Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number NEW PART 504 5 found under Valve Check by Val Matic Valve And Manufacturing. The National Stock Number assigned to this part is 4820012803944, 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 NEW PART 504 5.