Thickness Range for PQR?

[carlomaderazo]

i am preparing wps for pipe 6"dia & 10.97mm thickness, with GTAW process at root pass & hot pass, then SMAW process at fill & cap...I would like to know what will be the thickness range of base metal?

 

[metengr]

If you are qualifying the WPS to ASME B&PV Code, Section IX, the base metal thickness range is 2 x coupon thickness (10.97mm)

 

[carlomaderazo]

Thansk metengr..But I would like to know the minimum base metal thickness range, is it 1.5mm or 5.0mm? I have two welding processes involved.

 

[metengr]

carlomaderazo;
Do you have a copy of Section IX? Refer to Article IV, Table QW-451, the minimum thickness is 4.8mm, assuming a coupon thickness of between 10 and 19mm is used.

 

[weldtek]

carlo,
Just a little more, for base metal up to and including
10 mm in thickness, min qualified thickness is 1.5 mm. Over 10 mm, min qualified thickness is 5 mm.

 

[carlomaderazo]

but how about in combination process, can I separate the base metal thickness range of GTAW and SMAW so that I can get 1.5mm minimum thickness? How can I apply note 2 in Table QW-451?

 

[metengr]

Base metal thickness range is based on coupon thickness to qualify the WPS. Your question refers to weld deposit thickness range that is qualified for the welding process. Do you understand WPS qualification under Section IX?

 

[weldtek]

carlo,
So you have two thickness ranges to consider, 'T' for base metal, and 't' for weld deposit. Qualified ranges for your example, per QW 451, are x 2.
If your welder deposits 0.1875" using the GTAW process, you are qualified for up to 0.375" deposit thickness in production. Similarly, if the weld deposit for SMAW is 0.25" thick, you can deposit up to 0.5" thick using that process in production.

 

[WPSGuy]

Qualify on 1.5" or 1.75”

Thickness Range will = 3/16" through 5/8"" without CVN's or 5/8" through 8.0" with CVN's

Trust me; this is the best way to do it!

 

[weldtek]

I think you meant 3/16" thru 8" without impacts.

 

[WPSGuy]

No. Not if you qualify CVN's. The range would be 5/8" to 8" with impacts!

 

[weldtek]

I agree the range is 5/8" - 8" with impacts, however, you incorrectly stated the qualified range to be 3/16" - 5/8" without impacts. It should have been 3/16" thru 8" without impacts.