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How to Rectify defects in new Heat Exchanger at Manufacturer Site? 1

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Raza Rauf

Mechanical
Apr 4, 2020
9
Dear Reader,

Presently, we have identified defects in final fabricated heat exchanger. Please guide by mentioning the repair strategy of defect with exact reference of ASME Code / TEMA Code reference.

1. Few tubes ends are fused. (5mm Tubes are extended from tubesheet)
2. Pitting observed on 90 degree mitered elbow surface above this vertical heat exchanger. Is weld buildup and grinding right method to rectify? please confirm code reference.
3. 3mm Deformation of 90 degree mitered elbow surface near weld joint. How much deformation is acceptable? any code reference?
4. Misalignment between butt joint of tubesheet and shell? Any acceptable range? code reference?
5. Dimensions out of TEMA tolerances.

Please share repair method with code reference.
 
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Rizzo,

You claim that: Please guide by mentioning the repair strategy of defect with exact reference of ASME Code

Neither the ASME BPVC Code nor TEMA standards contains any "repair strategy" ....

Experience, workmanship inspection and defect management should have been part of your purchase contract requirements.

You have a mess ..... What were the requirements of your contract ?

Please post pictures of the exact defect

MJCronin
Sr. Process Engineer
 
Design code was ASME SEC VIII Div.1 and TEMA class B.

Workmanship and manufacturer due diligence was done but all this happened.

At least you can mention the reference of code of requirements to verify if it's in acceptable range or not. As repair / way forward is possible in your experience.

Can you share your contact details to share pictures? As due to organization privacy cannot be shared in public.
 
Raza Rauf, a lot is going to depend on whether the vessel has been stamped, the jurisdiction and contract requirements.

Ref 1) I don't understand the situation
2) This would more likely be a repair under NBIC, but it depends on the jurisdiction.
3) & 4) are likely addressed by Part UW, specifically UW-13 & UW-33
5) Most likely addressed by agreement among the parties

Due diligence huh? What a mess, best of luck.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand
 
Ratso ....

No .... You do your assigned job .... Don't demand that strangers on the internet do it for you !

You are DEMANDING answers to your questions ?????

You are "bargaining with me" to get equipment defect pictures ? ....... BWHAHAHAHA !!!

In the words f SnTMan, "What a mess"

MJCronin
Sr. Process Engineer
 
Dear MJ Cronin,

Apologies if you felt like this way. I'll share pictures soon. I am not demanding. I am just asking help from experts like you.

Dear SnTMan,

Yes, it's U stamp job.

For 1) the extended tube ends from tubesheet are fused. Probably, fused due high current at the time of welding.


 
Raza,

"Workmanship and manufacturer due diligence was done but all this happened".

On what basis you claim, good workmanship was done if this is a brand new HX.
Which side of the table do you sit?

Design/construction codes won't give you repair strategy. Try ASME PCC-2.

GDD
Canada
 
In general this is how things work:

[ol 1]
[li]The PO gives all the technical requirements. It is vital that everyone understand what is contained therein.[/li]
[li]Technical requirements means: Code requirements plus owner's requirements over and above Code and beside the Code.[/li]
[li]Technical requirements must be measurable (by QC), and all results included in the history docket.[/li]
[li]Deficiencies should be address by repairs (with or without NVRs), and Corrective Actions if warranted.[/li]
[li]If the previous is not satisfied then the issue is escalated to higher management and possibly lawyers (not the interweb).[/li]
[/ol]

Deficiencies are addressed as they are discovered as the constructor progresses through the ITP, not as the equipment is being loaded for transport.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."
 
Raza Rauf, yes but has it been stamped?

The problem with sloppy work is that the supply FAR EXCEEDS the demand
 
** NCRs not NVRs **

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."
 
Who has selected this manufacturer?
Where was the inspector during manufacturing?
Is this an experienced manufacturer?
I think this manufacturer was selected for a low price?

Regards
 
If the exchanger parts are out of tolerances of ASME Code / TEMA Code reference construction, reject the equipment and consult a qualified constructor.

luis
 

"Rectify a Failed Design"

Not possible, you must start over.
 
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