multiple PQR's- API 1104

[hex180]

Using API 1104, if welding from group b (x52) to group c (x70) the welding procedure for the higher strength is to be used. My question is about the PQR. The PQR is only for X70 but do I need a PQR specifically designed for:

1. welding x52 to x70?
2. Or is the PQR for x70 good enough to cover both grade
groups?
3. Or do I just need to attach seperate PQR's one for the
x52 and one for x70?

 

[JStephen]

In ASME, you'd normally do the qualification test welding A to B, and that qualifies A to A, B to B, or A to B. See if that's not the case in API 1104.