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Up Topic Welding Industry / General Welding Discussion / NDE limitations
- - By Kugan Date 01-06-2017 02:55
Hi all,

I am new to this forum. I am facing some challenge in terms of UT where the drawing requirement is 100% UT on a particular CAT 1 joint type. Design of the structure dose not have sufficient scanning area for any UT coverage. RT is also not possible. Need you advise on what is the next move forward which is in accordance to AWS requirement. Meaning that, If UT and RT is not possible, can we just proceed with 100% MPI and is this stated somewhere in AWS? Thanks in advance your answers.
Parent - By 803056 (*****) Date 01-06-2017 03:42
The response is dependent on your position and responsibility.

As the inspector, you can only state your concerns to the Engineer. You have not authority to change the project or code requirements.

As the Engineer, the code authorizes the Engineer to modify, eliminate, or add to the code requirements. The Engineer can also develop or approve alternative criteria and methods of inspection.

While an standard angle beam interrogation may not be possible with a standard size transducer, a smaller transducer may work or a straight beam transducer could be used with the realization it may not detect planar defects that are not oriented perpendicular to the sound. With that in mind, some information is better than no information.

This sounds like a job where a qualified ASNT ACCP Level III could be very helpful.

Best regards - Al
Parent - - By yojimbo (***) Date 01-06-2017 16:22
Kugan,

Check the relevant section of the code you're working to but keep in mind, per D1.1, inspection requirements need to be specified in the contract documents, and changes to those specifications after contract execution are the cost and responsibility of the owner, not the contractor/manufacturer.
Parent - - By Kugan Date 01-09-2017 05:43
Hi,

Thanks for your responses. The challenge now is that the order is already being provided to the contractor, which I am. After getting the scan plan out, 100% UT is not achievable. We have already propose an alternate NDE method which is MPI but the client refused to since the design was approved by the end user. This is why I am looking for way around this. There is one way around this by adding a pup piece but this involves cost and the clients is refusing to absorb this additional cost.

In situations like this, I am trying to find if there is any clause in ADW D1.1 that says if 100% UT and RT is not achievable, MPI will be the next method to move forward.
Parent - By yojimbo (***) Date 01-09-2017 16:17
Kugan,

Constructability is the responsibility of those that prepared the contract documents.  Inspection requirements are a part and function of constructability.  The code is clear regarding the responsibility for determining inspection requirements and post contract changes to the inspection requirements. Your client is avoiding their responsibility.

Same old story.  Everybody wants to go to heaven, nobody wants to die.

Best of luck.
Parent - By welderbrent (*****) Date 01-09-2017 22:16
If parts were under 5/16" thick then 100% UT would be a matter of what was within code requirements.

If Parts were too short and the UT transducer could not get the proper 'stroke' then it is not going to get done with the code compliant wedge and would need an alternate method.

For most applications, once quality has been confirmed the percentage rate can be dropped per code. 

As stated previously, it is their responsibility to specify and/or allow any method that will work since they are insisting on 100%. 

Changes to the contract and not providing the guidance per all the approved contract documents makes any changes their financial responsibility. 

THEY don't have a leg to stand on if I am understanding all the conditions correctly.

He Is In Control, Have a Great Day,  Brent
Parent - By engineer1984 (*) Date 01-09-2017 23:06
I just want to understand:

The end user wants 100% UT requirement

The OEM drew drawings to reflect this requirement

The subvendor (you) is not able to meet the requirement due to the current design given to you by the OEM?

If so, then the responsibility would fall on the OEM.  I work for an OEM.  This would be our mistake and our vendor (you, in this case) would not pay for our mistake.  Interesting that you are having a problem talking with the OEM.  I hope it's just the OEM Project Manager or Sourcing team being difficult.  I hope the OEM technical team would be open to a discussion on how to fix the problem. 

Our vendors have a way of creating a non conformance in our system.  They fill this out with a description of the problem.  If the problem is our fault (dwg, etc) then we pay the bill for fixing it.
Up Topic Welding Industry / General Welding Discussion / NDE limitations

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