B13.47 Large Flange Damage 1

[viper3982]

B16.47 Question

Greetings,

My Question is 2 parts:
We have a 48" 600# RFWN 44.5" bore SA-350 flange on a unit that was built to the B31.3. The unit fell off of the semi-truck transporting it resulting in damage to the OUTSIDE of the flange. (No flange face damage, just road rash to the outer diameter of the flange)

We have taken appropriate action for all other aspects of the incident but we are deliberating on what to do about the outer diameter.

The B16.47 contains specifications for many of the dimensions of the flange. Using table I-31 Dimensions of Class 600 Series A Flanges we have measured all the dimensions of the flange. The only thing we are coming up short on is the outer diameter "O" where the flange hit. The table references section 7 for tolerances. Section 7 gives dimensional requirements for everything EXCEPT outer diameter. 7.3.1 states tolerances for dimension 'A' but not 'O' and this is for welding ends, not the actual flange outer.

The debate between all parties involved is: do we leave the damage after smoothing out a bit of the road rash, or do we run a sub-arc and build it back up.

Q1.) Are there any tolerances that would govern the damage to this flange? Is there anything specific other than a general 'best practice' on damage/scuffs?

Q2.) If we decide to perform weld buildup, do we then have to PWHT the flange? The unit was originally PWHT'ed per customer requirements.

Any other thoughts or points of concern we have not addressed?

Thank you all in advance.
r/

 

[metengr]

Based on the observed damage I would clean (machine) the OD surface and remove all grooves so that a proper surface NDT can be performed. If the surface NDT results are acceptable, you obtain all necessary final dimensions as required to ensure compliance with B31.47. I would be concerned about the remaining ligament thickness between the OD and edge of the bolt hole.

 

[metengr]

If you need to weld repair your questions concerns me regarding your welding knowledge. The requirements for welding will default to ASME Section VIII Div 1. Hire a repair organization that has a current National Board R Certificate

 

[XL83NL]

You mean B16.47 and not B13.47 or B31.47, I assume?
Point of consideration should be if there's sufficient thickness left between the flange OD and bolt hole edge, as mentioned by metengr.

 

[viper3982]

XL83NL
You are correct. That was a mistype on my part. B16.47 is the code for the flanges.

metengr
We are a R Stamp holder. We run about 50% section I and section VIII vessels and 50% B31.1/B31.3.


Followup:
There are no specifications for what I can best describe as the bolt hole to outer flange ligament.

We spoke with our customer and they want the entirety of the road rash area to be ground down to smooth bare metal and then built back up. Speaking with our CWI QC guy, our best bet for this will be for us to run a subarc on it.

I also forgot to mention the other good news in that the vessel was designed for low temp service (-50 MDMT).

 

[pdiculous963]

You could always try to run the Sec. VIII Div. 1 Appendix 2 calculations with the reduced OD. If they pass, I see no reason to perform weld build up on the flange.

 

[SnTMan]

Stuff happens. The flange is going to be around for a looooong time. Just fix it.

Regards,

Mike

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

 

[SwinnyGG]

We spoke with our customer and they want the entirety of the road rash area to be ground down to smooth bare metal and then built back up. Speaking with our CWI QC guy, our best bet for this will be for us to run a subarc on it.

Sounds to me like the decision maker has spoken

 

[metengr]

Yes indeed and a wise choice given what I observed.

 

[LittleInch]

Although the client has spoken, I've always thought that the outer bit of the flange was very lowly stressed and you could do more or less what you wanted with it.

Provided that the nut hits the flange ( was that your red line on the photo?), then anything in excess of that is just not really needed. IMHO.

Adding heat into one bit of the flange would seem to me to add more issues than just dressing it up.

It would make an interesting question to the ASME committee for future reference, i.e. what is the tolerance on dimension "O"??

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[DekDee]

Have now spent 2 full beers studying the photo and trying to work out how you get gouges at 90 degrees to each other from falling off a truck ?
That truck must have been moving !