Link between material and valuation class?

Hello

Can somebody tell me the link between material (or mat-plant) and val class?

I see it on MM03-Accounting 1. its defined on intersection of material, plant , val type. Do I understand correctly that if there are no split valuation then it will be 1 to 1 relaion between mat-plant and val class? What is the table where this link is stored?

Alex