charpy test

[bhart192]

we ran a P8-P8 WPS 6" sch 40 , GTAW (T= .280") due to low temp, service we had Charpy Test done , we've run into questions concerning Thickness range limits of our WPS based on the Charpy test.I can't find a reference to any thickness range limits of a WPS based on the thickness of the sample sent for Charpy test , The only range reference for WPS I see is in Section IX for T = .280" range quailfied is .0625" to .560" ,is there a limit of thickness due to Charpy if so were is it. I do see a note for the thickness of the Charpy test samples but it does not refer to a qauified range for a WPS.

 

[Kiwi2671]

bhart192,
What is the construction code you are working to ?
That will govern which ranges of thickness you use,
Regards,
Kiwi

 

[bhart192]

opps forgot working to ASME B 31.3 Process pipe

 

[Kiwi2671]

bhart192,
See B31.3 Table 323.3.1
Qualification range is T/2 to T + 6 mm (1/4")whhere T is the thickness of your coupon.
Not sure of imperial but in metric your range of qualification is 3.55 to 13.33 mm.
Regards,
Kiwi

 

[Duwe6]

Kiwi2671 is correct. Sect IX is for generic requirements, and is modified by the Code-of-construction. Thus you get the PQR couton T of 0.280 and 1/4-inch more = 0.530", *not* your non-Charpy, standard WPS 2T limit = 0.560".

Pretty small difference, but if you get caught on the 'plus' side of that limit the normal remediation is either "Scrap & Refabricate" or "100% PWHT". Both are expensive.

If I was getting close to the 0.530" cutoff, I'd run a new PQR and increase the thickness range of the WPS, using both the old + the new PQR. Remember, a PQR/WPS is a Capitol expense -- they last longer than the building you are headquartered in.