Cobining WPS

[Ani18]

As per ASME sec 9
PQR 1 - GTAW T - 7.11mm , 1.5 to 14.22mm - A106 Gr.B

PQR 2 - SMAW T - 12.70mm, 5 to 25.4mm - A 106 Gr.B

No PWHT & No toughness.

My doubt is,1) is it possible to combine the above WPS to make GTAW &
SMAW combination.?
If possible wats thickness range.?

& Regardless of WPS,
My welder is qualified with Tig Process & Arc Process in seprately,
Is it possible to put them in production for Same A106gr.b material in
combination like Tig root & Arc Filler.
If it not possible. Pl tell me para which restricts this
According to QW200.4(a) and (b)
(b) For GTAW, SMAW, GMAW, PAW, and SAW,
or combinations of these processes, a PQR for a process
recording a test coupon that was at least 1⁄2 in. (13 mm)
thick may be combined with one or more other PQRs
recording another welding process and any greater base
metal thickness. In this case, the process recorded on the
first PQR may be used to deposit the root layers using
the process(es) recorded on that PQR up to 2t (for shortcircuiting
type of GMAW, see QW-404.32) in thickness
on base metal of the maximum thickness qualified by the
other PQR(s) used to support the WPS. The requirements
of Note (1) of tables QW-451.1 and QW-451.2 shall apply
By considering this para can we Combine this two PQR? Please explain

 

[david339933]

Hard to determine if you are combining two PQRs into a single WPS or using multiple WPSs in a single weld joint....but either is acceptable.

QW-200.4(a) first sentence tells you that you can use multiple WPSs in a single joint.

Using Multiple PQRs to make a multiprocess WPS:

Standard Designation: BPV Section IX
Edition/Addenda: 2015
Para./Fig./Table No: QW-200.4, QW-200.2(f)
Subject Description: SC IX; QW-200.4, QW-200.2(f) - Combination WPS
Date Issued: 06/06/2017
Record Number: 16-3074
Interpretation Number : BPV IX-17-30
Question(s) and Reply(ies):
Question: May a combination of two PQRs each of different welding processes, support a WPS combining the two processes in a single joint with all the essential and supplementary essential variables unchanged?

Reply: Yes, provided the base metal and deposited weld metal thickness limits of QW-451 are satisfied for each process.

You must meet the essential variables for both processes (thicknesses must overlap)....therefore thickness qualified is - 5mm - 14.22mm.

QW-200.4(b) is not applicable in this case. Get more familiar with Sec. IX then come back and we can tackle that one.

 

[Ani18]

Thanks David
But where it states thickness shall overlap?
Why dont the thickness limit qualifed from 1.5 to 25.4 so both of the PQRs thickness limits satisfied?

 

[Ani18]

Thanks David
But where it states thickness shall overlap?
Why dont the thickness limit qualifed from 1.5 to 25.4 so both of the PQRs thickness limits satisfied?

 

[DekDee]

Ani,
If you combine the two PQRs or WPSs you have to comply with the base metal and deposited weld metal thicknesses for both processes.
As David has stated they must "overlap".
As an example in reply to your question - 20 mm base metal.
It is covered by the SMAW PQR/WPS but it is outside of the qualified range of the GTAW so you could not use a GTAW/SMAW WPS on this thickness material.
You can combine both, no problem - but, again, as David has stated you are limited to 5 mm to 14.22 mm

 

[Ani18]

Thank you Dek

 

[Jovi Zhu]

Code tells yes or no but not always why.
For this case I'm thinking about if the upper and lower thickness limits can be linked to heat input range influencing the mechanical property and hence the ablility of the specific joint to pass the qualification test.

Heat input introduced should be by the preheat temperature, welding heat and heat treatment if any. Heat loss and conduction is main via base metal, so the thicker the faster, the thinner the slower.

If this can be at least a partially correct assumption of the intent of the Code, the set of variables for PQR 1 is not proved by the qualification test to be able to give sufficient heat input(especially preheat) for thk above 14.22mm. The weld metal and HAZ will cool too fast.

And PQR 2 is not proved to be able to give heat input low enouhg for thk below 5mm. The joint will cool too slow~

Open for comments and ideas~