Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 517990 found under Expander Packing Va by Westinghouse Air Brake Technologies. The National Stock Number assigned to this part is 2240004994936, and the Federal Supply Class is 2240 Locomotive And Rail Car Accessories And Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 517990.