Half Bead Weld Technique 1

[4fletch]

Can anyone help me locate a standard or specification for employing the half bead weld technique? Am considering using this or butter/temper bead to fillet weld shear lugs on a 2.25% chrome piping system in lieu of PWHT.

 

[Carburize]

I believe that the half bead technique is covered under ASME Boiler and Pressure Vessel Code - Code Case N-638

 

[GRoberts]

It is also covered in ASME B&PV code Section III

 

[GRoberts]

The "Welding Journal" November 1989 also contains an article called "Sensitivity Analysis of Half-Bead and Alternative GTAW Techniquies" by P.J. Alberry, subtitled "A six layer technique for repair welding nuclear reactors shows a tolerance to welding variables"

 

[4fletch]

Thank you, Gentlemen. I have some EPRI materials on the way in addition to your helpful suggestions.

 

[pipewelder1999]

It looks like you have the info you need but I thought I would add this.

I have done repairs on cracked steam drum ligaments using this technique. The National Board Inspection Code mentions this technique as an alternative to postweld heat treatment.

The preheat an interpass temperatures are very closely controlled and heat input is also critical.

There is some information at:

http://www.iamot.org/paperarchive/131B.PDF

I actually welded the PQR which consisted of a 2-1/2" vee groove on backing. The interetsing thing to note about this was that when I was done, the angular distortion on the plate was probably les than 3 degrees. No strongbacks or clamps were used. The grinding and waiting for the correct interpass temp made things pretty slow.

Good day

Gerald Austin
Iuka, Mississippi

http://www.weldinginspectionsvcs.com