Limits of rework responsibilities.

[michigander]

I have a client that fabricated a tank that was subsequently post weld heat treated. The tank was built and stamped to RT-3 so spot radiographhy was performed. The tank was subsequently hydroed, PWHT'd,signed off by the AI, and shipped. The client then decided to do a 100% UT of the vessel and found some problem areas. One of the UT found problems was an area that was previouly radiographed and found to be acceptable. This could be possible as UT is better at seeing cold lap and laminations in base material. The owner now expects the fabricator to repair this and re-PWHT at his own expense.

There are two issues here. One is to satisy a client and get him to come back again, but what are the expecations from a code standpoint? My sense is, that thats what the eff. factors are for, because we typically are not always perfect. If a client can go back after the fact and do 100% UT, and/or 100% RT and then expect everything to be repaired, that is nonsense. If thats what they need, then make it part of the fabrication requirements.

My sense is, that they will have to eat these repairs to satisfy the customer, but a clear line needs to be drawn regarding future work.

As a footnote, their insurer said that, yes, everything must be fixed, but what would you expect an insurer to say?

What say you??

Best Regards,

Michigander

 

[DSB123]

Michigander,
What are you paying the AI for???

 

[TGS4]

Unfortunately, this is a commercial issue and not a Code issue. This is where your lawyer can earn their fees.

I've been involved in performing FFS evaluations for a similar situation: a tie-in piping weld was 100% radiographed, and it was OK. However, a nearby weld (15-years old) was also radiographed and had rejectable porosity. The original pipe only received a 5% RT, and this was not one of the welds RT-ed. So, what do you do - you found a problem, so you can either fix it or perform an FFS evaluation to show that it is OK.

I feel for you - getting the design and fabrication basis changed after the fact is unfortunate. As you said, the final decision is probably a business-decision more than anything.

 

[eyec]

had the customer not found problem areas that passed RT but gave UT indications I would think you could have argued the contract required RT. however this did not give the customer a warm and fuzzy feeling.

as previously mentioned about paying the AI & lawyers, oh well.

a saving grace may be a shared cost approach to keep a customer. tough call either way.

good luck

Steven C
Senior Member
ThirdPartyInspections.com

 

[vesselfab]

Can the fabricator produce x-ray films and show that they were clear and good.

if they are, his ut person should ut the areas and see what the actual ""rejectable"" welds are.

cold lap can be ground, and if small areas of touch up welding can be preheated and welded per code with owner/ai concurence.

these kind of things generally get blown out of proportion until everyone settles down and looks at the rejects or what is considered a reject and look at NDE records/film and everyone settles on a course of action.

MY TAKE....from a fabricator's perspective....I did every thing I was paid to do. But I will do what I can to help out the owner of tank, but am not willing to bear the brunt of all costs on my own.

 

[DVWE]

If the contract did not state that the vessel will be UT tested by the buyer before final acceptance then they cannot hold you accountable for it. Tough one for sure, but vesselfab makes some very good points, especially about things getting blown out of proportion.

 

[metengr]

Something is fishy here. If the client performed UT under what rationale? Did the client decide that UT should have been used in lieu of RT during fabrication? I would go back and ask the client why they wanted UT examination? More important how was the UT examination performed (procedure) and what were the acceptance criteria?

Are these rejectable welds or did the UT examination find laminations in the base metal (plate)??? If laminations were found by UT of the base plate, this is an entirely different matter. This is unfortunate because as I see it, code compliance was met if this vessel was built to ASME B&PV Code requirements

The tank was built and stamped to RT-3 so spot radiography was performed. The tank was subsequently hydroed, PWHT'd,signed off by the AI, and shipped.

. Remember, code requirements are minimum to assure long term performance and safe operation. If the client wanted UT this should have been part of the bid specification during fabrication.

I would argue these are non-injurious defects in the plate and as such do not fall under fabrication requirements of the Code.

 

[Ballbearing1]

michigander,
Not sure what code you are working to but if it is ASME VIII this might help.

UW-52 SPOT EXAMINATION OF WELDED
JOINTS

Spot radiography in accordance with these rules will not ensure
a fabrication product of predetermined quality level throughout. It
must be realized that an accepted vessel under these spot radiography
rules may still contain defects which might be disclosed on further
examination. If all radiographically disclosed weld defects must be
eliminated from a vessel, then 100% radiography must be employed.

Regards,
BB

 

[michigander]

Thanks everyone. The responses are pretty much what I expected. My client, it really is a client ) , is stuck with an unsupportive AI and an owner with unrealistic expectations.

Best Regards,

Michigander.