Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 645P6 found under Valve Pneumatic Tank by Cornwell Quality Tools Co The. The National Stock Number assigned to this part is 4820002087110, 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 645P6.