Sammy,
You may have to give us a bit more information about the alloy, purpose and process to get a solid answer.
There are several governing codes that have "weld classes"
AWS D17.1 Code for Aerospace Welding has some weld classes.
You could also try AWS D3.6- for underwater welding. Class A, B, C, and O are covered.
My real point is that it doesn't matter if "class A" welds are covered if it is the wrong specification. What are you trying to weld?