Selection of IQI (Penetrameters) 2

[Quality2479]

Hello & Good Evening

Selection of IQI as per ASME Sec.V

With reference to ASME Sec.V Article 2, Cl.T-276.2(a) For Welds with reinforcements, the thickness on which IQI is selected is nominal Single Wall Thickness plus estimated weld reinforcement, Backing strips or rings shall not be considered as a part of thickness.

My question is that While considering the Weld reinforcement whether we have to consider both external reinforcement and internal root penetration for Selection of IQI or only we have to consider External reinforcement.

Thanks

 

[Kiwi2671]

Quality2479,
IMHO it is based on weld reinforcement (external) and weld protusion (internal) combined.
I cannot find anything definitive on this but if you look at T276.2 (a) it lists Welds with Reinforcements (note the plural)so if you have a double sided weld you would have to combine both reinforcements in the equation.
Again, IMHO there is no difference in weld thicknesses for IQI selection of 2 x weld reinforcement or alternatively 1 x reinforcement / 1 x internal protusion.
Hope that helps,
Regards,
Kiwi

 

[JR97]

Quality2479,

I agree with Kiwi. Looking at the welding requirements in both Sections III and VIII, the reinforcement requirement allies to both faces. Root convexity must be evaluated to the reinforcement criteria therefore, it would be included in the thickness determination for IQI selection. I also agree with Kiwi that including the root convexity would increase IQI by, at most, one step. If your radiographic technique is that borderline maybe you should look at optimizing your RT parameters a bit more.

JR97

 

[SectionIX]

Agreed with Kiwi and JR97.

All things being equal:

+ X-ray exposures, if properly made, should clearly show all wire diameters (ASTM 1A and 1B)

+ Depending on exposure conditions, the largest wire diameter in the 1A set should be visible. Since this is generally used on small diameter/thickness piping, if you can't see any wire, look to geometric unsharpness first. For the 1B set, at least five, and generally six wires should be clearly visible.



The only cavaet is that your fabrication/inspection specification may limit weld reinforcement, or require the a smaller diameter wire than is allowed by code.