Incorrect Nozzle Placement

[Ballbearing1]

Hello guys,
We have just had a 316 s/s tank delivered to site from overseas and they have cut the hole in the shell plate (8 mm thick)for a nozzle in the wrong place. They have rewelded the piece back in and it looks terrible.
If the NDT requirements were only for spot radiography would this "patch" require any NDT based on API 650.
Thanks and regards,
BB

 

[Bonswa]

First off...
Are you sure it's built to API-650?
I would think that if it's built and shipped to you, it was probably built to API-12F.

IF it were me... If it looks THAT bad, I'm not sure what you're role is on this job, but the authorized inspector and the owner/user have every right to visually reject the area and request 100% RT or UT shear wave on that small insert plate. This would be your best option.

OR...

If you're going to perform a hydrotest, once the tank arrives, you could just PT the weld and see if it holds up during the hydrotest.

Personally, while it's not in service yet, and it's such a small area, I would have the insert 100% X-rayed.

 

[Ballbearing1]

Bonswa,
Thank you for the response.
It is definitely built to API 650 and I am a CWI on a multi billion dollar Nickel Refinery project.
I was just wondering if there was a code requirement for NDT, cutting a hole in the wrong place is not something that is generally dealt with in the project specifications.
This is something that could turn into a political bunfight because this tank was signed off by our third party inspector and there was no NCR raised (in fact there is not even a mention of it in the Production Data Book)
Regards,
BB

 

[Bonswa]

OK, if that's what you're getting at then here's my thoughts:

It is a production weld. A tank with a shell that thin (8mm), requires very minimal RT as it is. Check out API-650, Figure 8-1. There isnt much at all required.

I guess my questions are the following:
What's the diameter of the tank?
Was it built to Appendix S (Stainless Steel)?
Was it built to Appendix A (field assembled small tanks)?
Was it built to Appendix J (shop built tanks less than 6m diameter)?
What is the joint efficiency? 0.85?

This is why i ask... If this tank was built to Appendix S, A, or J, and spot radiography is required, then it sends you to the following:

A.5.3 When radiographic inspection is required (joint efficiency = 0.85), the spot radiographs of vertical joints shall conform to 8.1.2.2, Item a only, excluding the 10 mm (3/8 in.) shell-thickness limitation in Item a and excluding the additional random spot radiograph required by Item a. The spot radiographs of horizontal joints shall conform to 8.1.2.3.

Basically, your additional random RT would not be required. Since it's a circle butt weld, you dont have any vertical or horizontal joints. If you translate it that way, then you wouldn't be required to RT.

What i was saying in my first post would be a good practice. If this would have happened to a tank built in the field, and i was the QC, i would have them X-ray the insert as if it were one that was done post commissioning in accordance with API-653. In your case though, when it comes to liabilities and technicalities, i would think that they're in the clear, and that no NDE is specifically required.

Let me know what happens with this. This would be good to know.

 

[Ballbearing1]

Cheers Bonswa,
Will put in an NCR and let the Engineering Department sort it out,
Regards,
BB