Damaged Flange

[MetalsInc]

Ok, I hate to ask a question like this with so little detail.... but I have to as it is bugging me.

Imagine a ~4"OD flange coming off a PV. Flange is about 18" long. It has been bent out of alignment.

No PV welders are available. It needs to be put back into alignment. Solutions?

PS- feel free to make any assumptions you want - that's all the info I have.

 

[metengr]

Very sketchy details indeed. My first inclination is to attempt to straighten the 4” nozzle by local application of heat with controlled force. I have seen this done with carbon and low alloy steel materials. This approach requires material expertise to determine optimum temperatures and location of heat along with post straightening NDT and hardness testing.

 

[ApC2Kp]

To MetalsInc,
The 4" OD flange tells me it is a small nozzle only NPS 0.5 to 1" which is flexible and prone to damage in shipment. Length of 18" is 3 times more than typical and even more likely to be bent during handling vessel.
If the amount of mis-alignment is small, then metengr's recommendation could be done. If the mis-alignment is very small (less than 1" ?) then a straightening without heating (especially for austenitic SS)might be acceptable with followup exam and testing.
This assumes that most deformation occurred in the nozzle neck. If most of deformation occurred at the shell wall then weld attachment may have significant damage if the mis-alignment is large (? greater than 3" = 9 deg. out)

 

[MJCronin]

Metals...

Is this an ASME coded vessel ?

This type of modification will require the services of a contractor with a National Board "repair" stamp.

Any possiblity the nozzle could be cut and shortened ?

(I agree that 18 inches is a very long nozzle neck)

-MJC

 

[DavidCR]

I would try to "work" on the neck and try to avoid touching as possible the neck-vessel and neck-flange juntions.