Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number APE 330-540 found under Valve Regulating Fl by Union Carbide Corp. The National Stock Number assigned to this part is 4820012839641, 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 APE 330-540.