for the qualification and certification of NDT personnel. The contractor has the ability to change the requirements to suit their needs. What is recommended by SNT-TC-1A is just that, recommendations only.

CP-189 is a standard for the qualification and certification of NDT pesonnel. The requirements are the minimum that have to be met. The requirements for the instructors providing the training are stipulated and the Level III(s) administering the program must hold the appropriate ASNT certification.

You only get what you ask for, so it is in your best interest to ask for the right credentials.

Best regards - Al

 

[henri2]

Great points GTAW..particularly the one regarding ASNT ACCP certification. IMO centralized certification is preferable to a company cert based on ASNT SNT-TC-1A

I never knew that VT was considered one of the NDT methods until I attended an AWS seminar.

 

[csd72]

You mentioned they were cantilevers - can they be load tested by hanging a known weight from the end giving equivalent service load moment?