Question about PQR QW-406 2

[CobusvanJ]

I am reviewing PQR's at the moment, and I have almost non-existant experience in ASME IX.

My question is regarding the Preheat (QW-406) section on the PQR. The PQR is for a GTAW/SMAW butt weld and the material is SA-516 Gr. 70 thickness 50mm.

On the PQR the manufacturer specified a preheat temperature of 100 deg C, but for the interpass temperature it is only stated "not applicable". Now my brain tells me that if a preheat is required, surely heating for interpass welding is required? I am using a flow chart from Nov. 1992 to assist me in checking the PQR, and it stated that if no interpass temperature is cited, the PQR should be rejected.

Is it possible for a PQR to have a preheat of 100 deg C and no interpass heating?

 

[DekDee]

Cobus,
With all due respoect what are you doing reviewing PQR's if you have no experience with ASME IX ?
Was the PQR subject to impact testing ?
If not the interpass temp does not need to be on the PQR.
QW 200.2 states essential and supplementary variables must be listed on the PQR - non-essential variables (if not impact tested then interpass is non-essential) can be listed at the manufacturers option,
Regards,
DD

 

[CobusvanJ]

Thank you for the quick answer.

To reply to your question, I am reviewing PQR's because there is no one else to do it.

 

[metengr]

CobusvanJ;
Interpass temperature is not always required for a WPS. Using an outdated flow chart to evaluate WPS/PQR's per ASME Section IX requirements will get you into trouble.

The interpass temperature is really applicable in situations where the WPS is either qualified for impact testing (notch toughness) or using base materials where heat input must be minimized during welding to avoid affecting corrosion resistance or to minimize distortion.

 

[gtaw]

If you are new to welding and you need some training, ASME offers a number of short courses that includes one titled "Practical Welding Technology" PD359. You might find it usefull.

The basics of WPSs and PQRs as well as welder performance qualification are subjects included in the three day course.

Best regards - Al

 

[qcrobert]

Cobusvan,

Gtaw and Metengr offer good advice, and if I may suggest that you purchase and study the Practical Guide to ASME Sec IX by Michael J. Houle through CASTI Publishing, Inc.

http://www.casti-publishing.com