V321 had a design revision in 2007 that made the original part numbers obsolete.
V321, DN65: 7312153000 - 7312153010
V321, DN80: 7312157000 - 7312157010
V321, DN100: 7312161000 - 7312161010
V321, DN125: 7312165000 - 7312165010
V321, DN150: 7312169000 - 7312169010
A change of material used in the plug (Brass to Stainless Steel) gave a revision in part numbers.
Please use the latest available revision in part number when ordering, See your local price list, or product data sheet, or contact your Orders Dept for details.