WPS LIMITATIONS IN PRODUCTION JOINTS 1

[kknnkk]

Hi all,

I have qualified a WPS (GTAW + FCAW ; GTAW= 8 MAX; FCAW=20.54) with supporting PQR (GTAW + FCAW ; GTAW-4 mm, FCAW 10.27 mm)

I have mentioned in the WPS that process used for production as GTAW+FCAW for butt, branch & fillet.

Can I use FCAW alone for fillet welds?

Can I use GTAW alone for butt welds with thickness 5.54 mm.

Which means can i split welding process mentioned in WPS and use for production joints provided I meet all essential,supplementary essential & non essential variables and comply QW 451 thickness limitations?
I need your valuable suggestions.

Thanks in advance.

 

[Arkaprava Ghosh]

YEs, FCAW can be used for fillet welds since you have already qualified WPS with backing

GTAW as a single process can be used to weld till 8mm since you have a qualified WPS for the same.

Yes, it can be split, provided all variables and thickness considerations are met.

 

[david339933]

See QW-200.4 (a)

 

[DekDee]

You will need to write a new WPS for the fillet welds.

 

[Arkaprava Ghosh]

DekDee,

A separate WPS will not be required for fillet welds, as per QW 451.4 of ASME section IX. The OP has already qualified WPS on groove welds with GTAW backing.

 

[DekDee]

Arkaprava,
I have no issue with the fact the groove weld qualifies a fillet weld.
A new WPS may not be a code requirement (and I am pretty sure it is) - it is common sense.
If the welder welds GTAW only on a groove weld using a GTAW/FCAW groove weld WPS there is very little difference.
Similarly if the welder welds FCAW only on a groove weld with backing using a GTAW/FCAW groove weld WPS there is very little difference.

However, if the welder is given a GTAW/FCAW groove weld WPS and asked to weld fillets they have an immediate problem.
Is single pass or multi-pass required ?
What is the minimum leg length or throat thickness required ?
Even amps, volts, travel speed will be vastly different between FCAW on a pipe (possibly vertical up) and FCAW on a plate in the 2F position

Please remember the main reason we have welding procedures - to provide guidance to the welder.
Having 1 x WPS to cover a multitude of processes, positions, thicknesses etc may be code compliant but it definitely doesn't help the welder,
Regards,
Shane

 

[kknnkk]

Thanks all.
Can we add a note in WPS that both process can be used individually subject to all essential variables, supplementary and non essential variables and applying thickness limitations if any.?
If it mentioned in WPS, we can use for production joints. right?

Dekdee,

Our case is fillet weld - supporting pad on pipe.
We are giving welder a instruction about size of a fillet weld case to case through welding supervisor since we have variety of thickness of supporting pad.

 

[DekDee]

QW-200.1
(c) Changes to the WPS. Changes may be made in the
nonessential variables of a WPS to suit production requirements
without requalification provided such
changes are documented with respect to the essential,
nonessential, and, when required, supplementary essential
variables for each process. This may be by amendment
to the WPS or by use of a new WPS.

Hope that helps,
Cheers,
Shane

 

[kknnkk]

DekDee,

Agreed. Thanks all once again.