Stub-In Branch Connection for B31.3

[NDTHAND1992]

I have a customer that wants to know if he can stub in a 6" branch pipe to a 16" run pipe both sch.40 P1 material utilizing his existing groove weld procedure or does a branch connection need a completely new procedure and welder qualification. My first answer was yes that is permissible since the procedure lets them complete unlimited fillets and the groove welds up to .864". I do not have access to section IX at this time. Thoughts please ?

 

[NDTHAND1992]

No input ?

 

[DekDee]

NDTHAND1992,
The original WPS is acceptable if all essential variables are complied with .
However if the joint configuration on the WPS is Single Vee then the WPS will need to be revised to reflect Single Bevel.
No new welder qualification required if all the essential variables are complied with.
Cheers,
DD

 

[NDTHAND1992]

Thanks allot

 

[Mec.tec]

The WPS is acceptable if all requirements of QW-250 are met however joint design is not an essential variable of WPS.

 

[Mec.tec]

Moreover do consider the backing variable (for single/double bevel) for applicability of WPS.

 

[NDTHAND1992]

So then , being that the groove design is not a essential variable for the WPS , and in turn it is not a essential variable for the Welder Qualification does the WPS even need to be revised to show a single bevel joint design ?

 

[weldstan]

Non-essential variables must also be addressed in the WPS.

 

[gtaw]

The intent of the WPS is to provide work direction to the welder so the results produce welds with the required mechanical properties.

As such, listing "All grooves and fillets" does not meet the obligation to provide the welder with sufficient information needed to properly prepare and fit the joint. It is acceptable to refer the reader to the detail drawings if the drawings do in fact list the groove details, i.e., groove angle, bevel depth, root opening, etc. An alternative is to refer to an "Annex" that shows the groove details. A third alternative is to show the groove details on the WPS. The latter is fine if the WPS is applicable to a few groove details, but it can be a problem if the WPS is applicable to a wide variety of different groove details, plug welds, slot welds, fillet welds etc.

Personally, I opt for an Annex that can be referenced by several WPSs and it lists all the weld types, joints, and details the welder can weld. The Annex depicts the weld details as well as the tolerances that are acceptable.

One point to keep in mind, the welder has to have access to the Annex.

Best regards - Al

 

[NDTHAND1992]

Thanks gentlemen for the insight , we made revisions to the WPS to include the single bevel groove design. Once again thanks for the advice.