Weld build-up/repair of structural steel flange

Date 09-11-2021 07:22

Happy weekend to all,

Came across a case recently when it was told that “ weld repair of flange is not allow” but the flange in question is purely for the purpose of structural connection between sections not mainly for shearing load with no pressure retaining or sealing purpose.

Weld build-up is common to restore pressure vessel base metal with qualified procedure and for flanges of pressure piping there may be concerns about weld repair of flange sealing surfaces making the weld repair not allowed. But this is a structural flange in question.

Nobody is telling why and the only reason is the spec. says so. It is doubted that some wording of technical requirement is indiscriminately quoted across different industries merely because something such as “flange” is sharing a same term or name.

Can anyone on the forum share any deeper insights specifically in the expertise of structural design, fabrication practices, and/or experiences for the specific topic?

Cheers,
JZ

By 803056

Date 09-15-2021 17:23

This is what the current edition of D1.1 has to say:

7.21.4.2 Correction. Root openings greater than those allowed in 7.21 .4.1 , but not greater than twice the thickness
of the thinner part or 3/4 in [20 mm] , whichever is less, may be corrected by welding to acceptable dimensions prior to
joining the parts by welding.
7.21.4.3 Engineer’s Approval. Root openings greater than allowed by 7.21 .4.2 may be corrected by welding only
with the approval of the Engineer.
7.21.5 Gouged Grooves. Grooves

I hope this helps.

Al

By Jovi Zhu (**)

Date 09-18-2021 02:14

Thanks Al and hope all is well~

The D1.1 wording you quoted did support the judgement that weld build-up of material to achieve required dimension is allowed under certain conditions and with approved procedures.

The key dispute of my case is the "flange" with a ring shape used for structural purpose which may not be the common materials such as I-beams, channels and plates for most steel stucture covered by industry standard of authority so people tend to indiscriminately apply requirements of other industries which may not be applicable to the speicifc service.

By 803056

Date 09-19-2021 17:23

I think we would need a lot more information before going out on the limb to say what would and what would not be an acceptable practice.

What is the application, the code, the circumstances, the material, etc.? These are but a few of the variables that would have to be considered.

That's why the engineer gets paid the big bucks.

Al

By Jovi Zhu (**)

Date 09-20-2021 11:11

Hi, Al,
It is shop fabrication of wind tower sections with carbon steel forged ring flanges and rolled plates.

Customers tend to quote existing codes such as D1.1 and other equivalent standards but none of these are specifically developed for the wind towers.

There is no code committee’s involvement like AWS or ASME so most technical issues are within the negotiation between buyer and seller. When there is dispute, it has to be solved in one way or another case by case.

By 803056

Date 09-21-2021 18:53

When the code doesn't address a subject, it usually defaults to the Engineer representing the Owner.

I would think it would by up to the fabricator to make a case and present it to the Engineer for review and approval.

Al

By Jovi Zhu (**)

Date 09-23-2021 16:41

Al, That was exactly the story but not an easy one.

In contrast for the very similar weld build-up I experienced in pressure part fabrication such as under ASME Section I, this has been very routine.

As stated in PG-78 of ASME Section I and UG-78 of VIII-1:

PG-78 REPAIRS OF DEFECTS IN MATERIALS

Defects in material may be repaired by the boiler Manufacturer
provided acceptance by the Inspector is first obtained
for the method and extent of repairs. Material that
cannot be satisfactorily repaired shall be rejected.

UG-78 REPAIR OF DEFECTS IN MATERIALS

Defects in material may be repaired, provided acceptance
by the Inspector is first obtained for the method
and extent of repairs. Defective material that cannot be
satisfactorily repaired shall be rejected.