ASME IX Base metal qualified thickness range PERMISSIBLE VARIATIONS 2

[abdomen]

Hi All,

Here is a nice case:

I have a P1 to P1 Welding procedure. The range qualified is 5mm to 46.02mm but I have pipe with a thickness of 50.8 mm. I know that according to table QW-451 this thickness is higher than 2T. But, I want to know is there a tolerance in ASME IX or elsewhere that we can use to avoid qualifying this pipe.

from my point of view even if a welder who welds a 46mm thick pipe can easily weld 50.8mm, I think that a WPS to qualify the thicker pipe is necessary. What is you opinion?


thank you

 

[vrkleo]

I pressume the test coupon thickness is 23.01 mm. There is no tolerance on upper limit of thickness qualified. The thickness ranges for procedures and welder are different and can't be compared. Since you referred the welder, please note that there is no upper limit on thickness for the welder if the test piece is minimum 13mm thick and minimum 3 passes are applied.

 

[jwhit]

Your qualification is limited to 2T for the base metal, so if as suggested you welded a 23mm plate your qualification falls short. If you would have welded a 25.4mm plate you would be good. A 38.1mm" plate will get you qualified for up to 203.2 mm in most cases pwht type may affect T). Unfortunately, the Code doesn't give any leeway. One thing you might consider is to query your customer in this case, there is a slim chance they will accept your procedure as is.

 

[abdomen]

Thank you all for your answers, I appreciate

 

[Kiwi2671]

Abdomen,
Do you have one weld to do or numerous ?
Is it possible to machine the ends of the pipes ?
I looked at ASTM A106 (as an example as you quoted P1) and the minimum thickness of 50.8 mm WT pipe is 44.45 mm.
Skim 2 mm off the OD of your pipe or transition the ID (if process fluid allows)
As long as you are in compliance with the applicable piping code based on reduction in WT you should be good to go,
Regards,
Kiwi