Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number AAE1821 found under Valve Pressure Equalizing Gaseou by Watson Mcdaniel Co. The National Stock Number assigned to this part is 4820016278567, 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 AAE1821.