Hi Bgundermann,

When PR line is created, all key values are fetched to the line at the point of line creation and any other subsequence change on part records do not reflect on PR line unless you remove and add the line again. Further, If you do not remove the line and add again, Purchase order line created from PR also has a previous part description rather than the new one.

Is changing part description more frequent on your business ? in that case, I believe you can create event action to make sure there are ongoing PR lines to be changed with new name or add line once again.

Part description cannot be refresh once you save the purchase requisition line. You need to add a new line with new description once change the description in the part. 

Having said that let me quoted the part description fetching sequence from help documentation.

1. From a possible existing Purchase Part Description with the same Language Code as entered on the Supplier.
2. From the Part Catalog Language Description
   if the Use Part Catalog Description as description for Purchase Part check box is selected
   and a Part Catalog Language Description exist with the same foreign Language Code as entered on the Supplier
3. From the Part Catalog Description if the Use Part Catalog Description as description for Purchase Part check box is selected
4. From the Purchase Part Description if the Use Part Catalog Description as description for Purchase Part check box is not selected
   
   Enable Centralized Part Description

The Centralized Part Description is defined for each Site and for each Part Type in the Site window where the Use Part Catalog Description as Description for Inventory Part check box on the Inventory tab indicates whether the centralized part description should be used for the Inventory parts on this site, and the Use Part Catalog Description as Description for Sales Part and Use Part Catalog Description as Description for Purchase Part check boxes on the Distribution tab indicates whether the centralized part description should be used for the Sales and/or Purchase part.