Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number BB1 100 1 1 4FPT found under Valve Butterfly by Milwaukee Valve Company Inc. The National Stock Number assigned to this part is 4820012538559, 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 BB1 100 1 1 4FPT.