Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 5400-15 found under Seat Valve by Bosworth Company The. The National Stock Number assigned to this part is 4820012277830, 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 5400-15.