Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 81M-3EP 1.25IN 82864 found under Valve Check by Griswold Industries Co. The National Stock Number assigned to this part is 4820011953767, 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 81M-3EP 1.25IN 82864.