Weld repairs to A105 Flange

[timmckee]

Steam leaks on pipe flanges is a common problem at our facility. Often the leaks can only be addressed during an annual maintenance outage. Usually by that time the flange face has been "cut" by the steam.

We have repaired these defects by mechanical removal (grinding, PT the excavation, fill the excavation with weld (SMAW 7018, 300 degree preheat in lieu of PWHT), machine the face to the proper finish (125rms), then PT the face again.

We use jurisdiction approved weld procedures and qualified welders.

Anyone see any problems or deficiencies with this method?

Is the 300 degree preheat necessary? (Sec II states weld repairs are permitted but PWHT is necessary. NBIC allows for 300 deg preheat in lieu of PWHT)

Thanks for your help.

 

[metengr]

No problem. Yes, the elevated preheat is required and NBIC Method 1 is a correct application.