Impact test Requirements

[K K]

Dear All,

Can any one describe me regarding Impact test requirement as per code ASME B31.3 ASME Sec VIII, API 582 and NACE 472 .

What is the thickness limits? and how i can I know that the piping line class required Impact test or not?

As per piping class what are the thing to I have to check?

And please describe me regarding ASME B31.3 Table- 323.3.1?

For stainless steel above 25 mm where required Impact test or Not?

Thanks In advance.

Regards 

Kiran