Flange Serration Face Damage 1

[Quality2479]

Hi,

Good Day!!!!

Design Code - ASME B31.3

Flange Dimensional Code - ASME B16.5

We have a WNRF Flange of Dia 20" of which the serration face is damaged (Approximately 3mm Depth and Length 60mm) due to the improper handling.

Can any one recommend me the correct procedure to rectify the damage and whether the code ASME B16.5/ASME B31.3 is permitting for such repairs or rejecting the flange is the only solution for this kind of cases.

Thanks in advance for your technical input.

 

[LittleInch]

Look at 16.5 flange face sections carefully.

Depth of allowable defects, especially axial ones are very small. 3mm deep sounds way too deep to me.

Normally you need to weld repair overlay and then re-mill to get the face acceptable.

If it wasn't my fault I would just send it back and get another one. The amount of time and effort you will spend getting it repaired is likely to be higher than the difference....

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[DSB123]

get whoever improperly handled it to provide you with a new one!

 

[moltenmetal]

Umm, assuming it's already welded to a piece of pipe, which is why the question is being asked. If it's new, send it back! If it's on a pipe, weld repair followed by in-place re-facing is what needs to be done. 3mm is too much to expect a gasket to handle.

 

[LittleInch]

It's table 3 of B 16.5 you need.

This only allows a 6mm long and / or deep imperfection deeper than the serrations.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[XL83NL]

During last year's ASME PVP conference in Paris, Warren Brown presented several interesting papers on, amongst others, BFJ's (Bolted Flange Joints)
In one of his papers he covered some nice 'shortcomings' of ASME B16.5 (& B16.47) flanges.
The paper is called "Dissecting the Dinosaur; Problems With B16.5 and B16.47 Flange Standards".

In the paper, he also covered the allowable flange face defects B16.5 handles, para 6.4.6. The paper reads the following to that remark;

The thing to keep in mind with this is that this is a specification for NEW flanges. It is hard to imagine why new flanges with a 0.25 inch deep defect in the flange surface finish which goes across a quarter of the gasket seating surface should be considered acceptable. It is obvious that from a sealing perspective, a radial flaw extending half or quarter of the way across the gasket seating surface will be detrimental to the joint integrity. The only explanation for the level of imperfections tolerated by B16.5 is to sanction poor fabrication and handling practices. It is recommended that the limits outlined in ASME PCC-1-2010 Appendix D be used in lieu of the limits presently outlined in ASME B16.5. End user specifications for flanges should be written such that the limits outlined in ASME PCC-1-2010 Appendix D for hard gaskets replace the requirements of B16.5 Section 6.4.6.

You might want to get a copy of that paper, to read the whole section on this subject, and see how interesting it is what still may be incorrect in B16.5.
If BFJ has your interest, there's more interesting work from Warren you might want to grab.