Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 7638 found under Filter Drier Refrigerant by Metrex Valve Corp. The National Stock Number assigned to this part is 4130002746358, and the Federal Supply Class is 4130 Refrigeration And Air Conditioning Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 7638.