Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number C3521-8PC162 found under Valve Safety Relief by Excello Corp Machine Tool Prod. The National Stock Number assigned to this part is 4820004463515, 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 C3521-8PC162.