Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 400 50 139 found under Disk Valve by Oerlikon Leybold Vacuum Usa Inc. The National Stock Number assigned to this part is 4820013152679, 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 400 50 139.