ASME IX & III

Date 06-01-2005 15:41

This sounds as though it might be the same issue you had here:

http://www.aws.org/cgi-bin/mwf/topic_show.pl?id=7062#32612

My interpretation would be yes. However, I would suggest running all the details by your AI in a phone call and getting his/her consent before making the decision.

I think buttering is allowed within the thickness limits established by the PQR. The bi-metallic joint issue should not impact this application since you are using a qualified (butt) WPS with the filler metal that was used in the PQR.

Good drill to run through. I wish I had more time to get to the bottom of it. Let us know how it turns out.

Charles

By welder5354 (**)

Date 06-01-2005 16:39

Buttering will be seperate WPS & PQR.
We just did the same thing at a refinery last fall. The Inspector wanted a seperate WPS & PQR for buttering. We had to change several 30" elbows that were cladded and the existing pipe was also cladded. After completion of the butt, we had to do buttering over the groove weld to match both the elbow and pipe.
There was a seperate WPS for the butt joint, that was also F43.
Sounds like similar jobs.

By chall

Date 06-01-2005 16:52

What you describe is either hardfacing or the application of corrosion resistant overlay. Both of those are considered "special processes" and do require separate qualification.

Buttering is the restoration of base metal thickness, or build up to restore dimensional thickness. It may be performed using a groove welding procedure.

Charles

By Bill Mc (**)

Date 06-01-2005 17:27

ASME Sect IX defines "Buttering" as: "The addition of material, by welding, on one or more faces of a joint, prior to the preparation of the joint for final welding, for the purpose of providing a suitable transition weld deposit for the subsequent completion of the joint"

ASME 9 also defines "Built-up of base metal/restoration of base metal thickness"-"This is the application of a weld material to a base metal so as to restore the design thickness and/or structural integrity. This build-up may be with a chemistry different from the base metal chemistry which has been qualified via a standard butt welded test coupon. Also, may be called base metal repair or build up".

Is this a repair to wasted areas, or new construction application? You said that this is a pressure boundry. Is the weld surfacing included in or beyond the minimum design thickness?

By Bulldog-99 (*)

Date 06-01-2005 19:35

This is by defintion a buttering procedure and it is with in the critical design dimensions. I think I have figured out what my issue was. I was aware that butter need be considered as a groove qualification but the probably I have is that the heat input is not addressed on the WPS. This is a simply fix in that the WPS is not acceptable however, the PQR does support the combination and I only need have the vendor correct the WPS. I Think.

Thanks for all the input
Bulldog

By GRoberts (***)

Date 06-01-2005 23:08

We use the buttering qualification as you propose quite frequently in situations that require PWHT for one base metal, and not for another. However, we qualify with a groove weld, and that qualifies the buttering as well. Buttering definately does not fall under the corrosion resistant overlay classification as it is structural, and overlay is not. What you are referring to in buttering seems to be fairly common practice. Often we will butter one metal (such as a P6) with F43 or A8 filler metal, PWHT, and then our customer may or may not join something to that buttering in the field. This would be qualified with a P6 to P43, or P6 to P8 groove weld. None of our customers have ever had a problem with this. Sounds like a similar situation.

By Jim Hughes (***)

Date 06-02-2005 23:38

Where does Sec. III come in?
Jim