Base Metal Range for Repair Qualification

I have some doubt about impact testing being applicable only to thicknesses between 12.7mm (0.500") and 25.4mm (1.000"). Your local code may differ from mine, but I have had to do impact testing for 3/8" (~9.53mm) vessels for 0°F (~-17.8°C) under U.S. Coast Guard rules.

I think, whatever the impact test is mandatory or not, the repair PQR-1458 with the same materials for the same thickness of 12.7 mm base metal, shall not qualify the repair WPS-5799-10 with metal thickness of 9.5 mm.

Where PQR-1485 with thickness 12.7 mm shall qualify only thicknesses range of 12.7 mm up to 25.4 mm.

Thanks, as always your suggestion is valuable..

if WPS 5799-10 has a base metal thickness of 12.7mm (same as PQR) but excavation depth for repair is only 9.5mm, then will it qualify?

As per ASME IX, the test specimen with thickness t, shall be used to qualify those thicknesses from t up to 2t only. So to proceed a weld deposit penetration up to 9.5 mm, you have to proceed a WPS & PQR with test coupon with 1/4" (6.35 mm) thickness (e.g) to qualify that range of thicknesses from 1/4" (6.35 mm) to 1/2" (12.7 mm) .

Proceed with caution, and make sure you understand the differernces between "t" and "T": t = deposited filler metal thickness; T = thickness of base metal. There are distinctions of the two within the same Section IX Table.

I am posting a delayed comment. Generally, if the relevant section of the referenced code is mentioned in the comments it will be useful for the general readers to understand better.

As per 451.1 of ASME IX, for test pieces~10mm, min thickness qualified is 5mm base metal. No minimum limit for weld metal is seen. Kindly help me with the relevant sections for limiting it (to "t"?).

Thanks