Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number X15-B3570 found under Seat Valve by Rix Industries. The National Stock Number assigned to this part is 4820012970040, and the Federal Supply Class is 4820 Valves Nonpowered. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like X15-B3570.