Stock Transport Orders Between Storage Locations, Requisition Consumption

Dear SCN Community,

We have Stock Transport Orders setup to transfer Materials from one Storage Location to another within the same Plant.

We are using "Stock Transport Orders with SD" (Order Type MM-PUR: UB; Movement Types MM-IM: GI 641, GR 101; Delivery Type SD: NL; Stock after GI: Stock in Transit):

http://help.sap.com/saphelp_470/helpdata/en/4d/2b90dc43ad11d189410000e829fbbd/content.htm

The problem/issue is that these Stock Transport Orders between two Storage Locations 'A' & 'B' within the same Plant 'X' consume already existing Purchase Requirements this Plant has against another Plant 'Y' within the same company.

Can this be prevented in this scenario?

And if yes, where would we need to make the change(s) (e.g. in the IMG)?

Best Regards