Random X-Ray and B31.3 compliance. 1

[k3_at_ke]

Scenario: Taking a subset of welds, hydrotesting them, placing them in service, and then later conducting x-ray examination of a predetermined weld. Is this practice code-compliant according to ASME B31.3?We are the owner-operator and are considering four spools for four different pieces of equipment in our facility. Each spool has five welds. To meet the 5% normal service requirement, we take one of the 20 welds and X-Ray it. However, is it code-compliant if we predetermine that we will X-Ray, say, weld number 17 out of 20, then have the welder weld and complete three of the four jobs—thus 15 welds—and without his knowledge, as he is working on the final spool for the final job (welds 16-20), can we hydrotest the completed three spools and put them in service? Once the last spool is completed, can we take an X-ray of the predetermined weld 17 and still be code-compliant?

 

[XL83NL]

The Owner has overall responsibility. Refer to 300(b)(1).

This is basically if an Owner is allowed to deviate from basic Code requirements. That's a tough one. I think the answer might be no (as per the first sentences of 345.1, where the hydro is required after examination - thus after welding), but I like to hear other's opinions as well, as I have no experience from an Owner's perspective in answering this question.

Also look for similar topics, although I haven't yet found an exact question as yours.

Huub
- You never get what you expect, you only get what you inspect.

 

[david339933]

Standard Designation:

B31.3

Edition/Addenda:

ASME B31.3 - 2012

Para./Fig./Table No:

M341/341 & M345/345

Subject Description:

Examination and Testing: VT/PT/MT & RT/UT vs Leak Testing & Pressure Testing

Date Issued:

09/25/2014

Record Number:

14-1401

Interpretation Number :

Question(s) and Reply(ies):

Question (1): Are the leak tests required in para. 345.1 independent from the examinations required in para. 341.4.1?

Reply (1): Yes.

Question (2): In accordance with para. 345.1 are the applicable examinations required by para. 341 to be performed prior to leak testing?

Reply (2): Yes.

Question (3): Are sensitive leak tests required along with pressure tests for category M piping?

Reply (3): We believe your question can be answered by previous interpretation 20-47, a copy of which is attached.

Question (4): Are the examination and testing requirements the same for new piping welds as well as replacement piping welds and repairs to welds such as repairing a buttweld or socket weld with a pinhole, crack, or other defect?

Reply (4): We believe your question can be answered by previous interpretation 19-49, a copy of which is attached.

 

[DekDee]

Yes, you are code compliant but I think you are missing the whole point of random radiography.

Random radiography is performed to enable the Employer(Be that Contractor or Client)to ascertain the welder or welders capability.
It is standard industry practice to do that as early as possible to ensure any issues with a welder or welders capabilities are identified ASAP.
You are taking a risk but as the Owner / Operator you are perfectly entitled to take that risk.
However, when it comes to hydro I agree with XL83NL - you are not complying with 345.1.
Until the 5% examination is completed you cannot hydro.
Cheers,
Shane

 

[EdStainless]

So the four spools are nearly identical?
Same materials, process, and so on?
If not, then they are separate jobs and cannot be lumped together for examination.
If you want to be picky about it.
But as stated, the Owner has a lot of latitude.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[k3_at_ke]

It seems a bit gray to me even with the interpretations. The RT is applicable to weld 17. Spool number 4 with the remaining 5 welds is to be x-rayed and then hydrotested with out a doubt in my mind. However I know spools 1-3 do not have any applicable examinations pending. So I was thinking I could hydrotest them and technically put them in service with the risk a progressive sampling nightmare. However I was operating under the belief I was still code compliant. I can make a case for both sides just not one that's stronger than the other.

 

[GBTorpenhow]

Doesn's seem gray to me at all. "are the applicable examinations required by para. 341 to be performed prior to leak testing?" "yes."

The RT is applicable to weld 17.

The 5% random RT requirement is applicable to the 'designated lot', not just the weld that happens to be the one randomly selected. In other words, until the NDE is performed to the required percentage for the whole designated lot, the lot has not been examined as required to proceed with leak testing.

Preselecting the weld to be examined also does not meet the 'random' requirement IMO, even if the welder is not informed beforehand which weld is to be tested.

If you are interested in putting the spools into service as they are completed, each spool can be a designated lot. When a spool is finished, RT one weld picked at random per spool then leak test.

"designated lot: a defined group of welded, brazed, fused, or
bonded piping joints from which a specified percentage is
randomly selected for examination."

 

[david339933]

All spools should be completed prior to NDE, for 1 shot.....otherwise there is no chance the unfinished spools will be chosen. Not very random.