Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4DHY4 found under Valve Check by Grainger Div Of W W Grainger Inc. The National Stock Number assigned to this part is 4820016060895, 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 4DHY4.